,transcriber's ,note3 ,in text1 italic is denoted by underscores around the word_/phrase4 ,the italic markup for single italicised letters 7such as pounds and pence symbols and in numbered lists7 are deleted for easier reading4 ,small capitals in the printed works have been transcribed as ,,all ,,capitals4 ,in chemical equations1 underscores before bracketed numbers denote a subscript1 e4g4 ,,co#b 7carbon dioxide74 ,more ,transcriber's ,notes may be found at the end of this text4 ,,the ,,romance ,,of ,,modern ,,mechanism ,illustration3 ,a ,,mechanical ,,sculptor ,the lower illustration shows the ,wenzel ,sculpturing ,machine at work on two blocks of stone ranged one on each side of a model4 ,this machine can make four copies simultaneously from one original4 ,the upper illustration shows the quality of work done by the automatic sculptor4 ,,the ,,romance ,,of ,,modern ,,mechanism ,,with ,,interesting ,,descriptions ,,in ,,non-,,technical ,,language ,,of ,,wonderful ,,machinery ,,and ,,mechanical ,,devices ,,and ,,marvellously ,,delicate ,,scientific ,,instruments1 c41 c4 ,,by ,,archibald ,,williams1 ,b4,a41 ,,oxon41 ,f4,r4,g4,s4 ,,author ,,of ,,the ,,romance ,,of ,,modern ,,invention1 ,,the ,,romance ,,of ,,modern ,,mining1 ,,the ,,romance ,,of ,,modern ,,engineering1 ,,the ,,romance ,,of ,,modern ,,exploration1 c4 c4 ,,with ,,thirty ,,illustrations ,,london ,,seeley ,,and ,,co4 ,,limited #ch ,,great ,,russell ,,street #aiaj ,,uniform ,,with ,,this ,,volume ,,the ,,library ,,of ,,romance ,extra ,crown #hvo4 ,with many illustrations4 #es4 each ,splendid volumes4--,the ,outlook4 ,this series has now won a considerable and well deserved reputation4--,the ,guardian4 ,each volume treats its allotted theme with accuracy1 but at the same time with a charm that will commend itself to readers of all ages4 ,the root idea is excellent1 and it is excellently carried out1 with full illustrations and very prettily designed covers4--,the ,daily ,telegraph4 ,by ,prof4 ,g4 ,f4 ,,scott ,,elliot1 ,m4,a41 ,b4,sc4 ,,the ,,romance ,,of ,,savage ,,life ,,the ,,romance ,,of ,,plant ,,life ,,the ,,romance ,,of ,,early ,,british ,,life ,by ,,edward ,,gilliat1 ,m4,a4 ,,the ,,romance ,,of ,,modern ,,sieges ,by ,,john ,,lea1 ,m4,a4 ,,the ,,romance ,,of ,,bird ,,life ,by ,,john ,,lea1 ,m4,a41 ,h4 ,,coupin1 ,d4,sc4 ,,the ,,romance ,,of ,,animal ,,arts ,,and ,,crafts ,by ,,sidney ,,wright ,,the ,,romance ,,of ,,the ,,world',s ,,fisheries ,by the ,rev4 ,j4 ,c4 ,,lambert1 ,m4,a41 ,d4,d4 ,,the ,,romance ,,of ,,missionary ,,heroism ,by ,g4 ,,firth ,,scott ,,the ,,romance ,,of ,,polar ,,exploration ,by ,,archibald ,,williams1 ,b4,a4 7,oxon471 ,f4,r4,g4,s4 ,,the ,,romance ,,of ,,early ,,exploration ,,the ,,romance ,,of ,,modern ,,exploration ,,the ,,romance ,,of ,,modern ,,mechanism ,,the ,,romance ,,of ,,modern ,,invention ,,the ,,romance ,,of ,,modern ,,engineering ,,the ,,romance ,,of ,,modern ,,locomotion ,,the ,,romance ,,of ,,modern ,,mining ,by ,,charles ,r4 ,,gibson1 ,a4,i4,e4,e4 ,,the ,,romance ,,of ,,modern ,,photography ,,the ,,romance ,,of ,,modern ,,electricity ,,the ,,romance ,,of ,,modern ,,manufacture ,by ,,edmund ,,selous ,,the ,,romance ,,of ,,the ,,animal ,,world ,,the ,,romance ,,of ,,insect ,,life ,by ,,agnes ,,giberne ,,the ,,romance ,,of ,,the ,,mighty ,,deep ,by ,e4 ,s4 ,,grew1 ,m4,a4 ,,the ,,romance ,,of ,,modern ,,geology ,by ,j4 ,c4 ,,philip1 ,d4,sc41 ,ph4,d4 ,,the ,,romance ,,of ,,modern ,,chemistry ,,seeley ,,co41 ,,limited ,,introduction ,in the beginning a man depended for his subsistence entirely upon his own efforts1 or upon those of his immediate relations and friends4 ,life was very simple in those days3 luxury being unknown1 and necessity the factor which guided man's actions at every turn4 ,with infinite labour he ground a flint till it assumed the shape of a rough arrow-head1 to be attached to a reed and shot into the heart of some wild beast as soon as he had approached close enough to be certain of his quarry4 ,the meat thus obtained he seasoned with such roots and herbs as nature provided--a poor and scanty choice4 ,presently he discovered that certain grains supported life much better than roots1 and he became an agriculturist4 ,but the grain must be ground2 so he invented a simple mill--a small stone worked by hand over a large one2 and when this method proved too tedious he so shaped the stones' surfaces that they touched at all points1 and added handles by which the upper stone could be revolved4 ,with the discovery of bronze1 and1 many centuries later1 of iron1 his workshop equipment rapidly improved4 ,he became an expert boat- and house-builder1 and multiplied weapons of offence and defence4 ,gradually separate crafts arose4 ,one man no longer depended on his individual efforts1 but was content to barter his own work for the products of another man's labour1 because it became evident that specialisation promoted excellence of manufacture4 ,a second great step in advance was the employment of machinery1 which1 when once fashioned by hand1 saved an enormous amount of time and trouble--the pump1 the blowing bellows1 the spinning-wheel1 the loom4 ,but all had to be operated by human effort1 sometimes replaced by animal power4 ,with the advent of the steam-engine all industry bounded forward again4 ,first harnessed by ,watt1 ,giant ,steam has become a commercial and political power4 ,everywhere1 in mill and factory1 locomotive1 ship1 it has increased the products which lend ease and comfort to modern life2 it is the great ally of invention1 and the ultimate agent for transporting men and material from one point on the earth's surface to another4 ,try as we may1 we cannot escape from our environment of mechanism1 unless we are content to revert to the loincloth and spear of the savage4 ,society has become so complicated that the utmost efforts of an individual are1 after all1 confined to a very narrow groove4 ,the days of the ,jack-of-all-trades are over4 ,success in life1 even bare subsistence1 depends on the concentration of one's faculties upon a very limited daily routine4 ,let the cobbler stick to his last is a maxim which carries an ever-increasing force4 ,the better to realise how dependent we are on the mechanisms controlled by the thousand and one classes of workmen1 let us consider the surroundings1 possessions1 and movements of the average1 well-to-do business man4 ,at seven o'clock he wakes1 and instinctively feels beneath his pillow for his watch1 a most marvellous assemblage of delicate parts shaped by wonderful machinery4 ,before stepping into his bath he must turn a tap1 itself a triumph of mechanical skill4 ,the razor he shaves with1 the mirror which helps him in the operation1 the very brush and soap1 all are machine-made4 ,with his clothes he adds to the burden of his indebtedness to mechanism4 ,the power-loom span the linen for his shirts1 the cloth for his outer garments4 ,shirts and collars are glossy from the treatment of the steam laundry1 where machinery is rampant4 ,his boots1 kept shapely by machine-made lasts1 should remind him that mechanical devices have played a large part in their manufacture1 very possibly the human hand has scarcely had a single duty to perform4 ,he goes downstairs1 and presses an electric button4 ,mechanism again4 ,while waiting for his breakfast his eye roves carelessly over the knives1 spoons1 forks1 table1 tablecloth1 wall-paper1 engravings1 carpet1 cruet-stand--all machine-made in a larger or less degree4 ,the very coals blazing in the grate were won by machinery2 the marble of the mantelpiece was shaped and polished by machinery2 also the fire-irons1 the chairs1 the hissing kettle4 ,machinery stares at him from the loaf on its machine-made board4 ,machines prepared the land1 sowed1 harvested1 threshed1 ground1 and probably otherwise prepared the grain for baking4 ,machines ground his salt1 his coffee4 ,machinery aided the capture of the tempting sole2 helped to cure the rasher of bacon2 shaped the dishes1 the plates1 the coffee-pot4 ,whirr-r-r6 ,the motor-car is at the door1 throbbing with the impulses of its concealed machinery4 ,our friend therefore puts on his machine-made gloves and hat and sallies forth4 ,that wonderful motor1 the product of the most up-to-date1 scientific1 and mechanical appliances1 bears him swiftly over roads paved with machine-crushed stone and flattened out by a steam-roller4 ,a book might be reserved to the motor alone2 but we must refrain1 for a few minutes' travel has brought the horseless carriage to the railway station4 ,mr4 ,smith1 being the holder of a season ticket1 does not trouble the clerk who is stamping pasteboards with a most ingenious contrivance for automatically impressing dates and numbers on them4 ,he strolls out on the platform and buys the morning paper1 which1 a few hours before1 was being battered about by one of the most wonderful machines that ever was devised by the brain of man4 ,mr4 ,smith doesn't bother his head with thoughts of the printing-press4 ,its products are all round him1 in timetables and advertisements4 ,nor does he ponder upon the giant machinery which crushed steel ingots into the gleaming rails that stretch into the far distance2 nor upon the marvellous interlocking mechanism of the signal-box at the platform-end2 nor upon the electric wires thrumming overhead4 ,no6 he had seen all these things a thousand times before1 and probably feels little of the romance which lies so thickly upon them4 ,a whistle blows4 ,the local is approaching1 with its majestic locomotive--a very orgy of mechanism--its automatic brakes1 its thousand parts all shaped by mechanical devices1--steam saws1 planes1 lathes1 drills1 hammers1 presses4 ,in obedience to a little lever the huge mass comes quickly to rest2 the steam pump on the engine commences to gasp2 a minute later another lever moves1 and ,mr4 ,smith is fairly on his way to business4 ,arrived at the metropolis1 he presses electricity into his service1 either on an electric tram or on a subterranean train4 ,in the latter case he uses an electric lift1 which lowers him into the bowels of the earth1 to pass him on to the current-propelled cars1 driven by power generated in far-away stations4 ,his office is stamped all over with the seal of mechanism4 ,in the lobby are girls hammering on marvellous typewriters2 on his desk rests a telephone1 connected through wires and most elaborately equipped exchanges with all parts of the country4 ,to get at his private and valuable papers ,mr4 ,smith must have recourse to his bunch of keys1 which1 with their corresponding locks1 represent ingenuity of a high degree4 ,all day long he is in the grasp of mechanism2 not even at lunch time can he escape it1 for the food set before him at the restaurant has been cooked by the aid of special kitchen machinery4 ,and when the evening draws on ,mr4 ,smith touches a switch to turn his darkness into light1 wrung through many wonderful processes from the stored illumination of coal4 ,were we to trace the daily round of the clerk1 artisan1 scientist1 engineer1 or manufacturer1 we should be brought into contact with a thousand other mechanical appliances4 ,space forbids such a tour of inspection2 but in the following pages we may rove here and there through the workshops of the world1 gleaning what seems to be of special interest to the general public1 and weaving round it1 with a machine-made pen1 some of the romance which is apt to be lost sight of by the most marvellous of all creations--,man4 ,,author',s ,,note ,,the author desires to express his indebtedness to the following gentlemen for the kind help they have afforded him in connection with the gathering of materials for the letterpress and illustration of this book3-- ,the proprietors of ,cassier's ,magazine1 ,the ,magazine of ,commence1 ,the ,world's ,work1 ,the ,motor ,boat2 ,the ,rexer ,automatic ,machine ,gun ,co42 ,the ,diesel ,oil ,engine ,co42 ,the ,cambridge ,scientific ,instrument ,co42 ,the ,marconi ,wireless ,telegraphy ,co42 ,the ,temperley ,transporter ,co42 ,messrs4 de ,dion1 ,bouton and ,co42 ,messrs4 ,merryweather and ,sons2 ,mr4 ,a4 ,crosby ,lockwood2 ,mr4 ,dan ,albone2 ,mr4 ,j4 ,b4 ,diplock2 ,mr4 ,w4 ,h4 ,oatway2 ,the ,national ,cash ,register ,co42 ,the ,wenzel ,sculpturing ,machine ,co42 ,mr4 ,e4 ,w4 ,gaz2 ,sir ,w4 ,g4 ,armstrong1 ,whitworth and ,co42 ,the ,international ,harvester ,co4 and ,messrs4 ,gwynne and ,co4 ,,table ,,of ,,contents ,,page ,,introduction v ,,author',s ,,note xi ,,chapter ,i ,,delicate ,,instruments--,,watches ,,and ,,chronometers--,,the ,,microtome--,,the ,,dividing ,,engine--,,measuring ,,machines #ag ,,chapter ,,ii ,,calculating ,,machines #db ,,chapter ,,iii ,,workshop ,,machinery--,,the ,,lathe--,,planing ,,machines--,,the ,,steam ,,hammer--,,hydraulic ,,tools--,,electrical ,,tools ,,in ,,the ,,shipyard #ei ,,chapter ,,iv ,,portable ,,tools #ij ,,chapter ,v ,,the ,,pedrail3 ,a ,,walking ,,steam-,,engine #ig ,,chapter ,,vi ,,internal ,,combustion ,,engines--,,oil ,,engines--,,engines ,,worked ,,with ,,producer ,,gas--,,blast ,,furnace ,,gas ,,engines #aab ,,chapter ,,vii ,,motor-,,cars--,,the ,,motor ,,omnibus--,,railway ,,motor-,,cars #acj ,,chapter ,,viii ,,the ,,motor ,,afloat--,,pleasure ,,boats--,,motor ,,lifeboats--,,motor ,,fishing ,,boats--,a ,,motor ,,fire ,,float--,,the ,,mechanism ,,of ,,the ,,motor ,,boat--,,the ,,two-,,stroke ,,motor--,,motor ,,boats ,,for ,,the ,,navy #aej ,,chapter ,,ix ,,the ,,motor ,,cycle #age ,,chapter ,x ,,fire ,,engines #ahe ,,chapter ,,xi ,,fire-,,alarms ,,and ,,automatic ,,fire ,,extinguishers #aia ,,chapter ,,xii ,,the ,,machinery ,,of ,a ,,ship--,,the ,,reversing ,,engine--,,marine ,,engine ,,speed ,,governors--,,the ,,steering ,,engine--,,blowing ,,and ,,ventilating ,,apparatus--,,pumps--,,feed ,,heaters--,,feed-,,water ,,filters--,,distillers--,,refrigerators --,,the ,,search-,,light--,,wireless ,,telegraphy ,,instruments--,,safety ,,devices--,,the ,,transmission ,,of ,,power ,,on ,a ,,ship #bjc ,,chapter ,,xiii ,,the ,,nurse ,,of ,,the ,,navy #bcf ,,chapter ,,xiv ,,the ,,mechanism ,,of ,,diving #bdj ,,chapter ,,xv ,,apparatus ,,for ,,raising ,,sunken ,,ships ,,and ,,treasure #bdh ,,chapter ,,xvi ,,the ,,handling ,,of ,,grain--,,the ,,elevator--,,the ,,suction ,,pneumatic ,,grain-,,lifter--,,the ,,pneumatic ,,blast ,,grain-,,lifter--,,the ,,combined ,,system #beb ,,chapter ,,xvii ,,mechanical ,,transporters ,,and ,,conveyers--,,ropeways--,,cableways--,, telpherage--,,coaling ,,warships ,,at ,,sea #beh ,,chapter ,,xviii ,,automatic ,,weighers #bgd ,,chapter ,,xix ,,transporter ,,bridges #bgg ,,chapter ,,xx ,,boat- ,,and ,,ship-,,raising ,,lifts #bhc ,,chapter ,,xxi ,a ,,self-,,moving ,,staircase #bie ,,chapter ,,xxii ,,pneumatic ,,mail ,,tubes #cja ,,chapter ,,xxiii ,,an ,,electric ,,postal ,,system #cae ,,chapter ,,xxiv ,,agricultural ,,machinery--,,ploughs--,,drills ,,and ,,seeders--,,reaping ,,machines--,,threshing ,,machines--,,petrol-,,driven ,,field ,,machinery--,,electrical ,,farming ,,machinery #cah ,,chapter ,,xxv ,,dairy ,,machinery--,,milking ,,machines--,,cream ,,separators--,a ,,machine ,,for ,,drying ,,milk #ccj ,,chapter ,,xxvi ,,sculpturing ,,machines #cce ,,chapter ,,xxvii ,,an ,,automatic ,,rifle--,a ,,ball-,,bearing ,,rifle #cde ,,list ,,of ,,illustrations ,,page ,a ,,carving ,,machine ,frontispiece ,,measuring ,,machines #cd ,a ,,cash ,,register #de ,,lathe ,,turning ,a ,,big ,,gun #ei ,,lathe ,,for ,,boring #af-;,,inch ,,gun #fe ,a ,,steam ,,hammer #gb ,a ,,huge ,,hydraulic ,,press #hb ,a ,,pedrail ,,traction ,,engine #ajh ,,great ,,gas ,,engine ,,for ,,blast ,,furnaces #abh ,,motor-,,car ,,and ,,motor-,,boat #aea ,a ,,motogodille #aef ,a ,,motor ,,lawn ,,mower #ahb ,,up-,,to-,,date ,,fire ,,brigade ,,engines #ahf ,,hoisting ,a ,,heavy ,,gun ,,on ,,board ,,man-,,of-,,war #bjd ,,fixing ,a ,,ram ,,to ,a ,,battleship #bbh ,a ,,tripod ,,crane #bcg ,,modern ,,diving ,,apparatus #bde ,,coaling ,,at ,,sea #bga ,a ,,transporter ,,bridge ,,at ,,bizerta #bgh ,a ,,canal ,,lift #bhi ,,an ,,american ,,cutter ,,and ,,binder #cbb ,a ,,motor ,,plough #cbg ,,girl ,,carving ,,by ,,machinery #cdc ,,the ,,rexer ,,gun #ceb ,,the ,,romance ,,of ,,modern ,,mechanism ,,chapter ,i ,,delicate ,,instruments ,,watches ,,and ,,chronometers--,,the ,,microtome--,,the ,,dividing ,,engine--,,measuring ,,machines ,owing to the universal use of watches1 resulting from their cheapness1 the possessor of a pocket timepiece soon ceases to take a pride in the delicate mechanism which at first added an inch or two to his stature4 ,at night it is wound up mechanically1 and thrust under the pillow1 to be safe from imaginary burglars and handy when the morning comes4 ,the awakened sleeper feels small gratitude to his faithful little servant1 which all night long has been beating out the seconds so that its master may know just where he is with regard to the enemy on the morrow4 ,at last a hand is slipped under the feather-bag1 and the watch is dragged from its snug hiding-place4 ,bother it1 says the sleepy owner1 half-past eight2 ought to have been up an hour ago6 and out he tumbles4 ,dressing concluded1 the watch passes to its day quarters in a darksome waistcoat pocket1 to be hauled out many times for its opinion to be taken4 ,the real usefulness of a watch is best learnt by being without one for a day or two4 ,there are plenty of clocks about1 but not always in sight2 and one gradually experiences a mild irritation at having to step round the corner to find out what the hands are doing4 ,a truly wonderful piece of machinery is a watch--even a cheap one4 ,an expensive1 high-class article is worthy of our admiration and respect4 ,here is one that has been in constant use for fifty years4 ,twice a second its little balance-wheel revolves on its jewelled bearings4 ,allowing a few days for repairs1 we find by calculation that the watch has made no less than three thousand million movements in the half-century6 ,and still it goes ticking on1 ready to do another fifty years' work4 ,how beautifully tempered must be the springs and the steel faces which are constantly rubbing against jewel or metal6 ,how perfectly cut the teeth which have engaged one another times innumerable without showing appreciable wear6 ,the chief value of a good watch lies in its accuracy as a time-keeper4 ,it is1 of course1 easy to correct it by standard clocks in the railway stations or public buildings2 but one may forget to do this1 and in a week or two a loss of a few minutes may lead to one missing a train1 or being late for an important engagement4 ,happy1 therefore1 is the man who1 having set his watch to ,london time1 can rely on its not varying from accuracy a minute in a week--a feat achieved by many watches4 ,the old-fashioned watch was a bulky affair1 protected by an outer case of ample proportions4 ,from year to year the size has gradually diminished1 until we can now purchase a reliable article no thicker than a five-shilling piece1 which will not offend the most fastidious dandy by disarranging the fit of his clothes4 ,into the space of a small fraction of an inch is crowded all the usual mechanism1 reduced to the utmost fineness4 ,watches have even been constructed small enough to form part of a ring or earring1 without losing their time-keeping properties4 ,for practical purposes1 however1 it is advantageous to have a timepiece of as large a size as may be convenient1 since the difficulties of adjustment and repair increase with decreasing proportions4 ,the ship's chronometer1 therefore1 though of watch construction1 is a big affair as compared with the pocket timepiece2 for above all things it must be accurate4 ,the need for this arises from the fact that nautical reckonings made by the observation of the heavenly bodies include an element of time4 ,we will suppose a vessel to be at sea out of sight of land4 ,the captain1 by referring to the dial of the mechanical log1 towed astern1 can reckon pretty accurately how far the vessel has travelled since it left port2 but owing to winds and currents he is not certain of the position on the globe's surface at which his ship has arrived4 ,to locate this exactly he must learn 7a7 his longitude1 i4e4 distance ,e4 or ,w4 of ,greenwich1 7b7 his latitude1 i4e4 distance ,n4 or ,s4 of the ,equator4 ,therefore1 when noon approaches1 his chronometers and sextant are got out1 and at the moment when the sun crosses the meridian the time is taken4 ,if this moment happens to coincide with four o'clock on the chronometers he is as far west of ,greenwich as is represented by four twenty-fourths of the #cfj into which the earth's circumference is divided2 that is1 he is in longitude #fj ,w4 ,the sextant gives him the angle made by a line drawn to the sun with another drawn to the horizon1 and from that he calculates his latitude4 ,then he adjourns to the chart-room1 where1 by finding the point at which the lines of longitude and latitude intersect1 he establishes his exact position also4 ,when the ship leaves ,england the chronometer is set by ,greenwich time1 and is never touched afterwards except to be wound once a day4 ,in order that any error may be reduced to a minimum a merchant ship carries at least two chronometers1 a man-of-war at least three1 and a surveying vessel as many as a dozen4 ,the average reading of the chronometers is taken to work by4 ,taking the case of a single chronometer1 it has often to be relied on for months at a time1 and during that period has probably to encounter many changes of temperature4 ,if it gains or loses from day to day1 and that consistently1 it may still be accounted reliable1 as the amount of error will be allowed for in all calculations4 ,but should it gain one day and lose another1 the accumulated errors would1 on a voyage of several months1 become so considerable as to imperil seriously the safety of the vessel if navigating dangerous waters4 ,as long ago as #agad the ,english ,government recognised the importance of a really reliable chronometer1 and in that year passed an ,act offering rewards of #aj1jjj1 #ae1jjj1 and #bj1jjj to anybody who should produce a chronometer that would fix longitude within sixty1 forty1 and thirty miles respectively of accuracy4 ,john ,harrison1 the son of a ,yorkshire carpenter1 who had already invented the ingenious gridiron pendulum for compensating clocks1 took up the challenge4 ,by #agfa he had made a chronometer of so perfect a nature that during a voyage to ,jamaica that year1 and back the next1 it lost only #a min4 #ed-a_/b sec4 ,as this would enable a captain to find his longitude within eighteen miles in the latitude of ,greenwich1 ,harrison claimed1 and ultimately received1 the maximum reward4 ,it was not till nearly a century later that ,thomas ,earnshaw produced the compensation balance1 now generally used on chronometers and high-class watches4 ,in cheap watches the balance is usually a little three-spoked wheel1 which at every tick revolves part of a turn and then flies back again4 ,this will not suffice for very accurate work1 because the moment of inertia varies at different temperatures4 ,to explain this term let us suppose that a man has a pound of metal to make into a wheel4 ,if the wheel be of small diameter1 you will be able to turn it first one way and then the other on its axle quite easily4 ,but should it be melted down and remade into a wheel of four times the diameter1 with the same amount of metal as before in the rim1 the difficulty of suddenly reversing its motion will be much increased4 ,the weight is the same1 but the speed of the rim1 and consequently its momentum1 is greater4 ,it is evident from this that1 if a wheel of certain size be driven by a spring of constant strength1 its oscillations will be equal in time2 but if a rise of temperature should lengthen the spokes the speed would fall1 because the spring would have more work to do2 and1 conversely1 with a fall of temperature the speed would rise4 ,earnshaw's problem was to construct a balance wheel that should be able to keep its moment of inertia constant under all circumstances4 ,he therefore used only two spokes to his wheel1 and to the outer extremity of each attached an almost complete semicircle of rim1 one end being attached to the spoke1 the other all but meeting the other spoke4 ,the rim-pieces were built up of an outer strip of brass1 and an inner strip of steel welded together4 ,brass expands more rapidly than steel1 with the result that a bar compounded of these two metals would1 when heated1 bend towards the hollow side4 ,to the rim-pieces were attached sliding weights1 adjustable to the position found by experiment to give the best results4 ,we can now follow the action of the balance wheel4 ,it runs perfectly correctly at1 say1 a temperature of #fj4 ,hold it over a candle4 ,the spokes lengthen1 and carry the rim-pieces outwards at their fixed ends2 but1 as the pieces themselves bend inwards at their free ends1 the balance is restored4 ,if the balance were placed in a refrigerating machine1 the spokes would shorten1 but the rim-pieces would bend outwards4 ,as a matter of fact1 the moment of inertia cannot be kept quite constant by this method1 because the variation of expansion is more rapid in cold than in heat2 so that1 though a balance might be quite reliable between #fj and #ajj1 it would fail between #cj and #fj4 ,so the makers fit their balances with what is called a secondary compensation1 the effect of which is to act more quickly in high than in low temperatures4 ,this could not well be explained without diagrams1 so a mere mention must suffice4 ,another detail of chronometer making which requires very careful treatment is the method of transmitting power from the main spring to the works4 ,as the spring uncoils1 its power must decrease1 and this loss must be counterbalanced somehow4 ,this is managed by using the drum and fusee action1 which may be seen in some clocks and in many old watches4 ,the drum is cylindrical1 and contains the spring4 ,the fusee is a tapering shaft1 in which a spiral groove has been cut from end to end4 ,a very fine chain connects the two parts4 ,the key is applied to the fusee1 and the chain is wound off the drum on to the larger end of the fusee first4 ,by the time that the spring has been fully wound1 the chain has reached the fusee's smaller extremity4 ,if the fusee has been turned to the correct taper1 the driving power of the spring will remain constant as it unwinds1 for it gets least leverage over the fusee when it is strongest1 and most when it is weakest1 the intermediate stages being properly proportioned4 ,to test this1 a weighted lever is attached to the key spindle1 with the weight so adjusted that the fully wound spring has just sufficient power to lift it over the topmost point of a revolution4 ,it is then allowed a second turn1 but if the weight now proves excessive something must be wrong1 and the fusee needs its diameter reducing at that point4 ,so the test goes on from turn to turn1 and alterations are made until every revolution is managed with exactly the same ease4 ,the complete chronometer is sent to ,greenwich observatory to be tested against the ,standard ,clock1 which1 at #aj a4m41 flashes the hour to other clocks all over ,great ,britain4 ,in a special room set apart for the purpose are hundreds of instruments1 some hanging up1 others lying flat4 ,assistants make their rounds1 noting the errors on each4 ,the temperature test is then applied in special ovens1 and finally the article goes back to the maker with a certificate setting forth its performances under different conditions4 ,if the error has been consistent the instrument is sold1 the buyer being informed exactly what to allow for each day's error4 ,at the end of the voyage he brings his chronometer to be tested again1 and1 if necessary1 put right4 ,here are the actual variations of a chronometer during a nineteen-day test1 before being used3-- ,gain in tenths ,day4 of seconds4 #ast #a_/b #bnd #c #crd #d #dth #d #eth #a_/b #fth #c #gth #j #hth #j #ith #d-a_/b #ajth #c #aath #d #abth #c #acth #c #adth #d #aeth #e #afth #b #agth #c #ahth #e #aith #a ,an average gain of just over one quarter of a second per diem6 ,quite extraordinary feats of time-keeping have been recorded of chronometers on long voyages4 ,thus a chronometer which had been to ,australia vi the ,cape and back vi the ,red ,sea was only fifteen seconds out2 and the ,encyclopdia ,britannica quotes the performance of the three instruments of ,s4,s4 ,orellana1 which between them accumulated an error of but #bc seconds during a sixty-three-day trip4 ,an instrument which will cut a blood corpuscle into several parts--that's the ,,microtome1 the small-cutter1 as the name implies4 ,for the examination of animal tissues it is necessary that they should be sliced very fine before they are subjected to the microscope4 ,perhaps a tiny muscle is being investigated and cross sections of it are needed4 ,well1 one cannot pick up the muscle and cut slices off it as you would off a ,german sausage4 ,to begin with1 it is difficult even to pick the object up2 and even if pieces one-hundredth of an inch long were detached they would still be far too large for examination4 ,so1 as is usually the case when our unaided powers prove unequal to a task1 we have recourse to a machine4 ,there are several types of microtomes1 each preferable for certain purposes4 ,but as in ordinary laboratory work the ,cambridge ,rocking ,microtome is used1 let us give our special attention to this particular instrument4 ,it is mounted on a strong cast-iron bed1 a foot or so in length and four to five inches wide4 ,towards one end rise a couple of supports terminating in knife-edges1 which carry a cross-bar1 itself provided with knife-edges top and bottom1 those on the top supporting a second transverse bar4 ,both bars have a long leg at right angles1 giving them the appearance of two large ,t's superimposed one on the other2 but the top ,t is converted into a cross by a fourth member--a sliding tube which projects forward towards a frame in which is clamped a razor1 edge upwards4 ,the tail of the lower ,t terminates in a circular disc1 pierced with a hole to accommodate the end of a vertical screw1 which has a large circular head with milled edges4 ,the upper ,t is rocked up and down by a cord and spring1 the handle actuating the cord also shifting on the milled screw-head a very small distance every time it is rocked backwards and forwards4 ,as the screw turns1 it gradually raises the tail of the lower member1 and by giving its cross-bar a tilt brings the tube of the upper member appreciably nearer the razor4 ,the amount of twist given to the screw at each stroke can be easily regulated by a small catch4 ,when the microscopist wishes to cut sections he first mounts his object in a lump of hard paraffin wax1 coated with softer wax4 ,the whole is stuck on to the face of the tube1 so as to be just clear of the razor4 ,the operator then seizes the handle and works it rapidly until the first slice is detached by the razor4 ,successive slices are stuck together by their soft edges so as to form a continuous ribbon of wax1 which can be picked up easily and laid on a glass slide4 ,the slide is then warmed to melt the paraffin1 which is dissolved away by alcohol1 leaving the atoms of tissue untouched4 ,these1 after being stained with some suitable medium1 are ready for the microscope4 ,a skilful user can1 under favourable conditions1 cut slices one twenty-five thousandth of an inch thick4 ,to gather some idea of what this means we will imagine that a cucumber one foot long and one and a-half inches in diameter is passed through this wonderful guillotine4 ,it would require no less than #gjj dinner-plates nine inches across to spread the pieces on6 ,if the slices were one-eighth of an inch thick1 the cucumber1 to keep a proportionate total size1 would be #bfj feet long4 ,after considering these figures we shall lose some of the respect we hitherto felt for the men who cut the ham to put inside luncheon-bar sandwiches4 ,in the preceding pages frequent reference has been made to index screws1 exactly graduated to a convenient number of divisions4 ,when such screws have to be manufactured in quantities it would be far too expensive a matter to measure each one separately4 ,therefore machinery1 itself very carefully graduated1 is used to enable a workman to transfer measurements to a disc of metal4 ,if the index-circle of an astronomical telescope--to take an instance--has to be divided1 it is centred on a large horizontal disc1 the circumference of which has been indented with a large number of teeth4 ,a worm-screw engages these teeth tangentially 7i4e4 at right angles to a line drawn from the centre of the plate to the point of engagement74 ,on the shaft of the screw is a ratchet pinion1 in principle the same as the bicycle free-wheel1 which1 when turned one way1 also twists the screw1 but has no effect on it when turned the other way4 ,stops are put on the screw1 so that it shall rotate the large disc only the distance required between any two graduations4 ,the divisions are scribed on the index-circle by a knife attached to a carriage over and parallel to the disc4 ,the ,,dividing ,,engine used for the graduation of certain astronomical instruments probably constitutes the most perfect machine ever made4 ,in an address to the ,institution of ,mechanical ,engineers1#a the ,president1 ,mr4 ,william ,henry ,maw1 used the following words3 ,the most recently constructed machine of the kind of which ,i am aware--namely1 one made by ,messrs4 ,warner and ,swasey1 of ,cleveland1 ,u4,s4,a4--is capable of automatically cutting the graduations of a circle with an error in position not exceeding one second of arc4 7,a second of an arc is approximately the angle subtended by a halfpenny at a distance of three miles47 ,this means that on a #bj-;inch circle the error in position of any one graduation shall not exceed #a_/bj1jjj inch4 ,now1 the finest line which would be of any service for reading purposes on such a circle would probably have a width equal to quite ten seconds of arc2 and it follows that the minute ,v-shaped cut forming this line must be so absolutely symmetrical with its centre line throughout its length1 that the position of this centre may be determined within the limit of error just stated by observations of its edges1 made by aid of the reading micrometer and microscope4 ,i may say that after the machine just mentioned had been made1 it took over a year's hard work to reduce the maximum error in its graduations from one and a-half to one second of arc4 ,the same address contains a reference to the great ,yerkes telescope1 which though irrelevant to our present chapter1 affords so interesting an example of modern mechanical perfection that it deserves parenthetic mention4 ,the diameter of a star of the seventh magnitude as it appears in the focus of this huge telescope is #a_/b1ejj inch4 ,the spiders' webs stretched across the object glass are about #a_/f1jjj inch in diameter4 ,the problem thus is1 says ,mr4 ,maw1 to move this twenty-two ton mass 7the telescope7 with such steadiness in opposition to the motion of the earth1 that a star disc #a_/b1ejj inch in diameter can be kept threaded1 as it were1 upon a spider's web #a_/f1jjj inch in diameter1 carried at a radius of thirty-two feet from the centre of motion4 ,i think that you will agree that this is a problem in mechanical engineering demanding no slight skill to solve2 but it has been solved1 and with the most satisfactory results4 ,the motions are controlled electrically2 and respecting them ,professor ,barnard1 one of the chief observers with this telescope1 some time ago wrote as follows3 ,it is astonishing to see with what perfect instantaneousness the clock takes up the tube4 ,the electric slow motions are controlled from the eye end4 ,so exact are they that a star can be brought from the edge of the field and stopped instantaneously behind the micrometer wire4 ,dividing engines are used for ruling parallel lines on glass and metal1 to aid in the measurements of microscopical objects or the wave-lengths of light4 ,a diffraction grating1 used for measuring the latter1 has the lines so close together that they would be visible only under a powerful microscope4 ,glass being too brittle1 a special alloy of so-called speculum metal is fashioned into a highly polished plate1 and this is placed in the machine4 ,a delicate screw arrangement gradually feeds the plate forwards under the diamond point1 which is automatically drawn across the plate between every two movements4 ,professor ,h4 ,a4 ,rowlands has constructed a parallel dividing engine which has ruled as many as #abj1jjj lines to the inch4 ,to get a conception of these figures we must once again resort to comparison4 ,let us therefore take a furrow as a line1 and imagine a ploughman going up and down a field #abj1jjj times4 ,if each furrow be eight inches wide1 the field would require a breadth of nearly fourteen miles to accommodate all the furrows6 ,again1 supposing that a plate six inches square were being ruled1 the lines placed end to end would extend for seventy miles6 ,professor ,rowlands' machine does the finest work of this kind4 ,another very perfect instrument has been built by ,lord ,blythswood1 and as some particulars of it have been kindly supplied1 they may fitly be appended4 ,if a first-class draughtsman were asked how many parallel straight lines he would rule within the space of one inch1 it is doubtful whether he would undertake more than #aej to #bjj lines4 ,lord ,blythswood's machine can rule fourteen parallel lines on a space equivalent to the edge of the finest tissue paper4 ,so delicate are the movements of the machine that it must be protected from variations of temperature1 which would contract or expand its parts2 so the room in which it stands is kept at an even heat by automatic apparatus1 and to make things doubly sure the engine is further sheltered in a large case having double walls inter-packed with cotton wool4 ,in constructing the machine it was found impossible1 with the most scientific tools1 to cut a toothed wheel sufficiently accurate to drive the mechanism1 but the errors discovered by microscopes were made good by the invention of a small electro-plating brush1 which added the thinnest imaginable layer of metal to any tooth found deficient4 ,during the process of ruling a grating of only a few square inches area1 the machine must be left severely alone in its closed case4 ,the slightest jar would cause unparallelism of a few lines1 and the ruin of the whole grating4 ,so for several days the diamond point has its own way1 moving backwards and forwards unceasingly over the hard metal1 in which it chases tiny grooves4 ,at the end the plate has the appearance of mother-of-pearl1 which is1 in fact1 one of nature's diffraction gratings1 breaking up white light into the colours of the spectrum4 ,you will be able to understand that these mechanical gratings are expensive articles4 ,sometimes the diamond point breaks half-way through the ruling1 and a week's work is spoilt4 ,also the creation of a reliable machine is a very tedious business4 ,ten pounds per square inch of grating is a low price to pay4 ,the greatest difficulty met with in the manufacture of the dividing engine is that of obtaining a mathematically correct screw4 ,turning on a lathe produces a very rough spiral1 judged scientifically4 ,some threads will be deeper than others1 and differently spaced4 ,the screw must1 therefore1 be ground with emery and oil introduced between it and a long nut which is made in four segments1 and provided with collars for tightening it up against the screw4 ,perhaps a fortnight may be expended over the grinding4 ,then the screw must undergo rigid tests1 a nut must be made for it1 and it has to be mounted in proper bearings4 ,the explanation of the method of eliminating errors being very technical1 it is omitted2 but an idea of the care required may be gleaned from ,professor ,rowlands' statement that an uncorrected error of #a_/cjj1jjj of an inch is quite sufficient to ruin a grating6 ,in the ,houses of ,parliament there is kept at an even temperature a bronze rod1 thirty-eight inches long and an inch square in section4 ,near the ends are two wells1 rather more than half an inch deep1 and at the bottom of the wells are gold studs1 each engraved with a delicate cross line on their polished surfaces4 ,the distance between the lines is the imperial yard of thirty-six inches4 ,the bar was made in #ahdd to replace the ,standard destroyed in #ahcd1 when both ,houses of ,parliament were burned4 ,the original ,standard was the work of ,bird1 who produced it in #agfj4 ,in ,june1 #ahbd1 an ,act had been passed legalising this ,standard4 ,it says3-- ,the same ,straight ,line or ,distance between the ,centers of the said ,two ,points in the said ,gold ,studs in the said ,brass ,rod1 the ,brass being at the temperature of ,sixty-two ,degrees by ,fahrenheit's ,thermometer1 shall be and is hereby denominated the ',imperial ,standard ,yard4' ,to provide for accidents to the bar1 the ,act continues3 ,and whereas it is expedient that the said ,standard ,yard1 if lost1 destroyed1 defaced1 or otherwise injured1 should be restored to the same ,length by reference to some invariable natural ,standard3 ,and whereas it has been ascertained by the ,commissioners appointed by ,his ,majesty to inquire into the subject of ,weights and ,measures1 that the ,yard hereby declared to be the ,imperial ,standard ,yard1 when compared with a ,pendulum vibrating ,seconds of ,mean ,time in the ,latitude of ,london in a ,vacuum at the ,level of the ,sea1 is in the proportion of ,thirty-six ,inches to ,thirty-nine ,inches and one thousand three hundred and ninety-three ten-thousandth ,parts of an ,inch4 ,the new bar was made1 however1 not by this method1 but by comparing several copies of the original and striking their average length4 ,four accurate duplicates of the new standard were secured1 one of which is kept in the ,mint1 one in the charge of the ,royal ,society1 one at ,westminster ,palace1 and the fourth at the ,royal ,observatory1 ,greenwich4 ,in addition1 forty copies were distributed among the various foreign governments1 all of the same metal as the original4 ,the ,french metre has also been standardised1 being equal to one ten-millionth part of a quadrant of the earth's meridian 7i4e4 of the distance from the ,equator to either of the ,poles71 that is1 to #cicgjghh inches4 ,professor ,a4 ,a4 ,michelson has shown that any standard of length may be restored by reference to the measurement of wave lengths of light1 with an error not exceeding one ten-millionth part of the whole4 ,it might be asked ,why should standards of such great accuracy be required8 ,in rough work1 such as carpentry1 it does not1 indeed1 matter if measurements are the hundredth of an inch or so out4 ,but when we have to deal with scientific instruments1 telescopes1 measuring machines1 engines for dividing distances on a scale1 or even with metal turning1 the utmost accuracy becomes needful2 and a number of instruments will be much more alike in all dimensions if compared individually with a common standard than if they were only compared with one another4 ,supposing1 for instance1 a bar of exact diameter is copied2 the copy itself copied2 and so on a dozen times2 the last will probably vary considerably from the correct measurements4 ,hence it became necessary to standardise the foot and the inch by accurate subdivisions of the yard4 ,this was accomplished by ,sir ,joseph ,whitworth1 who in #ahcd obtained two standard yards in the form of measure bars1 and by the aid of microscopes transferred the distance between the engraved lines to a rectangular end-measure bar1 i4e4 one of which the end faces are exactly a yard apart4 ,he next constructed his famous machine which is capable of detecting length differences of one millionth of an inch4 ,two bars are advanced towards each other by screw gearing3 one by a screw having twenty threads to the inch1 and carrying a graduated hand-wheel with #bej divisions on its rim2 the other by a similar screw1 itself driven by a worm-screw1 working on the rim1 which carries #bjj teeth4 ,the worm-screw has a hand-wheel with a micrometer graduation into #bej divisions of its circumference4 ,so that1 if this be turned one division1 the second screw is turned only #a_/bej #a_/bjj of a division1 and the bar it drives advances only #a_/bj #a_/bjj #a_/bej #a_/a1jjj1jjj of an inch4 ,the screw at the other end of the machine 7which in appearance somewhat resembles a metal lathe7 is used for rapid adjustment only4 ,illustration3 ,,delicate ,,measuring ,,machines ,the upper illustration shows a ,pratt-,whitney ,measuring ,machine in operation to decide the thickness of a cigarette paper1 which is one-thousandth of an inch thick4 ,this machine will measure variations of length or thickness as minute as one hundredth-thousandth of an inch4 ,the lower illustration shows a ,whitworth ,measuring ,machine which is sensitive to variations of one-millionth of an inch4 ,he 7,sir ,j4 ,whitworth7 obtained the subdivision of the yard by making three foot pieces as nearly alike as was possible1 and working these foot pieces down until each was equal to the others1 and placing them end to end in his millionth measuring machine2 the total length of the three foot pieces was then compared with a standard end-measure yard4 ,these three foot pieces were ground until they were exactly equal to each other1 and the three added together are equal to the standard yard4 ,the subdivision of the foot into inch pieces was made in the same way4#b ,a doubt may have arisen in the reader's mind as to the possibility of determining whether the measuring machine is screwed up to the exact tightness4 ,would the measuring bars not compress a body a little before it appeared tight8 ,workmen1 when measuring a bar with callipers1 often judge by the sense of touch whether the jaws of the callipers pass the bar with the proper amount of resistance2 but when one has to deal with millionths of an inch1 such a method would not suffice4 ,so ,sir ,joseph ,whitworth introduced a feeling-piece1 or gravity-piece4 ,mr4 ,t4 ,m4 ,goodeve thus describes it in ,the ,elements of ,mechanism3 ,the gravity-piece consists of a small plate of steel with parallel plane sides1 and having slender arms1 one for its partial support1 and the other for resting on the finger of the observer4 ,one arm of the piece rests on a part of the bed of the machine1 and the other arm is tilted up by the forefinger of the operator4 ,the plane surfaces are then brought together1 one on each side of the feeling-piece1 until the pressure of contact is sufficient to hold it supported just as it remained when one end rested on the finger4 ,this degree of tightness is perfectly definite1 and depends on the weight of the gravity-piece1 but not on the estimation of the observer4 ,in this way the expansion due to heat when a #cf-;inch bar has been touched for an instant with the finger-nail may be detected4 ,one of the most beautiful measuring machines commercially used comes from the factories of the ,pratt-,whitney ,co41 ,hartford1 ,connecticut1 the well-known makers of machine tools and gauges of all kinds4 ,it is made in different sizes1 the largest admitting an #hj-;inch bar4 ,variations of #a_/ajj1jjj of an inch are readily determined by the use of this machine4 ,it therefore serves for originating gauge sizes1 or for duplicating existing standards4 ,the adjusting screw has fifty threads to the inch1 and its index-wheel is graduated to #djj divisions1 giving an advance of #a_/bj1jjj inch for each division3 while by estimation this may be further subdivided to indicate one-half or even one-quarter of this small amount4 ,delicacy of contact between the measuring faces is obtained by the use of auxiliary jaws holding a small cylindrical gauge by the pressure of a light helical spring which operates the sliding spindle to which one of these auxiliary jaws is attached4 ,on one side of the head of the machine is a vertical microscope directed downwards on to a bar on the bed-plate1 in which are a number of polished steel plugs graved with very fine central cross lines1 each exactly an inch distant from either of its neighbours4 ,a cross wire in the microscope tells when it is accurately abreast of the line below it4 ,supposing1 then1 that a standard bar three inches in diameter has to be tested4 ,the head is slid along until the microscope is exactly over the zero plug line1 and the divided index-wheel is turned until the two jaws press each other with the minimum force that will hold up the feeling-piece4 ,then the head is moved back and centred on the #c-;inch line1 and the bar to be tested is passed between the jaws4 ,if the feeling-piece drops out it is too large1 and the wheel is turned back until the jaws have been opened enough to let the bar through without making the feeling-piece fall4 ,an examination of the index-wheel shows in hundred-thousandths of an inch what the excess diameter is4 ,on the other hand1 if the bar were too small1 the jaws would need to be closed a trifle3 this amount being similarly reckoned4 ,we have now got into a region of very practical politics1 namely1 the subject of gauges4 ,all large engineering works which turn out machinery with interchangeable parts1 e4g4 screws and nuts1 must keep their dimensions very constant if purchasers are not to be disgusted and disappointed4 ,the small motor machinery so much in evidence to-day demands that errors should be kept within the ten-thousandth of an inch4 ,an engineer therefore possesses a set of standard gauges to test the diameter and pitch of his screw threads and nuts2 the size of tubes1 wires2 the circumference of wheels1 etc4 ,great inconvenience having been experienced by ,american railroad-car builders on account of the varying sizes of the screws and bolts which were used on the different tracks--though all were supposed to be of standard dimensions--the masters determined to put things right2 and accordingly ,professors ,roger and ,bond and the ,pratt-,whitney ,co4 were engaged to work in collaboration in connection with the manufacture of tools for minute measurements1 viz4 to #a_/ej1jjj inch4 ,to give an idea of what is implied by this1 let it be supposed that a person should take a pair of dividing compasses and lay off #ej1jjj prick-marks #a_/h inch apart in a straight line4 ,to do this the line would require to be over #ebj feet1 or nearly a tenth of a mile long4 ,imagine that many prick-marks compressed into the space of an inch1 and you have an imperfect idea of the minuteness of the measurements which can now be made by the ,pratt and ,whitney ,co4#c ,the standard taps and dies were supplied to tool-makers and engineers1 who could thus determine whether articles supplied to them were of the proper dimensions4 ,nothing more was then heard of nuts being a trifle small or bolts a leetle large4 ,and so beautifully tempered were the dies made from the standards that one manufacturer claimed to have cut #ah1hjj cold-pressed nuts without any difference being perceptible in their sizes4 ,to appreciate what the difference of a thousandth of an inch makes in a true fit1 you should handle a set of plug and ring gauges2 the ring a true half-inch internally1 the plugs half-inch1 half an inch less one ten-thousandth of an inch1 and half an inch less one-thousandth1 in diameter4 ,the true half-inch plug needs to be forcibly driven into the ring on account of the friction between the surfaces4 ,the next1 if oiled1 will slide in quite easily1 but if left stationary a moment will seize1 and have to be driven out4 ,the third will wobble very perceptibly1 and would be at once discarded by a good workman as a bad fit4 ,for extremely accurate measurements of rods1 calliper gauges1 shaped somewhat like the letter ,y1 are used1 the horns terminating in polished parallel jaws4 ,such a gauge will detect a difference of #a_/bj1jjj inch quite easily4 ,so accurately can plug gauges be made by reference to a measuring machine1 that a gold leaf #a_/cj1jjj inch thick would be three times too thick to insert between the gauge and the jaws of the machine6 ,you must remember that in high-class workmanship these gauges are constantly being used4 ,as time goes on1 the limit of error allowed in many classes of machine parts is gradually lessened1 which shows the simultaneous improvement of all machinery used in the handling of metal4 ,james ,watt was terribly hampered1 when developing his steam-engine1 by the difficulty of procuring a true cylinder for his pistons to work in with any approach to steam-tightness4 ,his first cylinder was made by a smith of hammered iron soldered together4 ,the next was cast and bored1 but stuffing it with paper1 cork1 putty1 pasteboard1 and old hat proved useless to stem the leakage of steam4 ,no wonder1 considering that the finished cylinder was one-eighth of an inch larger in diameter at one end than at the other4 ,watt was in advance of his time4 ,neither machinery nor workmanship had progressed sufficiently to meet the requirements of the steam-engine4 ,to-day an engineer would confidently undertake to bore a cylinder five feet in diameter with a variation from truth of not more than one five-hundredth of an inch4 ,before passing from the subject of measuring machines1 which play so important a part in modern mechanism1 we may just glance at the electrical method of ,dr4 ,p4 ,e4 ,shaw4 ,he discovered recently that two clean metal surfaces can1 by means of an electric current1 feel one another on touching with a delicacy that far transcends that of the purely mechanical machine4 ,the mechanism he employs is thus devised3 ,a finely cut vertical screw having fifty threads to the inch has a disc graduated into #ejj parts4 ,the screw can be turned by means of a pulley string from a distance1 and it is thus possible to give the top end of the screw a movement of #a_/be1jjj inch1 when a movement corresponding to one graduation is made4 ,this small movement is reduced by a train of six levers1 the long arm of each bearing on the short arm of the one before it4 ,the movement of the last lever of the train is thus reduced to #a_/d1jjj of that of the screw point1 so a movement of #a_/d1jjj #a_/be1jjj inch #a_/ajj1jjj1jjj inch is obtained6 ,how can such a movement be judged8 ,a telephone and voltaic cell are joined to the last lever of the train and to the object whose movement is under examination4 ,if they touch1 the telephone sounds4 ,an observer listens in the telephone1 and if the object moves for any reason he can find out how much it moves by turning the screw until contact is made again4 ,out of the many applications of this apparatus three may be given4 7#a7 ,a short bar of iron when magnetised elongates about #a_/a1jjj1jjj of its length4 ,if further magnetised it contracts4 ,these changes can readily be measured with the instrument4 7#b7 ,the smallest sound audible in the telephone is due to a movement of the diaphragm of the telephone by about #a_/ej1jjj1jjj of an inch4 ,this has been actually measured by ,dr4 ,shaw and is by far the smallest distance ever directly recorded4 ,it is about twice the diameter of the molecules of matter4 7#c7 ,dispensing with levers1 the screw alone is used for rougher work4 ,dr4 ,shaw has shown that one hundred-thousandth of an inch is the smallest dimension visible under a microscope4 ,by fitting an electric measuring apparatus to the microscope carriage it becomes quite easy to measure minute distances4 ,the microscope contains a cross wire which1 when the object has been laid on the microscope stage1 is centred on one side of the object4 ,the electric contact screw is then advanced till it makes contact with the stage and a sound arises in the telephone4 ,a reading of the screw disc having been taken1 the screw is drawn in and the microscope stage is traversed sufficiently to bring the wire in line with the other side of the object4 ,once more the operator makes electrical contact and gets a second reading1 the difference between the two being the diameter of the object4 ,in this manner the bacillus of tuberculosis has been proved to have an average diameter of #ca_/bej1jjj of an inch4 ,the same method is employed to gauge the distance between the lines on a diffraction grating4 ,,footnotes3 #a ,april #aith1 #aija4 #b ,g4 ,m4 ,bond in a lecture delivered before the ,franklin ,institute1 ,february #bith1 #ahhd4 #c ,report on ,standard ,screw ,threads1 ,philadelphia1 #ahhd4 ,,chapter ,,ii ,,calculating ,,machines ,the simplest form of calculating machine was the ,abacus1 on which the schoolboys of ancient ,greece did their sums4 ,it consisted of a smooth board with a narrow rim1 on which were arranged rows of pebbles1 bits of bone or ivory1 or silver coins4 ,by replacing these little counters by sand1 strewn evenly all over its surface1 the abacus was transformed into a slate for writing or geometrical lessons4 ,the ,romans took the abacus1 along with many other spoils of conquest1 from the ,greeks and improved it1 dividing it by means of cross-lines1 and assigning a multiple value to each line with regard to its neighbours4 ,from their method of using the calculi1 or pebbles1 we derive our ,english verb1 to calculate4 ,during the ,middle ,ages the abacus still flourished1 and it has left a further mark on our language by giving its name to the ,court of ,exchequer1 in which was a table divided into chequered squares like this simple school appliance4 ,step by step further improvements were made1 most important among them being those of ,napier of ,merchiston1 whose logarithms vex the heads of our youth1 and save many an hour's calculation to people who understand how to handle them4 ,sir ,samuel ,morland1 ,gunter1 and ,lamb invented other contrivances suitable for trigonometrical problems4 ,gersten and ,pascal harnessed trains of wheels to their ready-reckoners1 somewhat similar to the well-known cyclometer4 ,all these devices faded into insignificance when ,mr4 ,charles ,babbage came on the scene with his famous calculator1 which is probably the most ingenious piece of mechanism ever devised by the human brain4 ,to describe the ,difference ,engine1 as it is called1 would be impossible1 so complicated is its character4 ,dr4 ,lardner1 who had a wonderful command of language1 and could explain details in a manner so lucid that his words could almost always be understood in the absence of diagrams1 occupied twenty-five pages of the ,edinburgh ,review in the endeavour to describe its working1 but gave several features up as a bad job4 ,another clever writer1 ,dr4 ,samuel ,smiles1 frankly shuns the task1 and satisfies himself with the following brief description3-- ,some parts of the apparatus and modes of action are indeed extraordinary--and1 perhaps1 none more so than that for ensuring accuracy in the calculated results--the machine actually correcting itself1 and rubbing itself back into accuracy1 by the friction of the adjacent machinery6 ,when an error is made the wheels become locked and refuse to proceed2 thus the machine must go rightly or not at all--an arrangement as nearly resembling volition as anything that brass and steel are likely to accomplish4#d ,mr4 ,babbage1 in #ahbb1 entered upon the task of superintending the construction of a machine for calculating and printing mathematical and astronomical tables4 ,he began by building a model1 which produced forty-four figures per minute4 ,the next year the ,royal ,society reported upon the invention1 which appeared so promising that the ,lords of the ,treasury voted ,mr4 ,babbage #a1ejj to help him perfect his apparatus4 ,he looked about for a first-rate mechanician of high intelligence as well as of extreme manual skill4 ,the man he wanted appeared in ,mr4 ,joseph ,clement1 who had already made his name as the inventor of a drawing instrument1 a self-acting lathe1 a self-centring chuck1 and fluted taps and dies4 ,mr4 ,clement soon produced special tools for shaping the various parts of the machine4 ,so elaborate was the latter1 that1 according to ,dr4 ,smiles1 the drawings for the calculating machinery alone--not to mention the printing machinery1 which was almost equally elaborate--covered not less than four hundred square feet of surface6 ,you will easily imagine1 especially if you have ever had a special piece of apparatus made for you by a mechanic1 that the bills mounted up at an alarming rate2 so fast1 indeed1 that the ,government began to ask1 ,why this great expense1 and so little visible result8 ,after seven years' work the engineers' account had reached #g1bjj1 and ,mr4 ,babbage had disbursed an additional #g1jjj out of his own pocket4 ,mr4 ,clement quarrelled with his employer--possibly because he harboured suspicions that they were both off on a wild-goose chase--and withdrew1 taking all his valuable tools with him4 ,the ,government soon followed his example1 and poor ,babbage was left with his half-finished invention1 a beautiful fragment of a great work4 ,it had been designed to calculate as far as twenty figures1 but was completed only sufficiently to go to five figures4 ,in #ahfb it occupied a prominent place among the mechanical exhibits at the ,great ,exhibition4 ,illustration3 ,a ,,mechanical ,,cashier ,the printing apparatus of a ,national ,cash ,register4 ,it impresses on a paper strip the amount and nature of every money transaction2 and also prints a date1 number1 advertisement1 money value1 and nature of business done on a ticket for the customer4 ,we learn1 with some satisfaction1 that all this effort was not fated to be fruitless4 ,two scientists of ,stockholm--,scheutz by name--were so impressed by ,dr4 ,lardner's account of this calculating machine that they carried ,babbage's scheme through1 and after twenty years of hard work completed a machine which seemed to be almost capable of thinking4 ,the ,english ,government spent #a1bjj on a copy1 which at ,somerset ,house entered upon the routine duty of working out annuity and other tables for the ,registrar-,general4 ,from ,babbage's wonderfully and fearfully made machine we pass to a calculator which to-day may be seen at work in hundreds of thousands of shops and offices4 ,it is the most modern substitute for the open till2 and1 by the aid of marvellous interior works1 acts as account-keeper and general detective to the money transactions of the establishment in which it is employed4 ,there are very many types of ,cash ,register1 and as it would be impossible to enumerate them all1 we will pass at once to the most perfect type of all1 known to the makers and vendors as ,number #ie4 ,this register has at the top an oblong window4 ,dotted about the surface confronting the operator are1 in the particular machine under notice1 fifty-seven keys2 six bearing the letters ,a1 ,b1 ,d1 ,e1 ,h1 ,k2 three the words ,paid out1 ,charge1 ,received on ,account2 and the others money values ranging from #i to #a_/d;d4 ,these are arranged in vertical rows4 ,at the left end of the instrument is a printing apparatus1 kept locked by the proprietor2 at the right end a handle and a small lever4 ,below the register are six drawers1 each labelled with an initial4 ,a customer enters the shop1 and buys goods to the value of #fs4 #aa;d4 ,an assistant1 to whom belongs the letter ,h1 receives a sovereign in payment4 ,he goes to the register1 and after making sure that his drawer is pushed in till it is locked1 first presses down the key ,h1 and then the keys labelled #fs4 and #aa;d4 ,suddenly1 like two ,jacks-in-the-box1 up fly into the window two tablets1 with #fs4 #aa;d4 on both their faces1 so that customer and assistant can see the figures4 ,simultaneously a bell of a certain tone rings1 drawer ,h flies open 7so that he may place the money in it and give change1 if necessary71 and a rotating arm in the window shows the word cash4 ,the assistant now revolves the handle and presses the little lever4 ,from a slot on the left side out flies a ticket1 on the front of which is printed the date1 a consecutive number1 the assistant's letter1 and the amount of the sale4 ,the back has also been covered with an advertisement of some kind4 ,the ticket and change are handed over to the customer1 the drawer is shut1 and the transaction is at an end1 except for an entry in the shop's books of the article sold4 ,a carrier next comes in with a parcel on which five-pence must be paid for transport4 ,mr4 ,a4 receives the goods1 goes to the register1 presses his letter1 the key with the words paid out on it1 and the key carrying #e;d41 takes out the amount wanted1 and gives it to the carrier4 ,again1 a gentleman enters1 and asks for change for half a sovereign4 ,mr4 ,b4 obliges him1 pressing down his letter1 but no figures4 ,fourthly1 a debtor to the shop pays five shillings to meet an account that has been against him for some time4 ,mr4 ,k4 receives the money and plays with the keys ,k1 ,received on account1 and #es41 giving a ticket receipt4 ,lastly1 a customer buys a pair of boots on credit4 ,mr4 ,d4 attends to him1 and though no cash is handled1 uses the register1 pressing the letter ,charge1 and1 say1 #afs4 #f;d4 ,now what has been going on inside the machine all this time8 ,let us lift up the cover1 take off the case of the printing apparatus1 and see4 ,a strip of paper fed through the printing mechanism has on it five rows of figures1 letters1 etc41 thus-- s4 d4 ,h #f #aa ,pd4 ,a #j #e ,b #j #j ,rc4 ,k #e #j ,ch4 ,d #af #f ,the proprietor is1 therefore1 enabled to see at a glance 7#a7 who served or attended to a customer1 7#b7 what kind of business he did with him1 7#c7 the monetary value of the transaction4 ,at the end of the day each assistant sends in his separate account1 which should tally exactly with the record of the machine4 ,simultaneously with the strip printing1 special counting apparatus has been 7a7 adding up the total of all money taken for goods1 7b7 recording the number of times the drawer has been opened for each purpose4 ,here1 again1 is a check upon the records4 ,this ingenious machine not only protects the proprietor against carelessness or dishonesty on the part of his employs1 but also protects the latter against one another4 ,if only one drawer and letter were used in common1 it would be impossible to trace an error to the guilty party4 ,the lettering system also serves to show which assistant does the most business4 ,where a cash register of this type is employed every transaction must pass through its hands--or rather mechanism4 ,it would be risky for an assistant not to use the machine1 as eyes may be watching him4 ,he cannot open his drawers without making a record2 nor can he make a record without first closing the drawers2 so that he must give a reason for each use of the register4 ,if he used somebody else's letter1 the ear of the rightful owner would at once be attracted by the note of his particular gong4 ,when going away for lunch1 or on business1 a letter can be locked by means of a special key1 which fits none of the other five locks4 ,the printing mechanism is particularly ingenious4 ,every morning the date is set by means of index-screws3 and a consecutive numbering train is put back to zero4 ,a third division accommodates a circular electro block for printing the advertisements1 and a fourth division the figure wheels4 ,the turn given to the handle passes a length of the ticket strip through1 a slot--prints the date1 the number of the ticket1 an advertisement on the back1 the assistant's letter1 the nature of the business done1 and feeds the paper on to the figures which give the finishing touch4 ,a knife cuts off the ticket1 and a special lever shoots it out of the slot4 ,the ,national ,cash ,register ,company1 for prudential reasons1 do not wish the details of the internal machinery to be described2 nor would it be an easy task even were the permission granted4 ,so we must imagine the extreme intricacy of the levers and wheels which perform all the tasks enumerated1 and turn aside to consider the origin and manufacture of the register1 which are both of interest4 ,the origin of the cash register is rather nebulous1 because twenty-five years ago several men were working on the same idea4 ,it first appeared as a practical machine in the offices of ,john and ,james ,ritty1 who owned stores and coalmines at ,dayton1 ,ohio4 ,james ,ritty helped and largely paid for the first experiments4 ,he needed a mechanical cashier for his own business1 and says that1 while on an ocean steamer en route to ,london the revolving machinery gave him the suggestion worked out1 on his return to ,dayton1 in the first dial-machine4 ,this gave way to the key-machine with its display tablet1 or indicator1 held up by a supporting bar moved back by knuckles on the vertical tablet rod4 ,illustration3 ,,fig4 #a ,the cut 7,fig4 #a7 shows the right side of this key register1 the action of which is thus described by the ,national ,cash ,register ,company4 ,the key ,a1 when pressed with the finger at its ordinary position--marked #a--went down to the point marked #b4 ,being a lever and pivoted to its centre1 pressing down a key elevated its extreme point ,b4 ,this pushed up the tablet-rod ,c1 having on its upper part the knuckle ,d4 ,this knuckle ,d1 pushed up1 took the position at ,e2 that is1 the knuckle pushed back the supporting-bar ,f1 and was pushed past it and held above it4 ,if the same operation were performed on another key1 the knuckle on its vertical rod1 going up1 would again push the supporting bar back1 which would release the first knuckled rod1 and leave the last one in its place4 ,this knuckled rod had on its upper end the display tablet1 or indicator ,g4 ,james and ,john ,ritty claimed and proved that they invented this1 but the attorney for the ,dayton ,company 7formed by them7 in the ,supreme ,court was compelled to admit that this mechanism was old4 ,yet if machines built like this were exhibited elsewhere1 they were at most only experimental models1 and none of them had ever gone into practical or commercial use4 ,in fact1 at this time nothing had been really contributed which was useful to the public or used by the public4 ,the trouble was that the knuckles1 being necessarily oiled1 held dust and dirt which interfered with their free movement4 ,and again1 a five-cent or ten-cent key would be used more than others1 and hence would become more worn4 ,as a practical result the tablets did not drop when wanted1 and the whole operation was thrown into confusion4 ,when one tablet went up the other tablet stayed up1 leaving a false indication4 ,the most valuable modification now made by these ,dayton inventors was to cease to rely on the knuckle to move back the supporting bar1 and to supply the place of this function by what became known as connecting mechanism1 especially designed for this purpose4 ,this was placed at the other1 or say the left1 side of the machine as you faced it4 ,cut ,no4 #b shows this new connecting mechanism4 ,the keys1 when pressed1 performed the functions as before1 on the right side of the machine1 viz4 to ring an alarm-bell1 etc42 but on the other1 or left1 side the key1 when pressed1 operated the connecting mechanism marked ,m1 ,n1 ,o1 ,p1 and ,q4 ,the key pressed down by its leverage pushed back a little lever 7,q71 the further end of which pressed back the supporting bar ,f1 and released the previously exposed indicator ,g1 without relying on the knuckle to perform this function4 ,the ,supreme ,court of the ,united ,states said that the suggestion or idea to correct the old trouble and to drop the display tablet with certainty1 and to accomplish this by dividing the force used1 and applying a portion of it to the new connecting mechanism on the left side of the machine1 was fine invention1 and that the results are so important1 and the ingenuity displayed to bring them about is such that we are not disposed to deny the patentees the merit of invention4 ,the combination described in the first claim was clearly new4 ,to revert for a moment to the origin of the invention4 ,mr4 ,john ,ritty gives an account differing from that of his brother2 but the two can probably be reconciled by supposing that the first ideas occurred simultaneously and were worked out in common4 ,late one summer night1 before dispersing home1 a group of men were in his store4 ,one of them said to the proprietor1 ,if you had a machine there to register the cash received1 you would get more of it1 and to the statement both owner and his clerks assented4 ,this raised a laugh4 ,but ,ritty who1 in spite of a large business1 which ranged over everything from a needle to a haystack1 did not make much profit by his sales1 took the suggestion seriously1 and put on his thinking-cap1 with the result that the first machine was patented1 and profits became very greatly increased4 ,illustration3 ,,fig4 #b ,before his machine had been perfected a rival was in the field4 ,mr4 ,thomas ,carney1 a man who had seen much life as a lumber merchant1 captain during the ,civil ,war1 explorer1 and railroad promoter1 settled down in #ahhd1 at ,chicago1 to the manufacture of coin-changers4 ,when in various businesses1 he says1 we used gold and silver only1 and it seemed to be a sheer necessity to have something of a money-changer to assist us in handling it and making change4 ,the custom then was to throw the different coins into a special receptacle marked for each4 ,i invented1 and in my own shop built this coin-changer1 the keys of which1 when touched1 would1 through the tube1 drop the coin into the hand as wanted4 ,at ,chicago we made five or six hundred of these coin-changers1 but by mistake placed the price too low1 and after some conference ,i became assured that there was not enough money in it4 ,a rich ,chicago manufacturer had become familiar with the urgent need of a cash register1 and the losses which followed in business without one4 ,the ,national1 at ,dayton1 had then been invented1 but had not then been perfected as it has been since4 ,parties at ,chicago agreed to put up the money if ,i would invent what would answer the purpose of a cash register and make a marketable machine4 ,i went home and gave the matter some hard thinking1 and talking with my son about the matter one night1 ,i looked up at the clock and said1 ',why1 ,harry1 there is the right thing4 ,sixty minutes make an hour2 one hundred cents make a dollar4 ,all ,i have got to do is to change the wheels a little1 put some keys into it1 and there will be a thing which will register cents1 dimes1 and dollars1 just as that clock will register time in minutes and hours4' ,in clocks the minute wheel1 when it has revolved to its sixty point1 throws its added result of sixty minutes over on to another wheel1 which takes up the story1 with one hour in place of the old sixty minutes4 ,the first wheel then begins again and goes its round4 ,a second complete revolution of the minute wheel throws another sixty minutes on to the hour1 and gives one more hour registered1 making two hours1 and so on4 ,i took some wheels1 and with pasteboard made hands and a machine4 ,it was very rough1 but ,i took it to my friends and explained it to them4 ,we went on1 but encountering difficulties and obstacles1 we merged our whole enterprise in the ,national4 ,i followed it1 and have since invented1 worked1 and helped along in the ,national ,cash ,register service4 ,i developed the ,no4 #ce machine which the company began on and uses yet4 ,it is now in use in every civilised country1 for it can be made to register ,english money and any decimal currency4 ,in #ahhc ,dayton contained five families4 ,the following year ,colonel ,robert ,patterson bought a large property in the neighbourhood1 and helped to develop a small town1 which has since grown into a thriving manufacturing centre4 ,his two sons1 ,john ,h4 ,patterson and ,frank ,j4 ,patterson1 bought out all the original proprietors of the ,national ,cash ,register1 greatly improved the machine's mechanism1 and built the huge factory which employs about #d1jjj men1 women1 and girls1 and is one of the best-equipped establishments in the world to promote both an economical output and the comfort of the employs4 ,the ,company's buildings at ,dayton cover #hib1add square feet of floor-space1 and utilise #adj acres of ground4 ,in convenience and attractiveness1 and for light1 heat1 and ventilation1 and all sanitary things1 these structures are designed to be models of any used for factory purposes4 ,a machine is made and sold every #b-a_/b minutes in the ,dayton1 ,berlin1 and ,toronto factories collectively4 ,according to its destination1 it records dollars1 shillings1 marks1 kronen1 korona1 francs1 kroner1 guildens1 pesetas1 pesos1 milreis1 rupees1 or roubles4 ,registers are also made to meet the needs of the ,celestials and the ,japanese4 ,so necessary is it for these machines to be ever improving1 that the ,company1 with a wisdom that prevails more largely1 perhaps1 in the ,united ,states than elsewhere1 offer substantial rewards to the employ who records in a book kept specially for the purpose any suggestion which the committee1 after due examination1 consider likely to improve some detail of mechanism or manufacture4 ,five departments are entirely devoted to experiments carried out by a corps of inventors working with a special body of skilled mechanics4 ,new patents accrue so fast as a result of this organised research that the ,national ,company now owns #ecg letters patent in the ,united ,states and #cid in foreign countries4 ,many ideas come from outside4 ,if they appear profitable they are bought and turned over to the ,patents ,department1 which hands them on to the experimenters4 ,these build an experimental model1 which differs in many respects from the types hitherto manufactured4 ,a cash register must be above all things strong1 so that it can bear a heavy blow without getting out of order1 and must retain its accuracy under all conditions4 ,the model finished1 it goes before the inspectors1 who thump it1 hammer it1 almost turn it inside out1 and send it back to the ,factory ,committee with reports on any defects that may have come to light4 ,if the inspectors can only knock the machine out of time they consider that they have done their duty2 for they argue that1 if weaknesses thus developed are put right1 no purchaser will ever be able to dislocate the machinery if he stops short of an actual brutal assault with violence4 ,next comes the building of the commercial type1 which will be sold by the thousand4 ,the machine goes down to the tool-makers1 a select board of seventy-five members1 who list all the parts1 and say how many drill-jigs1 mills1 fixtures1 gauges1 etc41 are necessary to make every part4 ,then they draw out an approximate estimate of the cost of producing the tools1 and after they have listed the parts1 they turn them over to the various departments1 such as the drafting-room1 blacksmiths' shop1 pattern shop1 foundry1 etc41 after which the various parts are machined up4 ,then the tool-maker assembles together the various tools1 and makes a number of the parts that each tool is designed for2 so that when all the tools have done their preliminary work1 the makers possess about fifty machines in bits4 ,these are assembled1 to prove whether the tools do their business efficiently4 ,if any part shows an inclination to jam1 or otherwise misbehave itself1 the tool responsible is altered till its products are satisfactory4 ,then1 and only then--a period of perhaps two years may have elapsed since the model was first put in hand--the ,company begins to entertain a prospect of getting back some of the money--any sum up to #ej1jjj--spent in preparations4 ,but they know that if people will only buy1 they won't have much fault to find with their purchase4 ,preparations brings success is the motto of the ,n4,c4,r4 ,so the ,company spares no money1 and is content to have #be1jjj locked up in its automatic screw-making machines alone6 ,human as well as inanimate machinery is well tended under the roof of the ,n4,c4,r4 ,the committee believe that a healthy1 comfortable employ means good--and therefore profitable--work2 and that to work well1 employs must eat and play well4 ,they therefore provide their boys with gardens1 #aj feet wide by #agj feet in length2 and pay an experienced gardener to direct their efforts4 ,to encourage a start1 bulbs1 seeds1 slips1 etc41 are supplied free2 while prizes of considerable value help to stimulate competition4 ,one day1 ten years or more ago1 ,mr4 ,patterson saw a factory girl trying to warm her tin bucket of cold coffee at the steam heater in the workshop4 ,he is a humane man1 and acting on the unintentional hint he built a lunch-room which contains1 besides accommodation for #dee people1 a piano and sewing-machine which the women can use during their noon recess of eighty minutes4 ,a cooking school1 dancing classes1 and literary club are all available to members4 ,the ,company encourages its workers to own the houses they inhabit1 and to make them as beautiful as their leisure will permit4 ,mr4 ,mosely1 who took over to ,america an ,industrial ,commission of ,experts in #aijb1 and an ,educational ,commission in the following year1 paid visits on both occasions to the ,national ,cash ,register ,works4 ,in a speech to the ,committee he said3 ,i do not know of any institution in the world which offers so beautiful an illustration of the proper working conditions as the ,national ,cash ,register ,company4 ,your ,president has asked me to criticise4 ,i cannot find anything to criticise in this factory4 ,i have never seen such conditions in any other factory in the world1 nor have ,i ever seen so many bright and intelligent faces as we have seen at luncheon in both the men's and women's dining rooms4 ,i believe this factory is as nearly perfect as social conditions will permit4 ,,note4--,the author desires to express his thanks to the ,national ,cash ,register ,company for the kind help given him in the shape of materials for writing and illustrating this chapter4 ,illustration3 ,by permission of ,the ,sphere4 ,the jacket of a #ab-;inch gun being turned in a monster lathe at ,messrs4 ,vickers ,maxim's works4 ,notice the long spiral strip coming off the edge of the cutting tool4 ,,footnote3 #d ,industrial ,biographies1 chap4 xiii4 ,,chapter ,,iii ,,workshop ,,machinery ,,the ,,lathe--,,planing ,,machines--,,the ,,steam ,,hammer--,,hydraulic ,,tools--,,electrical ,,tools ,,in ,,the ,,shipyard ,when ,i first entered this city1 said ,mr4 ,william ,fairbairn1 in an inaugural address to the ,british ,association at ,manchester in #ahfa1 the whole of the machinery was executed by hand4 ,there were neither planing1 slotting1 nor shaping machines1 and with the exception of very imperfect lathes and a few drills1 the preparatory operations of construction were effected entirely by the hands of the workmen4 ,now1 everything is done by machine tools1 with a degree of accuracy which the unaided hand could never accomplish4 ,the automaton1 or self-acting1 machine tool has within itself an almost creative power2 in fact1 so great are its powers of adaptation1 that there is no operation of the human hand that it does not imitate4 ,if such things could be said with justice forty-five years ago1 what would ,mr4 ,fairbairn think could he see the wonderful machinery with which the present-day workshop is equipped--machinery as relatively superior to the devices he speaks of as they were superior to the unaided efforts of the human hand8 ,invention never stands still4 ,the wonder of one year is on the scrap-heap of abandoned machines almost before another twelve months have passed4 ,some important detail has been improved1 to secure ease or economy in working1 and a more efficient successor steps into its place4 ,in his curious and original ,erewhon1 ,mr4 ,samuel ,butler depicts a community which1 from the fear that machinery should become too ingenious1 and eventually drain away man's capacity for muscular and mental action1 has risen in revolt against the automaton1 broken up all machines which had been in use for less than #bgj years--with the exception of specimens reserved for the national museums--and reverted to hand labour4 ,his treatment of the dangers attending the increased employment of lifeless mechanisms as a substitute for physical effort does not1 however1 show sympathy with the ,erewhonians2 since their abandonment of invention had obviously placed them at the mercy of any other race retaining the devices so laboriously perfected during the ages4 ,and we1 on our part1 should be extremely sorry to part with the inanimate helpers which in every path of life render the act of living more comfortable and less toilsome4 ,so dependent are we on machinery1 that we owe a double debt to the machines which create machines4 ,a big factory houses the parents which send out their children to careers of usefulness throughout the world4 ,we often forget1 in our admiration of the offspring1 the source from which they originated4 ,our bicycles1 so admirably adapted to easy locomotion1 owe their existence to a hundred delicate machines4 ,the express engine1 hurrying forward over the iron way1 is but an assemblage of parts which have been beaten1 cut1 twisted1 planed1 and otherwise handled by mighty machines1 each as wonderful as the locomotive itself4 ,but then1 we don't see these4 ,this and following chapters will therefore be devoted to a few peeps at the great tools employed in the world's workshops4 ,if you consider a moment1 you will soon build up a formidable list of objects in which circularity is a necessary or desirable feature--wheels1 shafts1 plates1 legs of tables1 walking-sticks1 pillars1 parts of instruments1 wire1 and so on4 ,the ,hindu turner1 whose assistant revolves with a string a wooden block centred between two short spiked posts let into the ground1 while he himself applies the tool1 is at one end of the scale of lathe users2 at the other1 we have the workman who tends the giant machine slowly shaping the exterior of a #ab-;inch gun1 a propeller shaft1 or a marble column4 ,all aim at the same object--perfect rotundity of surface4 ,the artisans of the ,middle ,ages have left us1 in beautiful balusters and cathedral screens1 ample proofs that they were skilled workmen with the ,,turning-,,lathe4 ,at the time of the ,huguenot persecutions large numbers of ,french artificers crossed the ,channel to ,england1 bringing with them lathes which could cut intricate figures by means of wheels1 eccentrics and other devices of a comparatively complicated kind4 ,the ,french had undoubtedly got far ahead of the ,english in this branch of the mechanical arts1 owing1 no doubt1 to the fact that the ,french noblesse had condescended to include turnery among their aristocratic hobbies4 ,with the larger employment of metal in all industries the need for handling it easily is increased4 ,much greater accuracy generally distinguishes metal as compared with woodwork4 ,in turning a piece of work on the old-fashioned lathe1 the workman applied and guided his tool by means of muscular strength4 ,the work was made to revolve1 and the turner1 holding the cutting tool firmly upon the long1 straight1 guiding edge of the rest1 along which he carried it1 and pressing its point firmly against the article to be turned1 was thus enabled to reduce its surface to the required size and shape4 ,some dexterous turners were able1 with practice and carefulness1 to execute very clever pieces of work by this simple means4 ,but when the article to be turned was of considerable size1 and especially when it was of metal1 the expenditure of muscular strength was so great that the workman soon became exhausted4 ,the slightest variation in the pressure of the tool led to an irregularity of surface2 and with the utmost care on the workman's part1 he could not avoid occasionally cutting a little too deep1 in consequence of which he must necessarily go over the surface again to reduce the whole to the level of that accidentally cut too deep1 and thus possibly the job would be altogether spoiled by the diameter of the article under operation being made too small for its intended purpose4#e ,any modern worker is spared this labour and worry by the device known as the ,,slide-,,rest4 ,its name implies that it at once affords a rigid support for the tool1 and also the means of traversing the tool in a straight line parallel to the metal face on which work is being done4 ,the introduction of the slide-rest is due to the ingenuity of ,mr4 ,henry ,maudslay1 who1 at the commencement of the nineteenth century1 was a foreman in the workshop of ,mr4 ,joseph ,bramah1 inventor of the famous hydraulic press and locks which bear his name4 ,his rest could be moved along the bed of the lathe by a screw1 and clamped in any position desired4 ,fellow-workmen at first spoke derisively of ,maudslay's go-cart2 but men competent to judge its real value had more kindly words to say concerning it1 when it had been adapted to machines of various types for planing as well as turning4 ,mr4 ,james ,nasmyth went so far as to state that its influence in improving and extending the use of machinery has been as great as that produced by the improvement of the steam-engine in respect to perfecting manufactures and extending commerce1 inasmuch as without the aid of the vast accession to our power of producing perfect mechanism which it at once supplied1 we could never have worked out into practical and profitable forms the conceptions of those master minds who1 during the last half century1 have so successfully pioneered the way for mankind4 ,the steam-engine itself1 which supplies us with such unbounded power1 owes its present perfection to this most admirable means of giving to metallic objects the most precise and perfect geometrical forms4 ,how could we1 for instance1 have good steam-engines if we had not the means of boring out a true cylinder1 or turning a true piston-rod1 or planing a valve face8 ,it is this alone which has furnished us with the means of carrying into practice the accumulated results of scientific investigation on mechanical subjects4 ,the screw-cutting lathe is so arranged that the slide-rest is moved along with its tool at a uniform speed by gear wheels actuated by the mechanism rotating the object to be turned4 ,by changing the wheels the rate of feed may be varied1 so that at every revolution the tool travels from #a_/fd of an inch upwards along the surface of its work4 ,this regularity of action adds greatly to the value of the slide-rest2 and the screw device also enables the workman to chase a thread of absolutely constant pitch on a metal bar2 so that a screw-cutting lathe is not only a shaping machine but also the equivalent of a whole armoury of stocks and dies4 ,some lathes have rests which carry several tools held at different distances from its axis1 the cuts following one another deeper and deeper into the metal in a manner exactly similar to the harvesting of a field of corn by a succession of reaping machines4 ,the recent improvements in tool-steel render it possible to get a much deeper cut than formerly1 without fear of injury to the tool from overheating4 ,this results in a huge saving of time4 ,for the boring of large cylinders an upright lathe is generally used1 as the weight of the metal might cause a dangerous sag were the cylinder attached horizontally by one end to a facing-plate4 ,huge wheels can also be turned in this type of machine up to #bj feet or more in diameter2 and where the cross-bar carrying the tools is fitted with several tool-boxes1 two or more operations may be conducted simultaneously1 such as the turning of the flange1 the boring of the axle hole1 and the facing of the rim sides4 ,illustration3 ,a ,gun ,lathe4 #aed feet long between centres1 for boring and turning guns which1 with their mountings1 weigh #afe tons when complete4 ,the makers are the ,niles-,bement-,pond ,co4 of ,new ,york4 ,perhaps the most imposing of all lathes are those which handle large cannon and propeller shafts1 such as may be seen in the works of ,sir ,w4 ,g4 ,armstrong1 ,whitworth1 and ,company2 of ,messrs4 ,vickers1 ,sons and ,maxim2 and of other armament and shipbuilding firms4 ,the ,midvale ,steel ,company have in their shops at ,hamilton1 ,ohio1 a monster boring lathe which will take in a shaft #fj feet long1 #cj inches in diameter1 and bore a hole from one end to the other #ad inches in diameter4 ,to do this1 the lathe must attack the shaft at both ends simultaneously1 as a single boring bar of #fj feet would not be stiff enough to keep the hole cylindrical4 ,the shaft is placed in a revolving chuck in the central portion of the lathe--which has a total length of over #agj feet--and supported further by two revolving ring rests on each side towards the extremities4 ,with work so heavy1 the feeding up of the tool to its surface cannot be done conveniently by hand control1 and the boring bars are therefore advanced by hydraulic pressure1 a very ingenious arrangement ensuring that the pressure shall never become excessive4 ,perhaps the type of lathe most interesting to the layman is the turret lathe1 generally used for the manufacture of articles turned out in great numbers4 ,the headstock--i4e4 the revolving part which grips the object to be turned--is hollow1 so that a rod may be passed right through it into the vicinity of the tools1 which are held in a hexagon turret1 one tool projecting from each of its sides4 ,when one tool has been finished with1 the workman does not have the trouble of taking it out of the rest and putting another in its place2 he merely turns the turret round1 and brings another instrument opposite the work4 ,if the object--say a water-cock--requires five operations performing on it in the lathe1 the corresponding tools are arranged in their proper order round the turret4 ,stops are arranged so that as soon as any tool has advanced as far as is necessary a trip-action checks the motion of the turret1 which is pulled back and given a turn to make it ready for the next attack4 ,one of the advantages of the turret lathe1 particularly of the automatic form which shifts round the tool-box without human intervention1 is its power of relieving the operator of the purely mechanical part of his work4 ,those who are familiar with the inside of some of our large workshops will have noticed men and boys who make the same thing all day and every day1 and are themselves not far removed from machines4 ,the articles they make are generally small and very rapidly produced1 and the endless repetition of the same movements on the part of the operator is very tedious to watch1 and must be infinitely more so to perform4 ,such an occupation is not elevating1 and those engaged in it cannot take much interest in their work1 or become fitted for a better position4 ,when this work is done by an automatic lathe the machine performs the necessary operations1 and the man supplies the intelligence1 and1 by exercising his thinking powers1 becomes more valuable to his employers and himself4 ,the introduction of new machines and methods generally has a stimulating effect on the whole shop1 whatever the ,erewhonians might say4 ,the hubs and spindles of bicycles are cut from the solid bar by these automata2 the tender has merely to feed them with metal1 and they go on smoothing1 shaping1 and cutting off until the material is all used up4 ,the existence of such lathes largely accounts for the low price of our useful metal steeds at the present time4 ,a great amount of shaping is now done by milling cutters in preference to firmly-fixed edged tools4 ,the cutter is a rod or disc which has its sides1 end1 or circumference serrated with deep teeth1 shaped to the section of the cut needed4 ,revolving at a tremendous speed1 it quickly bites its way into anything it meets just so far as a stop allows it to go4 ,one of the most ingenious machines to which the milling tool has been fitted is the well-known ,blanchard lathe1 which copies1 generally in wood1 repetitive work1 such as the stocks for guns and rifles4 ,the lathe has two sets of centres--one for the copy1 the other for the model--parallel on the same bed1 and turned at equal speeds and in the same direction by a train of gear wheels4 ,the milling cutter is attached to a frame1 from which a disc projects1 and is pressed by a spring against the model4 ,as the latter revolves1 its irregular shape causes the disc1 frame1 and cutter to move towards or away from its centre1 and therefore towards or away from the centre of the copy1 which has all superfluities whisked off by the cutter4 ,the frame is gradually moved along the model1 reproducing in the rough block a section similar to the part of the model which it has reached4 ,the self-centring chuck is an accessory which has proved invaluable for saving time4 ,it may most easily be described as a circular plate which screws on to the inner end of the mandrel 7the spindle imparting motion to the object being machined7 and has in its face three slots radiating from the centre at angles of #abj4 ,in each slot slides a stepped jaw1 the under side of which is scored with concentric grooves engaging with a helical scroll turned by a key and worm gear acting on its circumference4 ,the jaws approach or recede from the centre symmetrically1 so that if a circular object is gripped1 its centre will be in line with the axis of the lathe4 ,whether for gripping a tiny drill or a large wheel1 the self-centring chuck is indispensable4 ,,planing-,,machines ,not less important in engineering than the truly curved surface is the true plane1 in which1 as ,euclid would say1 any two points being taken1 the straight line between them lies wholly in that superficies4 ,the lathe depends for its efficiency on the perfect flatness of all areas which should be flat--the guides1 the surface plates1 the bottom and sides of the headstock1 and1 above all1 of the slide rest4 ,for making plane metal superficies1 a machine must first be constructed which itself is above suspicion2 but when once built it creates machines like itself1 capable of reproducing others ad infinitum4 ,many amateur carpenters pride themselves on the beautiful smoothness of the boards over which they have run their jack planes4 ,yet1 as compared with the bed of a lathe1 their best work will appear very inaccurate4 ,the engineer's planing-machine in no way resembles its wooden relative4 ,in the place of a blade projecting just a little way through a surface which prevents it from cutting too deep into the substance over which it is moving1 we have a steel chisel very similar to the cutting tools of a lathe attached to a frame passing up and down over a bed to which the member holding the chisel is perfectly parallel4 ,the article to be planed is rigidly attached to the bed and travels with it4 ,between every two strokes the tool is automatically moved sideways1 so that no two cuts shall be in the same line4 ,after the whole surface has been roughed1 a finishing cutter is brought in action1 and the process is repeated with the business edge of the tool rather nearer to the bed4 ,joseph ,clement1 a contemporary of ,babbage1 ,maudslay1 and ,nasmyth1 is usually regarded as the inventor of the planing-machine4 ,by #ahbe he had finished a planer1 in which the tool was stationary and the work moving under it on a rolling bed4 ,two cutters were attached to the overhead cross rail1 so that travel in either direction might be utilised4 ,the bed of the machine1 on which the work was laid1 passed under the cutters on perfectly true rollers or wheels1 lodged and held in their bearings as accurately as the best mandrel could be1 and having set screws acting against their ends1 totally preventing all end-motion4 ,the machine was bedded on a massive and solid foundation of masonry in heavy blocks1 the support at all points being so complete as effectually to destroy all tendency to vibration1 with the object of securing full1 round1 and quiet cuts4 ,the rollers on which the planing-machine travelled were so true1 that ,clement himself used to say of them1 ,if you were to put a paper shaving under one of the rollers it would at once stop the rest4 ,nor was this an exaggeration--the entire mechanism1 notwithstanding its great size1 being as true and accurate as a watch4#f ,mr4 ,clement next made a revolving attachment for the bed1 in which bodies could be revolved under the cutter1 on an axis parallel to the direction of travel4 ,according to the wish of the operator1 the object was converted into a cylinder1 cone1 or prism by its movements under the planing-tool4 ,so efficient was the machine that it earned its maker upwards of ten pounds a day1 at the rate of about eighteen shillings a square foot1 until rivals appeared in the field and finally reduced the cost of planing to a few pence for the same area4 ,there are two main patterns of planes now in general use4 ,the first follows the original design of ,clement2 the second has a fixed bed but a moving tool4 ,where the work is very heavy1 as in the case of armour-plates for battleships1 the power required to suddenly reverse the motion of a vast mass of metal is enormous1 many times greater than the energy expended on the actual planing4 ,for this reason the moving-bed machines have had to be greatly improved2 and in some cases replaced by fixed-bed planers4 ,it is an impressive sight to watch one of these huge mechanisms reducing a rough plate1 weighing twenty tons or more1 to a smoothness which would shame the best billiard table4 ,the machine1 which towers thirty feet into the air and completely dwarfs the attendant1 who has it as thoroughly under control as if it were a small file1 bites great shining strips forty feet long1 maybe1 off the surface of the passive metal1 and leaves a series of grooves as truly parallel as the art of man can make them4 ,there is no fuss1 no sticking1 no stop1 no noise2 the force of electricity or steam1 transmitted through wonderfully cut and arranged gear-wheels1 is irresistible4 ,the tool1 so hard that a journey through many miles of steel has no appreciable effect on its edge1 shears its way remorselessly over the surface which presently may be tempered to a toughness resembling its own4 ,if you want to resharpen the tool1 it will be no good to attack it with any known metal4 ,but somewhere in the works there is a machine whose buzzing emery-wheels are more than a match for it1 and rapidly grind the blunted edge into its former shape1 so that it is ready to flay another plate1 one skin at a time4 ,planing-machines are of many shapes4 ,some have an upright on each side of the bed limiting the width of the work they can take2 others are open-sided1 one support of extra strength replacing the two1 enabling the introduction of a plate twice as broad as the bed4 ,others1 again1 are built on the verge of a pit1 so that they may cut the edges of an up-ended plate1 and make it fit against its fellows so truly that you could not slip a sheet of paper edgeways between them4 ,thus has man1 so frail and delicate in himself1 shaped metal till it can torture its kind to suit his will1 which he makes known to it by opening this valve or pulling on that lever4 ,not only does he flay it1 but pierces it through and through2 twists it into all manner of shapes2 hacks masses off as easily as he would cut slices from a loaf2 squeezes it in terrible presses to a fraction of its original thickness2 and otherwise so treats it that we are glad that our scientific observations have as yet discovered no sentience in the substances reduced to our service4 ,,the ,,steam ,,hammer ,the ,scandinavian god ,thor was a marvellous blacksmith4 ,thursday should remind us weekly of ,odin's son1 from whose hammer flashed the lightning2 and1 through him1 of ,vulcan1 toiling at his smithy in the crater of ,vesuvius4 ,in spite of the pictures drawn for us by pagan mythologists of their god-smiths1 we are left with the doubt whether these beings1 if materialised1 might not themselves be somewhat alarmed by the steam hammer which mere mortals wield so easily4 ,the forge is without dispute the show-place of a big factory1 where huge blocks of metal feel the heavy hand of steam4 ,as children we watched the blacksmith at his anvil1 attracted and yet half-terrified by the spark-showers flying from a white-hot horseshoe4 ,and even the adult1 long used to startling sights1 might well be fascinated and dismayed by the terrific blows dealt on glowing ingots by the mechanical sledge4 ,illustration3 ,a steam hammer at work in ,woolwich ,arsenal1 forging a steel ingot for the inner tube of a big gun4 ,it delivers a blow equivalent to the momentum of a falling mass weighing #djjj tons4 ,as speech is inaudible1 the foreman gives hand signals to direct his men1 who wear large canvas fingerless gloves to protect their hands from the intense heat4 ,james ,nasmyth1 the inventor of this useful machine1 was the son of a landscape painter1 who from his earliest youth had taken great interest in scientific and mechanical subjects of all kinds4 ,at fifteen he made a steam-engine to grind his father's paints1 and five years later a steam carriage that ran many a mile with eight persons on it4 ,after keeping it in action two months1 he says in an account of his early life1 to the satisfaction of all who were interested in it1 my friends allowed me to dispose of it1 and ,i sold it--a great bargain--after which the engine was used in driving a small factory4 ,i may mention that in that engine ,i employed the waste steam to cause an increased draught by its discharge up the chimney4 ,this important use of waste steam had been introduced by ,george ,stephenson some years before1 though entirely unknown to me4 ,this interesting peep at the infancy of the motor carriage reveals mechanical capabilities of no mean order in young ,james4 ,he soon entered the service of ,mr4 ,joshua ,field1 ,henry ,maudslay's partner1 and in #ahcd set up a business on his own account at ,manchester4 ,at this date the nearest approach to the modern steam hammer was the tilt hammer1 operated by horse-1 water-1 or steam-power4 ,it resembled an ordinary hand hammer on a very large scale1 but as it could be raised only a small distance above its anvil1 it became less effective as the size of the work increased1 owing to the fall being gagged4 ,in #ahcg ,mr4 ,nasmyth interviewed the directors of the ,great ,western ,steamship ,company with regard to the manufacture of some unusually powerful tools which they needed for forging the paddle-shaft of the ,great ,britain4 ,as the invention of the steam-engine had demanded the improvement of turning methods1 so now the increase in the size of steamboats showed the insufficiency of forging machinery4 ,mr4 ,nasmyth put on his thinking-cap4 ,evidently the thing needed was a method for raising a very heavy mass of metal easily to a good height1 so that its great weight might fall with crushing force on the object between it and the anvil4 ,how to raise it8 ,brilliant idea6 ,steam6 ,in a moment ,nasmyth had mentally pictured an inverted steam cylinder rested on a solid upright overhanging the anvil and a block of iron attached to its piston-rod4 ,all that would then be necessary was to admit steam to the under side of the piston until the block had risen to its full height1 and to suddenly open a valve which would cut off the steam supply and allow the vapour already in the cylinder to escape4 ,by the next post he sent a sketch to the company1 who approved his design heartily1 but were unable to use it1 since the need for the paddle-shaft had already been nullified by the substitution of a screw as the motive power of their ship4 ,poor ,nasmyth knew that he had discovered a good thing1 but ,british forge-masters1 with a want of originality that amounted to sheer blind stupidity1 refused to look at the innovation4 ,we have not orders enough to keep in work the forge-hammers we have1 they wrote1 and we don't want any new ones1 however improved they may be4 ,his invention1 therefore1 appeared doomed to failure4 ,help1 however1 came from ,france in the person of ,mr4 ,schneider1 founder of the famous ,creusot ,iron ,works1 notorious afterwards as the birthplace of the ,boer ,long ,toms4 ,mr4 ,nasmyth happened to be away when ,mr4 ,schneider and a friend called at the ,manchester works1 but his partner1 ,mr4 ,gaskell1 showed the ,french visitors round the works1 and also told them of the proposed steam hammer4 ,the designs were brought out1 so that its details might be clearly explained4 ,years afterwards ,nasmyth returned the visit1 and saw in the ,creusot ,works a crank-shaft so large that he asked how it had been forged4 ,by means of your steam hammer1 came the reply4 ,you may imagine ,nasmyth's surprise on finding the very machine at work in ,france which his own countrymen had so despised1 and his delight over its obvious success4 ,on returning home he at once raised money enough to secure a patent1 protected his invention1 and began to manufacture what has been described as one of the most perfect of artificial machines and noblest triumphs of mind over matter that modern ,english engineers have developed4 ,a few weeks saw the first--a #cj-;cwt4--hammer at work4 ,people flocked to watch its precision1 its beauty of action1 and the completeness of control which could arrest it at any point of its descent so instantaneously as to crack without smashing a nut laid on the anvil4 ,its advantages were so obvious that its adoption soon became general1 and in the course of a few years ,nasmyth steam hammers were to be found in every well-appointed workshop both at home and abroad4#g ,nasmyth's invention was improved upon in #ahec by ,mr4 ,robert ,wilson1 his partner and successor4 ,he added an automatic arrangement which raised the tup1 or head1 automatically from the metal it struck1 so that time was saved and loss of heat to the ingot was also avoided4 ,the beauty of the balance valve1 as it was called1 will be more clearly understood if we remember that the travel of the hammer is constantly increasing as the piece on the anvil becomes thinner under successive blows4 ,under the influence of this very ingenious valve every variety of blow could be dealt4 ,by simply altering the position of a tappet lever by means of two screws1 a blow of the exact force required could be repeated an indefinite number of times4 ,it became a favourite amusement to place a wine-glass containing an egg upon the anvil1 and let the block descend upon it with its quick motion2 and so nice was its adjustment1 and so delicate its mechanism1 that the great block1 weighing perhaps several tons1 could be heard playing tap1 tap upon the egg without even cracking the shell1 when1 at a signal given to the man in charge1 down would come the great mass1 and the egg and glass would be apparently1 as ,walter ,savage ,landor has it1 'blasted into space4'#h ,later on ,mr4 ,wilson added an equally important feature in the shape of a double-action hand-gear1 which caused the steam to act on the top as well as the bottom of the piston1 thus more than doubling the effect of the hammer4 ,the largest hammer ever made was that erected by the ,bethlehem ,iron ,company of ,pennsylvania4 ,the tup weighed #abe tons4 ,after being in use for three years the owners consigned it to the scrap-heap1 as inferior to the hydraulic press for the manufacture of armour-plate1 though it had cost them #ej1jjj4 ,they then erected in its stead1 for an equal sum of money1 a #ad1jjj-ton pressure hydraulic press1 which fitly succeeds it as the most powerful of its kind in the world4 ,the change was made for three reasons4 ,first1 that the impact of so huge a block of metal necessitates the anvil being many times as heavy1 and even then the shock to surrounding machinery may be very severe4 ,secondly1 the larger the forging to be hammered1 the less is the reaction of the anvil1 so that all the force of the blow tends to be absorbed by the side facing the hammer2 whereas with a small bar the anvil's inertia would have almost as much effect as the actual blow4 ,thirdly1 the blow of the hammer is so instantaneous that the metal has not time to flow properly1 and this leads to imperfect forgings1 the surface of which may have been cracked4 ,for very large work1 therefore1 the hammer is going out of fashion and the press coming in1 though for lighter jobs it is still widely used4 ,before leaving the subject we may glance at the double-headed horizontal hammer1 such as is to be found in the forge-shop of the ,horwich ,railway ,works4 ,two hammers1 carried on rails and rollers1 advance in unison from each side and pound work laid on a support between them4 ,each acts as anvil to the other1 while doing its full share of the work4 ,so that not only is a great deal of weight saved1 but shocks are almost entirely absorbed2 while the fact that each hammer need make a blow of only half the length of what would be required from a single hammer1 enables twice as many blows to be delivered in a given time4 ,,hydraulic ,,tools ,before discussing these in detail we shall do well to trace the history of the ,bramah press1 which may be said to be their parent1 since the principle employed in most hydraulic devices for the workshop1 as also the idea of using water as a means of transmitting power under pressure1 are justly attributed to ,joseph ,bramah4 ,if you take a dive into the sea and fall flat on the surface instead of entering at the graceful angle you intended1 you will feel for some time afterwards as if an enemy had slapped you violently on the chest and stomach4 ,you have learnt by sad experience that water1 which seems to offer so little resistance to a body drawn slowly through it1 is remarkably hard if struck violently4 ,in fact1 if enclosed1 it becomes more incompressible than steel1 without in any way losing its fluidity4 ,we possess in water1 therefore1 a very useful agent for transmitting energy from one point to another4 ,shove one end of a column of water1 and it gives a push to anything at its other end2 but then it must be enclosed in a tube to guide its operation4 ,by a natural law all fluids press evenly on every unit of a surface that confines them4 ,you may put sand into a bucket with a bottom of cardboard and beat hard upon the surface of the sand without knocking out the bottom4 ,the friction between the sand particles and the bucket's sides entirely absorbs the blow4 ,but if water were substituted for sand and struck with an object that just fitted the bucket so as to prevent the escape of liquid1 the bottom1 and sides1 too1 would be ripped open4 ,the writer of this book once fired a candle out of a gun at a hermetically sealed tin of water to see what the effect would be4 7,another candle had already been fired through an iron plate #a_/d of an inch thick47 ,the impact slightly compressed the water in the tin1 which gave back all the energy in a recoil which split the sheet metal open and flung portions of it many feet into the air4 ,but the candle never got through the side4 ,this affords a very good idea of the almost absolute incompressibility of a liquid4 ,we may now return to history4 ,joseph ,bramah was born in #agdh at ,barnsley1 in ,yorkshire4 ,as the son of a farm labourer his lot in life would probably have been to follow the plough had not an accident to his right ankle compelled him to earn his living in some other way4 ,he therefore turned carpenter and developed such an aptitude for mechanics that we find him1 when forty years old1 manufacturing the locks with which his name is associated1 and six years later experimenting with the hydraulic press4 ,this may be described simply as a large cylinder in which works a solid piston of a diameter almost equal to that of the bore1 connected to a force pump4 ,every stroke of the pump drives a little water into the cylinder1 and as the water pressure is the same throughout1 the total stress on the piston end is equal to that on the pump plunger multiplied by the number of times that the one exceeds the other in area4 ,suppose1 then1 that the plunger is one inch in diameter and the piston one foot1 and that a man drives down the plunger with a force of #a1jjj lbs41 then the total pressure on the piston end will be #add #a1jjj lbs42 but for every inch that the plunger has travelled the piston moves only #a_/add of an inch1 thus illustrating the law that what is gained in time is lost in power1 and vice vers4 ,the great difficulty encountered by ,bramah was the prevention of leakage between the piston and the cylinder walls4 ,if he packed it so tightly that no water could pass1 then the piston jammed2 if the packing was eased1 then the leak recommenced4 ,bramah tried all manner of expedients without success4 ,at last his foreman1 ,henry ,maudslay--already mentioned in connection with the lathe slide-rest--conceived an idea which showed real genius by reason of its very simplicity4 ,why not1 he said1 let the water itself give sufficient tightness to the packing1 which must be a collar of stout leather with an inverted ,u-shaped section8 ,this suggestion saved the situation4 ,a recess was turned in the neck of the cylinder at the point formerly occupied by the stuffing-box1 and into this the collar was set1 the edges pointing downwards4 ,when water entered under pressure it forced the edges in different directions1 one against the piston1 the other against the wall of the recess1 with a degree of tightness proportioned to the pressure4 ,as soon as the pressure was removed the collar collapsed1 and allowed the piston to pass back into the cylinder without friction4 ,a similar device1 to turn to smaller things for a moment1 is employed in a cycle tyre inflater1 a cup-shaped leather being attached to the rear end of the piston to seal it during the pressure stroke1 though acting as an inlet valve for the suction stroke4 ,what we owe to ,joseph ,bramah and ,henry ,maudslay for their joint invention--the honour must be divided1 like that of designing the steam hammer between ,nasmyth and ,wilson--it would indeed be hard to estimate4 ,wherever steady but enormous effort is required for lifting huge girders1 houses1 ships2 for forcing wheels off their axles2 for elevators2 for advancing the boring shield of a tunnel2 for compressing hay1 wool1 cotton1 wood1 even metal2 for riveting1 bending1 drilling steel plates--there you will find some modification of the hydraulic press useful1 if not indispensable4 ,however1 as we are now prepared for a consideration of details1 we may return to our workshop1 and see what water is doing there4 ,outside stands a cylindrical object many feet broad and high1 which can move up and down in vertical guides4 ,if you peep underneath1 you notice the shining steel shaft which supports the entire weight of this tank or coffer filled with heavy articles--stones1 scrap iron1 etc4 ,the shaft is the piston-plunger of a very long cylinder connected by pipes to pumping engines and hydraulic machines4 ,it and the mass it bears up serves as a reservoir of energy4 ,if the pumping engines were coupled up directly to the hydraulic tools1 whenever a workman desired to use a press1 drill1 or stamp1 as the case might be1 he would have to send a signal to the engine-man to start the pumps1 and another signal to tell him when to stop4 ,this would lead to great waste of time1 and a danger of injuring the tackle from over driving4 ,but with an accumulator there is always a supply of water under pressure at command1 for as soon as the ram is nearly down1 the engines are automatically started to pump it up again4 ,in short1 the accumulator is to hydraulic machinery what their bag is to bagpipes1 or the air reservoir to an organ4 ,in large towns high-pressure water is distributed through special mains by companies who make a business of supplying factories1 engineering works1 and other places where there is need for it1 though not sufficient need to justify the occupiers in laying down special pumping plant4 ,london can boast five central distributing stations1 where engines of #f1ejj h4p4 are engaged in keeping nine large accumulators full to feed #abj miles of pipes varying in diameter from seven inches downwards4 ,the pressure is #gjj lbs4 to the square inch4 ,liverpool has twenty-three miles of pipes under #hej lbs4 pressure2 ,manchester seventeen miles under #a1ajj lbs4 ,to these may be added ,glasgow1 ,hull1 ,birmingham1 ,geneva1 ,paris1 ,berlin1 ,antwerp1 and many other large cities in both ,europe and the ,united ,states4 ,for very special purposes1 such as making metal forgings1 pressures up to twelve tons to the square inch may be required4 ,to produce this intensifiers are used1 i4e4 presses worked from the ordinary hydraulic mains which pump water into a cylinder of larger diameter connected with the forging press4 ,the largest ,english forging press is to be found in the ,openshaw ,works of ,sir ,w4 ,g4 ,armstrong1 ,whitworth1 and ,company4 ,its duty is to consolidate armour-plate ingots by squeezing1 preparatory to their passing through the rolling mills4 ,it has one huge ram #gh inches in diameter1 into the cylinder of which water is pumped by engines of #d1jjj h4p41 under a pressure of #f1gbj lbs4 to the square inch1 which gives a total ram force of #ab1jjj tons4 ,it has a total height of #cc feet1 is #bb feet wide1 and #age feet long1 and weighs #a1bhj tons4 ,on each side of the anvil is a trench fitted with platforms and machinery for moving the ingot across the ingot block4 ,two #ajj-ton electric cranes with hydraulic lifting cylinders serve the press4 ,illustration3 ,a ,,huge ,,hydraulic ,,press ,the #ab1jjj-ton pressure ,whitworth ,hydraulic ,press1 used for consolidating steel ingots for armour-plating4 ,water is forced into the ram cylinder at a pressure of three tons to the square inch4 ,notice the man to the left of the press4 ,the ,bethlehem ,works squeezer has two rams1 each of much smaller diameter than the ,armstrong-,whitworth1 but operated by a #aj-a_/b tons pressure to the square inch4 ,it handles ingots of over #abj tons weight for armour-plating4 ,in #ahie ,mr4 ,william ,corey1 of ,pittsburg1 took out a patent for toughening nickel steel plates by subjecting them1 while heated to a temperature of #b1jjj ,f41 to great compression1 which elongates them only slightly1 though reducing their thickness considerably4 ,the heating of a large plate takes from ten to twenty hours2 it is then ready to be placed between the jaws of the big press1 which are about a foot wide4 ,the plate is moved forward between the jaws after each stroke until the entire surface has been treated4 ,at one stroke a #ag-;inch plate is reduced to #af inches1 and subsequent squeezings give it a final thickness of #ad inches4 ,its length has meanwhile increased from #af to #ah-a_/b feet1 or in that proportion1 while its breadth has remained practically unaltered4 ,a simple sum shows that metal which originally occupied #cb-b_/c cubic inches has now been compressed into #ca cubic inches4 ,this alteration being effected without any injury to the surface1 a plate very tough inside and very hard outside is made4 ,the plate is next reheated to #a1cej ,f41 and allowed to cool very gradually to a low temperature to anneal it4 ,then once again the furnaces are started to bring it back to #a1cej1 when cold water is squirted all over the surface to give it a proper temper4 ,if it bends and warps at all during this process1 a slight reheating and a second treatment in the press restores its shape4 ,the hydraulic press is also used for bending or stamping plates in all manners of forms4 ,you may see #h-;inch steel slabs being quietly squeezed in a pair of huge dies till they have attained a semicircular shape1 to fit them for the protection of a man-of-war's big-gun turret2 or thinner stuff having its ends turned over to make a flange2 or still slenderer metal stamped into the shape of a complete steel boat1 as easily as the tinsmith stamps tartlet moulds4 ,in another workshop a pair of massive jaws worked by water power are breaking up iron pigs into pieces suitable for the melting furnace4 ,the manufacture of munitions of war also calls for the aid of this powerful ally4 ,take the field-gun and its ammunition4 ,the gun itself is a steel barrel1 hydraulically forged1 and afterwards wire-wound2 the carriage is built up of steel plates1 flanged and shaped in hydraulic presses2 the wheels have their naves composed of hydraulically flanged and corrugated steel discs1 and even the tyres are forced on cold by hydraulic tyre-setters1 the rams of which are powerful enough to reduce the diameter of the welded tyre until the latter tightly nips the wheel4 ,the shells for the gun are punched and drawn by powerful hydraulic presses1 and the copper driving-bands are fixed on the projectiles in special hydraulic presses4 ,quick-firing cartridge-cases are capped1 drawn1 and headed by an hydraulic press1 whose huge mass always impresses the uninitiated as absurdly out of proportion to the small size of the finished case1 and finally the cordite firing charge is dependent on hydraulic presses for its density and shape4#i ,the press for placing the driving-band on a shell is particularly interesting4 ,after the shell has been shaped and its exterior turned smooth and true1 a groove is cut round it near the rear end4 ,into this groove a band of copper is forced to prevent the leakage of gas from the firing charge past the shell1 and also to bite the rifling which imparts a rotatory motion to the shell4 ,the press for performing the operation has six cylinders and rams arranged spoke-wise inside a massive steel ring2 the rams carrying concave heads which1 when the full stroke is made1 meet at the centre so as to form a complete circle4 ,pressure is admitted1 says ,mr4 ,petch1 to the cylinders by copper pipes connected up to a circular distributing pipe4 ,the press takes water from the #gjj-pounds main for the first #c_/h-;inch of the stroke1 and for the last #a_/h-;inch water pressure at #c tons per square inch is used4 ,the total pressure on all the rams to band a #f-;inch shell is only #fjj tons1 but for a #ab-;inch shell no less than #b1hjj tons is necessary4 ,,electric ,,tools ,,in ,a ,,shipyard ,of late years electricity has taken a very prominent part in workshop equipment1 on account of the ease with which it can be applied to a machine1 the freedom from belting and overhead gear which it gives1 and its greater economy4 ,in a lathe-shop1 where only half the lathes may be in motion at a time1 the shafting and the belts for the total number is constantly whirling1 absorbing uselessly a lot of power4 ,if1 however1 a separate motor be fitted to each lathe1 the workman can switch it on and off at his pleasure4 ,the ,new ,york ,shipbuilding ,company1 a very modern enterprise1 depends mainly on electrical power for driving its machinery1 in preference to belting1 compressed air1 or water4 ,let us stroll through the various shops1 and note the uses to which the current has been harnessed4 ,before entering1 our attention is arrested by a huge gantry crane1 borne by two columns which travel on rails4 ,from the cross girder1 or bridge1 #hh feet long1 hang two lifting magnets1 worked by #be h4p4 motors1 which raise the load at the rate of #bj feet per minute4 ,motors of equal power move the whole gantry along its rails over the great piles of steel plates and girders from which it selects victims to feed the maw of the shops4 ,the main building is of enormous size1 covering with its single roof no less than eighteen acres6 ,just imagine four acres of skylights and two acres of windows1 and you may be able to calculate the little glazier's bill that might result from a bad hailstorm4 ,in this immense chamber are included the machine1 boiler1 blacksmith1 plate1 frame1 pipe1 and mould shops1 the general storerooms1 the building ways1 and outfitting slips4 ,the material which enters the plate and storage rooms at one end1 does not leave the building until it goes out as a part of the completed ship for which it was intended1 when the vessel is ready to enter service2 there are installed in one main building1 and under one roof1 all the material and machinery necessary for the construction of the largest ship known to commerce1 and eight sets of ship-ways1 built upon masonry foundations1 covered by roofs of steel and glass1 and spanned by cranes up to #ajj tons lifting capacity1 are practically as much a part of the immense main building as the boiler shop or machine shop4#aj ,a huge #ajj-ton crane of #aba-;foot span dominates the machine-shop and ship-ways at a height of #abj feet4 ,it toys with a big engine or boiler1 picking it up when the riveters1 caulkers1 and fitters have done their work1 and dropping it gently into the bowels of a partly-finished vessel4 ,a number of smaller cranes run about with their loads4 ,those which handle plates are1 like the big gantry already referred to1 equipped with powerful electro-magnets which fix like leeches on the metal1 and will not let go their hold until the current is broken by the pressing of a button somewhere on the bridge4 ,sometimes several plates are picked up at once1 and then it is pretty to see how the man in charge drops them in succession1 one here1 another there1 by merely opening and closing the switch very quickly1 so that the plate furthest from the magnets falls before the magnetism has passed out of the nearer plates4 ,another interesting type is the extension-arm crane1 which shoots out an arm between two pillars1 grips something1 and pulls it back into the main aisle1 down which it travels without impediment4 ,on every side are fresh wonders4 ,here is an immense rolling machine1 fed with plates #bg feet wide1 which bends the #a-a_/h-;inch thick metal as if it were so much pastry2 or turns over the edges neatly at the command of a #ej h4p4 motor4 ,there we have an electric plate-planer scraping the surface of a sheet half the length of a cricket pitch4 ,as soon as a stroke is finished the bed reverses automatically1 while the tool turns over to offer its edge to the metal approaching from the other side4 ,all so quietly1 yet irresistibly done6 ,now mark these punches as they bite #a-a_/d-;inch holes through steel plates over an inch thick1 one every two seconds4 ,a man cutting wads out of cardboard could hardly perform his work so quickly and well4 ,almost as horribly resistless is the circular saw which eats its way quite unconcernedly through bars six inches square1 or snips lengths off steel beams4 ,what is that strange-looking machine over there8 ,it has three columns which move on circular rails round a table in the centre4 ,up and down each column passes a stage carrying with it a workman and an electric drill working four spindles4 ,look6 here comes a crane with a boiler shell1 the plates of which have been bolted in position4 ,the crane lets down its load1 end-up1 on to the table1 and trots off1 while the three workmen move their columns round till the twelve drills are opposite their work4 ,then whirr6 a dozen twisted steel points1 ranged in three sets of four1 one drill above the other1 bite into the boiler plates1 opening out holes at mathematically correct intervals all down the overlapping seam-plates4 ,this job done1 the columns move round the boiler1 and their drills pierce it first near the lower edge1 then near the upper4 ,the crane returns1 grips the cylinder1 and bears it off to the riveters1 who are waiting with their hydraulic presses to squeeze the rivets into the holes just made1 and shape their heads into neat hemispheres4 ,as it swings through the air the size of the boiler is dwarfed by its surroundings2 but if you had put a rule to it on the table you would have found that it measured #bj feet in diameter and as many in length4 ,a few months hence furnaces will rage in its stomach1 and cause it to force tons of steam into the mighty cylinders driving some majestic vessel across the ,atlantic4 ,we pass giant lathes busy on the propeller shafts1 huge boring mills which slowly smooth the interior of a cylinder1 planers which face the valve slides2 and we arrive1 eye-weary1 at the launching-ways where an ocean liner is being given her finishing touches4 ,then we begin to moralise4 ,that #fjj-;foot floating palace is a concretion of parts1 shaped1 punched1 cut1 planed1 bored1 fixed by electricity4 ,where does man come in8 ,well1 he harnessed the current1 he guided it1 he said ,do this1 and it did it4 ,does not that seem to be his fair share of the work8 ,,footnotes3 #e ,industrial ,biographies1 ,dr4 ,s4 ,smiles4 #f ,industrial ,biographies4 #g ,industrial ,biographies4 #h ,chambers's ,encyclopdia4 #i ,mr4 ,a4 ,f4 ,petch in ,cassier's ,magazine4 #aj ,cassier's ,magazine4 ,,chapter ,,iv ,,portable ,,tools ,if the mountain won't come to ,mahomet1 says the proverb1 ,mahomet must go to the mountain4 ,this is as true in the workshop as outside2--,mahomet being the tool1 the mountain the work on which it must be used4 ,with the increase in size of machinery and engineering material1 methods half a century old do not1 in many cases1 suffice2 especially at a time when commercial competition has greatly reduced the margin of profits formerly expected by the manufacturer4 ,to take the case of a large shaft1 which must have a slot cut along it on one side to accommodate the key-wedge1 which holds an eccentric for moving the steam valves of a cylinder1 or a screw-propeller1 so that it cannot slip4 ,the mass weighs1 perhaps1 twenty tons4 ,one way of doing the job is to transport the shaft under a drill that will cut a hole at each end of the slot area1 and then to turn it over to the planer for the intermediate metal to be scraped out4 ,this is a very toilsome and expensive business1 entailing the use of costly machinery which might be doing more useful work1 and the sacrifice of much valuable time4 ,inventors have therefore produced portable tools which can perform work on big bodies just as efficiently as if it had been done by larger machinery1 in a fraction of the time and at a greatly reduced cost4 ,to quote an example1 the cutting of a key-way of the kind just described by big machines would consume perhaps a whole day1 whereas the light1 portable1 easily attached miller1 now generally used1 bites it out in ninety minutes4 ,,pneumatic ,,tools ,the best known of these is the pneumatic hammer4 ,it consists of a cylinder1 inside which moves a solid piston having a stroke of from half an inch to six inches4 ,air is supplied through flexible tubing from a compressing pump worked by steam4 ,the piston beats on a loose block of metal carried in the end of the tool1 which does the actual striking4 ,the piston suddenly decreases in diameter at about the centre of its length1 leaving a shoulder on which air can work to effect the withdrawal stroke4 ,by a very simple arrangement of air-ports the piston is made to act as its own valve4 ,as the plane side of the piston has a greater area than that into which the piston-rod fits1 the striking movement is much more violent than the return4 ,under a pressure of several hundreds of pounds to the square inch a pneumatic hammer delivers upwards of #g1jjj blows per minute2 the quick succession of comparatively gentle taps having the effect of a much smaller number of heavier blows4 ,for the flat hammer head can be substituted a curved die for riveting1 or a chipping chisel1 or a caulking iron1 to close the seams of boilers4 ,the riveter is peculiarly useful for ship and bridge-building work where it is impossible to apply an hydraulic tool4 ,a skilled workman will close the rivet heads as fast as his assistant can place them in their holes2 certainly in less than half the time needed for swing-hammer closing4 ,even more effective proportionately is the pneumatic chipper4 ,the writer has seen one cut a strip off the edge of a half-inch steel plate at the rate of several inches a minute4 ,to the uninitiated beholder it would seem impossible that a tool weighing less than two stone could thus force its way through solid metal4 ,the speed of the piston is so high that1 though it scales but a few pounds1 its momentum is great enough to advance the chisel a fraction of an inch1 and the individual advances1 following one another with inconceivable rapidity1 soon total up into a big cut4 ,automatic chisels are very popular with ornamental masons1 as they lend themselves to the sculpturing of elaborate designs in stone and marble4 ,their principle1 modified to suit work of another character1 is seen in percussive rock drills1 such as the ,ingersoll ,sergeant4 ,in this case the piston and tool are solid1 and the air is let into the cylinder by means of slide valves operated by tappets which the piston strikes during its movements4 ,some types of the rock-drill are controllable as to the length of their stroke1 so that it can be shortened while the entry of the hole is being made and gradually increased as the hole deepens4 ,for perpendicular boring the drill is mounted on a heavily weighted tripod1 the inertia of which effectively damps all recoil from the shock of striking2 for horizontal work1 and sometimes for vertical1 the support is a pillar wedged between the walls of the tunnel1 or shaft4 ,an ingenious detail is the rifled bar which causes the drill to rotate slightly on its axis between every two strokes1 so that it may not jam4 ,the drills are light enough to be easily erected and dismantled1 and compact1 so that they can be used in restricted and out-of-the way places1 while their simplicity entails little special training on the part of the workman4 ,with pneumatic and other power-drills the cost of piercing holes for explosive charges is reduced to less than one-quarter of that of jumping with a crowbar and sledgehammers4 ,with the hand method two men are required1 usually more2 one man to hold1 guide1 and turn the drill2 and the other1 or others1 to strike the blows with hammers4 ,the machine1 striking a blow far more rapidly than can be done by hand1 reduces the number of operators to one man1 and perhaps his helper4 ,so durable is the metal of these wonderful little mechanisms that the delivery of #cfj1jjj blows daily for months1 even though each is given with a force of perhaps half a ton1 fails to wear them out2 or at the most only necessitates the renewal of some minor and cheap part4 ,the debt that civilisation owes to the substitution of mechanical for hand labour will be fully understood by anyone who is conversant with the history of tunnel-driving and mining4 ,another application of pneumatics is seen in the device for cutting off the ends of stay bolts of locomotive boilers4 ,it consists of a cylinder about fifteen inches in diameter1 the piston of which operates a pair of large nippers capable of shearing half-inch bars4 ,the whole apparatus weighs but three-quarters of a hundredweight1 yet its power is such that it can trim bolts forty times as fast as a man working with hammer and cold-chisel1 and more thoroughly4 ,then there is the machine for breaking the short bolts which hold together the outer and inner shells of the water-jacket round a locomotive furnace4 ,a threaded bar1 along which travels a nut1 has a hook on its end to catch the bolt4 ,the nut is screwed up to make the proper adjustment1 and a pneumatic cylinder pulls on the hook with a force of many tons1 easily shearing through the bolt4 ,we must not forget the pneumatic borer for cutting holes in wood or metal1 or enlarging holes already existing4 ,the head of the borer contains three little cylinders1 set at an angle of #abj1 to rotate the drill1 the valves opening automatically to admit air at very high pressures behind the pistons4 ,any carpenter can imagine the advantage of a drill which has merely to be forced against its work1 the movement of a small lever by the thumb doing the rest6 ,next on the list comes the pneumatic painter1 which acts on much the same principle as the scent-spray4 ,mechanical painting first came to the fore in #ahic1 when the huge ,chicago ,exposition provided many acres of surfaces which had to be protected from the weather or hidden from sight4 ,the following description of one of the machines used to replace hand-work is given in ,cassier's ,magazine3 ,the paint is atomized and sprayed on to the work by a stream of compressed air4 ,from a small air-compressor the air is led1 through flexible hose1 to a paint-tank1 which is provided with an air-tight cover and clamping screws4 ,the paint is contained in a pot which can be readily removed and replaced by another when a different colour is required4 ,this arrangement of interchangeable tins is also important as facilitating easy cleaning4 ,the container is furnished with a semi-rotary stirrer1 the spindle passing through a stuffing-box in the cover1 and ending in a handle by which the whole thing complete may be carried about4 ,the compressor is necessarily fixed or stationary1 but the paint-tank1 connected to it by the single air-hose1 can be moved close to the work1 while the length of hose from the tank to the nozzle gives the freedom of movement necessary4 ,air-pressure is admitted to the tank by a bottom valve1 and forces the paint up an internal pipe and along a hose from the tank to the spraying nozzle1 to which air-pressure is also led by a second hose4 ,the nozzle is practically an injector of special form4 ,the flow of paint at the nozzle is controlled by a small plug valve and spring lever1 on which the operator keeps his thumb while working1 and which1 on release1 closes automatically4 ,when it is required to change from one colour to another1 or to use a different material1 such as varnish1 the can1 previously in use1 is removed1 and air1 or1 if necessary1 paraffin oil1 is blown through the length of hose which supplies the paint until it is completely clean4 ,the writer then mentions as an instance of the machine's efficiency that it has covered a #cj feet by #h feet boiler in less than an hour1 and that at one large bridge yard a #gj feet by #f feet girder with all its projecting parts was coated with boiled oil in two hours--a job which would have occupied a man with a brush a whole day to execute4 ,apart from saving time1 the machine produces a surface quite free from brush marks1 and easily reaches surfaces in intricate mouldings which are difficult to get at with a brush4 ,the pneumatic sand-jet is used for a variety of purposes3 for cleaning off old paint1 or the weathered surface of stonework2 for polishing up castings and forgings after they have been brazed4 ,at the cycle factory you will find the sand-jet hard at work on the joints of cycle frames1 which must be cleared of all roughness before they are fit for the enameller4 ,the writer1 a few days before penning these lines1 watched a jet removing ,london grime from the face of a large hotel4 ,down a side street stood a steam-engine busily compressing air1 which was led by long pipes to the jet1 situated on some lofty scaffolding4 ,the rapidity with which the flying grains scoured off smoke deposits attracted the notice of a large crowd1 which gazed with upturned heads at the whitened stones4 ,a peculiarity about the jet is that it proves much more effective on hard material than on soft1 as the latter1 by offering an elastic surface1 robs the sand of its cutting power4 ,after merely mentioning the pneumatic rammer for forcing sand into foundry moulds1 we pass to the pneumatic sand-papering machine1 which may be described briefly as a revolving disc carrying a circle of sand-paper on its face revolved between guards which keep it flat to its work4 ,the disc flies round many hundreds of times per minute1 rapidly wearing down the fibrous surface of the wood it touches4 ,when the coarse paper has done its work a finely-grained cloth is substituted to produce the finish needful for painting4 ,,chapter ,v ,,the ,,pedrail3 ,a ,,walking ,,steam-,,engine ,have you ever watched carefully a steam-roller's action on the road when it is working on newly laid stones8 ,if you have1 you noticed that the stones1 gravel1 etc41 in front of the roller moved with a wave-like motion1 so that the engine was practically climbing a never-ending hill4 ,no wonder then that the mechanism of such a machine needs to be very strong1 and its power multiplied by means of suitable gearing4 ,again1 suppose that an iron-tyred vehicle1 travelling at a rapid pace1 meets a large stone1 what happens8 ,either the stone is forced into the ground or the wheel must rise over it4 ,in either case there will be a jar to the vehicle and a loss of propulsive power4 ,do not all cyclists know the fatigue of riding over a bumpy road--fatigue to both muscles and nerves8 ,as regards motors and cycles the vibration trouble has been largely reduced by the employment of pneumatic tyres1 which lap over small objects1 and when they strike large ones minimise the shock by their buffer-like nature4 ,yet there is still a great loss of power1 and if pneumatic-tyred vehicles suffer1 what must happen to the solid1 snorting1 inelastic traction-engine8 ,on hard roads it rattles and bumps along1 pulverising stones1 crushing the surface4 ,when soft ground is encountered1 in sink the wheels1 because their bearing surface must be increased until it is sufficient to carry the engine's weight4 ,but by the time that they are six inches below the surface there will be a continuous vertical belt of earth six inches deep to be crushed down incessantly by their advance4 ,how much more favourably situated is the railway locomotive or truck4 ,their wheels touch metal at a point but a fraction of an inch in length2 consequently there is nothing to hamper their progression4 ,so great is the difference between the rail and the road that experiment has shown that1 whereas a pull of from #h to #aj lbs4 will move a ton on rails1 an equal weight requires a tractive force of #ej to #ajj lbs4 on the ordinary turnpike4 ,in order to obviate this great wastage of power1 various attempts have been made to provide a road locomotive with means for laying its own rail track as it proceeds4 ,about forty years ago ,mr4 ,boydell constructed a wheel which took its own rail with it1 the rails being arranged about the wheel like a hexagon round a circle1 so that as the wheel moved it always rested on one of the hexagon's sides1 itself flat on the ground4 ,this device had two serious drawbacks4 ,in the first place1 the plates made a rattling noise which has been compared to the reports of a ,maxim gun2 secondly1 though the contrivance acted fairly well on level ground1 it failed when uneven surfaces were encountered4 ,thus1 if a brick lay across the path1 one end of a plate rested on the brick1 the other on the ground behind1 and the unsupported centre had to carry a sudden1 severe strain4 ,furthermore1 the plates1 being connected at the angles of the hexagon1 could not tilt sideways1 with the result that breakages were frequent4 ,of late years another inventor1 ,mr4 ,j4 ,b4 ,diplock1 has come forward with an invention which bids fair to revolutionise heavy road traffic4 ,at present1 though it has reached a practical stage and undergone many tests satisfactorily1 it has not been made absolutely perfect1 for the simple reason that no great invention jumps to finality all at once4 ,are not engineers still improving the locomotive8 ,the ,pedrail1 as it has been named1 signifies a rail moving on feet4 ,mr4 ,diplock1 observing that a horse has for its weight a tractive force much in excess of the traction-engine1 took a hint from nature1 and conceived the idea of copying the horse's foot action4 ,the reader must not imagine that here is a return to the abortive and rather ludicrous attempts at a walking locomotive made many years ago1 when some engineers considered it proper that a railway engine should be propelled by legs4 ,mr4 ,diplock's device not merely propels1 but also steps1 i4e4 selects the spot on the ground which shall be the momentary point at which propulsive force shall be exerted4 ,to make this clearer1 consider the action of a wheel4 ,first1 we will suppose that the spokes1 any number you please1 are connected at their outer ends by flat plates4 ,as each angle is passed the wheel falls flop on to the next plate4 ,the greater the number of the spokes1 the less will be each successive jar 7or step72 and consequently the perfect wheel is theoretically one in which the sides have been so much multiplied as to be infinitely short4 ,a horse has practically two wheels1 its front legs one1 its back legs the other4 ,the shoulder and hip joints form the axles1 and the legs the spokes4 ,as the animal pulls1 the leg on the ground advances at the shoulder past the vertical position1 and the horse would fall forwards were it not for the other leg which has been advanced simultaneously4 ,each step corresponds to our many-sided wheel falling on to a flat side--and the hammer1 hammer1 hammer on the hard high road is the horsey counterpart of the metallic rattle4 ,on rough ground a horse has a great advantage over a wheeled tractor1 because it can put its feet down on the top of objects of different elevations1 and still pull4 ,a wheel cannot do this1 and1 as we have seen1 a loss of power results4 ,our inventor1 therefore1 created in his pedrail a compromise between the railway smoothness and ease of running and the selective and accommodating powers of a quadruped4 ,we must now plunge into the mechanical details of the pedrail1 which is1 strictly speaking1 a term confined to the wheel alone4 ,our illustration will aid the reader to follow the working of the various parts4 ,in a railway we have 7a7 sleepers1 on the ground1 7b7 rails attached to the sleepers1 7c7 wheels rolling over the rails4 ,in the pedrail the order1 reckoning upwards1 is altered4 ,on the ground is the ped1 or movable sleeper1 carrying wheels1 over which a rail attached to the moving vehicle glides continuously4 ,the principle is used by anyone who puts wooden rollers down to help him move heavy furniture about4 ,of course1 the peds cannot be put on the ground and left behind2 they must accompany their rollers and rails4 ,we will endeavour to explain in simple words how this is effected4 ,to the axles of the locomotive is attached firmly a flat1 vertical plate1 parallel to the sides of the fire-box4 ,pivoted to it1 top and bottom1 at their centres1 are two horizontal rocking arms2 and these have their extremities connected by two bow-shaped bars1 or cams1 their convex edges pointing outwards1 away from the axle4 ,powerful springs also join the rocking arms1 and tend to keep them in a horizontal position4 ,thus we have a powerful frame1 which can oscillate up and down at either end4 ,the bottom arm is the rail on which the whole weight of the axle rests4 ,the rotating and moving parts consist of a large1 flat1 circular case1 the sides of which are a few inches apart4 ,its circumference is pierced by fourteen openings1 provided with guides1 to accommodate as many short sliding spokes1 which are in no way attached to the main axle4 ,each spoke is shaped somewhat like a tuning-fork4 ,in the ,v is a roller-wheel1 and at the tip is a ped1 or foot4 ,as the case revolves1 the tuning-fork spokes pass1 as it were1 with a leg on each side of the framework referred to above2 the wheel of each spoke being the only part which comes into contact with the frame4 ,strong springs hold the spokes and rollers normally at an equal distance from the wheel's centre4 ,it must now be stated that the object of the framework is to thrust the rollers outwards as they approach the ground1 and slide them below the rail4 ,the side-pieces of the frame are1 as will be noticed 7see ,fig4 #c71 eccentric1 i4e4 points on their surfaces are at different distances from the axle centre4 ,this is to meet the fact that the distance from the axle to the ground is greater in an oblique direction than it is vertically1 and therefore for three spokes to be carrying the weight at once1 two of them must be more extended than the third4 ,so then a spoke is moved outward by the frame till its roller gets under the rail1 and as it passes off it it gradually slides inwards again4 ,it will be obvious to the reader that1 if the peds were attached inflexibly to the ends of their spokes they would strike the ground at an angle1 and1 of course1 be badly strained4 ,now1 ,mr4 ,diplock meant his peds to be as like feet as possible1 and come down flat4 ,he therefore furnished them with ankles1 that is1 ball-and-socket joints1 so that they could move loosely on their spokes in all directions2 and as such a contrivance must be protected from dust and dirt1 the inventor produced what has been called a crustacean joint1 on account of the resemblance it bears to the overlapping armour-plates of a lobster's tail4 ,the plates1 which suggest very thin quoits1 are made of copper1 and can be renewed at small cost when badly worn4 ,an elastic spring collar at the top takes up all wear automatically1 and renders the plates noiseless4 ,this detail cost its inventor much work4 ,the first joint made represented an expenditure of #f2 but now1 thanks to automatic machinery1 any number can be turned out at #cs4 #f;d4 each4 ,a word about the feet4 ,a wheel has fourteen of these4 ,they are eleven inches in diameter at the tread1 and soled with rubber in eight segments1 with strips of wood between the segments to prevent suction in clay soil4 ,the segments are held together by a malleable cast-iron ring around the periphery of the feet and a tightening core in the centre4 ,these wearing parts1 being separate from the rest of the foot1 are easily and cheaply renewed1 and repairs can be quickly effected1 if necessary1 when on the road4 ,the surface in contact with the ground being composed of the three substances--metal1 wood1 and rubber1 which all take a bearing1 provides a combination of materials adapted to the best adhesion and wear on any class of road1 or even on no road at all4 ,illustration3 ,,fig4 #c ,motive power is transmitted by the machinery to the wheel axle1 from that to the casing1 from the casing to the sliding spokes4 ,as there are alternately two and three feet simultaneously in contact with the ground1 the power of adhesion is very great--much greater than that of an ordinary traction-engine4 ,this is what ,professor ,hele-,shaw says in a report on a pedrail tractor3 ,the weight of the engine is spread over no less than twelve feet1 each one of which presses upon the ground with an area immensely greater--probably as much as ten times greater--than that of all the wheels 7of an ordinary traction-engine7 taken together on a hard road4 ,upon a soft road all comparison between wheels and the action of these feet ceases4 ,the contact of each of the feet of the ,pedrail is absolutely free from all slipping action1 and attains the absolute ideal of working1 being merely placed in position without sliding to take up the load1 and then lifted up again without any sliding to be carried to a new position on the road4 ,it is necessary that the feet should come down flat on the ground4 ,if they struck it at all edgeways they would sprain their ankles2 otherwise1 probably break off at the ball joint4 ,mechanism was1 therefore1 introduced by which the feet would be turned over as they approached the ground1 and be held at the proper angle ready for the step4 ,without the aid of a special diagram it would be difficult to explain in detail how this is managed2 and it must suffice to say that the chief feature is a friction-clutch worked by the roller of the foot's spoke4 ,to the onlooker the manner in which the pedrail crawls over obstacles is almost weird4 ,the writer was shown a small working model of a pedrail1 propelled along a board covered with bits of cork1 wood1 etc4 ,the axle of the wheel scarcely moved upwards at all1 and had he not actually seen the obstacles he would have been inclined to doubt their existence4 ,an ordinary wheel of equal diameter took the obstructions with a series of bumps and bounds that made the contrast very striking4 ,illustration3 ,,fig4 #d ,an extreme instance of the pedrail's capacity would be afforded by the ascent of a flight of steps 7see ,fig4 #d74 ,in such a case the three peds carrying the weight of an axle would not be on the same level4 ,that makes no difference1 because the frame merely tilts on its top and bottom pivots1 the front of the rail rising to a higher level than the back end1 and the back spokes being projected by the rail much further than those in front1 so that the engine is simply levered over its rollers up an inclined plane4 ,similarly1 in descending1 the front spokes are thrust out the furthest1 and the reverse action takes place4 ,with so many moving parts everything must be well lubricated1 or the wear would soon become serious4 ,the feet are kept properly greased by being filled with a mixture of blacklead and grease of suitable quality1 which requires renewal at long intervals only4 ,the sliding spokes1 rollers1 and friction-clutches are all lubricated from one central oil-chamber1 through a beautiful system of oil-tubes1 which provides a circulation of the oil throughout all the moving parts4 ,the central oil-chamber is filled from one orifice1 and holds a sufficient supply of oil for a long journey4 ,we may now turn for a moment from the pedrail itself to the vehicles to which it is attached4 ,here1 again1 we are met by novelties1 for in his engines ,mr4 ,diplock has so arranged matters1 that not only can both front and back pairs of wheels be used as drivers1 but both also take part in the steering4 ,as may be imagined1 many difficulties had to be surmounted before this innovation was complete4 ,but that it was worth while is evident from the small space in which a double-steering tractor can turn1 thanks to both its axles being movable1 and from the increased power4 ,another important feature must also be noticed1 viz4 that the axles can both tip vertically1 so that when the front left wheel is higher than its fellow1 the left back wheel may be lower than the right back wheel4 ,in short1 flexibility and power are the ideals which ,mr4 ,diplock has striven to reach4 ,how far he has been successful may be gathered from the reports of experts4 ,professor ,hele-,shaw1 ,f4,r4,s41 says3 ,the ,pedrail constitutes1 in my belief1 the successful solution of a walking machine1 which1 whilst obviating the chief objections to the ordinary wheel running upon the road1 can be made to travel anywhere where an ordinary wheel can go1 and in many places where it cannot4 ,at the same time it has the mechanical advantages which have made the railway system such a phenomenal success4 ,it constitutes1 in my belief1 the solution of one of the most difficult mechanical problems1 and deserves to be considered as an invention quite apart from any particular means by which it is actuated1 whether it is placed upon a self-propelled carriage or a vehicle drawn by any agency1 mechanical or otherwise4444 ,the way in which all four wheels are driven simultaneously so as to give the maximum pulling effect by means of elastic connection is in itself sufficient to mark the engine as a most valuable departure from common practice4 ,hitherto this driving of four wheels has never been successfully achieved1 partly because of the difficulty of turning the steering-wheels1 and partly because1 until the present invention of ,mr4 ,diplock1 the front and hind wheels would act against each other1 a defect at first experienced and overcome by the inventor in his first engine4 ,illustration3 ,a ,,pedrail ,,tractor ,,engaged ,,in ,,war ,,office ,,trials ,the inventor1 ,mr4 ,j4 ,b4 ,diplock1 is standing on the left of the group4 ,observe the manner in which the feet gradually assume a horizontal position as they approach the ground4 ,on ,january #hth1 #aijb1 ,mr4 ,diplock tried an engine fitted with two ordinary wheels behind and two pedrails in front4 ,the authority quoted above was present at the trials1 and his opinion will therefore be interesting4 ,the points which struck me immediately were 7#a7 the marvellous ease with which it started into action1 7#b7 the little noise with which it worked4444 ,another thing which ,i noticed was the difference in the behaviour of the feet and wheels4 ,the feet did not in any way seem to affect the surface of the road4 ,throwing down large stones the size of the fist into their path1 the feet simply set themselves to an angle in passing over the stones1 and did not crush them2 whereas1 the wheel coming after invariably crushed the stones1 and1 moreover1 distorted the road surface4 ,coming to the top of the hill1 ,i made the ,pedrail walk first over #c-;inch planks1 then #f-;inch1 and finally over a #i-;inch balk4444 ,one could scarcely believe1 on witnessing these experiments1 that the whole structure was not permanently distorted and strained1 whereas it was evidently within the limits of play allowed by the mechanism4 ,as a proof of this the ,diplock engine walked down to the works1 and ,i then witnessed its ascent of a lane1 beside the engineering works1 which had ruts eight or ten inches deep1 and was a steep slope4 ,this lane was composed in places of the softest mud1 and whereas the wheels squeezed out the ground in all directions1 the feet of the ,pedrails set themselves at the angles of the rut where it was hard1 or walked through the soft and yielding mud without making the slightest disturbance of the surrounding ground4444 ,i came away from that trial with the firm conviction that ,i had seen what ,i believe to be the dawn of a new era in mechanical transport4 ,mr4 ,diplock does not regard the pedrail as an end in itself so much as a means to an end1 viz4 the development of road-borne traffic4 ,for very long distances which must be covered in a minimum of time the railway will hold its own4 ,but there is a growing feeling that unless the railways can be fed by subsidiary methods of transport more effectively than at present1 and unless remote country districts1 whither it would not pay to carry even a light railway1 are brought into closer touch with the busier parts1 our communications cannot be considered satisfactory1 and we are not getting the best value out of our roads4 ,for many classes of goods cheapness of transportation is of more importance than speed2 witness the fact that coal is so often sent by canal rather than by rail4 ,here1 then1 is the chance for the pedrail tractor and its long train of vehicles fitted with pedrail wheels1 which will tend to improve the road surfaces they travel over4 ,mr4 ,diplock sets out in his interesting book1 ,a ,new ,system of ,heavy ,goods ,transport on ,common ,roads1 a scheme for collecting goods from branch routes on to main routes1 where a number of cars will be coupled up and towed by powerful tractors4 ,with ordinary four-wheeled trucks it is difficult to take a number round a sharp corner1 since each truck describes a more sudden circle than its predecessor1 the last often endeavouring to climb the pavement4 ,four-wheeled would therefore be replaced by two-wheeled trucks1 provided with special couplings to prevent the cars tilting1 while allowing them to turn4 ,cars so connected would follow the same track round a curve4 ,the body of the car would be removable1 and of a standard size4 ,it could be attached to a simple horse frame for transport into the fields4 ,there the farmer would load his produce1 and when the body was full it would be returned to the road1 picked up by a crane attached to the tractor1 swung on to its carriage and wheels1 and taken away to join other cars4 ,by making the bodies of such dimensions as to fit three into an ordinary railway truck1 they could be entrained easily4 ,on reaching their destination another tractor would lift them out1 fit them to wheels1 and trundle them off to the consumer4 ,by this method there would be no breaking bulk of goods required from the time it was first loaded till it was exposed in the market for sale4 ,these things are1 of course1 in the future4 ,of more present importance is the fact that the ,war ,office has from the first taken great interest in the new invention1 which promises to be of value for military transport over ground either rough or boggy4 ,trials have been made by the authorities with encouraging results4 ,that daring writer1 ,mr4 ,h4 ,g4 ,wells1 has in his ,land ,ironclads pictured the pedrail taking an offensive part in warfare4 ,huge steel-plated forts1 mounted on pedrails1 and full of heavy artillery and machine guns1 sweep slowly across the country towards where the enemy has entrenched himself4 ,the forts are impervious alike to shell and bullet1 but as they cross ditch or hillock in their gigantic stride1 their artillery works havoc among their opponents1 who are finally forced to an unconditional surrender4 ,even if the pedrail is not made to carry weapons of destruction1 we can1 after our experiences with horseflesh in the ,boer ,war1 understand how important it may become for commissariat purposes4 ,the feats which it has already performed mark it as just the locomotive to tackle the rough country in which baggage trains often find themselves4 ,to conclude with a more peaceful use for it4 ,when fresh country is opened up1 years must often pass before a proper high road can be made1 yet there is great need of an organised system of transport4 ,whither ordinary traction-engines1 or carts1 even horses1 could scarcely penetrate1 the pedrail tractor1 thanks to its big1 flat feet1 which give it1 as someone has remarked1 the appearance of a cross between a traction-engine and an elephant1 will be able to push its way at the forefront of advancing civilisation4 ,at home we shall have good reason to welcome the pedrail if it frees us from those terrible corrugated tracks so dreaded by the cyclist1 and to bless it if it actually beats our roads down into a greater smoothness than they now can boast4 ,,chapter ,,vi ,,internal ,,combustion ,,engines ,,oil ,,engines--,,engines ,,worked ,,with ,,producer ,,gas--,,blast ,,furnace ,,gas ,,engines ,if carbon and oxygen be made to combine chemically1 the process is accompanied by the phenomenon called heat4 ,if heat be applied to a liquid or gas in a confined space it causes a violent separation of its molecules1 and power is developed4 ,in the case of a steam-engine the fuel is coal 7carbon in a more or less pure form71 the fluid1 water4 ,by burning the fuel under a boiler1 a gas is formed which1 if confined1 rapidly increases the pressure on the walls of the confining vessel4 ,if allowed to pass into a cylinder1 the molecules of steam1 struggling to get as far as possible from one another1 will do useful work on a piston connected by rods to a revolving crank4 ,we here see the combustion of fuel external to the cylinder1 i4e4 under the boiler1 and the fuel and fluid kept apart out of actual contact4 ,in the gas or oil-vapour engine the fuel is brought into contact with the fluid which does the work1 mixed with it1 and burnt inside the cylinder4 ,therefore these engines are termed internal combustion engines4 ,supposing that a little gunpowder were placed in a cylinder1 of which the piston had been pushed almost as far in as it would go1 and that the powder were fired by electricity4 ,the charcoal would unite with the oxygen contained in the saltpetre and form a large volume of gas4 ,this gas1 being heated by the ignition1 would instantaneously expand and drive out the piston violently4 ,a very similar thing happens at each explosion of an internal combustion engine4 ,into the cylinder is drawn a charge of gas1 containing carbon1 oxygen1 and hydrogen1 and also a proportion of air4 ,this charge is squeezed by the inward movement of the piston2 its temperature is raised by the compression1 and at the proper moment it is ignited4 ,the oxygen and carbon seize on one another and burn 7or combine71 the heat being increased by the combustion of the hydrogen4 ,the air atoms are expanded by the heat1 and work is done on the piston4 ,but the explosion is much gentler than in the case of gunpowder4 ,during recent years the internal combustion engine has been making rapid progress1 ousting steam power from many positions in which it once reigned supreme4 ,we see it propelling vehicles along roads and rails1 driving boats through the water1 and doing duty in generating stations and smelting works to turn dynamos or drive air-pumps--not to mention the thousand other forms of usefulness which1 were they enumerated here1 would fill several pages4 ,a decade ago an internal combustion engine of #ajj h4p4 was a wonder2 to-day single engines are built to develop #c1jjj h4p41 and in a few years even this enormous capacity will doubtless be increased4 ,it is interesting to note that the rival systems--gas and steam--were being experimented with at the same time by ,robert ,street and ,james ,watt respectively4 ,while ,watt applied his genius to the useful development of the power latent in boiling water1 ,street1 in #agid1 took out letters patent for an engine to be worked by the explosions caused by vaporising spirits of turpentine on a hot metal surface1 mixing the vapour with air in a cylinder1 exploding the mixture1 and using the explosion to move a piston4 ,in his1 and subsequent designs1 the mixture was pumped in from a separate cylinder under slight pressure4 ,lenoir1 in #ahfj1 conceived the idea of making the piston suck in the charge1 so abolishing the need of a separate pump2 and many engines built under his patents were long in use1 though1 if judged by modern standards1 they were very wasteful of fuel4 ,two years later ,alphonse ,beau de ,rochas proposed the further improvement of utilising the cylinder1 not only as a suction pump1 but also as a compressor2 since he saw that a compressed mixture would ignite very much more readily than one not under pressure4 ,rochas held the secret of success in his grasp1 but failed to turn it to practical account4 ,the ,otto cycle1 invented by ,dr4 ,otto in #ahgf1 is really only ,rochas's suggestion materialised4 ,the large majority of internal combustion engines employ this cycle of operations1 so we may state its exact meaning3-- 7#a7 ,a mixture of explosive gas and air is drawn into the cylinder by the piston as it passes outwards 7i4e4 in the direction of the crank71 through the inlet valve4 7#b7 ,the valve closes1 and the returning piston compresses the mixture4 7#c7 ,the mixture is fired as the piston commences its second journey outwards1 and gives the power stroke4 7#d7 ,the piston1 returning again1 ejects the exploded mixture through the outlet or exhaust valve1 which began to open towards the end of the third stroke4 ,briefly stated1 the cycle is--suction1 compression1 explosion1 expulsion2 one impulse being given during each cycle1 which occupies two complete revolutions of the fly-wheel4 ,since the first1 second1 and third operations all absorb energy1 the wheel must be heavy enough to store sufficient momentum during the power stroke to carry the piston through all its three other duties4 ,year by year1 the compression of the mixture has been increased1 and improvements have been made in the methods of governing the speed of the engine1 so that it may be suitable for work in which the load is constantly varying4 ,by doubling1 trebling1 and quadrupling the cylinders the drive is rendered more and more steady1 and the elasticity of a steam-engine more nearly approached4 ,the internal combustion engine has arrived so late because in the earlier part of last century conditions were not favourable to its development4 ,illuminating gas had not come into general use1 and such coal gas as was made was expensive4 ,the great oil-fields of ,america and ,russia had not been discovered4 ,but while the proper fuels for this type of motor were absent1 coal1 the food of the steam-engine1 lay ready to hand1 and in forms which1 though useless for many purposes1 could be advantageously burnt under a boiler4 ,now the situation has altered4 ,gas is abundant2 and oil of the right sort costs only a few pence a gallon4 ,inventors and manufacturers have grasped the opportunity4 ,to-day over #c1jjj1jjj h4p4 is developed continuously by the internal combustion engine4 ,steam would not have met so formidable a rival had not that rival had some great advantages to offer4 ,what are these8 ,well1 first enter a factory driven by steam power1 and carefully note what you see4 ,then visit a large gas- or oil-engine plant4 ,you will conclude that the latter scores on many points4 ,there are no stokers required4 ,no boilers threaten possible explosions4 ,the heat is less4 ,the dust and dirt are less4 ,the space occupied by the engines is less4 ,there is no noisome smoke to be led away through tall and expensive chimneys4 ,if work is stopped for an hour or a day1 there are no fires to be banked or drawn--involving waste in either case4 ,above all1 the gas engine is more efficient1 or1 if you like to express the same thing in other words1 more economical4 ,if you use only one horse-power for one hour a day1 it doesn't much matter whether that horse-power-hour costs #d;d4 or #e;d4 ,but in a factory where a thousand horse-power is required all day long1 the extra pence make a big total4 ,if1 therefore1 the proprietor finds that a shilling's-worth of gas or oil does a quarter as much work again as a shilling's-worth of coal1 and that either form of fuel is easily obtained1 you may be sure that1 so far as economy is concerned1 he will make up his mind without difficulty as to the class of engine to be employed4 ,a pound of coal burnt under the best type of steam-engine gives but #aj per cent4 of its heating value in useful work4 ,a good oil-engine gives #bj-be per cent41 and in special types the figures are said to rise to #ce-dj per cent4 ,we may notice another point1 viz4 that1 while a steam-engine must be kept as hot as possible to be efficient1 an internal combustion engine must be cooled4 ,in the former case no advantage1 beyond increased efficiency1 results4 ,but in the latter the water passed round the cylinders to take up the surplus heat has a value for warming the building or for manufacturing processes4 ,putting one thing with another1 experts agree that the explosion engine is the prime mover of the future4 ,steam has apparently been developed almost to its limit4 ,its rival is but half-grown1 though already a giant4 ,some internal combustion engines use petroleum as their fuel1 converting it into gas before it is mixed with air to form the charge2 others use coal-gas drawn from the lighting mains2 poor gas made in special plants for power purposes2 or natural gas issuing from the ground4 ,natural gas occurs in very large quantities in the ,united ,states1 where it is conveyed through pipes under pressure for hundreds of miles1 and distributed among factories and houses for driving machinery1 heating1 and cooking4 ,in ,england and ,europe the petroleum engine and coal-gas engine have been most utilised2 but of late the employment of smelting-furnace gases--formerly blown into the air and wasted--and of producer gas has come into great favour with manufacturers4 ,the latest development is the suction gas engine1 which makes its own gas by drawing steam and air through glowing fuel during the suction stroke4 ,we will consider the various types under separate headings devoted 7#a7 ,to the oil-fuel engine1 7#b7 ,the producer-gas engine and the suction-gas engine1 7#c7 ,blast-furnace gas engines1 with reference to the installations used in connection with the last two4 ,all explosion engines 7excepting the very small types employed on motor cycles7 have a water-jacket round the cylinders to absorb some of the heat of combustion1 which would otherwise render the metal so hot as to make proper lubrication impossible1 and also would unduly expand the incoming charge of gas and air before compression4 ,the ideal engine would take in a full charge of cold mixture1 which would receive no heat from the walls of the cylinder1 and during the explosion would pass no heat through the walls4 ,in other words1 the ideal metal for the cylinders would be one absolutely non-receptive of heat4 ,in the absence of this1 engineers are obliged to make a compromise1 and to keep the cylinder at such a temperature that it can be lubricated fittingly1 while not becoming so cold as to absorb too much of the heat of explosion4 ,,oil ,,engines ,these fall into two main classes3-- 7a7 ,those using light1 volatile1 mineral oils--such as petrol and benzoline--and alcohol1 a vegetable product4 7b7 ,those using heavy oils1 such as paraffin oil 7kerosene7 and the denser constituents of rock-oil left in the stills after the kerosene has been driven off4 ,american petroleum is rich in burning-oil and petrol2 ,russian in the very heavy residue1 called astakti4 ,given the proper apparatus for vaporisation1 mineral oils of any density can be used in the explosion engine4 ,the first class is so well known as the mover of motor vehicles and boats that we need not linger here on it4 ,it may1 however1 be remarked that engines using the easily-vaporised oils are not of large powers1 since the fuel is too expensive to make them valuable for installations where large units of power are needed4 ,they have been adopted for locomotives on account of their lightness1 and the ease with which they can be started4 ,petrol vaporises at ordinary temperatures1 so that air merely passed over the spirit absorbs sufficient vapour to form an explosive mixture4 ,the jet carburetter1 now generally employed1 makes the mixture more positive by atomising the spirit as it passes through a very fine nozzle into the mixing chamber under the suction from the cylinder4 ,on account of their small size spirit engines work at very high speeds as compared with the large oil or gas engine4 ,thus1 while a #b1jjj h4p4 ,krting gas engine develops full power at eighty-five revolutions a minute1 the tiny cycle motor must be driven at #b1jjj to #c1jjj revolutions4 ,speaking generally1 as the size increases the speed decreases4 ,of heavy oil engines there are some dozens of well-tried types4 ,they differ in their methods of effecting the following operations4 #a4 ,the feeding of the oil fuel to the engine4 #b4 ,the conversion of the oil into vapour4 #c4 ,the ignition of the charge4 #d4 ,the governing of speed4 ,all these engines have a vaporiser1 or chamber wherein the oil is converted into gas by the action of heat4 ,when starting-up the engine1 this chamber must be heated by a specially designed lamp1 similar in principle to that used by house painters for burning old paint off wood or metal4 ,let us now consider the operations enumerated above in some detail4 #a4 ,the oil supply4 ,fuel is transferred from the storage tank to the vaporiser either by the action of gravity through a regulating device to prevent flooding1 or by means of a small pump1 or by the suction of the piston1 which lifts the liquid4 ,in some engines the air and gas enter the cylinder through a single valve2 in others through separate valves4 #b4 ,vaporisation4 ,as already remarked1 the vaporising chamber must be heated to start the engine4 ,when work has begun the lamp may be removed if the engine is so designed that the chamber stores up sufficient heat in its walls from each explosion to vaporise the charge for the next power stroke4 ,the ,crossley engine has a lamp continuously burning2 the ,hornsby-,ackroyd depends upon the storage of heat from explosions in a chamber opening into the cylinder4 ,the best designs are fairly equally divided between the two systems4 #c4 ,ignition of the compressed charge is effected in one of four ways3 by bringing the charge1 at the end of the compression stroke1 into contact with a closed tube projecting from the cylinder and heated outside by a continuously burning lamp2 by the heat stored in some part of the combustion chamber 7i4e4 that portion of the cylinder not swept by the piston72 by an electric spark2 or by the mere heat of compression4 ,the second and third methods are confined to comparatively few makes2 and the ,diesel ,oil ,engine 7of which more presently7 has a monopoly of the fourth4 #d4 ,governing4 ,all engines which turn machinery doing intermittent work--such as that of a sawmill1 or electric generating plant connected with a number of motors--must be very carefully guarded from overrunning4 ,imagine the effect on an engine which is putting out its whole strength and getting full charges of fuel1 if the belt suddenly slipped off and it were allowed its head4 ,a burst fly-wheel would be only one of the results4 ,the steam-engine is easily controlled by the centrifugal action of a ball-governor1 which1 as the speed increases1 gradually spreads its balls and lifts a lever connected with a valve in the steam supply pipe4 ,owing to its elastic nature1 steam will do useful work if admitted in small quantities to the cylinder4 ,but a difficulty arises with the internal combustion engine if the supply of mixture is similarly throttled1 because a loss of quantity means loss of compression and bad ignition4 ,many oil engines are therefore governed by apparatus which1 when the speed exceeds a certain limit1 cuts off the supply altogether1 either by throwing the oil-pump temporarily out of action1 or by lifting the exhaust valve so that the movement of the piston causes no suction--the hit-and-miss method1 as it is called4 ,the means adopted depends on the design of the engine2 and it must be said that1 though all the devices commonly used effect their purpose1 none are perfect2 this being due rather to the nature of an internal explosion engine than to any lack of ingenuity on the part of inventors4 ,the steadiest running is probably given with the throttle control1 which diminishes the supply4 ,on motor cars this method has practically ousted the hit-and-miss governed exhaust valve2 but in stationary engines we more commonly find the speed controlled by robbing the mixture of the explosive gas in inverse proportion to the amount of the work required from the engine4 ,,the ,,diesel ,,oil ,,engine1 on account of some features peculiar to it1 is treated separately4 ,in #aija an expert wrote of it that the engine has not attained any commercial position4 ,herr ,rudolph ,diesel1 the inventor1 has1 however1 won a high place for his prime-mover among those which consume liquid fuel1 on account of its extraordinary economy4 ,the makers claim--as the result of many tests--that with the crude rock-oil 7costing in bulk about #b;d4 a gallon7 which it uses1 a horse-power can be developed for one hour by this engine for one-tenth of a penny4 ,the daily fuel bill for a #ajj h4p4 engine running ten hours per day would therefore be #hs4 #d;d4 ,to compete with the ,diesel engine a steam installation would have to be of the very highest class of triple-expansion type1 of not less than #djj h4p41 and using every hour per horse-power only #a-c_/d lbs4 of coal at #is4 per ton4 ,very few large steam-engines work under conditions so favourable1 and with small sizes #c-d lbs4 of coal would be burnt for every horse-power-hour4 ,the ,diesel differs from other internal combustion engines in the following respects3-- #a4 ,it works with very much higher compression4 #b4 ,the ignition is spontaneous1 resulting from the high compression of the charge alone4 #c4 ,the fuel is not admitted into the cylinder until the power-stroke begins1 and enters in the form of a fine spray4 #d4 ,the combustion of the fuel is much slower1 and therefore gives a more continuous and elastic push to the piston4 ,the engine works on the ordinary ,otto cycle4 ,to start it1 air compressed in a separate vessel is injected into the cylinder4 ,the piston flies out1 and on its return squeezes the air to about #ejj lbs4 to the square inch1 thus rendering it incandescent4#aa ,just as the piston begins to move out again a valve in the cylinder-head opens1 and a jet of pulverised oil is squirted in by air compressed to #ajj lbs4 per square inch more than the pressure in the cylinder4 ,the vapour1 meeting the hot air1 burns1 but comparatively slowly3 the pressure in the cylinder during the stroke decreasing much more gradually than in other engines4 ,governing is effected by regulation of the amount of oil admitted into the cylinder4 ,in spite of its high compression this engine runs with very little vibration4 ,the writer saw a penny stand unmoved on its edge on the top of a cylinder in which the piston was reciprocating #ejj times a minute6 ,,engines ,,worked ,,by ,,producer-,,gas ,these engines are worked by a special gas generated in an apparatus called a producer4 ,if air is forced through incandescent carbon in a closed furnace its oxygen unites with the carbon and forms carbonic acid gas1 known chemically as ,,co#b1 because every molecule of the gas contains one atom of carbon and two of oxygen4 ,this gas1 being the product of combustion1 cannot burn 7i4e4 combine with more oxygen71 but as it passes up through the glowing coke1 coal1 or other fuel1 it absorbs another carbon atom into every molecule1 and we have ,c#b,o#b1 or #b ,,co1 which we know as carbon monoxide4 ,this gas may be seen burning on the top of an open fire with a very pale blue flame1 as it once more combines with oxygen to form carbonic acid gas4 ,the carbon monoxide is valuable as a heating agent1 and when mixed with air forms an explosive mixture4 ,if along with the air sent into our furnace there goes a proportion of steam1 further chemical action results4 ,the oxygen of the steam combines with carbon to form carbon monoxide1 and sets free the hydrogen4 ,the latter gas1 when it combines with oxygen in combustion1 causes intense heat2 so that if from the furnace we can draw off carbon monoxide and hydrogen1 we shall be able to get a mixture which during combustion will set up great heat in the cylinder of an engine4 ,in #ahgh ,mr4 ,emerson ,dowson invented an apparatus for manufacturing a gas suitable for power plant1 the gas being known as ,producer or ,poor ,gas1 the last term referring to its poorness in hydrogen as compared with coal and other gases4 ,while the hydrogen is a desirable ingredient in an explosive charge1 it must not form a large proportion1 since under compression it renders the mixture in which it takes part dangerously combustible1 and liable to spontaneous ignition before the piston has finished the compression stroke4 ,water-gas1 very rich in hydrogen1 and made by a very similar process1 is therefore not suitable for internal combustion engines4 ,there are many types of producers1 but they fall under two main heads1 i4e4 the pressure and the suction4 ,the pressure producer contains the following essential parts3-- ,the generator1 a vertical furnace fed from the top through an air-tight trap1 and shut off below from the outside atmosphere by having its foot immersed in water4 ,any fuel or ashes which fall through the bars into the water can be abstracted without spoiling the draught4 ,air and steam are forced into the generator1 and pass up through the fuel with the chemical results already described4 ,the gases then flow into a cooler1 enclosed in a water-jacket1 through which water circulates1 and on into a scrubber1 where they must find their way upwards through coke kept dripping with water from overhead jets4 ,the water collects impurities of all sorts1 and the gas is then ready for storage in the gas-holders or for immediate use in the engines4 ,a pound of anthracite coal thus burnt will yield enough gas to develop #a h4p4 for one hour4 ,suction ,gas ,plants4--,with these gas is not stored in larger quantities than are needed for the immediate work of the engine4 ,in fact1 the engine itself during its suction strokes draws air and steam through a very small furnace1 coolers1 and scrubbers direct into the cylinder4 ,the furnace is therefore fed with air and water1 not by pressure from outside1 but by suction from inside1 hence the name suction producer4 ,at the present time suction gas engines are being built for use on ships1 since a pound of fuel thus consumed will drive a vessel further than if burnt under a steam boiler4 ,very possibly the big ocean liners of twenty years hence may be fitted with such engines in the place of the triple and quadruple expansion steam machinery now doing the work4 ,,blast-,,furnace ,,gas ,,engines ,every iron blast-furnace is very similar in construction and action to the generator of a producer-gas plant4 ,into it are fed through a hopper1 situated in the top1 layers of ore1 coal or coke1 and limestone4 ,at the bottom enters a blast of air heated by passing through a stove of firebrick raised to a high temperature by the carbon monoxide gas coming off from the furnace4 ,when the stove has been well heated the gas supply is shut off from it and switched to the engine-house to create power for driving the huge blowers4 ,the gas contains practically no hydrogen1 as the air sent through the furnace is dry2 but since it will stand high compression1 it is very suitable for use in large engines4 ,formerly all the gas from the furnace was expelled into the open air and absolutely wasted2 then it was utilised to heat the forced draught to the furnace2 next1 to burn under boilers2 and last of all1 at the suggestion of ,mr4 ,b4 ,h4 ,thwaite1 to operate internal combustion engines for blowing purposes4 ,thus1 in the fitness of things1 we now see the biggest gas engines in the world installed where gas is created in the largest quantities1 and an interesting cycle of actions results4 ,the engine pumps the air2 the air blows the furnace and melts the iron out of the ore2 the furnace creates the gas2 the gas heats the air or works the engines to pump more air4 ,so engines and furnace mutually help each other1 instead of all the obligation being on the one side4 ,when1 a few years ago1 the method was first introduced1 engines were damaged by the presence of dust carried with the gas from the furnace4 ,mr4 ,b4 ,h4 ,thwaite has1 however1 perfected means for the separation of injurious matter1 and blast-furnace gas is coming into general use in ,england and on the ,continent4 ,some idea of the power which has been going to waste in ironworks for decades past may be gathered from a report of ,professor ,hubert after experiments made in #aijj4 ,he says that engines of large size do not use more than #ajj cubic feet of average blast-furnace gas per effective horse-power-hour1 which is less than one-fourth of the consumption of gas required to develop the same power from boilers and good modern condensing steam-engines1 so that there is an immense surplus of power to be obtained from a blast-furnace if the blowing engines are worked by the gas it generates1 a surplus which can be still further increased if the gas is properly cleaned4 ,it is estimated that for every #ajj tons of coke used in an ordinary ,cleveland blast-furnace1 after making ample allowance for gas for the stoves and power for the lifts1 pumps1 etc41 and for gas for working the necessary blowing engines1 there is a surplus of at least #a1ejj h4p42 so that by economising gas by cleaning1 and developing the necessary power by gas engines1 every furnace owner would have a very large surplus of power for his steel or other works1 or for selling in the form of electricity or otherwise4 ,yet all this gas had been formerly turned loose for the breezes to warm their fingers at6 ,truly1 as an observant writer has recorded1 the sight of a special plant being put up near a blast furnace to manufacture gas for the blowing engines suggests the pumping of water uphill in order to get water-power6 ,messrs4 ,westgarth and ,richardson1 of ,middlesbrough2 the ,john ,cockerill ,company1 of ,seraing1 ,belgium2 and the ,de la ,vergne ,company1 of ,new ,york1 are among the chief makers of the largest gas engines in the world1 ranging up to #c1gej h4p4 each4 ,these immense machines1 some with fly-wheels #cj feet in diameter1 and cylinders spacious enough for a man to stand erect in1 work blowers for furnaces or drive dynamos4 ,at the works of the manufacturers mentioned the engines helped to make the steel1 and turn the machinery for the creation of brother monsters4 ,illustration3 ,,gigantic ,,gas ,,engines ,five of sixteen #b1jjj h4p4 ,krting ,gas ,engines built by the ,de la ,vergne ,company of ,new ,york ,city for blowing the blast furnaces of the ,lackawanna ,steel ,company4 ,the gas-engine plant at these works is the largest in the world4 ,notice the man to the left4 ,this use of a bye-product of industry is remarkable1 but it can be paralleled4 ,furnace slag1 once cast away as useless1 is now recognised to be a valuable manure1 or is converted into bricks1 tiles1 cement1 and other building materials4 ,again1 the former waste from the coal-gas purifier assumes importance as the origin of aniline dyes1 creosote1 saccharine1 ammonia1 and oils4 ,we really appear to be within sight of the happy time when waste will be unknown4 ,and it therefore is curious that we still burn gas as an illuminant1 when the same1 if made to work an engine1 would give more lighting power in the shape of electric current supplying incandescent lamps4 ,,footnote3 #aa ,the fact that air is heated to combustion point by compression has long been known to the ,chinese4 ,in ,the ,river of ,golden ,sand1 ,captain ,gill writes3 ,the natives have an apparatus by which they strike a light by compressed air4 ,the apparatus consists of a wooden cylinder #b-a_/b inches long by #c_/d inch in diameter4 ,this is closed at one end2 the bore being about the size of a stout quill pen1 an air-tight piston fits into this with a large flat knob at the top4 ,the other end of the piston is slightly hollowed out1 and a very small piece of tinder is placed on the top thus formed4 ,the cylinder is held in one hand1 the piston inserted and pushed about half-way down2 a very sharp blow is then delivered with the palm of the hand on to the top of the knob2 the hand must at the same time close on the knob1 and instantly withdraw the piston1 when the tinder will be found alight4 ,the compression of the air produces heat enough to light the tinder2 but this will go out again unless the piston is withdrawn very sharply4 ,i tried a great many times1 but covered myself with confusion in fruitless efforts to get a light1 for the natives never miss it4 ,,chapter ,,vii ,,motor-,,cars ,,the ,,motor ,,omnibus--,,railway ,,motor-,,cars ,the development of the motor-car has been phenomenal4 ,early in #ahif the only mechanically moved vehicles to be seen on our roads were the traction-engine1 preceded by a man bearing a red flag1 the steam-roller1 and1 in the towns1 a few trams4 ,to-day the motor is apparent everywhere1 dodging through street traffic1 or raising the dust of the country roads and lanes1 or lumbering along with its load of merchandise at a steady gait4 ,as a purely speed machine the motor-car has practically reached its limit4 ,with #ajj h4p4 or more crowded into a vehicle scaling only a ton1 the record rate of travel has approached two miles in a minute on specially prepared and peculiarly suitable tracks4 ,even up steep hills such a monster will career at nearly eighty miles an hour4 ,next to the racing car comes the touring car1 engined to give sixty miles an hour on the level in the more powerful types1 or a much lower speed in the car intended for quieter travel1 and for people who are not prepared to face a big bill for upkeep4 ,the luxury of the age has invaded the design of automobiles till the gorgeously decorated and comfortably furnished ,pullman of the railway has found a counterpart in the motor caravan with its accommodation for sleeping and feeding4 ,while the town dweller rolls along in electric landaulet1 screened from wind and weather1 the tourist may explore the roads of the world well housed and lolling at ease behind the windows of his #b1jjj-;guinea machine1 on which the engineer and carriage builder have lavished their utmost skill4 ,the taunt of unreliability once levelled--and with justice--at the motor-car1 is fast losing its force1 owing to the vast improvements in design and details which manufacturers have been stimulated to make4 ,the motor-car industry has a great future before it1 and the prizes therein are such as to tempt both inventor and engineer4 ,every week scores of patents are granted for devices which aim at the perfection of some part of a car1 its tyres1 its wheels1 or its engines4 ,until standard types for all grades of motor vehicles have been established1 this restless flow of ideas will continue4 ,its volume is the most striking proof of the vitality of the industry4 ,the uses to which the motor vehicle has been put are legion4 ,on railways the motor carriage is catering for local traffic4 ,on the roads the motor omnibus is steadily increasing its numbers4 ,tradesmen of all sorts1 and persons concerned with the distribution of commodities1 find that the petrol- or steam-moved car or lorry has very decided advantages over horse traction4 ,our postal authorities have adopted the motor mail van4 ,the ,war ,office looks to the motor to solve some of its transportation difficulties4 ,in short1 the motor age has arrived1 which will1 relatively to the railway age1 play much the same part as that epoch did to the horse age4 ,at the ultimate effects of the change we can only guess2 but we see already1 in the great acceleration of travel wherever the motor is employed1 that many social institutions are about to be revolutionised4 ,but for the determined opposition in the 'thirties of last century to the steam omnibus we should doubtless live to-day in a very different manner4 ,our population would be scattered more broadcast over the country instead of being herded in huge towns4 ,many railways would have remained unbuilt1 but our roads would be kept in much better condition1 special tracks having been built for the rapid travel of the motor4 ,we have only to look to a country now in course of development to see that the road1 which leads everywhere1 will1 in combination with the motor vehicle1 eventually supplant1 or at any rate render unnecessary1 the costly network of railways which must be a network of very fine mesh to meet the needs of a civilised community4 ,in the scope of a few pages it is impossible to cover even a tithe of the field occupied by the ubiquitous motor-car1 and we must1 therefore1 restrict ourselves to a glance at the manufacture of its mechanism1 and a few short excursions into those developments which promise most to alter our modes of life4 ,we will begin with a trip over one of the largest motor factories in the world1 selecting that of ,messrs4 ,dion and ,bouton1 whose names are inseparable from the history of the modern motor-car4 ,they may justly claim that to deal with the origin1 rise1 and progress of the huge business which they have built up would be to give an account1 in its general lines1 of all the phases through which the motor1 especially the petrol motor1 has passed from its crudest shape to its present state of comparative perfection4 ,the ,count ,albert de ,dion was1 in his earlier days1 little concerned with things mechanical4 ,he turned rather to the fashionable pursuit of duelling1 in which he seems to have made a name4 ,but he was not the man to waste his life in such inanities1 and when1 one day1 he was walking down the ,paris boulevards1 his attention was riveted by a little clockwork carriage exposed for sale among other ,new ,year's gifts4 ,that moment was fraught with great consequences1 for an inventive mind had found a proper scope for its energy4 ,why1 thought he1 could not real cars be made to run by some better form of motive power8 ,on inquiring he learnt that a workman named ,bouton had produced the car4 ,the ,count1 therefore1 sought the artisan2 with whom he worked out the problem which had now become his aim in life4 ,hence it is that the names ,dion--,bouton are found on thousands of engines all over the world4 ,the partners scored their first successes with steam- and petrol-driven tricycles1 built in a small workshop in the ,avenue ,malakoff in ,paris4 ,the works were then transferred to ,puteaux1 which has since developed into the great automobile centre of the world1 and after two more changes found a resting-place on the ,quai ,national4 ,here close upon #c1jjj hands are engaged in supplying the world's requirements in motors and cars4 ,let us enter the huge block of buildings and watch them at work4 ,the drawing-office is the brain of the factory4 ,within its walls new ideas are being put into practical shape by skilled draughtsmen4 ,the drawings are sent to the model-making shop1 where the parts are first fashioned in wood4 ,the shop contains dozens of big benches1 circular saws1 and planing machines1 one of them in the form of a revolving drum carrying a number of planes1 which turns thousands of times a minute1 and shapes off the rough surface of the blocks of hard wood as if it were so much clay4 ,these blocks are cut1 planed1 and turned1 and then put into the hands of a remarkably skilled class of workmen1 who1 with rule1 calliper1 and chisel1 shape out cylinders and other parts to the drawings before them with wonderful patience and exactness4 ,after the model has been fashioned1 the next step is to make a clay mould from the same1 with a hole in the top through which the molten metal is poured4 ,the foundry is most picturesque in a lurid1 ,rembrandtesque fashion3 ,it is black everywhere4 ,the floor1 walls1 and roof are black1 and the foundry hands look like unwashed penitents in sackcloth and ashes4 ,at the end of the building there is a raised brickwork1 and when the visitor is able to see in the darkness1 he distinguishes a number of raised lids along the top1 while here and there are strewn about huge iron ladles like buckets4 ,on the foreman giving the word1 a man steps up on the brickwork and removes the lid1 when a column of intense white light strikes upwards4 ,it gives one the impression of coming from the bowels of the earth1 like a hole opening out in a volcano4 ,the man bestrides the aperture1 down which he drops the ladle at the end of a long pole1 and then pulling it up again full of a straw-coloured1 shining liquid1 so close to him that we shudder at the idea of its spilling over his legs and feet1 he pours the molten metal into a big ladle1 which is seized by two men who pour the liquid into the moulds4 ,the work is more difficult than it looks1 for it requires a lot of practice to fill the moulds in such a way as to avoid blow-holes and flaws that prove such a serious item in foundry practice4 ,in the case-hardening department1 next door1 there are six huge ovens with sliding fronts4 ,therein are set parts which have been forged or machined1 and are subjected to a high temperature while covered in charcoal1 so that the skin of the metal may absorb carbon at high temperatures and become extremely tough4 ,all shafts1 gears1 and other moving parts of a car are subjected to this treatment1 which permits a considerable reduction in the weight of metal used1 and greatly increases its resistance to wear4 ,after being carbonised1 the material is tempered by immersion in water while of a certain heat1 judged by the colour of the hot metal4 ,we now pass to the turning-shop1 where the cylinders are bored out by a grinding disc rapidly rotating on an eccentric shaft1 which is gradually advanced through the cylinder as it revolves4 ,the utmost accuracy1 to the #a_/aj1jjj part of an inch1 is necessary in this operation1 since the bore must be perfectly cylindrical1 and also of a standard size1 so that any standard piston may exactly fit it4 ,after being bored1 or rather ground1 the walls of the cylinder are highly polished1 and the article is ready for testing4 ,the workman entrusted with this task hermetically closes the ends by inserting the cylinder between the plates of an hydraulic press1 and pumps in water to a required pressure4 ,if there be the slightest crack1 crevice1 or hole1 the water finds its way through1 and the piece is condemned to the rubbish heap4 ,in the motor-room are scores of cylinders1 crank-cases1 and gears ready for finishing4 ,here the outside of bored cylinders is touched up by files to remove any marks and rough projections left by the moulds4 ,the crank-cases of aluminium are taken in hand by men who chisel the edges where the two halves fit1 chipping off the metal with wonderful skill and precision4 ,the edges are then ground smooth1 and after the halves have been accurately fitted1 the holes for the bolts connecting them are drilled in a special machine1 which presents a drill to each hole in succession4 ,having seen the various operations which a cylinder has to go through1 we pass into another shop given up to long lines of benches where various motor parts are being completed4 ,each piece1 however small1 is treated as of the utmost importance1 since the failure of even a tiny pin may bring the largest car to a standstill4 ,we see a man testing pump discs against a standard template to prove their absolute accuracy4 ,close by1 another man is finishing a fly-wheel1 chipping off specks of metal to make the balance true4 ,we now understand that machine tools cannot utterly displace the human hand and eye4 ,the fitters1 with touches of the file1 remove matter in such minute quantities that its removal might seem of no consequence4 ,but matter in the wrong place is the cause of many breakdowns4 ,we should naturally expect that engines cast from the same pattern1 handled by the same machines1 finished by the same men1 would give identical results4 ,but as two bicycles of similar make will run differently1 so do engines of one type develop peculiarities4 ,the motors are therefore taken into a testing-room and bolted to two rows of benches1 forty at a time4 ,here they run under power for long periods1 creating a deafening uproar1 until all parts work sweetly4 ,the power of the engines is tested by harnessing them to dynamos and noting the amount of current developed at a certain speed4 ,we might linger in the departments where accumulators1 sparking plugs1 and other parts of the electrical apparatus of a car are made1 or in the laboratory where chemists pry into the results of a new alloy1 aided by powerful microscopes and marvellously delicate scales4 ,but we will stop only to note the powerful machine which is stretching and crushing metal to ascertain its toughness4 ,no care in experimenting is spared4 ,the chemist1 poring over his test tubes1 plays as important a part in the construction of a car as the foundry man or the turner4 ,the machine-shop is an object-lesson among the tools noticed in previous chapters of this book4 ,here is a huge planing machine travelling to and fro over a copper bar4 ,a crank shaft has been cut out of solid steel by boring holes close together through a thick plate1 and the two sides of the plate have been broken off1 leaving the rough shaft with its edges composed of a considerable number of semicircles4 ,the shaft is slowly rotated on a lathe1 and tiny clouds of smoke arise as the tool nicks off pieces of metal to reduce the shaft to a circular shape4 ,other machines1 with high-speed tool steel1 are finishing gear shafts4 ,fly-wheels are being turned and worm shafts cut4 ,all these laborious operations are carried out by the machines1 each under the control of one man whose mind is intent upon the work1 ready to stop the machine or adjust the material as may be required4 ,as a contrast to the heavy machines we will pass to the light automatic tools which are grouped in a gallery4444 ,the eye is bewildered by the moving mass1 but the whirling of the pulley shafts and the clicking of the capstan lathes is soothing to the ear1 while the mind is greatly impressed by the ingenuity of man in suppressing labour by means of machines1 of which half a dozen can be easily looked after by one hand1 who has nothing to do but to see that they are fed with material4 ,a rod of steel is put into the machine1 and the turret1 with half a dozen different tools1 presents first one and then the other to the end of the rod bathed in thick oil1 so that it is rapidly turned1 bored1 and shaped into caps1 nuts1 bolts1 and the scores of other little accessories required in fitting up a motor-car4 ,on seeing how all this work is done mechanically and methodically1 with scarcely any other expense but the capital required in the upkeep of the machines and in driving them1 one wonders how the automobile industry could be carried on without this labour-saving mechanism4 ,in any event1 if all these little pieces had to be turned out by hand1 it is certain that the cost of the motor-car would be considerably more than it is1 even if it did not reach to such a figure as to make it prohibitive to all but wealthy buyers4 ,down one side of the gallery the machines are engaged in cutting gears with so much precision that1 when tested by turning them together on pins on a bench at the end of the gallery1 it is very rare indeed that any one of them is found defective4 ,this installation of automatic tools is one of the largest of its kind in a motor-car works1 if not in any engineering shop1 and each one has been carefully selected in view of its efficiency for particular classes of work1 so that we see machines from ,america1 ,england1 ,france1 and ,germany4 ,in the fitting-shops the multitude of parts are assembled to form the chassis or mechanical carriage of the car1 to which1 in a separate shop1 is added the body for the accommodation of passengers4 ,the whole is painted and carefully varnished after it has been out on the road for trials to discover any weak spot in its anatomy4 ,then the car is ready for sale4 ,when one considers the racketing that a high-powered car has to stand1 and the high speed of its moving parts1 one can understand why those parts must be made so carefully and precisely1 and also how this care must conduce to the expense of the finished article4 ,it has been said that it is easy to make a good watch1 but difficult to make a good motor2 for though they both require an equal amount of exactitude and skill1 the latter has to stand much more wear in proportion4 ,when you look at a first-grade car bearing a great maker's name1 you have under your eyes one of the most wonderful pieces of mechanism the world can show4 ,we will not leave the de ,dion-,bouton ,works without a further glance at the human element4 ,the company never have a slack time1 and consequently can employ the same number of people all the year round4 ,they pride themselves on the fact that the great majority of the men have been in their employ for several years1 with the result that they have around them a class of workmen who are steady1 reliable and1 above all1 skilful in the particular work they are engaged upon4 ,there are more than #b1fjj men and about #ajj women1 these latter being employed chiefly in the manufacture of sparking plugs and in other departments where there is no night work4 ,they are mostly the wives or widows of old workmen1 and in thus finding employment for them the firm provides for those who would otherwise be left without resource1 and at the same time earns the gratitude of their employs4 ,,note4--,the author gratefully acknowledges the help given by ,messrs4 de ,dion-,bouton1 ,ltd41 in providing materials for this account of their works4 ,,the ,,motor ,,omnibus ,prior to the emancipation of the road automobile in #ahif1 permission had been granted to corporations to run trams driven by mechanical power through towns4 ,the steam tram1 its engine protected by a case which hid the machinery from the view of restive horses1 panted up and down our streets1 drawing one or more vehicles behind it4 ,the electric tram presently came over from ,america and soon established its superiority to the steamer with respect to speed1 freedom from smell and smoke1 and noiselessness3 the system generally adopted was that invented in #ahhg by ,frank ,j4 ,sprague1 in which an overhead cable supported on posts or slung from wires spanning the track carries current to a trolley arm projecting from the vehicle4 ,the return current passes through the rails1 which are made electrically continuous by having their individual lengths either welded together or joined by metal strips4 ,in ,america1 where wide streets and rapidly growing cities are the rule1 the electric tramway serves very useful ends2 the best proof of its utility being the total mileage of the tracks4 ,statistics for #aijb show that since #ahij the mileage had increased from #a1bfa to #ba1ibj miles2 and the number of passengers carried from #b1jbc1jaj1bjb to #d1hac1dff1jja1 or an increase of #acgid per cent4 ,it is interesting to note that electricity has in the ,united ,states almost completely ousted steam and animal traction so far as street cars are concerned2 since the #e1ffa miles once served by animal power have dwindled to #bei1 and steam can claim only #afi miles of track4 ,next to the ,united ,states comes ,germany as a user of electricity for tractive purposes2 though she is a very bad second with only about #f1jjj miles of track2 and ,england takes third place with about #c1jjj miles4 ,that the ,british ,isles1 so well provided with railways1 should be so poorly equipped with tramways is comprehensible when we consider the narrowness of the streets of her largest towns1 where a good service of public vehicles is most needed4 ,the installation of a tram-line necessitates the tearing up of a street1 and in many cases the closing of that street to traffic4 ,we can hardly imagine the dislocation of business that would result from such a blockage of1 say1 the ,strand and ,high ,holborn2 but since it has been calculated that no less than five millions of pounds sterling are lost to our great metropolis yearly by the obstructions of gas1 water1 telegraph1 and telephone operations1 which only partially close a thoroughfare1 or by the relaying of the road surface1 which is not a very lengthy matter if properly conducted1 we might reckon the financial loss resulting from the laying of tram-rails at many millions4 ,even were they laid1 the trouble would not cease1 for a tram is confined to its track1 and cannot make way for other traffic4 ,this inadaptability has been the cause of the great outcry lately raised against the way in which tram-line companies have monopolised the main streets and approaches to many of our largest towns4 ,while the electric tram is beneficial to a large class of people1 as a cheap method of locomotion between home and business1 it sadly handicaps all owners of vehicles vexatiously delayed by the tram4 ,at ,brentford1 to take a notorious example1 the double tram-line so completely fills the ,high ,street that it is at places impossible for a cart or carriage to remain at the kerbstone4 ,another charge levelled with justice at the tram-line is that the rails and their setting are dangerous to cyclists1 motorists1 and even heavy vehicles1 especially in wet weather1 when the side-slip demon becomes a real terror4 ,english municipalities are therefore faced by a serious problem4 ,improved locomotion is necessary2 how can it best be provided8 ,by smooth-running1 luxurious1 well-lighted electric trams1 travelling over a track laid at great expense1 and a continual nuisance to a large section of the community2 or by vehicles independent of a central source of power1 and free to move in any direction according to the needs of the traffic8 ,where tramways exist1 those responsible for laying them at the rate of several thousand pounds per mile are naturally reluctant to abandon them4 ,but where the fixed track has not yet arrived an alternative method of transport is open1 viz4 the automobile omnibus4 ,quite recently we have seen in ,london and other towns a great increase in the number of motor buses1 which often ply far out into the country4 ,from the point of speed they are very superior to the horsed vehicle1 and statistics show that they are also less costly to run in proportion to the fares carried1 while passengers will unanimously acknowledge their greater comfort4 ,to change from the ancient1 rattling two-horse conveyance1 which jolts us on rough roads1 and occasionally sends a thrill up the spine when the brakes are applied1 to the roomy steam- or petrol-driven bus1 which overtakes and threads its way through the slower traffic1 is a pleasant experience4 ,so the motor buses are crowded1 while the horsed rivals on the same route trundle along half empty4 ,since the one class of vehicles can travel at an average pace of ten miles an hour1 as against the four miles an hour of the other1 no wonder that this should be so4 ,even if the running costs of a motor bus for a given distance exceed that of an electric tram1 we must remember that1 whereas a bus runs on already existing roads1 an immense amount of capital must be sunk in laying the track for the tram1 and the interest on this sum has to be added to the total running costs4 ,the next decade will probably decide whether automobiles or trams are to serve the needs of the community in districts where at present no efficient service of any kind exists4 ,in ,london motor buses are being placed on the roads by scores1 and the day cannot be far distant when the horse will disappear from the bus as it is already fast vanishing from the front of the tram4 ,both petrol and steam1 and in some cases a combination of petrol and electricity1 are used to propel the motor bus4 ,it has not yet been decided which form of power yields the best results4 ,petrol is probably the cheaper fuel1 but steam gives the quieter running2 and could electric storage batteries be made sufficiently light and durable they would have a strong claim to precedence4 ,there has lately appeared a new form of accumulator--the von ,rothmund--which promises well1 since weight for weight it far exceeds in capacity any other type1 and is so constructed that it will stand a lot of rough usage4 ,a car fitted with a von ,rothmund battery scaling about #a1ejj lbs4 has run #bjj miles on one charge1 and it is anticipated that with improvements in motors a #a1ajj-lb4 battery will readily be run #aej miles as against the #ej miles in the case of a lead battery of equal weight4 ,there is a large sphere open to the motor bus outside districts where the electric tram would enter into serious competition with it4 ,we have before us a sketch-map of the ,great ,western ,railway1 one of the most enterprising systems with regard to its use of motors to feed its rails4 ,no less than thirty road services are in operation1 and their number is being steadily augmented4 ,in fact1 it looks as if in the near future the motor service will largely supplant the branch railway1 blessed with very few trains a day4 ,a motor bus service plying every half-hour between a town and the nearest important main-line station would be more valuable to the inhabitants than half a dozen trains a day1 especially if the passenger vehicles were supplemented by lorries for the carriage of luggage and heavy goods4 ,in this connection we may notice an invention of ,m4 ,renard--a motor train of several vehicles towed by a single engine4 ,we have all seen the traction-engine puffing along with its tail of trucks1 and been impressed by the weight of the locomotive1 and also by the manner in which the train occupies a road when passing a corner4 ,the weight is necessary to give sufficient grip to move the whole train1 while the spreading of the vehicles across the thoroughfare on a curve arises from the fact that each vehicle does not follow the path of that preceding it1 but describes part of a smaller circle4 ,m4 ,renard has1 in his motor train1 evaded the need for a heavy tractor by providing every vehicle with a pair of driving wheels1 and transmitting the power to those wheels by a special flexible propeller shaft which passes from the powerful motor on the leading vehicle under all the other vehicles1 engaging in succession with mechanism attached to all the driving axles4 ,in this manner each car yields its quotum of adhesion for its own propulsion1 and the necessity for great weight is obviated4 ,special couplings ensure that the path taken by the tractor shall be faithfully followed by all its followers4 ,a motor train of this description has travelled from ,paris to ,berlin and drawn to itself a great deal of attention4 ,will it1 asks a writer in ,the ,world's ,work1 ultimately displace the conventional traction-engine and its heavy trailing waggons8 ,every municipality and ,county ,council is only too painfully cognisant of the dire effects upon the roads exercised by the cumbrous wheels of these unwieldy locomotives and trains4 ,with the ,renard train1 however1 the trailing coaches can be of light construction1 carried on ordinary wheels which do not cut up or otherwise damage the roadway surface4 ,many other advantages inherent in such a train might be enumerated4 ,the most important1 however1 are the flexibility of the whole train2 its complete control2 faster speed without any attendant danger2 its remarkable braking arrangements as afforded by the continuous propeller shaft gearing directly with the driving-wheels of each carriage2 its low cost of maintenance1 serviceability1 and instant use2 and the reduction in the number of men requisite for the attention of the train while on a journey4 ,were the system a success1 it would find plenty of scope to convey passengers and commodities through districts too sparsely populated to render a railway profitable4 ,people would talk about travelling or sending goods by the ten-thirty motor train1 just as now we speak of the eleven-fifteen to town4 ,as a carrier and distributer of mails1 the motor van has already established a position4 ,to quote but a couple of instances1 there are the services between ,london and ,brighton1 and ,liverpool and ,manchester4 ,in the ,isle of ,wight motor omnibuses connect all the principal towns and villages4 ,each bus is a travelling post-office in which1 by an arrangement with the ,postmaster-,general1 anybody may post letters at the recognised stopping-places or whenever the vehicle has halted for any purpose4 ,in ,paris1 ,london1 ,berlin1 the motor mail van is a common sight4 ,it has even penetrated the interior of ,india1 where the ,maharajah of ,gwalior uses a specially fitted steam car for the delivery of his private mails4 ,and1 as though to show that man alone shall not profit by the new mode of locomotion1 ,paris owns a motor-car which conveys lost dogs from the different police-stations to the ,dogs' ,home6 ,in fact1 there seems to be no purpose to which a horse-drawn vehicle can be put1 which either has not been1 or shortly will be1 invaded by the motor4 ,,railway ,,motor-,,cars ,in the early days of railway construction vehicles were used which combined a steam locomotive with an ordinary passenger carriage4 ,after being abandoned for many years1 the steam carriage was revived1 in #aijb1 by the ,london and ,south ,western and ,great ,western railways for local service and the handling of passenger traffic on branch lines4 ,since that year rail motor-cars have multiplied2 some being run by steam1 others by petrol engines1 and others1 again1 by electricity generated by petrol engines4 ,the first class we need not describe in any detail1 as it presents no features of peculiar interest4 ,the ,north ,eastern has had in use two rail-motors1 each fifty-two feet long1 with a compartment at each end for the driver1 and a central saloon to carry fifty-two passengers4 ,an #hj h4p4 four-cylindered ,wolseley petrol motor drives a ,westinghouse electric generator1 which sends current into a couple of #ee h4p4 electric motors geared to the running-wheels4 ,an air compressor fitted to the rear bogie supplies the ,westinghouse air brakes1 while in addition a powerful electric brake is fitted1 acting on the rails as well as the wheels4 ,the coach scales thirty-five tons4 ,the chief advantage of this composite system of power transmission is that the engine is kept running at a constant speed1 while the power it develops at the electric motors is regulated by switches which control the action of the armature and field magnets4 ,when heavy work must be done the engine is supplied with more gaseous mixture1 and the generators are so operated as to develop full power4 ,in this manner all the variable speed gears and clutches necessary when the petrol motor is connected to the driving-wheels are done away with4 ,the latter system gives1 however1 greater economy of fuel1 and the ,great ,northern ,railway has adopted it in preference to the petrol-electric4 ,this railway has many small branch lines running through thinly populated districts1 which1 though important as feeders of the main tracks1 are often worked at a loss4 ,a satisfactory type of automobile carriage would not only avoid this loss1 but also largely prevent the competition of road motors4 ,the car should be powerful enough to draw an extra van or two on occasion1 since horses and heavy luggage may sometimes accompany the passengers4 ,messrs4 ,dick1 ,kerr1 and ,company have built a car1 which1 when loaded with its complement of passengers1 weighs about sixteen tons4 ,the motive power is supplied by two four-cylinder petrol engines of the ,daimler type1 each giving #cf h4p4 ,these are suspended on a special frame1 independent of that which carries the coach body1 so that the passengers are not troubled by the vibration of the engines1 even when the vehicle is at rest4 ,the great feature of the car is the lightness of the machinery--only two tons in weight--though it develops sufficient power to move the carriage at fifty miles per hour4 ,after travelling #b1jjj miles the machinery showed no appreciable signs of wear2 so that the company considers that it has found a reliable type of motor for the working of the short line between ,hatfield and ,hertford4 ,since one man can drive a petrol car1 while two--a driver and a stoker--are necessary on a steam car1 a considerable reduction in wages will result from the employment of these vehicles4 ,engineers find motor-trolleys very convenient for inspecting the lines under their care4 ,on the ,london and ,south ,western ,railway a trolley driven by a #f-h h4p4 engine1 and provided with a change-gear giving six1 fifteen1 and thirty miles per hour in either direction1 is at work4 ,it seats four persons4 ,in the colonies1 notably in ,south ,africa1 where coal and wood fuel is scarce or expensive1 the motor-trolley1 capable of carrying petrol for #cjj miles' travel1 is rapidly gaining ground among railway inspectors4 ,makers are turning their attention to petrol shunting engines1 useful in goods yards1 mines1 sewerage works4 ,firms such as ,messrs4 ,maudslay and ,company1 of ,coventry2 the ,wolseley ,tool and ,motor ,car ,company2 ,messrs4 ,panhard and ,levassor2 ,messrs4 ,kerr1 ,stuart1 and ,company have brought out locomotives of this kind which will draw loads up to sixty tons4 ,the fact that a petrol engine is ready for work at a moment's notice1 and when idle is not eating its head off1 and has no furnace or boiler to require attention1 is very much in its favour where comparatively light loads have to be hauled4 ,,chapter ,,viii ,,the ,,motor ,,afloat ,,pleasure ,,boats--,,motor ,,lifeboats--,,motor ,,fishing ,,boats--,a ,,motor ,,fire ,,float--,,the ,,mechanism ,,of ,,the ,,motor ,,boat--,,the ,,two-,,stroke ,,motor--,,motor ,,boats ,,for ,,the ,,navy ,having made such conquests on land1 and rendered possible aerial feats which could scarcely have been performed by steam1 the explosion motor further vindicates its versatility by its fine exploits in the water4 ,at the ,paris ,exhibition of #ahhi ,gottlieb ,daimler1 the inventor who made the petrol engine commercially valuable as an aid to locomotion1 showed a small gas-driven boat1 which by most visitors to the ,exhibition was mistaken for an ordinary steam launch1 and attracted little interest4 ,not deterred by this want of appreciation1 ,mr4 ,daimler continued to perfect the idea for which1 with a prophet's eye1 he saw great possibilities2 and soon motor launches became a fairly common sight on ,german rivers4 ,they were received with some enthusiasm in the ,united ,states1 as being particularly suitable for the inland lakes and waterways with which that country is so abundantly blessed2 but met with small recognition from the ,english1 who might reasonably have been expected to take great interest in any new nautical invention4 ,now1 however1 ,english manufacturers have awaked fully to their error2 and on all sides we see boats built by firms competing for the lead in an industry which in a few years' time may reach colossal proportions4 ,illustration3 ,a ,,modern ,,car ,,and ,,boat ,in the background is the racing motor boat ,napier ,,ii41 which on a trial trip travelled over the measured mile at #cjic miles per hour4 ,in the foreground is a ,napier racing car1 which has attained a speed of #ajdh miles per hour4 ,until quite recently the marine motor was a small affair1 developing only a few horse-power4 ,but because the gas-engine for automobile work had been so vastly improved in the last decade1 it attracted notice as a rival to steam for driving launches and pleasure boats1 and soon asserted itself as a reliable mover of vessels of considerable size4 ,to promote the development of the industry1 to test the endurance of the machine1 and to show the weak spots of mechanical design1 trials and races were organised on much the same lines as those which have kept the motor-car so prominently before the public--races in the ,solent1 across the ,channel1 and across the ,mediterranean4 ,the speed1 as in the case of cars1 has risen very rapidly with the motor boat4 ,when1 in ,february1 #aije1 a ,napier racer did some trial spins over the measured mile in the ,thames at ,long ,reach1 she attained #bheg miles per hour on the first run4 ,on turning1 the tide was favourable1 and the figures rose to #cjic m4p4h41 while the third improved on this by over a mile4 ,her mean speed was #biibe m4p4h41 or about #b_/c m4p4h4 better than the previous record--standing to the credit of the ,american ,challenger4 ,the latter had1 however1 the still waters of a lake for her venue1 so that the ,napier's performance was actually even more creditable than the mere figures would seem to imply4 ,at a luncheon which concluded the trial1 ,mr4 ,yarrow1 who had built the steel hull1 said3 ,to give an idea of what an advance the adoption of the internal combustion engine really represents1 ,i should like to state that1 if we were asked to guarantee the best speed we could with a boat of the size of ,napier ,,ii41 fitted with the latest form of steam machinery of as reliable a character as the internal combustion engine in the present boat1 we should not like to name more than sixteen knots4 ,so that it may be taken that the adoption of the internal combustion engine1 in place of the steam-engine1 for a vessel of this size1 really represents an additional speed of ten knots an hour4 ,i should here point out that the speed of a vessel increases rapidly with its size4 ,for example3 in what is termed a second-class torpedo boat1 sixty feet in length1 the best speed we could obtain would be twenty knots2 but for a vessel of1 say1 #bjj feet in length1 with similar but proportionately larger machinery1 a speed of thirty knots could be obtained4 ,therefore1 the obtaining of a speed of practically twenty-six knots in the ,yarrow-,napier boat1 only forty feet in length1 points to the possibility1 in the not far-distant future1 of propelling a vessel #bbj feet in length at even forty-five knots per hour4 ,all that remains to be done is to perfect the internal combustion engine1 so as to enable large sizes to be successfully made4 ,boats of #cjj h4p4 and upwards are being built2 and the project has been mooted of holding a transatlantic race1 open to motor boats of all sizes1 which should be quite self-contained and able to carry sufficient fuel to make the passage without taking in fresh supplies4 ,in view of the perils that would be risked by all but large craft1 and in consideration of the prejudice that motor boats might incur in event of any fatalities1 the ,automobile ,club of ,france set its face against the venture1 and it fell through4 ,it is possible1 however1 that the scheme may be revived as soon as larger motor boats are afloat1 since the ,atlantic has actually been crossed by a craft of #ab h4p41 measuring only forty feet at the water-line4 ,this happened in #aijb1 when ,captain ,newman and his son1 a boy twelve years old1 started from ,new ,york1 and made ,falmouth ,harbour after thirty days of anxious travel over the uncertain and sometimes tempestuous ocean4 ,the boat1 named the ,abiel ,abbot ,low1 carried auxiliary sails of small size1 and was not by any means built for such a voyage4 ,the engine--a two-cylinder--burned kerosene4 ,captain ,newman received #a1jjj from the ,new ,york ,kerosene ,oil ,engine ,company for his feat4 ,the money was well earned4 ,though provided with proper navigating instruments--which he knew how to use well--,newman had a hard time of it to keep his craft afloat1 his watches sometimes lasting two days on end when the weather was bad4 ,yet the brave pair won through2 and probably even more welcome than the sense of success achieved and the reward gained was the long two-days' sleep which they were able to get on reaching ,falmouth ,harbour4 ,,pleasure ,,boats ,we may now consider the pleasure and commercial uses of the motor boat and marine motor4 ,as a means of recreation a small dinghy driven by a low-powered engine offers great possibilities4 ,its cost is low1 its upkeep small1 and its handiness very great4 ,already a number of such craft are furrowing the surface of the ,thames1 ,seine1 ,rhine1 and many other rivers in ,europe and ,america4 ,while racing craft are for the wealthy alone1 many individuals of the class known as the man of moderate means do not mind putting down #gj to #ajj for a neat boat1 the maintenance of which is not nearly so serious a matter as that of a small car4 ,tyre troubles have no counterpart afloat4 ,the marine motor dispenses with change gears4 ,water being a much more yielding medium than ,mother ,earth1 the shocks of starting and stopping are not such as to strain machinery4 ,then again1 the cooling of the cylinders is a simple matter with an unlimited amount of water almost washing the engine4 ,and as the surface of water does not run uphill1 a small motor will show to better advantage on a river than on a road4 ,thus1 a #e h4p4 car will not conveniently carry more than two people if it is expected to climb slopes at more than a crawl4 ,affix a motor of equal power to a boat which accommodates half a dozen persons1 and it will move them all along at a smart pace as compared with the rate of travel given by oars4 ,after all1 on a river one does not want to travel fast--rather to avoid the hard labour which rowing undoubtedly does become with a craft roomy enough to be comfortable for a party4 ,the marine motor also scores under the heading of adaptability4 ,a wagonette could not be converted into a motor-car with any success4 ,but a good-sized row-boat may easily blossom out as a useful self-propelled boat4 ,you may buy complete apparatus--motor1 tanks1 screw1 batteries1 etc4--for clamping direct on to the stern1 and there you are--a motor boat while you wait6 ,even more sudden still is the conversion effected by the ,motogodille1 which may be described as a motor screw and rudder in one4 ,the makers are the ,buchet ,company1 a well-known ,french firm4 ,engine and carburetter1 petrol tank1 coil1 accumulator1 lubricating oil reservoir1 exhaust box1 propeller shaft1 and propeller with guard are all provided1 so that the outfit requires no additional accessories4 ,for mounting in position at the stern of the boat1 the complete set is balanced on a standard1 and carries a steering arm1 on which the tanks are mounted2 and also the stern tube and propeller guard1 which are in one solid piece1 in addition to the engine4 ,in order that no balancing feats shall be required of the person in charge1 there is1 on the supporting standard1 a quadrant1 in the notches of which a lever on the engine frame engages1 thus allowing the rigid framework1 and therefore the propeller shaft1 to be maintained at any angle to the vertical without trouble4#ab ,the #b h4p4 engine drives a boat #af feet long by #d feet #f inches beam at #f-a_/b miles per hour through still water4 ,as the ,motogodille can be swerved to right or left on its standard1 it acts as a very efficient rudder1 while its action takes no way off the boat4 ,for people who like an easy life on hot summer days1 reclining on soft cushions1 and peeping up through the branches which overhang picturesque streams1 there is the motor punt1 which can move in water so shallow that it would strand even a row-boat4 ,the ,oxford undergraduate of to-morrow will explore the leafy recesses of the ,cher1 not with the long pole laboriously raised and pushed aft1 but by the power of a snug little motor throbbing gently at the stern4 ,and on the open river we shall see the steam launch replaced by craft having much better accommodation for passengers1 while free from the dirt and smells which are inseparable from the use of steam-power4 ,the petrol launch will rival the electric in spaciousness1 and the steamer in its speed and power1 size for size4 ,some people have an antipathy to this new form of river locomotion on account of the risks which accompany the presence of petrol4 ,were a motor launch to ignite in1 say1 ,boulter's ,lock on a summer ,sunday1 or at the ,henley ,regatta1 there might indeed be a catastrophe4 ,the same danger has before now been flaunted in the face of the automobilist on land2 yet cases of the accidental ignition of cars are very1 very rare1 and on the water would be more rare still1 because the tanks can be more easily examined for leaks4 ,still1 it behoves every owner of a launch to keep his eye very widely open for leakage1 because any escaping liquid would create a collection of gas in the bottom of the boat1 from which it could not escape like the gas forming from drops spilled on the road4 ,illustration3 ,photo ,branger ,cie1 ,paris4 ,,the ,,motogodille ,the ,motogodille1 or ,motor ,rudder1 consists of a screw propeller fitted to a small ,buchet motor4 ,the whole apparatus is mounted on a standard in the stern1 and the operator1 by moving the inboard arm to right or left1 can steer the boat as he wishes4 ,a #b-;h4p4 motor gives a speed of #e to #f miles an hour4 ,the future popularity of the motor boat is assured4 ,the waterside dweller will find it invaluable as a means of carrying him to other parts of the stream4 ,the longshoreman will be able to venture much further out to sea than he could while he depended on muscles or wind alone1 and with much greater certainty of returning up to time4 ,a whole network of waterways intersects civilised countries--often far better kept than the roads--offering fresh fields for the tourist to conquer4 ,river scenery and beautiful scenery more often than not go together4 ,the car or cycle may be able to follow the course of a stream from source to mouth2 yet this is the exception rather than the rule4 ,we shoot over the stream in the train or on our machines2 note that it looks picturesque2 wonder vaguely whither it flows and whence it comes2 and continue our journey1 recking little of the charming sights to be seen by anyone who would trust himself to the water4 ,hitherto the great difficulty has been one of locomotion4 ,in a narrow stream sailing is generally out of the question2 haulage by man or beast becomes tedious1 even if possible2 and rowing day after day presupposes a good physical condition4 ,in the motor boat the holiday maker has an ideal craft4 ,it occupies little room2 can carry fuel sufficient for long distances2 is unwearying2 and is economical as regards its running expenses4 ,we ought not to be surprised1 therefore1 if in a few years the jaded business man turns as naturally to a spin or trip on the rivers and canals of his country as he now turns to his car and a rush over the dusty highway4 ,then will begin another era for the disused canal1 the vegetation-choked stream2 and our maps will pay more attention to the paths which ,nature has water-worn in the course of the ages4 ,to the scientific explorer also the motor affords valuable help4 ,many countries1 in which roads are practically non-existent1 can boast fine rivers fed by innumerable streams4 ,what fields of adventure1 sport1 and science would be open to the possessor of a fast launch on the ,amazon1 the ,congo1 the ,mackenzie1 or the ,orinoco1 provided only that he could occasionally replenish his fuel tanks6 ,,motor ,,lifeboats ,turning to the more serious side of life1 we find the marine motor still much in evidence4 ,on account of its comparatively short existence it is at present only in the experimental stage in many applications1 and time must pass before its position is fully established4 ,take1 for instance1 the motor lifeboat lately built for the ,royal ,national ,lifeboat ,institution4 ,here are encountered difficulties of a kind very different from those of a racing craft4 ,a lifeboat is most valuable in rough weather1 which means more or less water often coming aboard4 ,if the water reached the machinery1 troubles with the electrical ignition apparatus would result4 ,so the motor must be enclosed in a water-tight compartment4 ,and if so enclosed it must be specially reliable4 ,also1 since a lifeboat sometimes upsets1 the machinery needs to be so disposed as not to interfere with her self-righting qualities4 ,the list might easily be extended4 ,an account of the first motor life-saver will interest readers1 so we once again have recourse to the chief authority on such topics--the ,motor ,boat--for particulars4 ,the boat selected for experiment was an old one formerly stationed at ,folkestone1 measuring thirty-eight feet long by eight feet beam1 pulling twelve oars1 double-banked1 and of the usual self-righting type1 rigged with jib1 fore-lug1 and mizzen4 ,after she had been hauled up in ,mr4 ,guy's yard1 where some of the air-cases under the deck amidships were taken out1 a strong mahogany case1 measuring four feet long by three feet wide and as high as the gunwales1 lined with sheet copper so as to be water-tight1 with a close-fitting lid which could be easily removed on shore1 was fitted in place1 and the whole of the vital parts of the machinery1 comprising a two-cylinder motor of #aj h4p41 together with all the necessary pumps1 carburetter1 electric equipment1 etc41 were fitted inside this case4 ,the engine drives a three-bladed propeller through a long shaft with a disconnecting clutch between1 so that for starting or stopping temporarily the screw can be disconnected from the engine4 ,the petrol1 which serves as fuel for the engine1 is carried in a metal tank stored away inside the forward end box1 where it is beyond any possibility of accidental damage4 ,sufficient fuel for a continuous run of over ten hours is carried4 ,the engine is started by a handle fitted on the fore side of the case1 which can be worked by two men4 ,the position and size of the engine-case is such that only two oars are interfered with1 but it does not follow that the propelling power of the two displaced men is entirely lost1 because they can double bank some of the other oars when necessary4 ,fitted thus1 the lifeboat was tested in all sorts of weather during the month of ,april1 and it was found that she could be driven fairly well against a sea by means of the motor alone2 but when it was used to assist the sails the true use of the motor as an auxiliary became apparent1 and the boat would work to windward in a way previously unattainable4 ,neither the pitching or rolling in a seaway1 in any weather then obtainable1 interfered at all with the proper working or starting of the motor1 which worked steadily and well throughout4 ,having been through these preliminary tests1 she was more severely tried4 ,running over the measured mile with full crew and stores on board1 she developed over six knots an hour4 ,the men were then replaced by equivalent weights lashed to the thwarts1 and she was capsized by a crane four times1 her sails set and the sheets made fast1 yet she righted herself without difficulty4 ,an interesting feature of the capsize was that the motor stopped automatically when the boat had partly turned over4 ,this arrangement prevents her from running away from the crew if they should be pitched out4 ,the motor started again after a few turns of the handle1 so proving that the protecting compartment had kept the water at bay4 ,from this account it is obvious that a valuable aid to life-saving at sea has been found4 ,the steam lifeboat1 propelled by a jet of water squirted out by pumps below the water line1 is satisfactory so long as the boat keeps upright4 ,but in event of an upset the fires must necessarily be extinguished4 ,no such disability attends the petrol-driven craft1 and we shall be glad to think that the brave fellows who risk their lives in the cause of humanity will be spared the intense physical toil which a long row to windward in a heavy sea entails4 ,the general adoption of this new ally will take time1 and must depend largely on the liberality of subscribers to the fine institution responsible for lifeboat maintenance2 but it is satisfactory to learn that the ,committee has given the boat in question a practical chance in the open sea by stationing her at ,newhaven1 ,sussex1 as a unit in the lifeboat fleet4 ,,motor ,,fishing ,,boats ,it is a pretty sight to watch a fishing fleet enter the harbour with its catch1 taken far away on the waters beyond the horizon while landsmen slept4 ,the sails1 some white1 some brown1 some wondrously patched and bearing the visible marks of many a hard fight with the wind1 belly out in graceful lines as the boats slip past the harbour entrance4 ,no wonder that the painter has so often found subjects for his canvas and brushes among the toilers of the deep4 ,but underlying the romance and picturesqueness of the craft there is stern business4 ,those boats may be returning with full cargoes1 such as will yield good profits to owner and crew2 or1 on the other hand1 the hold may be empty1 and many honest hearts be heavy at the thought of wasted days4 ,a few years ago the ,yarmouth herring fleet is said to have returned on one occasion with but a single fish to the credit of the whole fleet6 ,this might have been a mere figure of speech2 it stands1 at any rate1 for many thousands of pounds lost by the hardy fishermen4 ,when the boats have been made fast1 the fish1 if already disentangled from the nets1 is usually sold at once by auction1 the price depending largely on the individual size and freshness of the catch4 ,now1 with the increase in the number of boats and from other causes1 the waters near home have been so well fished over that much longer journeys must be made to the grounds than were formerly necessary4 ,trawling1 that is1 dragging a large bag-net--its mouth kept open by a beam and weights--along the bottom of the sea for flatfish1 has long been performed by powerful steam vessels1 which may any day be seen leaving or entering ,hull or ,grimsby in large numbers4 ,surface fishing1 wherein a long drift-net1 weighted at its lower edge and buoyed at the upper edge to enable it to keep a perpendicular position1 is used for herring and mackerel1 and in this industry wind power alone is generally used by ,british fishermen4 ,the herring-boat sets sail for the grounds in the morning1 and at sundown should be at the scene of action4 ,her nets1 aggregating1 perhaps1 a mile in length1 are then shot1 and the boat drifts along towing the line behind her4 ,if fish appear1 the nets are hauled in soon after daybreak by the aid of a capstan4 ,the labour of bringing a mile of nets aboard is very severe--so severe1 in fact1 that the larger boats in many cases employ the help of a small steam-engine4 ,during the return voyage the fish is freed from the meshes1 and thrown into the hold ready for sale as soon as land is reached4 ,fish1 whether for salting or immediate consumption1 should be fresh4 ,no class of human food seems to deteriorate so quickly when life is extinct as the denizens of the deep1 so that it is of primary importance to fishermen that their homeward journey should be performed in the shortest possible time4 ,if winds are contrary or absent there may be such delay as to need the liberal use of salt1 and even that useful commodity will not stave off a fall in value4 ,it therefore often happens that a really fine catch arrives at its market in a condition which spells heavy loss to the catchers4 ,a slow return also means missing a day's fishing1 which may represent #bjj to #cjj4 ,for this reason the ,dogger ,bank fishing fleet is served by steam tenders1 which carry off the catches as they are made1 and thus obviate the necessity for a boat's return to port when its hold is full4 ,such a system will not1 however1 be profitable to boats owned by individuals1 and working within a comparatively short distance of land4 ,each boat must depend on its particular powers1 the first to return getting rather better prices than those which come with the crowd4 ,so steam power is in some cases installed as an auxiliary to the sails1 though it may entail the outlay of #b1jjj as first cost1 and a big bill for upkeep and management4 ,small men cannot afford this expense1 and they would be doomed to watch their richer brethren slip into the market before them had not the explosion motor come to their aid4 ,this just meets their case2 it is not nearly so expensive to install as steam1 occupies much less room1 is easier to handle1 and therefore saves the expense of trained attendants4 ,fishermen are notoriously conservative4 ,to them a change from methods sanctioned by many years of practice is abhorrent4 ,what sufficed for their fathers1 they say1 should suffice for them4 ,their trade is so uncertain that a bad season would see no return for the cost of the motor1 since1 where no fish are caught1 it makes little difference whether the journey to port be quick or slow4 ,however1 the motor is bound to come4 ,it has been applied to fishing boats with marked success4 ,while the nets are out1 the motor is stopped1 and costs not a penny more till the time comes for hauling in4 ,then it is geared up with a capstan1 and saves the crew much of their hardest work4 ,when all is aboard1 the capstan hands over the power to the screw1 which1 together with the sails1 propels the vessel homewards at a smart pace4 ,the skipper is certain of making land in good time for the market2 and he will be ready for the out voyage next morning4 ,another point in favour of the motor is that1 when storms blow up1 the fleet will be able to run for shelter even if the wind be adverse2 and we should hear less of the sacrifice of life which makes sad reading after every severe gale4 ,as to the machinery to be employed1 ,mr4 ,f4 ,miller1 of ,oulton ,broad1 who first applied the gas-motor to a fishing smack--the ,pioneer--considers that a #ab h4p4 engine would suffice as an auxiliary for small craft of the class found in the northern parts of ,great ,britain4 ,the ,norfolk boats would require a #cj h4p42 and a full-powered boat--i4e4 one that could depend on the motor entirely--should carry a three-cylinder engine of #hj h4p4 ,in any case1 the machinery must be enclosed and well protected2 while the lubrication arrangements should be such as to be understood easily by unskilled persons1 and absolutely reliable4 ,owing to the moisture in the atmosphere the ordinary high-tension coil ignition1 such as is used on most motor-cars1 would not prove efficient1 and it is therefore replaced by a low-tension type which makes and breaks the primary circuit by means of a rocking arm working through the walls of the cylinder4 ,lastly1 all parts which require occasional examination or adjustment must be easily accessible1 so that they may receive proper attention at sea1 and not send the vessel home a lame duck under sail4 ,the advantages of the motor are so great that the ,scotch authorities have taken the matter up seriously1 appointing an expert to make inquiries4 ,it is therefore quite possible that before many years have elapsed the motor will play an important part in the task of supplying our breakfast tables with the dainty sole or toothsome herring4 ,a ,,motor ,,fire ,,float ,as a good instance of this particular adaptation of the explosion engine to fire-extinction work1 we may quote the apparatus now in attendance on the huge factory of ,messrs4 ,huntley and ,palmer1 the famous ,reading biscuit makers4 ,the factory lies along the banks of the river ,kennet1 which are joined by bridges so close to the water that a steamer could not pass under them4 ,messrs4 ,merryweather accordingly built the motor float1 #cb feet long1 #i-a_/b feet beam1 and drawing #bg inches4 ,two engines1 each having four cylinders of a total of #cj h4p41 drive two sets of three-cylinder ,hatfield pumps1 which give a continuous feed to the hose4 ,engines and pumps are mounted on a single bed-plate1 and are worked separately1 unless it be found advisable to ,siamese the hoses to feed a single #a-a_/b-;inch jet1 which can be flung to a great height4 ,one of the most interesting features of the float is the method of propulsion4 ,as its movements are limited to a few hundred yards1 the fitting of a screw was considered unnecessary1 its place being taken by four jets1 two at each end1 through which water is forced against the outside water by the extinguishing pumps4 ,these will move the float either forward or astern1 steer her1 or turn her round4 ,so here once again petrol has trodden upon the toes of ,giant ,steam3 and very effectively1 too4 ,,the ,,mechanism ,,of ,,the ,,motor ,,boat ,in many points the marine motor reproduces the machinery built into cars4 ,the valve arrangements1 governors1 design of cylinders and water-jackets are practically the same4 ,small boats carry one cylinder or perhaps two1 just as a small car is content with the same number2 but a racing or heavy boat employs four1 six1 and1 in one case at least1 twelve cylinders1 which abolish all dead points and enable the screw to work very slowly without engine vibration1 as the drive is continuous4 ,the large marine motor is designed to run at a slower rate than the land motor1 and its cylinders are1 therefore1 of greater size4 ,some of the cylinders exhibited in the ,automobile ,show at the ,london ,olympia seemed enormous when compared with those doing duty on even high-powered cars2 being more suggestive of the parts of an electric lighting plant than of a machine which has to be tucked away in a boat4 ,except for the reversing gear1 gearing is generally absent on the motor boat4 ,the chauffeur has not to keep changing his speed lever from one notch to another according to the nature of the country4 ,on the sea conditions are more consistently favourable or unfavourable1 and1 as in a steamboat1 speed is controlled by opening or closing the throttle4 ,the screw will always be turned by the machinery1 but its effect on the boat must depend on its size and the forces acting in opposition to it4 ,since water is yielding1 it does not offer a parallel to the road4 ,should a car meet a hill too steep for its climbing powers1 the engines must come to rest4 ,the wheel does not slip on the road1 and so long as there is sufficient power it will force the car up the severest incline2 as soon as the power proves too small for the task in hand the car lies down4 ,in a motor boat1 however1 the engine may keep the screw moving without doing more against wind and tide than prevent the boat from advancing backwards4 ,the only way to make the boat efficient to meet all possible conditions would be to increase the size or alter the pitch of the screw1 and to install more powerful engines4 ,gearing down--as in a motor-car--being useless1 the only mechanism needed on a motor boat in connection with the transmission of power from cylinders to screw is the reversing gear4 ,though engines have been designed with devices for reversing by means of the cams operating the valves1 the reversal of the screw's movement is generally effected through gears on the transmission apparatus4 ,the simplest arrangement1 though not the most perfect mechanically1 is a reversible screw1 the blades of which can be made to feather this way or that by the movement of a lever4 ,sometimes two screws are employed1 with opposite twists1 the one doing duty while the other revolves idly4 ,but for fast and heavy boats a single solid screw with immovable blades is undoubtedly preferable2 its reversal being effected by means of friction clutches4 ,the inelasticity of the explosion motor renders it necessary that the change be made gradually1 or the kick of the screw against the motor might cause breakages4 ,the clutch1 gradually engaging with a disc revolved by the propeller shaft1 first stops the antagonistic motion1 and then converts it into similar motion4 ,many devices have been invented to bring this about1 but as a description of them would not be interesting1 we pass on to a consideration of the fuel used in the motor boat4 ,petrol has the upper hand at present1 yet heavier oil must eventually prevail1 on account both of its cheapness and of its greater safety4 ,the only objection to its use is the difficulty attending the starting of the engine with kerosene2 and this is met by using petrol till the engine and carburetter are hot1 and then switching on the petroleum4 ,when once the carburetter has been warmed by exhaust gases to about #bgj ,fahrenheit it will work as well with the heavy as with the light fuel4 ,since any oil or spirit may leak from its tanks and cause danger1 an effort has been made to substitute solid for liquid fuel4 ,the substance selected is naphthalene--well known as a protector of clothes against moths4 ,at the ,olympia ,automobile ,exhibition of #aije the writer saw an engine--the ,chenier ,leon--which had been run with balls of this chemical1 fed to the carburetter through a melting-pot4 ,for a description of this engine we must once again have recourse to the ,motor ,boat4 ,the inventors had decided to test its performance with petrol1 paraffin1 and naphthalene respectively4 ,the motor1 screwed to a testing bench1 was connected by the usual belt to a dynamo1 so that the power developed under each variety of fuel might be electrically measured1 and was then started up on petrol4 ,as soon as the parts were sufficiently warmed up by the exhaust heat1 the petrol was turned off1 and the motor run for some time on paraffin1 until sufficient naphthalene was thoroughly melted to the consistency of a thick syrup4 ,the naphthalene was then fed to its mixing valve through a small pipe dipping into the bottom of the melting-pot1 and thence sprayed into the induction chamber to carburate the air therein4 ,hitherto1 the motor had given an average of #ab electrical h4p4 at #a1jjj revolutions per minute1 and it was noticed that as soon as the change was made1 this was fully maintained4 ,this test1 when continued1 bore out others which had previously been made by the firm1 and showed the consumption of each of the three fuels to be a little over #ab lbs4 per hour for the #ab electrical h4p4 given by the motor4 ,still1 the paraffin and naphthalene worked out about equal as to cost1 and considering that the latter was in its purest form1 as sold for a clothes preservative1 we have yet to see how much better its commercial showing will be with lower grades1 assuming beforehand that its thermal efficiency and behaviour are as good4 ,on the ground of convenience naphthalene1 as a solid1 is a very long way in front of its liquid rival1 kerosene4 ,its exhaust1 too1 was much freer from odour1 and it appears that1 unlike paraffin1 it forms neither tar1 soot1 nor sticky matter1 but1 on the contrary1 has a tendency to brighten all valves1 cylinders1 walls1 etc41 any little deposit being a light powder which would be carried into the exhaust4 ,,the ,,two-,,stroke ,,motor ,in the ordinary ,otto-cycle motor an explosion occurs once in every two revolutions of the crank4 ,with a single cylinder the energy of the explosion must be stored up in a heavy fly-wheel to carry the engine through the three other operations of scavenging1 sucking in a fresh charge1 and compressing it preparatory to the next explosion4 ,with two cylinders the fly-wheel can be made lighter1 as an explosion occurs every revolution2 and in a four-cylinder engine we might almost dispense with the wheel altogether1 since the drive is continuous1 just as in a double-cylindered steam-engine4 ,the two-stroke motor1 i4e4 one which makes an explosion for every revolution1 is an attempt to unite the advantages of a two-cylindered engine of the ,otto type with the lightness of a single-cylindered engine4 ,as it has been largely used for motor boats1 especially in ,america1 a short description of its working may be given here4 ,in the first place1 all moving cylinder valves are done away with1 their functions being performed by openings covered and opened by the movements of the piston4 ,the crank chamber is quite gas-tight1 and has in it a non-return valve through which vapour is drawn from the carburetter every time the piston moves away from the centre4 ,there is also a pipe connecting it with the lower part of the cylinder1 but the other end of this is covered by the piston until it has all but finished its stroke4 ,let us suppose that an explosion has just taken place4 ,the piston rushes downwards1 compressing the gas in the crank chamber to some extent4 ,when the stroke is three-parts performed a second hole1 on the opposite side of the cylinder from the aperture already referred to1 is uncovered by the piston1 and the exploded gases partly escape4 ,immediately afterwards the second hole is uncovered also1 and the fresh charge rushes in from the crank case1 being deflected upwards by a plate on the top of the piston1 so as to help drive out the exhaust products4 ,the returning piston covers both holes and compresses the charge till the moment of explosion1 when the process is repeated4 ,it may be said in favour of this type of engine that it is very simple and free from vibration2 against it that1 owing to the imperfect scavenging of exploded charges1 it does not develop so much power as an ,otto-cycle engine of equal cylinder dimensions2 also that it is apt to overheat1 while it uses double the amount of electric current4 ,,motor ,,boats ,,for ,,the ,,navy ,a country which1 like ,england1 depends on the command of the sea for its very existence may well keep a sharp eye on any invention that tends to render that command more certain4 ,in recent years we have heard a lot said1 and read a lot written1 about the importance of swift boats which in war time could be launched against a hostile fleet1 armed with the deadly torpedo4 ,the ,russo-,japanese ,war has given us a fine example of what can be accomplished by daring men and swift torpedo craft4 ,for some reason or other the ,british ,navy has not kept abreast of ,france in the number of her torpedo vessels4 ,reference to official figures shows that1 while our neighbours can boast #bhj hornets1 we have to our credit only #bbe4 ,in the ,house of ,commons1 on ,august #ajth1 #aijd1 ,mr4 ,henry ,norman1 ,m4,p41 asked the ,secretary of the ,admiralty whether1 in view of the proofs recently afforded of trustworthiness1 speed1 simplicity1 and comparatively low cost of small vessels propelled by petrol motors1 he would consider the advisability of testing this class of vessel in ,his ,majesty's ,navy4 ,the ,secretary replied that the ,admiralty had kept a watch on the recent trials and meant to make practical tests with motor pinnaces4 ,in view of the danger that would accompany the storage of petrol on board ship1 the paraffin motor was preferable for naval purposes2 and an #hj h4p4 four-cylindered motor of this type has been ordered from ,messrs4 ,vosper1 of ,portsmouth4 ,mr4 ,norman1 writing in ,the ,world's ,work on the subject1 says3 ,there can be no question that such high speed and cheap construction 7#hj h4p4 giving in the little boat as much speed--to consider that only--as eight thousand in the big boat7 point to the use of motor boats for naval purposes in the near future4 ,a torpedo boat exists only to carry one or two torpedoes within launching distance of the enemy4 ,the smaller and cheaper she can be1 and the fewer men she carries1 provided always she be able to face a fairly rough sea1 the better4 ,now the ordinary steam torpedo boat carries perhaps twenty men1 and costs anything from #ej1jjj to #ajj1jjj4 ,a motor boat of equal or greater speed could probably be built for #ae1jjj1 and would carry a crew of two men4 ,six motor boats1 therefore1 could be built for the cost of one steamboat1 and their total crews would not number so many as the crew of the one4 ,moreover1 they could all be slung on board a single vessel1 and only set afloat near the scene of action4 ,a prophetic friend of mine declares that the most dangerous warship of the future will be a big vessel1 unarmoured and only lightly armed1 but of the utmost possible speed1 carrying twenty or more motor torpedo boats slung on davits4 ,she will rely on her greater speed for her own safety1 if attacked2 she will approach as near the scene of action as possible1 and will drop all her little boats into the water1 and they will make a simultaneous attack4 ,their hulls would be clean1 their machinery in perfect order1 their crews fresh and full of energy1 and it would be strange if one of the twenty did not strike home4 ,and the destruction of a battleship or great cruiser at the cost of a score of these little wasps1 manned by two-score men1 would be a very fine naval bargain4 ,mr4 ,norman omits one recommendation that must in active service count heavily in favour of the motor boat1 and that is its practical invisibility in the day or at night time4 ,the destroyer1 when travelling at high speed1 betrays its presence by clouds of smoke or red-hot funnels4 ,the motor boat is entirely free from such dangerous accompaniments2 the exhaust from the cylinders is invisible in every way4 ,the very absence of funnels must also be in itself a great advantage4 ,the eye1 roving over the waters1 might easily pick up a series of stumpy1 black objects of hard outline2 but the motor boat1 riding low and flatly on the waves1 would probably escape notice1 especially when a search-light alone can detect its approach4 ,it may reasonably be said that the ,admiralty knows its own business best1 and that the outsider's opinion is not wanted4 ,the man in the street has become notorious for his paper generalship and strategy1 and fallen somewhat into disrepute as an adviser on military and naval matters4 ,yet we must not forget this3 that many--we might say most--of the advances in naval mechanisms1 armour1 and weapons of defence have not been evolved by naval men1 but by the highly educated and ingenious civilian who1 unblinded by precedent or professional conservatism1 can watch the game even better in some respects than the players themselves1 and see what the next move should be4 ,that move may be rather unorthodox--like the application of steam to men-o'-war--but none the less the correct one under the circumstances4 ,we allowed other nations to lead us in the matter of breech-loading cannon1 armour-plate1 submarines1 the abolition of combustible material on warships4 ,shall we also allow them to get ahead with motor boats1 and begin to consider that there may be something in motor auxiliaries for the fleet when they are already well supplied8 ,if there is a country which should above all others lose no time in adding the motor to her means of defence1 that country is ,great ,britain4 ,,footnote3 #ab ,the ,motor ,boat1 ,march #afth1 #aije4 ,,chapter ,,ix ,,the ,,motor ,,cycle ,in #ahhd the ,count de ,dion1 working in partnership with ,messrs4 ,bouton and ,trpardoux1 produced a practical steam tricycle4 ,two years later appeared a somewhat similar vehicle by the same makers which attained the remarkable speed of forty miles an hour4 ,mr4 ,serpollet1 now famous for his steam cars1 built at about the same time a three-wheeled steam tricycle1 which also proved successful4 ,but the continuous stoking of the miniature boilers1 and the difficulty of keeping them properly supplied with water1 prevented the steam-driven cycle from becoming popular2 and when the petrol motor had proved its value on heavy vehicles1 inventors soon saw that the explosion engine was very much better suited for a light automobile than had been the cumbrous fittings inseparable from the employment of steam4 ,by #ahie a neat petrol tricycle was on the market2 and after the de ,dion machines had given proof in races of their capabilities1 they at once sprang into popular favour4 ,for the next five years the motor tricycle was a common sight in ,france1 where the excellent roads and the freedom from the restrictions prevailing on the other side of the ,channel recommended it to cyclists who wished for a more speedy method of locomotion than unaided legs could give1 yet could not afford to purchase a car4 ,the motor bicycle soon appeared in the field4 ,the earlier types of the two-wheeled motor were naturally clumsy and inefficient4 ,the need of a lamp constantly burning to ignite the charges in the cylinder proved a much greater nuisance on the bicycle than on the tricycle1 which carried its driving gear behind the saddle4 ,the writer well remembers trying an early pattern of the ,werner motor bicycle in the ,champs ,elyses in #ahig1 and his alarm when the owner1 while starting the blowlamp on the steering pillar1 was suddenly enveloped in flames1 which played havoc with his hair1 and might easily have caused more serious injuries4 ,riders were naturally nervous at carrying a flame near the handle-bars1 so close to a tank of inflammable petrol liable to leak and catch fire4 ,the advent of electrical ignition for the gaseous charges opened the way for great improvements1 and the motor bicycle slowly but surely ousted its heavier three-wheeled rival4 ,designs were altered2 the engine was placed in or below the frame instead of over the front wheel1 and made to drive the back wheel by means of a leather belt4 ,in the earliest types the motive force had either been transmitted by belt to the front wheel1 or directly to the rear wheel by the piston rods working cranks on its spindle4 ,the progress of the motor bicycle has1 since #aijj1 been rapid1 and many thousands of machines are now in use4 ,the fact that the engines must necessarily be very small compels all possible saving in weight1 and an ability to run continuously at very high speeds without showing serious wear and tear4 ,details have therefore been perfected1 and though at the present day no motor cyclist of wide experience can claim immunity from trouble with his speedy little mount1 a really well-designed and well-built machine proves wonderfully efficient1 and opens possibilities of locomotion to the man of moderate means which were beyond the reach of the rider of a pedal-driven bicycle4 ,in its way the motor cycle may claim to be one of the most marvellous products of human mechanical skill4 ,weight has been reduced until a power equal to that of three horses can be harnessed to a vehicle which1 when stored with sufficient petrol and electricity to carry it and rider #aej miles1 scales about a hundredweight4 ,it will pursue its even course up and down hill at an average of twenty or more miles an hour1 the only attention it requires being an occasional charge of oil squirted into the air-tight case in which the crank and fly-wheels revolve4 ,the consumption of fuel is ridiculously small1 since an economical engine will cover fifteen miles on a pint of spirit1 which costs about three-halfpence4 ,practically all motor-cycle engines work on the ,otto-cycle principle4 ,motors which give an impulse every revolution by compressing the charge in the crank-case or in a separate cylinder1 so that it may enter the working cylinder under pressure1 have been tried1 but hitherto with but moderate success4 ,there is1 however1 a growing tendency to compass an explosion every revolution by fitting two cylinders1 and from time to time four-cylindered cycles have appeared4 ,the disadvantages attending the care and adjustment of so many moving parts has been the cause of four-cylindered cycle motors being unsuccessful from a commercial standpoint1 though riders who are prepared to risk extra trouble and expense may find compensation in the quiet1 vibrationless drive of a motor which gives two impulses for every turn of the fly-wheel4 ,the acme of lightness in proportion to power developed has been attained by the ,barry engine1 in which the cylinders and their attachments are made to revolve about a fixed crank1 and perform themselves the function of a fly-wheel4 ,so great is the saving of weight that the makers claim a horse-power for every four pounds scaled by the engines2 thus1 a #c-a_/b h4p4 motor would only just tip the beam against one stone4 ,as the writer has personally inspected a ,barry engine1 he is able to give a brief account of its action4 ,it has two cylinders1 arranged to face one another on opposite sides of a central air-tight crank-case1 the inner end of each cylinder opening into the case4 ,both pistons advance towards1 and recede from1 the centre of the case simultaneously4 ,the air-and-gas mixture is admitted into the crank-case through a hole in the fixed crank-spindle1 communicating with a pipe leading from the carburetter4 ,the inlet is controlled by a valve1 which opens while the pistons are parting1 and closes when they approach one another4 ,we will suppose that the engine is just starting4 ,the pistons are in a position nearest to the crank-case4 ,as they separate they draw a charge--equal in volume to double the cubical contents of one cylinder--into the crank-case through its inlet valve4 ,during the return stroke the charge is squeezed1 and passes through a valve into a chamber which forms1 as it were1 the fourth spoke of a four-spoked wheel1 of which the other three spokes are the cylinders and the silencer4 ,this chamber is connected by pipes to the inlet valves of the cylinders1 which are mechanically opened alternately by the action of special cams on the crank-shaft4 ,the cylinder which gets the contents of the compression chamber receives considerably more mixture than would flow in under natural suction1 and the compression is therefore greater than in the ordinary type of cycle motor1 and the explosion more violent4 ,hence it comes about that the cylinders1 which have a bore of only #b in4 and a #b-;in4 stroke for the piston1 develop nearly #b h4p4 each4 ,it may at first appear rather mysterious how1 if the cranks are rigidly attached to the cycle frame1 any motion can be imparted to the driving-wheel4 ,the explanation is simple enough3 a belt pulley is affixed to one side of the crank-case1 and revolves with the cylinders1 the silencer1 and compression chamber4 ,the rotation is caused by the effort of the piston to get as far as possible away from the closed end of the cylinder after an explosion4 ,where a crank is movable but the cylinder fixed1 the former would be turned round2 where the crank is immovable but the cylinder movable1 the travel of the piston is possible only if the cylinder moves round the crank4 ,a series of explosions following one another in rapid succession gives the moving parts of the ,barry engine sufficient momentum to suck in charges1 compress them1 and eject the burnt gases4 ,the plan is ingenious1 and as the machine into which this type of engine is built weighs altogether only about #gj lbs41 the sport of motor cycling is open to those people whose age or want of strength would preclude them from the use of the heavy mounts which are still to be seen about the roads4 ,in the future we may expect to find motor cycles approach very closely to a half-hundredweight standard without sacrificing the rigidity needful for fast locomotion over second-class roads4 ,for pace-making on racing tracks1 motor cycles ranging up to #bd h4p4 have been used2 but these are essentially freak machines of no practical value for ordinary purposes4 ,even #c-d h4p4 cycles have set up wonderful records1 exceeding fifty miles in the hour1 a speed equal to that of a good express train4 ,in comparison with the feats of motor-cars1 their achievements may not appear very startling2 but when we consider the small size and weight1 and the simplicity of the mechanisms which propel cycle and rider at nearly a mile a minute1 the result seems marvellous enough4 ,during the last few years the tricycle has again come into favour1 but with the arrangement of its wheels altered2 two steering-wheels being placed in front1 and a single driving-wheel behind4 ,the main advantage of this inversion is that it permits the fixing of a seat in front of the driver1 in which a passenger can be comfortably accommodated4 ,the modern tricar1 with its high-powered1 doubled-cylindered engines1 its change-speed gears1 its friction clutch for bringing the engines gradually into action1 its forced water circulation for cooling the cylinders1 and its spring-hung frame1 is in reality more a car than a cycle1 and escapes from the former category only on account of the number of its wheels4 ,to the tourist1 or to the person who does not find pleasure in solitary riding1 the tricar offers many advantages1 and1 though decidedly more expensive to keep up than a motor bicycle1 entails only very modest bills in comparison with those which affect many owners of cars4 ,the development of the motor cycle has been hastened and fostered by frequent speed and reliability contests1 in which the nimble little motor has acquitted itself wonderfully4 ,a hill a mile long1 with very steep gradients1 has been ascended in considerably less than two minutes by a #c-a_/d h4p4 motor4 ,we read of motor cycles travelling from ,land's ,end to ,john-o'-,groats2 from ,calcutta to ,bombay2 from ,sydney to ,melbourne2 from ,paris to ,rome--all in phenomenal times considering the physical difficulties of the various routes4 ,such tests prove the endurance of the motor cycle1 and pave the way to its use in more profitable employments4 ,volunteer cycling corps often include a motor or two1 which in active service would be most valuable for scouting purposes1 especially if powerful enough to tow a light machine-gun4 ,commercial travellers1 fitting a box to the front of a tricar1 are able to scour the country quickly and inexpensively in quest of orders for the firms they represent4 ,the police find the motor helpful for patrolling the roads4 ,on the ,continent1 and especially in ,germany1 town and country postmen collect and deliver parcels and letters with the aid of the petrol-driven tricycle1 and thereby save much time1 while improving the service4 ,before long1 ,hark 'tis the twanging horn will once again herald the postman's approach in a thousand rural districts1 but the horn will not hang from the belt of a horseman1 such as the poet ,cowper describes1 but will be secured to the handle-bars of a neat tricar4 ,thus history repeats itself4 ,illustration3 ,photo ,cribb1 ,southsea4 ,a ,,motor ,,lawn-,,mower ,a machine of this kind will cut several acres a day1 and also acts as an efficient roller4 ,the operator is able to empty the contents of the catch-box without leaving his seat4 ,that the motor cycle is still far from perfect almost goes without saying2 but every year sees a decided advance in its design and efficiency4 ,the messy1 troublesome accumulator will eventually give way to a neat little dynamo1 which is driven by the engine and creates current for exploding the cylinder charges as the machine travels4 ,when the cycle is at rest there would then be no fear of electricity leaking away through some secret short circuit1 since the current ceases with the need for it1 but starts again when its presence is required4 ,the proper cooling of the cylinders has been made an easier matter than formerly by the introduction of fans which direct a stream of cold air on to the cylinder head4 ,professor ,h4 ,l4 ,callendar has shown in a series of experiments that a fan1 which absorbs only #b to #c per cent4 of an engine's power1 will increase the engine's efficiency immensely when a low gear is being used for hill climbing1 and the rate of motion through the air has fallen below that requisite to carry off the surplus heat of the motor4 ,if an engine maintains a good working temperature when it progresses through space two feet for every explosion1 it would overheat if the amount of progression were1 through the medium of a change-gear attachment1 reduced to one foot1 a change which would be advisable on a steep hill4 ,the fan then supplies the deficiency by imitating the natural rush of air4 ,as ,professor ,callendar says3 ,the most important point for the motor cyclist is to secure the maximum of power with the minimum of weight4 ,with this object1 the first essentials are a variable speed gear of wide range1 and some efficient method of cooling to prevent overheating at low gears4444 ,it is unscientific to double the weight and power of the machine in order to climb a few hills1 when the same result can be secured with a variable gear4 ,it is unnecessary to resort to the weight and complication of water cooling when a light fan will do all that is required4 ,thus1 with the aid of a fan and a gear which will give at least two speeds1 the motor cyclist can1 with an engine of #b h4p41 climb almost any hill1 even without resorting to the help of the pedals4 ,his motion is therefore practically continuous4 ,to be comfortable1 he desires immunity from the vibration which quick movement over any but first-class roads sets up in the machine1 especially in its forward parts4 ,several successful spring forks and pneumatic devices have been invented to combat the vibration bogy2 and these1 in conjunction with a spring pillar for the saddle1 which can itself be made most resilient1 relieve the rider almost entirely of the jolting which at the end of a long day's ride is apt to induce a feeling of exhaustion4 ,the motor tricycle1 which once had a rather bad name for its rough treatment of the nerves1 is also now furnished with springs to all wheels1 and approximates to the car in the smoothness of its progression4 ,assuming1 then1 that we have motor vehicles so light as to be very manageable1 sufficiently powerful to climb severe gradients1 reliable1 comfortable to ride1 and economical in their consumption of fuel and oil1 we are able to foresee that they will modify the conditions of social existence4 ,the ordinary pedal-driven cycle has made it possible for the worker to live much further from his work than formerly4 ,to-morrow1 with a motor bicycle1 his home may be fifteen miles away1 and those extra miles will make a great difference in rent1 and in the health of his family4 ,in fact1 it almost promises to reconcile the ,garden ,city ideal with the industrial conditions of to-day1 by enabling a man to work in the town1 and have his home in the country4 ,this advantage applies1 of course1 less to ,london than to other great cities1 on account of the seemingly endless miles of streets to be traversed before the country is reached4 ,in most manufacturing centres1 however1 the motoring workman could get to his cottage home by a journey of a few miles4 ,even in ,london1 moreover1 this disadvantage will be overcome to a large extent in the future1 for it is as certain as anything of the kind can be that we must ultimately have special highways1 smooth1 dustless1 reserved for motor traffic1 leading out of ,london in the principal directions4444 ,my own conviction is that motor cycling1 the simplest1 the quickest1 the cheapest independent locomotion that has ever been known1 is destined to enjoy enormous development4 ,i believe that within a few years the motor bicycle and tricycle will be sold by hundreds of thousands1 and that many of the social and industrial conditions of our time will be greatly and beneficially affected by them4#ac ,,footnote3 #ac ,henry ,norman1 ,esq41 ,m4,p41 in ,the ,world's ,work4 ,,chapter ,x ,,fire ,,engines ,a good motto to blazon over the doors of a fire-brigade station would be ,he gives help twice who gives help quickly4 ,the spirit of it is certainly shown by the brave men who1 as soon as the warning signal comes1 spring to the engines and in a few minutes are careering at full speed to the scene of operations4 ,speed and smartness have for many years past been associated with our fire brigades4 ,we read how horses are always kept ready to be led to the engines2 how their harness is dropped on to them and deft fingers set the buckles right in a twinkling1 so that almost before an onlooker has time to realise what is happening the sturdy animals are beating the ground with flying hoofs4 ,and few dwellers in large cities have not heard the cry of the firemen1 as it rises from an indistinct murmur into a loud shout1 before which the traffic1 however dense1 melts away to the side of the road and leaves a clear passage for the engines1 driven at high speed and yet with such skill that accidents are of rare occurrence4 ,the noise1 the gleam of the polished helmets1 the efforts of the noble animals1 which seem as keen as the men themselves to reach the fire1 combine to paint a scene which lingers long in the memory4 ,but efficient as the horsed engine is1 it has its limitations4 ,animal strength and endurance are not an indefinite quantity2 while the fireman grudges even the few short moments which are occupied by the inspanning of the team4 ,in many towns1 therefore1 we find the mechanically propelled fire engine coming into favour4 ,the power for working the pumps is now given a second duty of turning the driving-wheels4 ,a parallel can be found in the steam-engine used for threshing-machines1 which once had to be towed by horses1 but now travels of itself1 dragging machine and other vehicles behind it4 ,the earlier types of automobile fire engines used the boiler's steam to move them over the road4 ,liverpool1 a very enterprising city as regards the extinction of fire1 has for some time past owned a powerful steamer1 which can be turned out within a minute of the call1 can travel at any speed up to thirty miles an hour1 and can pump #ejj gallons per minute continuously4 ,its success has led to the purchase of other motor engines1 some fitted with a chemical apparatus1 which1 by the action of acid on a solution of soda in closed cylinders1 is enabled to fling water impregnated with carbonic acid gas on to the fire the moment it arrives within working distance of the conflagration1 and gives very valuable first aid while the pumping apparatus is being got into order4 ,illustration3 ,two ,motor ,fire-engines built by ,messrs4 ,merryweather1 ,london4 ,that on the left is driven by petrol1 and in addition to pumping-gear carries a wheeled fire-escape4 ,that on the right is driven by steam4 ,both types are much faster than horses1 being able to travel at a rate of over #bj miles an hour4 ,as might reasonably be expected1 the petrol motor has found a fine field for its energies in connection with fire extinction4 ,since it occupies comparatively little space1 more accommodation can be allowed for the firemen and gear4 ,furthermore1 a petrol engine can be started in a few seconds by a turn of a handle1 whereas a steamer is delayed until steam has been generated4 ,messrs4 ,merryweather have built a four-cylindered1 #cj h4p4 petrol fire engine capable of a speed of forty miles an hour4 ,it has two systems of ignition--the magneto 7or small dynamo7 and the ordinary accumulator and coil--so that electrical breakdowns are not likely to occur4 ,a fast motor of this kind1 with a pumping capacity of #cjj gallons per minute1 is peculiarly suited for large country estates1 where it can be made to perform household or farm duties when not required for its primary purpose4 ,considering the great number of country mansions1 historically interesting1 and full of artistic treasures1 which ,england boasts1 it is a matter for regret that such an engine is not always included among the appliances with which every such property is furnished4 ,how often we read ,old mansion totally destroyed by fire1 which usually means that in a few short hours priceless pictures1 furniture1 and other objects of art have been destroyed1 because help1 when it did come1 arrived too late4 ,owners are1 however1 more keenly alive to their responsibilities now than formerly4 ,the small hand-worked engine1 or the hydrant of moderate pressure1 is not considered a sufficient guard for the house and its contents4 ,in many establishments the electric lighting engines are designed to work either the dynamo or a set of pumps as occasion may demand2 or the motor is mounted on wheels so that it may be easily dragged by hand to any desired spot4 ,the latest thing in motor fire engines is one which carries a fire-escape with it1 in addition to water-flinging machinery4 ,an engine of this type is to be found in some of the ,london suburbs4 ,a chemical cylinder lies under the driver's seat1 where it is well out of the way1 and coiled beside it is its reel of hose4 ,the escape rests on the top of the vehicle1 the wheels hanging over the rear end1 while the top projects some distance in front of the steering wheels4 ,the ladder1 of telescopic design1 can be extended to fifty feet as soon as it has been lowered to the ground4 ,since the saving of life is even more important than the saving of property1 it is very desirable that a means of escape should be at hand at the earliest possible moment after an outbreak4 ,this combination apparatus enables the brigade to nip a fire in the bud1 if it is still a comparatively small affair1 and also to rescue any people whose exit may have been cut off by the fire having started on or near the staircases4 ,the ,wolseley ,motor-,car ,company has established a type of chemical motor fire engine which promises to be very successful4 ,a #bj h4p4 motor is placed forward under the frame to keep the centre of gravity low4 ,when fully laden1 it carries a crew of eight men1 two #i-;foot ladders1 two portable chemical extinguishers1 a #ej-;gallon chemical cylinder1 and a reel on which is wound a hose fifty-three yards long4 ,the wheels are a combination of the wooden artillery and the wire spider1 wires being strung from the outer end of the hub to the outer ends of the wooden spokes to give them increased power to resist the strain of sudden turns or collisions4 ,an artillery wheel1 not thus reinforced1 is apt to buckle sideways and snap its spokes when twisted at all4 ,england has always led the way in matters relating to fire extinction1 and to her is due the credit of first harnessing mechanical motive power to the fire engine4 ,other countries are following her example1 and consequently we find fire apparatus moved by the petrol motor in places so far apart as ,cape ,town1 ,valparaiso1 ,mauritius1 ,sydney1 ,berlin1 ,new ,york1 ,montreal4 ,there can be no doubt but that in a very few years horse-traction will be abandoned by the brigades of our large towns4 ,it has been suggested that the fire-pump of the future will be driven by electricity drawn from switches on the street mains2 enough current being stored in accumulators to move the pump from station to fire4 ,in such a case it would be possible to use very powerful pumps1 as an electric motor is extremely vigorous for its size and weight4 ,even to-day steam fire engines can fling #b1jjj gallons per minute1 and fire floats 7for use on the water7 considerably more4 ,possibly the engine of to-morrow will pour #e1jjj gallons a minute on the flames if it can get that amount from the water mains1 and so render it unnecessary to summon in a large number of engines to quell a big conflagration4 ,three hundred thousand gallons an hour ought to check a very considerable blaze4 ,the force with which a jet of water leaves the huge nozzle of a powerful engine is so great that it would seriously injure a spectator at a distance of fifty yards4 ,the kick-back of the water on the nozzle is sometimes sufficient to overcome the power of one man to hold the nozzle in position with his hands1 and it becomes needful to provide supports with pointed ends to stick into the ground1 or hooks which can be attached to the rungs of a ladder4 ,for an attack on the upper storeys of a house a special water tower is much used in ,america4 ,it consists of a lattice-work iron frame1 about twenty-five feet long1 inside which slides an extensible iron tube five inches in diameter4 ,the tower is attached to one end of a wagon of unusual length and breadth1 and is raised to a vertical position by a rack gearing with a quadrant built into its base below the trunnions or pivots on which it swings4 ,carbonic acid gas1 generated in a cylinder carried on the wagon1 works a piston connected with the racks1 and on a tap being turned slowly brings the tower to the perpendicular1 when it is locked4 ,the telescopic tube1 carrying the hose inside it1 is then pulled up by windlasses1 until the #b-a_/b-;inch nozzle is nearly fifty feet from the ground4 ,the nozzle itself can be rotated from below by rods and gearing1 and the angle of the stream regulated by a rope4 ,if several engines simultaneously deliver their water to the tower hoses #a1jjj gallons a minute can be concentrated in a continuous #b-a_/b-;inch jet on to the fire4 ,the ordinary horsed fire engine is simple in its design and parts4 ,the vertical boiler contains a number of nearly horizontal water tubes1 which offer a great surface to the furnace gases1 so that it may raise steam very quickly4 ,the actual water capacity of the boiler is small1 and therefore it must be fed continuously by a special pump4 ,the pumps1 two or three in number1 usually have piston rods working direct from the steam cylinders on the plungers of the pumps4 ,between cylinders and pumps are slots in the rods in which rotate cranks connected with one another and with a fly-wheel which helps to keep the running steady4 ,after leaving the pumps the water enters a large air vessel1 which reduces the sudden shocks of delivery by the cushioning effect of the air1 and causes a steady pressure on the water in the hoses4 ,,chapter ,,xi ,,fire-,,alarms ,,and ,,automatic ,,fire ,,extinguishers ,assuming that a town has a well-appointed fire brigade1 equipped with the most up-to-date engines1 it still cannot be considered efficiently protected against the ravages of the fire-fiend unless the outbreak of a fire can be notified immediately to the stations1 and local mechanical means of suppression come into action almost simultaneously with the commencement of the conflagration4 ,what you do1 do quickly is the keynote of successful fire-suppression2 and its importance has been practically recognised in the invention of hundreds of devices1 some of which we will glance at in the following pages4 ,the electric circuit is the most valuable servant that we have to warn us of danger4 ,dotted about the streets are posts carrying at the top a circular box1 which contains a knob4 ,as soon as a fire is observed1 anyone may run to such a post1 smash the glass screening the knob1 and pull out the latter4 ,this action flashes the alarm to the nearest fire-station1 and a few minutes later an engine is dashing to the rescue4 ,help may also be summoned by means of the ordinary telephone exchanges or from police-stations in direct telephonic communication with the brigade depts4 ,all devices depending for their ultimate value on human initiative leave a good deal to be desired4 ,they presuppose conditions which may be absent4 ,for instance1 an electric wire in a large factory ignites some combustible material during the night4 ,a passer-by may happen to see flames while the fire is in an early stage4 ,on the other hand1 it is equally probable that the conflagration may be well established before the alarm is given1 with the result that the fire brigade arrives too late to do much good4 ,what we need1 therefore1 is a mechanical means of calling attention to the danger automatically1 with a quickness which will give the brigade or people close at hand a chance of strangling the monster almost as soon as it is born1 and with a precision as to locality that will save the precious time wasted in hunting for the exact point to be attacked4 ,mr4 ,g4 ,h4 ,oatway1 ,m4,i4,e4,e41 in a valuable paper read before the ,international ,congress of ,fire ,brigades in ,london in #aijc1 says that the difference between the damage resulting from a fire signalled in its early stage1 and the same fire reported when it has spread to two or three floors1 is often the difference between a nominal loss and a burn out4 ,the reformer1 he continues1 who aims at reducing fire waste must turn his attention primarily to hastening the alarm4 ,the true cure of the matter is1 not what quantity of gear it takes to deal with huge conflagrations1 but how to concentrate at the earliest stage upon the outbreaks as they occur1 and to check them before they have grown beyond control4 ,he cites the fire record of ,glasgow of #aijb1 from which it appears that three fires alone accounted for #dj per cent4 of the year's total loss1 ten fires for #gc per cent41 and the other #gjf for only #bg per cent41 or an average of #gb per fire4 ,had the first three fires only been notified at an earlier stage1 nearly #gb1jjj would have been saved4 ,captain ,sir ,e4 ,m4 ,shaw1 late ,chief of the ,london ,fire ,brigade1 has put the following on record3 ,having devoted a very large portion of the active period of my working life in bringing into general use mechanical and hydraulic appliances for dealing with fires after they have been discovered1 ,i nevertheless give and have always given the highest place to the early discovery and indication of fire1 and not by any means to the steam1 the hydraulic1 or the numerous other mechanical appliances on which the principal labours of my life have been bestowed4 ,a fire given fifteen minutes' start is often hard to overtake4 ,imagine a warehouse alight on three floors before the alarm is raised6 ,engines may come one after another and pour deluges of water on the flames1 yet as likely as not we read next morning of total destruction4 ,no stitch in time has saved nine6 ,the sad part about fires is that they represent so much absolute waste4 ,in commercial transactions1 if one party loses the other gains2 wealth is merely transferred1 and still remains in the community4 ,but in the matter of fire this is not the case4 ,supposing that a huge cotton mill is burnt down4 ,the re-erection will1 it is true1 cause a lot of money to change hands2 but what has resulted from the money that has already been put into the mill8 ,nothing4 ,so many hundred thousands of pounds have been dematerialised and left nothing behind to represent them4 ,the great ,ottawa fire of a few years ago may be remembered as a terrible example of such total loss of human effort4 ,,the ,,history ,,of ,,fire-,,alarms ,the first recorded specification for an automatic detecting device bears the date #agfc4 ,in that year a ,mr4 ,john ,greene patented an arrangement of cords1 weights1 and pulleys1 which1 when the cord burnt through1 caused the movement of an indicating semaphore arm4 ,as this action appealed only to the eye1 it might easily pass unnoticed1 and we can imagine that ,mr4 ,greene did not find a gold mine in his invention4 ,twenty-four years later an advance was made when ,william ,stedman introduced a philosophical fire alarum4 ,his apparatus consisted of a pivoted bulb having an open neck1 and containing mercury1 spirit or other liquid4 ,as the heat of the room increased1 the expansion of the fluid caused it to spill over1 release a trigger1 and allow a mechanical gong to run down4 ,this arrangement1 whilst an advance upon the first referred to1 is quite impracticable4 ,evaporation of fluid1 expansion of mercury1 a stiff crank1 or other causes which will readily occur to you1 and the thing is useless4#ad ,in #ahjf an automatic method for sprinkling water over a fire appeared4 ,the idea was simplicity itself3 a network of water mains1 with taps controlled by cords1 which burnt through and turned on the water4 ,william ,congreve patented1 three years later1 a sprinkler which was an improvement1 in that it indicated the position of the fire in a building by dropping one of a number of weights4 ,but string is not to be relied upon4 ,it may perish and break when no fire is about1 and any system of extinction depending on it might prove a double-edged weapon4 ,the nineteenth century produced hundreds of devices for alarming and extinguishing automatically4 ,all depended upon the principle of the expansion or melting of metal in the increased temperature arising from a fire4 ,at one time the circuit-closing thermometer was popular on account of its simplicity4 ,its drawback1 says ,mr4 ,oatway1 is the smallness of its heat-collecting surface1 its isolation1 and1 last and worst of all1 its fixity of operation4 ,in thermometer or fuse-alarm practice it is usual to place the detectors at intervals of about ten feet or so1 so that a room of any size will contain a number4 ,if a fire breaks out1 the ceiling is blanketed with heat1 and every detector feels its influence4 ,each is affected1 but none can give the alarm until some one of the number absolutely reaches the set point or melts out4 ,having no means of varying the composition of the solder or shifting the wire1 an actuating point must be selected which is high enough to give a good working margin over the maximum industrial or seasonal heat of the year2 and thus it comes about that if the fire breaks out in winter1 or when the room is at its lowest temperature1 the amount of loss is considerably and quite unnecessarily increased4 ,in a device set to fuse at #aej ,fahrenheit1 it will be clear to every one that the measure of the damage will depend upon the normal temperature of the room at the time of the outbreak4 ,if the mercury is in the nineties1 there is only some sixty degrees of a rise to wait for2 whilst if it happens to be a winter's night1 the alarm is held back for a rise of perhaps #abj4 ,what chance is there in this case for a good stop8 ,mr4 ,oatway has examined the fuses under different conditions1 and his conclusions are drawn from practical tests4 ,great intelligence will not be required to appreciate the force of his arguments4 ,inasmuch as the rise of temperature caused by a fire is relative1 during the early stages at least1 to the general heat of the atmosphere1 it becomes obvious that an automatic fire-alarm should be one which will keep parallel1 as it were1 with fluctuations of natural heat4 ,thus1 if the danger rise be fixed at #ajj1 the alarm should be given on a cold night as certainly as at midday in summer4 ,it was the failure of early patterns in this respect that led to their being discredited by the fire-brigade authorities4 ,the writer already quoted has laid down the functions of a perfect alarm3-- 7a7 ,to detect the fire at a uniformly early period1 under all atmospheric and industrial conditions4 7b7 ,to give the alarm upon the premises1 and simultaneously to the brigade1 by a definite and unmistakable message4 7c7 ,to facilitate the work of extinction by indicating the position of the outbreak in the building attacked4 ,the ,may ,oatway alarm has got round the first difficulty in a most ingenious manner by adapting the principle of the compensation methods already described in connection with watches4 ,the alarm consists of a steel rod of a section found to be most suitable for the purpose4 ,to the side is attached by screws entering the rod near the ends a copper wire1 which is long enough to sag slightly at its centre1 from which depends a silver chain carrying a carbon contact-piece4 ,a short distance below the carbon are the two terminals of the electric circuit which1 when completed by the lowering of the carbon1 gives the alarm4 ,now if there be a very gradual change of temperature the steel rod lengthens slowly1 and so does the copper wire1 so that the amount of sag remains practically what it was before4 ,but in event of a fire the copper expands much more quickly than the steel1 and sags until the carbon completes the circuit4 ,the whole thing is beautifully simple1 very durable1 quite consistent1 and reliable4 ,as soon as the temperature diminishes1 on the extinction of the fire1 the alarm automatically returns to its normal position1 ready for further work4 ,now for the second function1 that of giving the alarm in many places at once4 ,the closed circuit does not itself directly cause bells to ring3 it works a relay1 that is1 a second and more powerful circuit4 ,in fact1 it is the counterpart of the engine driver1 who does not himself make the locomotive move1 but merely turns on the steam4 ,an installation has been introduced in the ,poplar ,workhouse--to quote an instance4 ,were a fire to break out1 one of the #bgf detectors would soon set twenty-five bells in action1 one in each officer's room4 ,similarly1 in the ,warehousemen's ,orphanage at ,cheadle ,hulme1 every dormitory would be aroused1 and every officer1 including the ,principal in his house some distance away4 ,messrs4 ,arthur and ,company1 of ,glasgow1 have a warehouse fortified with #fjj of these nerve centres1 all yoked to four position indicators1 three of which actuate a master indicator connected with the central fire-station4 ,there is no hole or corner in this huge establishment where the fire-demon could essay his fell work without being at once spied upon by a detector4 ,we may glance for a moment at the mechanism which sends an unmistakable message for help4 ,at the brigade station there is a number of small tablets1 each protected by a flap1 on the outside of which is the word ,,safe1 on the inside ,,fire4 ,normally the flap is closed4 ,as soon as the circuit is completed1 a magnet releases the flap1 and a bell begins to ring4 ,now1 it is possible that the circuit might be closed accidentally by contact somewhere between the premises it serves and the fire-station4 ,so that the official on guard1 seeing ,j4 ,brown and ,company on the uncovered tablet1 might despatch the engines to the place indicated on a wild-goose chase4 ,to prevent such false alarms the transmitter not only rings the station up1 but automatically sends an unmistakable message4 ,when a fire occurs an automatic printing machine is set in motion to despatch a cipher in the ,morse code four times to the station4 ,an accidental circuit could not do this2 therefore1 when the officer sees on the receiving tape the well-known cipher1 he turns out his men with all speed4 ,on arriving at their destination the firemen receive valuable help from the position indicator1 which guides them to their work4 ,on a special board is seen a row1 or rows1 of shutters similar to those already mentioned4 ,each row belongs to a floor2 each unit of the row to a room4 ,a glance suffices to tell that the trouble is1 say1 in the most southerly room of the second floor4 ,no notice is therefore taken of smoke rolling out of other parts of the building1 until the danger spot has been attacked4 ,that the firemen appreciate such an ally goes without saying4 ,every fire extinguished is a point to their credit4 ,also1 the risks they run are greatly diminished1 while the wear and tear of tackle is proportionately reduced4 ,the fireman is noted for his courage and unflinching performance of duty4 ,the discomforts of his profession are sometimes severe1 and its dangers as certain as they are at times appalling4 ,therefore we welcome any mechanical method which at once shortens his work1 lessens his peril1 and protects property from damage4 ,mr4 ,oatway draws special attention to the need for simultaneous warning on the premises and at the fire-station4 ,i remember1 he says1 many cases1 but perhaps no better illustration need be looked for than the case of a cotton mill in ,lancashire about two years ago 7#aija74 ,the fire was seen to start at a few minutes past seven2 a fuse blew out1 and sparked some cotton2 but it looked such a simple job that the operatives elected to deal with it4 ,at twenty minutes to eight it dawned upon somebody that the brigade had better be sent for1 because the fire was getting away2 and in due course they arrived2 but the mill1 already doomed1 became a total loss4 ,in every centre similar instances can be quoted4 ,there is nothing in any automatic system to discourage individual effort4 ,inmates can put the fire out1 if able2 but in any case the brigade gets timely and definite notice1 and if on their arrival they find the fire extinguished1 as ,chief ,superintendent ,thomas put it when we opened the ,dingle ,station after the fatal train-burning1 ',so much the better1 we shall get to our beds all the quicker4' ,this is the common-sense view of it4 ,helpers work none the less intelligently because they know the brigade is coming2 and it is necessary to provide some automatic method of calling them1 because you can never rely upon anybody who is unfamiliar with fire doing the right thing at the proper time4 ,messrs4 ,may and ,oatway1 who give their name to the alarm described above1 first introduced their apparatus in ,new ,zealand1 from which country it has spread over the ,british ,empire4 ,the largest installation is at ,messrs4 ,clark and ,company's ,anchor ,mills1 ,paisley4 ,the whole of the immense block of buildings1 the greater part of which was previously protected by sprinklers only1 is now electrically protected also2 and connected up with the fire brigade1 and through their station with the sleeping quarters of every fireman4 ,some figures will be interesting here4 ,there are #aai miles of internal alarm circuits2 #e-a_/d miles of underground cable between buildings2 #ai automatic telegraphs2 #ba automatic position indicators2 #bj alarm gongs a foot in diameter4 ,early in ,january1 #aije1 a fire broke out in these buildings during the dinner hour1 when most of the works' firemen were at their midday meal4 ,the alarm sounded simultaneously at the works' fire-station and at the firemen's houses1 which are situated on the other side of the street from the mill4 ,the firemen were on the spot immediately1 and were enabled to subdue the flames1 which had broken out in the building occupied as warehouse and office1 before it had got a firm hold of the inflammable material1 although not before one of the large stacks of finished thread was ablaze4 ,the brigade1 however1 were soon masters of the situation1 and the damage done was under #ajj4 ,there is little doubt1 had the alarm been left to the ordinary course1 the building would have been totally destroyed4#ae ,in those few minutes the installation saved its entire cost many times over4 ,truly ,a little fire is quickly trodden out1 ,which1 being suffered1 rivers cannot quench4 ,here1 in a ,shakespearean nutshell1 is the whole science of fire protection4 ,,automatic ,,sprinklers ,as these have been referred to several times a short description may appropriately be given4 ,the building which they protect is fitted with a network of mains and branches ramifying into each room4 ,at the end of each branch is a nozzle1 the mouth of which is bridged over by a metal arch carrying a small plate4 ,between the bridge and a glass plug closing the nozzle is a bar of easily fusible solder4 ,when the temperature has risen to danger point the solder melts1 and the plug is driven out by the water1 which strikes the plate and scatters in all directions4 ,this device has proved very valuable on many occasions4 ,the ,encyclopdia ,britannica 7,tenth ,edition7 states that1 in the record of the ,american ,associated ,factory ,mutual companies for the #e-a_/b years ending ,january #a1 #aijj1 it appears that out of #efc fires where sprinklers came into play #abi were extinguished by one jet2 #hc by two jets2 #fa by three2 #dd by four2 #dj by five4 ,the fire-bucket is the simplest device we have as a first aid2 and very effective it often proves4 ,insurance statistics show that more fires are put out by pails than by all other appliances put together4 ,the important point to be remembered in connection with them is that they should always be kept full2 so that1 at the critical moment1 there may be no hurried rushing about to find the two gallons of liquid which each is supposed to contain permanently4 ,in ,cassier's ,magazine 7vol4 xx4 p4 #he7 is given an account of the manner in which an ingenious mill superintendent ensured the pails on the premises being ready for duty4 ,the hooks carrying the pails were fitted up with pieces of spring steel strong enough to lift the pail when nearly empty1 but not sufficiently so to lift a full pail4 ,just over each spring1 in such a position as to be out of the way of the handle of the pail1 was set a metal point1 connected with a wire from an open-circuit battery4 ,so long as the pails were full1 their weight1 when hung on their hooks1 kept the springs down1 but as soon as one was removed1 or lost a considerable part of its contents by evaporation or otherwise1 the spring on its hook would rise1 come into contact with the metal point1 thus close the battery circuit and ring a bell in the manager's office1 at the same time showing which was the bucket at fault4 ,the bell continued to ring till the deficiency had been made right2 and by this simple contrivance the buckets were protected from misuse or lack of attention4 ,,footnotes3 #ad ,mr4 ,w4 ,h4 ,oatway4 #ae ,glasgow ,evening ,news4 ,,chapter ,,xii ,,the ,,machinery ,,of ,a ,,ship ,,the ,,reversing ,,engine--,,marine ,,engine ,,speed ,,governors--,,the ,,steering ,,engine--,,blowing ,,and ,,ventilating ,,apparatus--,,pumps--,,feed ,,heaters--,,feed-,,water ,,filters--,,distillers--,,refrigerators --,,the ,,search-,,light--,,wireless ,,telegraphy ,,instruments--,,safety ,,devices--,,the ,,transmission ,,of ,,power ,,on ,a ,,ship ,with many travellers by sea the first impulse1 after bunks have been visited and baggage has been safely stored away1 is to saunter off to the hatches over the engine-room and peer down into the shining machinery which forms the heart of the vessel4 ,some engine is sure to be at work to remind them of the great power stored down there below1 and to give a foretaste of what to expect when the engine-room gong sounds and the man in charge opens the huge throttle controlling some thousands of horse-power4 ,by craning forward over the edge of the ship1 a jet of water may be seen spurting from a hole in the side just above the water-line1 denoting either that a pump is emptying the bilge1 or that the condensers are being cooled ready for the work before them4 ,towards the forecastle a busy little donkey engine is lifting bunches of luggage off the quay by means of a rope passing over a swinging spar attached to the mast1 and lowering it into the nether regions where stevedores pack it neatly away4 ,in a small compartment on the upper deck is some mysterious1 and not very important-looking1 gear3 yet1 as it operates the rudder1 it claims a place of honour equalling that of the main engines which turn the screw4 ,to the ordinary passenger the very existence of much other machinery--the reversing engines1 the air-pumps1 the condensers1 the feed heaters1 the filters1 the evaporators and refrigerators1 and the ventilators--is most probably unsuspected4 ,the electric light he would1 from his experience of things ashore1 vaguely connect with an engine somewhere4 ,but the apparatus referred to either works so unobtrusively or is so sequestered from the public eye that one might travel for weeks without even hearing mention of it4 ,on a warship the amount of machinery is vastly increased4 ,in fact1 every war vessel1 from the first-class battleship to the smallest destroyer1 is practically a congeries of machines2 accommodation for human beings taking a very secondary place4 ,big guns must be trained1 fed1 and cleaned by machinery2 and these processes1 simple as they sound1 need most elaborate devices4 ,the difference in respect of mechanism between the ,king ,edward ,,vii4 and ,nelson's ,victory is as great as that between a motor-car and a farmer's cart4 ,it would not be too much to say that the mechanical knowledge of any period is very adequately gauged from its fighting vessels4 ,illustration3 ,photo ,cribb1 ,southsea4 ,a gigantic sheer-legs used for lowering boilers1 big guns1 turrets1 etc41 into men-of-war4 ,the legs rise to a height of #adj feet1 and will handle weights up to #aej tons4 ,during the last twenty years marine engines have been enormously improved4 ,but the advance of auxiliary appliances has been even more marked4 ,in earlier times the matter considered of primary importance was the propulsion of the vessel2 and engineers turned their attention to the problem of crowding the greatest possible amount of power into the least possible amount of space4 ,this was effected mainly by the compounding of engines--using the steam over and over again in cylinders of increasing size--and by improving the design of boilers4 ,as soon as this business had been well forwarded1 auxiliary machinery1 which1 though not absolutely necessary for movement1 greatly affected the ease1 comfort1 and economy of working a ship1 got its share of notice1 with the result that a tour round the works of a modern battleship or liner is a growing wonder and a liberal education in itself4 ,this chapter will deal with the auxiliaries to be found in large vessels designed for peaceful or warlike uses4 ,many devices are common to ships of both classes1 and some are confined to one type only1 though the steel wall certainly has the advantage with regard to multiplicity4 ,we may begin with ,,the ,,reversing ,,engine ,all marine engines should be fitted with some apparatus which enables the engineer to reverse them from full speed ahead to full speed astern in a few seconds4 ,the effort required to perform the operation of shifting over the valves is such as to necessitate the help of steam4 ,therefore you will find a special device in the engine-room which1 when the engineer moves a small lever either way from the normal position1 lets steam into a cylinder and moves rods reversing the main engine4 ,by a link action 7which could not be explained without a special diagram7 the valves of the auxiliary are closed automatically as soon as the task has been performed2 so that there is no constant pressure on the one or the other side of its piston4 ,to prevent the reversal being too sudden1 the auxiliary's piston-rod is prolonged1 and fitted to a second piston working in a second cylinder full of glycerine or oil4 ,this piston is pierced with a small hole1 through which the incompressible liquid passes as the piston moves4 ,since its passage is gradual1 the engines are reversed deliberately enough to protect their valves from any severe strains4 ,these reversing engines can1 if the steam serving them fails1 be worked by hand4 ,,marine ,,engine ,,speed ,,governors ,when a ship is passing through a strong sea and pitches as she crosses the waves1 the screw is from time to time lifted clear of the water1 and the engines which a moment before had been doing their utmost1 suddenly find their load taken off them4 ,the result is racing of the machinery1 which makes itself very unpleasantly felt from one end of the ship to the other4 ,then the screw1 revolving at a speed much above the normal1 suddenly plunges into the water again1 and encounters great resistance to its revolution4 ,a series of changes from full to no load1 as engineers term it1 must be harmful to any engines1 even though the evil effects are not shown at once4 ,great strains are set up which shake bolts loose1 or may crack the heavy standards in which the cranks and shaft work1 and even seriously tax the shaft itself and the screw4 ,on land every stationary engine set to do tasks in which the load varies--which practically means all stationary engines--are fitted with a governor1 to cut off the steam directly a certain rate of revolution is exceeded4 ,these engines are the more easily governed because they carry heavy fly-wheels1 which pick up or lose their velocity gradually4 ,a marine engine1 on the other hand1 has only the screw to steady it1 and this is extremely light in proportion to the power which drives it2 in fact1 has scarcely any controlling influence at all as soon as it leaves the water4 ,marine engineers1 therefore1 need some mechanical means of restraining their engines from running away4 ,the device must be very sensitive and quick acting1 since the engines would increase their rate threefold in a second if left ungoverned when running free2 while on the other hand it must not throttle the steam supply a moment after the work has begun again when the screw takes the water4 ,many mechanisms have been invented to curb the marine engine4 ,some have proved fairly successful1 others practically useless2 and the fact remains that1 owing to the greater difficulty of the task1 marine governing is not so delicate as that of land engines4 ,a great number of steamships are not fitted with governors1 for the simple reason that the engineers are sceptical about such devices as a class and would rather not be bothered with them4 ,but whatever may have been its record in the past1 the marine governor is at the present time sufficiently developed to form an item in the engine-rooms of many of our largest ships4 ,we select as one of the best devices yet produced that known as ,andrews' ,patent ,governor2 and append a short description4 ,it consists of two main parts--the pumps and the ram closing the throttle4 ,the pumps1 two in number1 are worked alternately by some moving part of the engine1 such as the air-pump lever4 ,they inject water through a small pipe into a cylinder1 the piston-rod of which operates a throttle valve in the main steam supply to the engines4 ,at the bottom of this cylinder is a by-pass1 or artificial leak1 through which the water flows back to the pumps4 ,the size of the flow through the by-pass is controlled by a screw adjustment4 ,we will suppose that the governor is set to permit one hundred revolutions a minute4 ,as long as that rate is not exceeded the by-pass will let out as much water as the pumps can inject into the cylinder1 and the piston is not moved4 ,but as soon as the engines begin to race1 the pumps send in an excess1 and the piston immediately begins to rise1 closing the throttle4 ,as the speed falls1 the leak gets the upper hand again1 and the piston is pushed down by a powerful spring1 opening the throttle4 ,it might be supposed that1 when the screw races1 the pumps would not only close the throttle1 but also press so hard on it as to cause damage to some part of the apparatus before the speed had fallen again4 ,this is prevented by the presence of a second control valve 7or leak7 worked by a connecting-rod rising along with the piston-rod of the ram4 ,the two rods are held in engagement by a powerful spring which presses them together1 so that a hollow in the first engages with a projection on the second4 ,immediately the pressure increases and the piston rises1 the second valve is shut by the lifting of its rod1 and so farther augments the pressure in the cylinder and quickens the closing of the throttle valve4 ,this pressure increase must1 however1 be checked1 or the piston would overrun and stop the engines4 ,so when the piston has nearly finished its stroke the connecting-rod comes into contact with a stop which disengages it from the piston-rod and allows the second control valve to be fully opened by the spring pulling on its rod4 ,the piston at once sinks to such a position as the pressure allows1 and the action is repeated time after time4 ,the governing is practically instantaneous1 though without shock1 and is said to keep the engine within #c per cent4 of the normal rate4 ,that is1 if #ajj be the proper number of revolutions1 it would not be allowed to exceed #ajc or drop below #ig4 ,such governing is1 in technical language1 very close4 ,the idea is very ingenious3 pumps working against a leak1 and as soon as they have mastered it1 being aided by a secondary valve which reduces the size of the leak so as to render the effect of the pumps increasingly rapid until the throttle has been closed4 ,then the secondary valve is suddenly thrown out of action1 gives the leak full play1 and causes the throttle to open quickly so that the steam may be cut off only for a moment4 ,by the turning of a small milled screw-head a couple of inches in diameter the pace of #e1jjj h4p4 engines is as fully regulated as if a powerful brake were applied the moment they exceeded the legal limit4 ,,steering ,,engines ,the uninitiated may think that the man on the bridge1 revolving a spoked-wheel with apparently small exertion1 is directly moving the rudder to port or to starboard as he wishes4 ,but the helm of a large vessel1 travelling at high speed1 could not be so easily deflected were not some giant at work down below in obedience to the easy motions of the wheel4 ,sometimes in a special little cabin on deck1 but more often in the engine-room1 where it can be tended by the staff1 there is the steering engine1 usually worked by steam-power4 ,two little cylinders turn a worm-screw which revolves a worm-wheel and a train of cogs1 the last of which moves to right or left a quadrant attached to the chains or cables which work the rudder4 ,all that the steersman has to do with his wheel is to put the engine in forward1 backward1 or middle gear4 ,the steam being admitted to the cylinders quickly moves the helm to the position required4 ,a particularly ingenious steam gear is that made by ,messrs4 ,harfield and ,company1 of ,london4 ,its chief feature is the arrangement whereby the power to move the rudder into any position remains constant4 ,if you have ever steered a boat1 you will remember that1 when a sudden curve must be made1 you have to put far more strength into the tiller than would suffice for a slight change of direction4 ,now1 if a steam-engine and gear were so built as to give sufficient pressure on the helm in all positions1 it would1 if powerful enough to put the ship hard-a-port1 evidently be overpowered for the gentler movements1 and would waste steam4 ,the ,harfield gear has the last of the cog-train--the one which engages with the rack operating the tiller--mounted eccentrically4 ,the rack itself is not part of a circle1 but almost flat centrally1 and sharply bent at the ends4 ,in short1 the curve is such that the rack teeth engage with the eccentric cog at all points of the latter's revolution4 ,when the helm is normal the longest radius of the eccentric is turned towards the rack4 ,in this position it exerts least power2 but least power is then needed4 ,as the helm goes over1 the radius of the cogs gradually decreases1 and its leverage proportionately increases4 ,so that the engine is taxed uniformly all the time4 ,some war vessels1 including the ill-fated ,russian cruiser ,variag1 have been fitted with electric steering gear1 operated by a motor in which the direction of the current can be varied at the will of the helmsman4 ,all power gears are so arranged that1 in case of a breakdown of the power1 a hand-wheel can be quickly brought into play4 ,,blowing ,,and ,,ventilating ,,apparatus ,a railway locomotive sends the exhaust steam up the funnel with sufficient force to expel all air from the same and to create a vacuum4 ,the only passage for the air flying to fill this empty space lies through the fire-box and tubes traversing the boiler from end to end4 ,were it not for the induced draught--the invention of ,george ,stephenson--no locomotive would be able to draw a train at a higher speed than a few miles an hour4 ,on shipboard the fresh water used in the boilers is far too precious to be wasted by using it as a fire-exciter4 ,salt water to make good the loss would soon corrode the boilers and cause terrible explosions4 ,therefore the necessary draught is created by forcing air through the furnaces instead of by drawing it4 ,the stoke-hold is entirely separated from the outer air1 except for the ventilators1 down which air is forced by centrifugal pumps at considerable pressure4 ,this draught serves two purposes4 ,it lowers the temperature of the stoke-hold1 which otherwise would be unbearable1 and also feeds the fires with plenty of oxygen4 ,the air forced in can escape in one way only1 viz4 by passing through the furnaces4 ,when the ship is slowed down the forced draught is turned off1 and then you see the poor stokers coming up for a breath of fresh air4 ,in the ,red ,sea or other tropical latitudes these grimy but useful men have a very hard time of it4 ,while passengers up above are grumbling at the heat1 the stoker below is almost fainting1 although clad in nothing but the thinnest of trousers4 ,in the engine-room also things at times become uncomfortably warm4 ,take the case of the ,united ,states monitor ,amphitrite1 which went into commission in #ahie for a trial run4 ,both stoke-hold and engine-room were very insufficiently ventilated4 ,the vessel started from ,hampton ,roads for ,brunswick1 ,georgia4 ,the trip of about #ejj miles occupied five days in the latter part of ,july1 and1 for sheer suffering1 has perhaps seldom been equalled in our naval history4 ,the fire-room 7stoke-hold7 temperature was never below #aej1 and often above #agj1 while the engine-room ranged closely about #aej4 ,for the first twenty-four hours the men stood it well1 but on the second day seven succumbed to the heat and were put on the sick list1 one of them nearly dying2 before the voyage was ended1 twenty-eight had been driven to seek medical attendance4 ,the gaps thus created were partially filled with inexperienced men from the deck force1 until there was only a lifeboat's crew left in each watch4444 ,on the evening of the fourth day out our men had literally fought the fire to a finish and had been vanquished2 the watch on duty broke down one by one1 and the engines1 after lumbering along slower and slower1 actually stopped for want of steam4444 ,at daybreak the next morning we got under way and steamed at a very conservative rate to our destination1 fortunately only about ten miles distant4 ,the scene in the fire-room that morning was not of this earth1 and far beyond description4 ,the heat was almost destructive to life2 steam was blowing from many defective joints and water columns2 tools1 ladders1 doors1 and all fittings were too hot to touch2 and the place was dense with smoke escaping from furnace doors1 for there was absolutely no draught4 ,the men collected to build up the fires were the best of those remaining fit for duty1 but they were worn out physically1 were nervous1 apprehensive1 and dispirited4 ,rough ,irish firemen1 who would stand in a fair fight till killed in their tracks1 were crying like children1 and begging to be allowed to go on deck1 so completely were they unmanned by the cruel ordeal they had endured so long4 ',hell afloat' is a nautical figure of speech often idly used1 but then we saw it4 ,for a month thereafter the ship was actively employed on the southern coast1 drilling militia at different ports1 and sweltering in the new dock at ,port ,royal4 ,one trip of twenty-nine hours broke the record for heat1 the fire-room being frequently above #ahj4 ,all fire-room temperatures were taken in the actual spaces where the men had to work1 and not from hot corners or overhead pockets4#af ,the ventilators were subsequently altered1 and the men enjoyed comparative comfort4 ,the words quoted will suffice to establish the importance of a proper current of air where men have to work4 ,one of the greatest difficulties encountered in deep mining is that1 while the temperature approaches and sometimes passes that of a stoke-hold1 the task of sending down a cool current from above is1 with depths of #d1jjj ft4 and over1 a very awkward one to carry out4 ,on passenger ships the fans ventilating the cabins and saloons are constantly at work1 either sucking out foul air or driving in fresh4 ,the principle of the fan is very similar to that of the centrifugal water pump--vanes rotating in a case open at the centre1 through which the air enters1 to be flung by the blades against the sides of the case and driven out of an opening in its circumference4 ,sometimes an ordinary screw-shaped fan1 such as we often see in public buildings1 is employed4 ,,pumps ,every steamship carries several varieties of pump4 ,first1 there are the large pumps1 generally of a simple type1 for emptying the bilge or any compartment of the ship which may have sprung a leak4 ,all hands to the pumps6 is now seldom heard on a steamer1 for the opening of a steam-cock sets machinery in motion which will successfully fight any but a very severe breach4 ,it is needless to say that these pumps form a very important part of a ship's equipment1 without which many a fine vessel would have sunk which has struggled to land4 ,the pumps for the condensers form another class4 ,these are centrifugal force pumps2 their duty is to circulate cold sea-water round the nests of tubes through which steam flows after passing through the cylinders4 ,it is thus converted once more into water1 ready for use again in the boiler4 ,every atom of the water is evaporated1 condensed1 and pumped back into the boiler once in a period ranging from fifteen minutes to an hour1 according to the type of boiler and the size of the supply tanks4 ,some condensers have the cooling water passed through the tubes1 and the steam circulated round these in an air-tight chamber4 ,in any case1 the condenser should be so designed as to offer a large amount of cold surface to the hot vapour4 ,a breakdown of the condenser pumps is a serious mishap1 since steam would then be wasted1 which represents so much fresh water--hard to replace in the open sea4 ,it would be comparable to the disarrangement of the circulating pump on a motor-car1 though the effects are different4 ,we must not forget the feed-pumps for the boilers4 ,on their efficient action depends the safety of the ship and her passengers4 ,water must be maintained at a certain level in the boiler1 so that all tube and other surfaces in direct contact with the furnace gases may be covered4 ,the disastrous explosions we sometimes hear of are often caused by the failure of a pump1 the burning of a tube or plate1 and the inevitable collapse of the same4 ,the firms of ,weir and ,worthington are among the best-known makers of the special high-pressure pumps used for throwing large quantities of water into the boilers of mercantile and war vessels4 ,,feed ,,heaters ,as the fuel supply of a vessel cannot easily be replenished on the high seas1 economy in coal consumption is very desirable4 ,if you put a cold spoon into a boiling saucepan ebullition is checked at once1 though only for a moment1 while the spoon takes in the temperature of the water4 ,similarly1 if cold water be fed into a boiler the steam pressure at once falls4 ,therefore the hotter the feed water is the better4 ,the feed heater is the reverse of the condenser4 ,in the latter1 cold water is used to cool hot steam2 in the former1 hot steam to heat cold water4 ,there are many patterns of heaters4 ,one type1 largely used1 sprays the cold water through a valve into a chamber through which steam is passed from the engines4 ,the spray1 falling through the hot vapour1 partially condenses it and takes up some of its heat4 ,the surplus steam travels on to the condensers4 ,a float in the lower part of the chamber governs a valve admitting steam to the boiler pumps1 so that as soon as a certain amount of water has accumulated the pumps are started1 and the hot liquid is forced into the boiler4 ,another type1 the ,hampson feeder1 sends steam through pipes of a wavy form surrounded by the feed water1 there being no actual contact between liquid and vapour4 ,an ally of the heater is the ,,feed-,,water ,,filter1 which removes suspended matter which1 if it entered the boiler1 would form a deposit round the tubes1 and while decreasing their efficiency1 make them more liable to burning4 ,the most dangerous element caught by the filters is fatty matter--oil which has entered the cylinders and been carried off by the exhaust steam4 ,the filter is either high pressure1 i4e4 situated between the pump and the boiler2 or low pressure1 i4e4 between the pump and the reservoir from which it draws its water4 ,the second class must have large areas1 so as not to throttle the supply unduly4 ,many kinds of filtering media have been tried--fabrics of silk1 calico1 cocoanut fibre1 towelling1 sawdust1 cork dust1 charcoal1 coke2 but the ideal substance1 at once cheap1 easily obtainable1 durable1 and completely effective1 yet remains to be found4 ,a filter should be so constructed that the filtering substance is very accessible for cleansing or renewal4 ,,distillers ,we now come to a part of a ship's plant very necessary for both machines and human beings4 ,many a time have people been in the position of the ,ancient ,mariner1 who exclaimed3-- ,water1 water1 everywhere1 ,but not a drop to drink6 ,water is so weighty that a ship cannot carry more than a very limited quantity1 and that for the immediate needs of her passengers4 ,the boilers1 in spite of their condensers1 waste a good deal of steam at safety valves through leaking joints and packings1 and in other ways4 ,this loss must be made good1 for1 as already remarked1 salt water spells the speedy ruin of any boiler it enters4 ,the distiller in its simplest form combines a boiler for changing water into vapour1 with a condenser for reconverting it to liquid4 ,solids in impure water do not pass off with the steam1 so that the latter1 if condensed in clean vessels1 is fit for drinking or for use in the engine boilers4 ,a pound of steam will1 under this system1 give a pound of water4 ,but as such procedure would be extravagant of fuel1 compound condensers are used1 which act in the following manner4 ,high-pressure steam is passed from the engine boilers into the tubes of an evaporator1 and converts the salt water surrounding it into steam4 ,the boiler steam then travels into its own condenser or into the feed water heater1 while the steam it generated passes into the coils of a second evaporator1 converts water there into steam1 and itself goes to a condenser4 ,the steam generated in the second evaporator does similar duty in a third evaporator4 ,so that one pound of high-pressure steam is directly reconverted to water1 and also indirectly produces between two and three pounds of fresh water4 ,the condensers used are similar to those already described in connection with the engines1 and need no further comment4 ,about the evaporators1 it may be said that they are so constructed that they can be cleaned out easily as soon as the accumulation of salt and other matter renders the operation necessary4 ,usually one side is hinged1 and provided with a number of bolts all round the edges which are quickly removed and replaced4 ,the ,united ,states ,navy includes a ship1 the ,iris1 whose sole duty is to supply the fleet she attends with plenty of fresh water4 ,she was built in #ahhe by ,messrs4 ,r4 and ,w4 ,hawthorn1 of ,newcastle-on-,tyne1 and measures #caj feet in length1 #ch-a_/b feet beam4 ,for her size she has remarkable bunker capacity1 and can accommodate nearly #b1ejj tons of coal4 ,fore and aft are huge storage tanks to hold between them about #agj1jjj gallons of fresh water4 ,her stills can produce a maximum of #fj1jjj gallons a day4 ,it has been reckoned that each ton of water distilled costs only #ah cents2 or1 stated otherwise1 that #dj gallons cost one penny4 ,at many ports fresh water costs three or four times this figure2 and even when procured is of doubtful purity4 ,during the ,spanish-,american ,war the ,iris and a sister ship1 the ,rainbow1 proved most useful4 ,,refrigerators ,of late years the frozen-meat trade has increased by leaps and bounds4 ,australia1 ,new ,zealand1 ,argentina1 ,canada1 and the ,united ,states send millions of pounds' worth of mutton and beef across the water every year to help feed the populations of ,england and ,europe4 ,in past times the live animals were sent1 to be either killed when disembarked or fatted up for the market4 ,this practice was expensive1 and attended by much suffering of the unfortunate creatures if bad weather knocked the vessel about4 ,refrigerating machinery has altered the traffic most fundamentally4 ,not only can more meat be sent at lower rates1 but the variety is increased2 and many other substances than flesh are often found in the cold stores of a ship--butter and fruit being important items4 ,certain steamship lines1 such as the ,shaw1 ,savill1 and ,albion--plying between ,england and ,australasia--include vessels specially built for the transport of vast numbers of carcases4 ,upwards of a million carcases have been packed into the hull of a single ship and kept perfectly fresh during the long six weeks' voyage across the ,equator4 ,every passenger-carrying steamer is provided with refrigerating rooms for the storage of perishable provisions2 and as the comfort of the passengers1 not to say their luxury1 is bound up with these compartments1 it will be interesting to glance at the method employed for creating local frost amid surrounding heat4 ,the big principle underlying the refrigerator is this--that a liquid when turned into gas absorbs heat 7thus1 to convert water into steam you must feed it with heat from a fire71 and that as soon as the gas loses a certain amount of its heat it reverts to liquid form4 ,now take ammonia gas4 ,the spirits of hartshorn we buy at the chemist's is water impregnated with this gas4 ,at ordinary living temperatures the water gives out the gas1 as a sniff at the bottle proves in a most effective manner4 ,if this gas were cooled to #cgc below zero it would assume a liquid state1 i4e4 that temperature marks its boiling point4 ,similarly steam1 cooled to #bab ,fahr41 becomes water4 ,boiling point1 therefore1 merely means the temperature at which the change occurs4 ,ammonia liquid1 when gasifying1 absorbs a great amount of heat from its surroundings--air1 water1 or whatever they may be4 ,so that if we put a tumbler full of the liquid into a basin of water it would rob the water of enough heat to cause the formation of ice4 ,the refrigerating machine1 generally employed on ships1 is one which constantly turns the ammonia liquid into gas1 and the gas back into liquid4 ,the first process produces the cold used in the freezing-rooms4 ,the apparatus consists of three main parts3-- 7#a7 ,the compressor1 for squeezing ammonia gas4 7#b7 ,the condenser1 for liquefying the gas4 7#c7 ,the evaporator1 for gasifying the liquid4 ,the compressor is a pump4 ,the condenser1 a tube or series of tubes outside which cold water is circulated4 ,the evaporator1 a spiral tube or tubes passing through a vessel full of brine4 ,between the condenser and evaporator is a valve1 which allows the liquid to pass from the one to the other in proper quantities4 ,we can now watch the cycle of operations4 ,the compressor sucks in a charge of very cold gas from the evaporator1 and squeezes it into a fraction of its original volume1 thereby heating it4 ,the heated gas now passes into the condenser coils and1 as it expands1 encounters the chilling effects of the water circulating outside1 which robs it of heat and causes it to liquefy4 ,it is next slowly admitted through the expansion valve into the evaporator4 ,here it gradually picks up the heat necessary for its gaseous form3 taking it from the brine outside the coils1 which has a very low freezing-point4 ,the brine is circulated by pumps through pipes lining the walls of the freezing-room1 and robs the air there of its heat until a temperature somewhat below the freezing-point of water is reached4 ,the room is well protected by layers of charcoal or silicate cotton1 which are very bad conductors of heat4 ,how the chamber strikes a novice can be gathered from the following description of a ,cunard liner's refrigerating room4 ,it is a curious and interesting sight4 ,it may be a hot day on deck1 nearing ,new ,york1 and everyone is going about in sun hats and light clothes4 ,we descend a couple of flights of stairs1 turn a key1 and here is winter1 sparkling in glassy frost upon the pale carcases of fowls and game1 and ruddy joints of meat1 crystallising the yellow apples and black grapes to the likeness of sweetmeats in a grocer's shop1 gathering on the wall-pipes in scintillating coats of snow nearly an inch deep4 ,you can make a snowball down here1 if you like1 and carry it up on deck to astonish the languid loungers sheltering from the sun under the protection of the promenade-deck roof4 ,such is the modern substitute for the old-time salt-beef cask and bags of dried pease6 ,the larder is so near the kitchen that while below decks we may just peep into the kitchens1 where a white-capped chef presides over an army of assistants4 ,inside a huge oven are dozens of joints turning round and round by the agency of an invisible electric-motor4 ,but what most tickles the imagination is an electrical egg-boiling apparatus1 which ensures the correct amount of cooking to any egg4 ,a row of metal dippers1 with perforated bottoms1 is suspended over a trough of boiling water4 ,each dipper is marked for a certain time--one minute1 two1 three1 four1 and so on4 ,the dippers1 filled with eggs1 are pushed down into the water4 ,no need to worry lest they should be done to a bullet1 for at the expiry of a minute up springs the one-minute dipper2 and after each succeeding minute the others follow in due rotation4 ,where #b1jjj eggs or more are devoured daily this ingenious automatic device plays no mean part4 ,,the ,,search-,,light ,all liners and war vessels now carry apparatus which will enable them to detect danger at night time1 whether rocks or an enemy's fleet1 icebergs or a water-logged derelict4 ,on the bridge1 or on some other commanding part of the vessel's structure1 is a circular1 glass-fronted case1 backed with a mirror of peculiar shape4 ,inside are two carbon points almost touching1 across which1 at the turn of a handle1 leaps a shower of sparks so continuous as to form a dazzling light4 ,the rays from the electric arc1 as it is called1 either pass directly through the glass lens1 or are caught by the parabolic reflector and shot back through it in an almost parallel pencil of wonderful intensity1 which illumines the darkness like a ray of sunshine slanting through a crack in the shutter of a room4 ,the search-light draws its current from special dynamos1 which absorb many horse-power in the case of the powerful apparatus used on warships4 ,at a distance of several miles a page of print may be easily read by the beams of these scrutinisers of the night4 ,the finest search-lights are to be found ashore at naval ports1 where1 in case of war1 a sharp look-out must be kept for hostile vessels4 ,portsmouth boasts a light of over a million candle-power1 but even this is quite eclipsed by a monster light built by the ,schuckert ,company1 of ,nuremberg1 ,germany1 which gives the effect of #haf1jjj1jjj candles4 ,an instrument of such power would be useless on board ship1 owing to the great amount of current it devours1 but in a port1 connected with the lighting plant of a large town1 it would serve to illumine the country round for many miles4 ,in addition to its value as an eye1 the search-light can be utilised as an ear4 ,ernst ,ruhmer1 a ,german scientist1 has discovered a method of telephoning along a beam of light from a naval projector4 ,the amount of current passing into the arc is regulated by the pulsations of a telephone battery and transmitter4 ,if the beam be caught by a parabolic reflector1 in the focus of which is a selenium cell connected with a battery and a pair of sensitive telephone receivers1 the effect of these pulsations of light is heard4 ,selenium being a metal which varies its resistance to an electric circuit in proportion to the intensity of light shining upon it1 any fluctuations of the search-light's beams cause electric fluctuations of equal rapidity in the telephone circuit2 and since these waves arise from the vibrations of speech1 the electric vibrations they cause in the selenium circuit are retransformed at the receiver into the sounds of speech4 ,this ,german apparatus makes it possible to send messages nine or ten miles over a powerful projector beam4 ,in the ,united ,states ,navy1 and in other navies as well1 night signals are flashed by the electric light4 ,the pattern of lamp used in the ,united ,states ,navy is divided transversely into two compartments1 the upper having a white1 the lower a red1 lens4 ,four of these lamps are hung one above the other from a mast4 ,a switch-board connected with the eight incandescent lamps in the series enables the operator to send any required signal1 one letter or figure being flashed at a time4 ,during the ,spanish-,american ,war the ,united ,states fleet made great use of this simple system1 which on a clear night is very effective up to distances of four miles4 ,large arc-lamps slung on yards over the deck give great help for coaling and unloading vessels at night time4 ,the touch of a switch lights up the deck with the brilliancy of a well-equipped railway station4 ,the day of the lantern1 dimly burning1 has long passed away from the big liner1 cargo boat1 and warship4 ,,wireless ,,telegraphy ,,instruments ,solitude is being rapidly banished from the earth's surface4 ,by solitude we mean entire separation from news of the world1 and the inability to get into touch with people far away4 ,on the remote ranches of the ,united ,states1 in sequestered ,norwegian fiords1 in the folds of the eternal hills where the only other living creature is the eagle1 man may still be as conversant with what is going on in ,china or ,peru as if he were living in the busy streets of a capital town4 ,the electric wire is the magic news-bringer4 ,wherever man can go it can go too1 and also into many places besides4 ,we must make one exception--the surface of the sea4 ,cables rest on ocean's bed1 but they would be useless if floated on its surface to act as marine telegraph offices4 ,winds and waves would soon batter them to pieces1 even if they could be moored1 which in a thousand fathoms may be considered impracticable4 ,so until a few years back the occupants of a ship were truly isolated from the time that they left port until they reached land again1 except for the rare occasions when a passing vessel might give them a fragment of news4 ,this has all been changed4 ,stroll into the saloon of one of our large ,atlantic liners and you will see telegram forms lying on the tables4 ,in the 'nineties they would have been about as useful aboard ships as a mackintosh coat in the ,sahara4 ,a glance1 however1 at pamphlets scattered around informs you that the ship carries a ,marconi wireless installation1 and that a ,marconi telegram1 handed in at the ship's telegraph office1 will be despatched on the wings of ether waves to the land far over the horizon4 ,inside the cabin streams of sparks scintillate with a cracking noise1 and your message shoots into space from a wire suspended on insulators from one of the mast heads4 ,if circumstances favour1 you may receive a reply from the ,unseen before the steamer has got out of range of the coast stations4 ,the immense installations at ,poldhu1 ,cornwall1 and in ,newfoundland1 could be used to flash the words to a ship at any point of the transatlantic journey4 ,owing to lack of space1 and consequently power1 the steamer's transmitting apparatus has a limited capacity4 ,the first shipping company to grasp the possibilities of the commercial working of the ,marconi system was the ,nord-,deutscher-,lloyd1 whose mail steamer1 ,kaiser ,wilhelm der ,grosse1 was fitted in ,march1 #aijj4 ,at the present time many of the large ,atlantic steamship companies carry a wireless installation as a matter of course1 ranking it among necessary things4 ,the ,cunard1 ,american ,atlantic ,transport1 ,allan1 ,compagnie ,transatlantique1 ,hamburg-,american1 and ,nord-,deutscher-,lloyd lines make full use of the system1 as the conveniences it gives far outweigh any expense4 ,a short time since maritime signalling was extremely limited in its range1 being effected by flags1 semaphores1 lights1 and sounds1 which in stormy weather became uncertain agents1 and in foggy1 useless4 ,also the operations of transmitting and receiving were so slow that many a message had to remain uncompleted4 ,the following paragraph1 which appeared in ,the ,times of ,december #aath1 #aijc1 is significant of the very practical value of marine wireless telegraphy4 ,the ,american steamer ,kroonland1 from ,antwerp for ,new ,york1 which1 as reported yesterday1 disabled her steering gear when west of the ,fastnet1 and had to put back1 arrived yesterday morning at ,queenstown4 ,the saloon passengers speak in the highest terms of praise of the utility of the ,marconi wireless telegraphy with which the liner is fitted1 and of the facility with which1 when the accident occurred1 the passengers were able to communicate with their friends1 in ,england1 ,scotland1 and the ,continent1 and even ,america1 and get replies before the ,irish coast was sighted4 ,the accident occurred on ,tuesday about noon1 when the liner was #acj miles west of the ,fastnet1 and communication was at once made with the ,marconi station at ,crookhaven4 ,captain ,doxrud was enabled accordingly to send messages to the chief agents of the ,american line1 at ,antwerp1 stating the nature of the damage to the steering gear of the steamer1 and that he would have to abandon the idea of prosecuting the western voyage4 ,within an hour and a half a message was received by the captain from the agents instructing him what to do1 and at once the ,kroonland was headed for ,queenstown4 ,three-fourths of the total number of the saloon passengers and a goodly number of the second cabin sent messages to their friends in various parts of the world1 and replies were received even from the ,continent before the ,fastnet was sighted4 ,seven or eight passengers telegraphed to relatives for money1 and replies were received in four instances1 authorising the purser to advance the amounts required1 and the money was paid over in each case to the passengers4 ,the possibility of thus communicating between vessel and land1 or vessel and vessel1 removes much of the anxiety attending a sea voyage4 ,business men1 for whom even a few days' want of touch with the mercantile markets may be a serious matter1 can send long messages in code or otherwise instructing their agents what to do2 while they can receive information to shape their actions when they reach land4 ,the uncommercial traveller also is pleased and grateful on receiving a message from home4 ,the feeling of loneliness is eliminated4 ,the ocean has lost its right to the term bestowed by ,horace--dissociabilis1 the separator4 ,illustration3 ,photo ,cribb1 ,southsea4 ,,fixing ,a ,,battle-,,ram ,the ram of a battleship being placed in position with the aid of a huge crane4 ,the size of the ram will be appreciated from the dwarfing effect it has on that of the man perched near the lifting tackle4 ,steamship companies vie with one another in their efforts to keep their passengers well posted in the latest news4 ,bulletins1 or small newspapers1 are issued daily during the voyage1 which give1 in very condensed form1 accounts of events interesting to those on board4 ,the amount of fresh news a steamer gathers during a passage is considerable1 and is greatly relished by the passengers1 who are invariably ravenous for signs of the busy life they left behind1 more especially when they have departed on the verge of some important event taking place2 and the bulletins are eagerly sought for when it is announced that an inward-bound ship is in communication4 ,the shipowners realise the importance and usefulness of being able to communicate with their commanders before the huge vessels enter narrow waters1 and issue instructions concerning their movements4 ,the stations1 which are placed at carefully-selected points at well-adapted distances around the coast1 are connected with either the land telegraph or telephone line1 or are close to a telegraph office4 ,they are kept open night and day1 as the times of the ships passing are1 of course1 greatly dependent on the weather encountered during the voyage4 ,for those on shore who are anxious to greet their friends on arrival--with good or bad news1 as the case may be--this arrangement enables them to be informed of the exact time of the ship's expected arrival1 and they are left free to their own devices1 instead of enduring long waits on draughty piers and docks--which1 on a wet or windy day1 are almost enough to damp the warmest and most enthusiastic welcome4 ,cases have occurred where a telegram1 sent from the ,american side to an outlying ,english land-station two days after a ship has left1 has been transmitted to an outgoing steamer1 which in turn has re-transmitted it to the astonished passenger two days prior to his arrival off the ,english coast2 and it has now become quite a common thing for competing teams on vessels many miles apart1 and out of sight of each other1 to arrange chess matches with each other1 some of these interesting events taking two or more days to be played to a finish4#ag ,for naval purposes1 wireless telegraphy has assumed an importance which can hardly be overestimated1 as the whole efficiency of a fine fleet may depend upon a single message flashed through space4 ,all navies are fitting instruments1 the ,british ,admiralty being well to the fore4 ,even in manoeuvres and during the execution of tactical formations the apparatus is constantly at work4 ,the admiral gives the word1 and a dozen paper tapes moving jerkily through ,morse machines1 pass the message round the fleet4 ,the ,japanese naval successes have1 doubtless1 been largely due to their up-to-date employment of this latest development of ,western electrical science4 ,no one knows how soon the time may come when the fate of a nation may depend on the proper working of a machine covering a few square feet of a cabin table2 for1 rapid as has been the growth of wireless telegraphy1 it is yet in its infancy4 ,,safety ,,devices ,a ship is usually divided into compartments by cross bulkheads of steel4 ,in event of a collision or damage by torpedoes or shell1 the water rushing through the break can be prevented from swamping the ship by closing the bulkhead doors4 ,messrs4 ,j4 ,stone and ,company1 of ,deptford1 have patented a system of hydraulically operated bulkhead doors1 which is finding great favour among shipbuilders on account of its versatility4 ,each door is closed by an hydraulic cylinder placed above it4 ,the valves of the cylinder are opened automatically by a float when the water rises in the compartment1 and every cylinder is also controllable independently from the bridge and other stations in the ship1 and by separate hand levers alongside the bulkhead4 ,the doors can therefore be closed collectively or individually4 ,should it happen that1 when a door has been closed1 someone is imprisoned1 the prisoner can open the door by depressing a lever inside the compartment1 and make his escape4 ,but the door is closed behind him by the action of the float4 ,,the ,,transmission ,,of ,,power ,,on ,a ,,ship ,there are four power agents available on board ship1 all derived directly or indirectly from the steam boilers4 ,they are3-- 7#a7 ,steam4 7#b7 ,high-pressure water4 7#c7 ,compressed air4 7#d7 ,electricity4 ,on some ships we may find all four working side by side to drive the multifarious auxiliaries1 since each has its peculiar advantages and disadvantages4 ,at the same time1 marine engineers prefer to reduce the number as far as possible1 since each class of transmission needs specially trained mechanics1 and introduces its special complications4 ,let us take the four agents in order and briefly consider their value4 ,steam is so largely used in all departments of engineering that its working is better understood by the bulk of average mechanics than hydraulic power1 compressed air1 or electricity4 ,but for marine work it has very serious drawbacks1 especially on a war vessel4 ,imagine a ship which contains a network of steam-pipes running from end to end1 and from side to side4 ,the pipes must1 on account of the many obstacles they encounter1 twist and turn about in a manner which might be avoided on land1 where room is more available4 ,every bend means friction and loss of power4 ,again1 the condensation of steam in long pipes is notorious4 ,even if they are well jacketed1 a great deal of heat will radiate from the ducts into the below-deck atmosphere1 which is generally too close and hot to be pleasant without any such further warming4 ,so that1 while power is lost1 discomfort increases1 with a decided lowering of human efficiency4 ,we must not forget1 either1 the risk attending the presence of a steam-pipe4 ,were it broken1 by accident or in a naval engagement1 a great loss of life might result1 or1 at least1 the abandonment of all neighbouring machinery4 ,for these reasons there is1 therefore1 a tendency to abolish the direct use of steam in the auxiliary machinery of a modern vessel4 ,high-pressure water is free from heating and danger troubles1 and consequently is used for much heavy work1 such as training guns1 raising ashes and ammunition1 and steering4 ,one of its great advantages is its inelasticity1 which prevents the overrunning of gear worked by it4 ,water1 being incompressible1 gives a positive drive2 thus1 if the pump delivers a pint at each stroke in the engine-room a pint must pass into the motor1 assuming that all joints are tight1 and the work due from the passage of one pint is done4 ,air and steam--and electricity too1 if not very delicately controlled--are apt to work in fits and starts when operating against varying resistance1 and run away from the engineer4 ,an objection to hydraulic power is1 that all leakage from the system must be replaced by fresh water manufactured on board1 which1 as we have seen1 is no easy task4 ,compressed air1 like steam1 may cause explosions2 but when it escapes in small quantities only it has a beneficial effect in cooling and freshening the air below decks4 ,the exhaust from an air-driven motor is welcome for the same reason1 that it aids ventilation4 ,on a fighting ship it is of the utmost importance that the personnel should be in good physical condition2 and when the battle-hatches have been battened down for an engagement any supply of fresh oxygen means an increased staying power for officers and crew4 ,poisoned air brings mental slackness1 and weakening of resolve2 so that if the motive power of heavy machinery can be made to do a second duty1 so much the better for all concerned4 ,compressed air also proves useful as a water-excluder4 ,if a vessel contain1 as it should1 a number of water-tight compartments1 any water rushing into one of these can be expelled by injecting air until the pressure inside is equal to that of the draught of water of the vessel outside4 ,on land compressed-air installations include reservoirs of large size in which air can be stored till needed1 and which take the place of the accumulator used with hydraulic power4 ,on shipboard want of space reduces such reservoirs to minimum dimensions1 so that the compressors must squirt their air almost directly into the cylinders which do the work4 ,when the load1 or work1 is constantly varying1 this direct drive proves somewhat of a nuisance1 since the compressors1 if worked continuously at their maximum capacity1 must waste large quantities of air1 while if run spasmodically1 as occasion demands1 they require much more attention4 ,it is therefore considered advisable by some marine engineers to make compressed air perform as many functions as possible when it is present on a vessel4 ,the ,united ,states monitor ,terror is an instance of a warship which depends on this agency for working her guns and turrets1 handling ammunition1 and--a somewhat unusual practice--controlling the helm4 ,the last operation is performed by two large cylinders placed face to face athwart the ship4 ,they have a common piston-rod1 in the middle of which is a slot for the tiller to pass through4 ,air is admitted to the cylinders by a valve which is controlled by wires passing over a train of wheels from different stations on the ship4 ,an ingenious device automatically prevents the tiller from moving over too fast1 and also helps to lessen the shocks given to the rudder by a heavy sea4 ,we now come to electricity1 the fourth and most modern form of transmission4 ,its chief recommendation is that the wires through which it flows lend themselves readily to a tortuous course without in any way throttling the passage of power4 ,and as every ship must carry a generating plant for lighting purposes1 the same staff will serve to tend a second plant for auxiliary machinery4 ,electric motors work with practically no vibration1 are light for their power1 and can be very easily controlled from a distance4 ,they therefore enjoy increasing favour2 and are found in deck-winches1 anchor-capstans1 ammunition hoists1 ventilation blowers1 and cranes4 ,they also control the movements of gun-turrets1 having been found most suitable for this work4 ,if the current were to get loose in a ship it would undoubtedly cause more damage than an escape of compressed air or water4 ,electricity1 even when every known means of keeping it within bounds has been tried1 is suspected of causing deterioration to the metalwork of ships4 ,but these disadvantages are not serious enough to hamper the progress of electrical science as applied to marine engineering2 and the undoubted economy of the electric motor1 its noiselessness1 its manageableness1 and comparatively small size will1 no doubt1 in the future lead to its much more extensive use on board our floating palaces and floating forts4 ,,footnotes3 #af ,f4 ,m4 ,bennett1 in the ,journal of the ,american ,society of ,naval ,engineers4 #ag ,charles ,v4 ,daly1 in ,the ,magazine of ,commerce4 ,,chapter ,,xiii ,,the ,,nurse ,,of ,,the ,,navy ,just as a navy requires floating distilleries1 floating coal stores and floating docks1 so does it find very important uses for a floating workshop1 which can accompany a fleet to sea and execute such repairs as might otherwise entail the return of a ship to port4 ,the ,british ,navy has a valuable ally of this kind in the torpedo dept ship ,vulcan1 which contains so much machinery1 in addition to the auxiliaries already described1 that a short account of this vessel will be interesting4 ,the ,vulcan1 known as ,the ,nurse of the ,navy1 was launched in #ahhi4 ,she measures #cej feet in length1 #eh feet in beam1 and has a displacement of #f1hcj tons4 ,her bunkers1 of which there are twenty-one1 hold #a1jjj tons of coal1 independently of an extra #cjj tons which can be stowed in other neighbouring compartments4 ,when fully coaled she can cruise for #g1jjj miles at a speed of #aj knots2 or travel at first-class cruiser speed for shorter distances4 ,the most striking objects on the ,vulcan are two huge hydraulic cranes1 placed almost amidships abreast of one another4 ,they have a total height of #fe feet1 and overhang #ce feet1 so as to be able to lift boats when the torpedo-nets are out and the sides of the vessel cannot be approached4 ,the feet of the cranes sink #cj feet through the ship to secure rigidity1 and the upper deck1 which bears most of the strain1 is strongly reinforced4 ,inside the pillar of each crane is the lifting machinery1 an hydraulic ram #ag-a_/b inches in diameter and of #aj-;foot stroke4 ,by means of fourfold pulleys the lift is increased to #dj feet4 ,when working under the full pressure of #a1jjj lbs4 to the square inch1 the cranes have a hoisting power of twenty tons4 ,in addition to the main ram there is a much smaller one1 the function of which is to keep the slings 7or cables by which the boat is hoisted7 taut after a boat has been hooked until the actual moment of lifting comes4 ,but for this arrangement there would be a danger of the slings slackening as the boat rises and falls in a seaway4 ,the small ram controls the larger1 and the latter cannot come into action until its auxiliary has tightened up the slings1 so that no dangerous jerk can occur when the hoisting begins4 ,the cranes are revolved by two sets of hydraulic rams1 which operate chains passing round drums at the feet of the cranes1 and turn them through three-quarters of a circle4 ,on the ,vulcan's deck lie six torpedo boats and three despatch boats4 ,the former are #fj feet long1 and can attain a speed of #af knots an hour4 ,when an enemy is sighted these would be sent off to worry the hostile vessels with their deadly torpedoes1 and on their return would be quickly picked up and restored to their berths1 ready for further use4 ,illustration3 ,photo ,cribb4 ,a #ab-;inch gun being lowered into its place in the turret of a warship by a gigantic sheer-leg crane1 one leg of which is partly visible on the left of the picture4 ,the cranes also serve to lift on board heavy pieces of machinery from other vessels for repair4 ,down below decks is the workshop1 wherein jobs are done on the high seas4 ,it has quite a respectable equipment3 five lathes1 ranging from #ae feet to #c-a_/b feet in length2 drilling1 planing1 slotting1 shaping1 punching machines2 a carpenter's bench2 fitters' benches2 and a furnace for melting steel4 ,there is also a blacksmith's shop with an hydraulic forging press and a forge blown by machinery2 not to mention a large array of tools of all kinds4 ,special engines are installed to operate the repairs department4 ,the ,vulcan also carries search-lights of #be1jjj candle-power2 bilge pumps which will deliver over #e1jjj tons of water per hour2 two sets of engines for supplying the hydraulic machinery2 air-compressing engines to feed the ,whitehead torpedoes2 a distilling plant2 and last1 but by no means least1 main engines of #ab1jjj h4p4 drawing steam from four huge cylindrical boilers #ag feet long and #ad feet in diameter4 ,altogether1 the ,vulcan is a very complete floating workshop1 sufficiently speedy to keep up with a fleet1 and even to do scouting work4 ,her guns and her torpedo craft would render her a very troublesome customer in a fight1 though1 being practically unarmoured1 she would keep as clear of the conflict as possible1 acting on the offensive through the proxy of her hornets4 ,she constitutes the first of a type of vessel which has been suggested by experts1 viz4 one of high speed and unarmoured1 but capable of carrying a swarm of torpedo boats which could be launched in pursuit of the foe4 ,even if #ej per cent4 of the craft were destroyed1 the price would be small if a single torpedo were successfully fired at a battleship4 ,the naval motor boat1 to which reference has already been made1 would just fill the bill for such a cruiser2 and in the event of a score of them being dropped into the water at a critical moment1 they might easily turn the scale in favour of their side4 ,,chapter ,,xiv ,,the ,,mechanism ,,of ,,diving ,diving being a profession which can be carried on in its simplest form with the simplest possible apparatus--merely a rope and a stone--its history reaches back into the dim and inexplorable past4 ,we may well believe that the first man who explored the depths of the sea for treasure lived as long ago as the first seeker for minerals in the bosom of the earth4 ,even when we come to the various appliances which have been gradually developed in the course of centuries1 our records are very imperfect4 ,alexander the ,great is said to have descended in a machine which kept him dry1 while he sought for fresh worlds to conquer below the waves4 ,aristotle mentions a device enabling men to remain some time under water4 ,this is all the information1 and a very meagre total1 too1 that we get from classical times4 ,stepping across #a1ejj years we reach the thirteenth century1 about the middle of which ,roger ,bacon is said to have invented the diving-bell4 ,but like some other discoveries attributed to that ,middle-,age physicist1 the authenticity of this rests on very slender foundations4 ,in a book published early in the sixteenth century there appears an illustration of a diver wearing a cap or helmet1 to which is attached a leather tube floated on the surface of the water by an inflated bag4 ,this is evidently the diving dress in its crudest form2 and when we read how1 in #aech1 two ,greeks made a submarine trip under a huge inverted chamber1 which kept them dry1 in the presence of the great ,emperor ,charles ,v4 and some #ab1jjj spectators1 we recognise the diving-bell1 now so well known4 ,the latter device did not reach a really practical form till #agag1 when ,dr4 ,halley1 a member of the ,royal ,society1 built a bell of wood lined with lead4 ,the divers were supplied with air by having casks-full lowered to them as required4 ,to quote his own words3 ,to supply air to this bell under water1 ,i caused a couple of barrels of about thirty gallons each to be cased with lead1 so as to sink empty1 each of them having a bunghole in its lowest parts to let in the water1 as the air in them condensed on their descent1 and to let it out again when they were drawn up full from below4 ,and to a hole in the uppermost parts of these barrels ,i fixed a leathern hose1 long enough to fall below the bunghole1 being kept down by a weight appended1 so that the air in the upper parts of the barrels could not escape1 unless the lower ends of these hose were first lifted up4 ,the air-barrels being thus prepared1 ,i fitted them with tackle proper to make them rise and fall alternately1 after the manner of two buckets in a well2 and in their descent they were directed by lines fastened to the under edge of the bell1 which passed through rings on both sides of the leathern hose in each barrel1 so that1 sliding down by these lines1 they came readily to the hand of a man1 who stood on purpose to receive them1 and to take up the ends of the hose into the bell4 ,through these hose1 as soon as their ends came above the surface of the water in the barrels1 all the air that was included in the upper parts of them was blown with great force into the bell1 whilst the water entered at the bungholes below and filled them1 and as soon as the air of one barrel had been thus received1 upon a signal given that was drawn up1 and at the same time the other descended1 and by an alternate succession1 provided air so quick and in such plenty that ,i myself have been one of five who have been together at the bottom1 in nine to ten fathoms water1 for above an hour and a half at a time1 without any sort of ill-consequence1 and ,i might have continued there so long as ,i pleased for anything that appeared to the contrary4 ,after referring to the fact that1 when the sea was clear and the sun shining1 he could see to read or write in the submerged bell1 thanks to a glass window in it1 the ,doctor goes on to say3 ,this ,i take to be an invention applicable to various uses1 such as fishing for pearls1 diving for coral or sponges and the like1 in far greater depths than has hitherto been thought possible2 also for the fitting and placing of the foundations of moles1 bridges1 etc41 in rocky bottoms1 and for cleaning and scrubbing ships' bottoms when foul1 in calm weather at sea4 ,i shall only intimate that1 by an additional contrivance1 ,i have found it not impracticable for a diver to go out of an engine to a good distance from it1 the air being conveyed to him with a continued stream by small flexible pipes1 which pipes may serve as a clue to direct him back again when he would return to the bell4 ,we have italicised certain words to draw attention to the fact that ,dr4 ,halley had invented not only the diving bell1 but also the diving dress4 ,though he foresaw practically all the uses to which diving mechanism could be put1 the absence of a means for forcing air under pressure into the bell or dress greatly limited the utility of his contrivances1 since the deeper they sank below the water the further would the latter rise inside them4 ,it was left for ,john ,smeaton1 of ,eddystone ,lighthouse fame1 to introduce the air-pump as an auxiliary1 which1 by making the pressure of the air inside the bell equal to that of the water outside1 kept the bell quite free of water4 ,smeaton replaced ,halley's tub by a square1 solid cast-iron box1 #ej cwt4 in weight1 large enough to accommodate two men at a time4 ,the modern bell is merely an enlarged edition of this type1 furnished with telephones1 electric lamps1 and1 in some cases1 with a special air-lock1 into which the men may pass when the bell is raised4 ,the pressure in the air-lock is very gradually decreased after the bell has reached the surface1 if work has been conducted at great depths1 so that the evil effects sometimes attending a sudden change of pressure on the body may be avoided4 ,diving bells are very useful for laying submarine masonry1 usually consisting of huge stone blocks set in hydraulic cement4 ,helmet divers explore and prepare the surface on which the blocks are to be placed4 ,then the bell1 slung either from a crane on the masonry already built above water-level1 or from a specially fitted barge1 comes into action4 ,the block is lowered by its own crane on to the bottom4 ,the bell descends upon it and the crew seize it with tackle suspended inside the bell4 ,instructions are sent up as to the direction in which the bell should be moved with its burden1 and as soon as the exact spot has been reached the signal for lowering is given1 and the stone settles on to the cement laid ready for it4 ,the modern diver is not sent out from a bell1 but has his separate and independent apparatus4 ,the first practical diving helmet was that of ,kleingert1 a ,german4 ,this enclosed the diver as far as the waist1 and constituted a small diving bell1 since the bottom was open for the escape of vitiated air4 ,twenty years later1 or just a century after the invention of ,halley's bell1 ,augustus ,siebe1 the founder of the present great ,london firm of ,siebe1 ,gorman1 and ,company1 produced a more convenient open dress1 consisting of a copper helmet and shoulder-plate in one piece1 attached to a waterproof jacket reaching to the hips4 ,the disadvantage of the open dress was1 that the diver had to maintain an almost upright position1 or the water would have invaded his helmet4 ,mr4 ,siebe therefore added a necessary improvement1 and extended the dress to the feet1 giving his diver a close protection from the water4 ,we may pass over the gradual development of the close dress and glance at the most up-to-date equipment in which the toilers of the deep explore the bed of ,old ,ocean4 ,the dress--legging1 body1 and sleeves--is all in one piece1 with a large-enough opening at the shoulders for the body to pass through4 ,the helmet1 with front and side windows1 is attached by a bayonet joint to the shoulder-plate1 itself made fast to the upper edge of the dress by screws which press a metal ring against the lower edge of the plate so as to pinch the edge of the dress4 ,illustration3 ,photo ,cribb4 ,,the ,,diver ,,at ,,work ,note the telephone attachment1 the wires of which are embedded in the life-line held by the bluejacket on the left4 ,by means of the telephone the diver can give and receive full instructions about his work4 ,at the back are an inlet and an outlet valve4 ,between the front and a side window is the transmitter of a loud-sounding telephone1 and in the crown the receiver and the button of an electric bell4 ,the telephone wires1 and also the wires for a powerful electric light1 working on a ball-and-socket joint in front of the dress1 are embedded into the life-line4 ,the air-tube1 of canvas and rubber1 has a stiffening of wire to prevent its being throttled on coming into contact with any object4 ,a pair of weighted boots1 each scaling #ag lbs41 two #dj-lb4 lead weights slung over the shoulder1 and a knife worn at the waist-belt1 complete the outfit of the diver1 which1 not including the several layers of underclothing necessary to exclude the cold found at great depths1 totals nearly #adj lbs4 ,of this the copper helmet accounts for #cf lbs4 ,on the surface are the air-pumps1 which may be of several types--single-cylinder1 double-acting2 double-cylinder1 double-acting2 or three or four cylinder1 single-acting--according to the nature of the work4 ,all patterns are so constructed that the valves may be easily removed and examined4 ,the pressure on a diver increases in the ratio of about #d-a_/d lbs4 for every ten feet he descends below the surface4 ,a novice experiences severe pains in the ears and eyes at a few fathoms' depth1 which1 however1 pass off when the pressures both inside and outside of the various organs have become equalised4 ,on rising to the surface again the pains recur1 since the external pressure on the body falls more quickly than the internal4 ,the rule for all divers1 therefore1 is slow down1 slow up4 ,men of good constitution and resourcefulness are needed for the profession of diving4 ,only a few can work at extreme depths1 though an old hand is able to remain for several hours at a time in sixty feet of water4 ,the record depth reached by a diver is claimed by ,james ,hooper1 who1 when removing the cargo of the ,cape ,horn1 wrecked off the coast of ,south ,america1 made seven descents to #bja feet1 one of which lasted forty-two minutes4 ,in spite of the dangers and inconveniences attached to his calling1 the diver finds in it compensations1 and even fascinations1 which outweigh its disadvantages4 ,the pay is good--#a to #b a day--and in deep-sea salvage he often gets a substantial percentage of all the treasure recovered1 the percentage rising as the depth increases4 ,thus the diver ,alexander ,lambert1 who performed some plucky feats during the driving of the ,severn ,tunnel1#ah received #d1jjj for the recovery of #gj1jjj worth of gold from the ,alphonso ,,xii41 sunk off ,grand ,canary4 ,divers ,ridyard and ,penk recovered #ej1jjj from the ,hamilla ,mitchell1 which lay in #afj feet of water off ,shanghai1 after nearly being captured by ,chinese pirates2 and we could add many other instances in which treasure has been rescued from the maw of the sea4 ,the most useful sphere for a diver is undoubtedly connected with the harbour work and the cleaning of ships' bottoms4 ,for the latter purpose every large warship in the ,british ,navy carries at least one diver4 ,after ships have been long in the water barnacles and marine growths accumulate on the below-water plates in such quantities as to seriously diminish the ship's speed1 which means a great waste of fuel1 and would entail a loss of efficiency in case of war breaking out4 ,armed with the proper tools1 a gang of divers will soon clean the foul bottom1 at a much smaller cost of time and money than would be incurred by dry-docking the vessel4 ,the ,navy has at ,portsmouth1 ,sheerness1 and ,devonport schools where diving is taught to picked men1 the depth in which they work being gradually increased to #abj feet4 ,messrs4 ,siebe and ,gorman employ hundreds of divers in all parts of the world1 on all kinds of submarine work1 and they are able to boast that never has a defect in their apparatus been responsible for a single death4 ,this is due both to the very careful tests to which every article is subjected before it leaves their works1 and also to the thorough training given to their employs4 ,in the sponge and pearl-fishing industries the diving dress is gradually ousting the unaided powers of the naked diver4 ,one man equipped with a standard dress can do the work of twenty natural divers1 and do it more efficiently1 as he can pick and choose his material4 ,this chapter may conclude with a reference to the apparatus now used in exploring or rescue work in mines1 where deadly fumes have overcome the miners4 ,it consists of an air-tight mask connected by tubes to a chamber full of oxygen and to a bag containing materials which absorb the carbonic acid of exhaled air4 ,the wearer uses the same air over and over again1 and is able to remain independent of the outer atmosphere for more than an hour4 ,the apparatus is also useful for firemen when they have to pass through thick smoke4 ,,footnote3 #ah ,vide ,the ,romance of ,modern ,engineering1 p4 #bab4 ,,chapter ,,xv ,,apparatus ,,for ,,raising ,,sunken ,,ships ,,and ,,treasure ,it is somewhat curious that1 while the sciences connected with the building of ships have progressed with giant strides1 little attention has been paid to the art of raising vessels which have found watery graves in comparatively shallow depths4 ,the total shipping losses of a single year make terrible reading1 since they represent the extinction of many brave sailors and the disappearance of huge masses of the world's wealth4 ,a life lost is lost for ever1 but cargoes can be recovered if not sunk in water deeper than #ahj feet4 ,yet with all our modern machinery the percentage of vessels raised from even shallow depths is small4 ,there are practically only two methods of raising a foundered ship3 first1 to caulk up all leaks and pump her dry2 and secondly1 to pass cables under her1 and lift her bodily by the aid of pontoons1 or camels4 ,the second method is that more generally used1 especially in the estuaries of big rivers where there is a considerable tide4 ,the pontoons1 having a united displacement greater than that of the vessel to be raised1 are brought over her at low tide4 ,divers pass under her bottom huge steel cables1 which are attached to the camels4 ,as the tide flows the pontoons sink until they have displaced a weight of water equal to that of the vessel1 and then they begin to raise her1 and can be towed into shallower water1 to repeat the process if necessary next tide4 ,as soon as the deck is above water the vessel may be pumped empty1 when all leaks have been stopped4 ,in water where there is no tide the natural lift must be replaced by artificial power4 ,under such circumstances the salvage firms use lighters provided with powerful winches1 each able to lift up to #hjj tons on huge steel cables nearly a foot in diameter4 ,the winches can be moved across a lighter1 the cables falling perpendicularly1 through transverse wells almost dividing the lighter into separate lengths1 so as to get a direct pull4 ,if the wreck has only half the displacement of the lighters1 the cables can be passed over rollers on the inner edges of the pontoons1 the weight of the raising vessel being counteracted by water let into compartments in the outer side of the pontoons4 ,there are ten great salvage companies in the ,british ,isles and ,europe4 ,the best equipped of these is the ,neptune ,company1 of ,stockholm1 which has raised #a1ejj vessels1 worth over #e1jjj1jjj sterling even in their damaged condition1 among them the ill-fated submarine ,a#a4 ,yet this total represents but a small part of the wealth that has gone to the bottom within a short distance of our coasts4 ,turning from the salvage of wrecks to the salvage of precious metal and bulky objects that are known to strew the sea-floor in many places1 we must notice the ,hydroscope1 the invention of ,cavaliere ,pino1 an ,italian4 ,in #agjb there sank in ,vigo ,bay1 on the north-west coast of ,spain1 twenty-five galleons laden with treasure from ,america1 as the result of an attack by ,english and ,dutch men-of-war4 ,gold representing #bh1jjj1jjj was on those vessels4 ,down it went to the bottom1 and there it is still4 ,so rich a prize has naturally not failed to attract daring spirits1 among whom was ,giuseppe ,pino4 ,this inventor has produced many devices1 the most notable among them the hydroscope1 which may best be described as a huge telescope for peering into the depths of the sea4 ,a large circular tank floats on the top of the water4 ,from the centre of its bottom hangs a series of tubes fitting one into the other1 so that the whole series can be shortened or lengthened at will4 ,through the tubes a man can descend to the chamber at their lower extremity1 in the sides of which are twelve lenses specially made by ,saint ,gobain1 of ,paris1 which act as submarine telescopes4 ,pino's hydroscope has been at work for some time in ,vigo ,bay1 its operations closely watched by a ,spanish war vessel1 which will exact #bj per cent4 of all treasure recovered4 ,while the hydroscope acts as an eye1 the lifting of an object is accomplished by attaching to it large canvas bags furnished with air-tight internal rubber bladders4 ,these have air pumped into them till its pressure overcomes that of the water outside1 and the bag then rises like a cork1 carrying its load with it4 ,an elevator--nine sacks fixed to one frame--will raise twenty-five to thirty tons4 ,so far ,cavaliere ,pino has salvaged old ,spanish guns1 cannon-balls1 and pieces of valuable old wood2 and presently he may alight on the specie which is the main object of his search4 ,another ,spanish wreck1 the ,florida1 which was a unit of the ,spanish ,armada1 and sank in ,tobermory ,bay1 the ,isle of ,mull1 has many times been attacked by divers4 ,the last attempt made to recover the treasure which that ill-fated vessel was reputed to bear is that of the steam lighter ,sealight1 which employed a very powerful sand pump to suck up any objects which it might encounter on the sea-bottom4 ,many interesting relics have been raised by the pumps and attendant divers--coins1 bones1 jewels1 timbers1 cannon1 muskets1 pistols1 swords1 and a compass1 which is so constructed that pressure on the top causes the legs to spread4 ,one of the cannon1 fifty-four inches long1 has a separate powder chamber1 the shot and wad still in the gun1 and traces of powder in the chamber4 ,it is curious that what we usually consider so modern an invention as the breech-loading cannon should be found side by side with stone balls4 ,the heavier objects were1 of course1 raised by divers4 ,in this quest also the treasure deposit has not yet been tapped4 ,,chapter ,,xvi ,,the ,,handling ,,of ,,grain ,,the ,,elevator--,,the ,,suction ,,pneumatic ,,grain-,,lifter--,,the ,,pneumatic ,,blast ,,grain-,,lifter--,,the ,,combined ,,system ,,the ,,elevator ,on or near the quays of our large seaports1 ,london1 ,liverpool1 ,manchester1 ,bristol1 ,hull1 ,leith1 ,dublin1 may be seen huge buildings of severe and ugly outline1 utterly devoid of any attempt at decoration4 ,yet we should view them with respect1 for they are to the inhabitants of the ,british ,isles what the inland granaries of ,egypt were to the dwellers by the ,nile in the time of ,joseph4 ,could we strip off the roofs and walls of these structures1 we should see vast bins full of wheat1 or spacious floors deeply strewn with the material for countless loaves4 ,the grain warehouses of ,britain--the ,americans would term them elevators--have a total capacity of #aj1jjj1jjj quarters4 ,multiply those figures by eight1 and you have the number of bushels1 each of which will yield the flour for about forty #b-lb4 loaves4 ,in these granaries is stored the grain which comes from abroad4 ,with the opening up of new lands in ,north and ,south ,america1 and the exploitation of the great wheat-growing steppes of ,russia1 ,english agriculture has declined1 and we are content to import five-sixths of our breadstuffs1 and an even larger proportion of grain foods for domestic animals4 ,it arrives from the ,united ,states1 ,india1 ,russia1 ,argentina1 ,canada1 and ,australia in vessels often built specially for grain transport2 and as it cannot be immediately distributed1 must be stored in bulk in properly designed buildings4 ,these contain either many storeys1 over which the grain is spread to get rid of superfluous moisture which might cause dangerous heating2 or huge bins1 or silos1 in which it can be kept from contact with the air4 ,experiments have proved that wheat is more successfully preserved if the air is excluded than if left in the open1 provided that it is dry4 ,the ancient ,egyptians used brick granaries1 filled from the top1 and tapped at the bottom1 in which1 to judge by the account of a grievous famine given in the book of ,genesis1 their wheat was preserved for at least seven years4 ,during last century the silo fell into disrepute2 but now we have gone back to the ,egyptian plan of closed bins1 which are constructed of wood1 brick1 ferro-concrete1 or iron1 and are of square1 hexagonal1 or round section4 ,they are set close together1 many under one roof1 to economise space2 as many as #b1ihe1jjj bushels being provided for in the largest ,english storehouse4 ,such vast quantities of grain require well-devised machinery for their transport from ship to bin or floor1 weighing1 clearing1 and for their transference to barges1 coasting vessels1 or railway trucks4 ,the ,alexander ,grain ,warehouse of ,liverpool may be taken as a typical example of a well-equipped silo granary4 ,it measures #bdj by #agb feet1 and contains #bej hexagonal bins of brickwork1 each #hj feet deep and #ab feet in diameter4 ,the grain is lifted from barges by four elevators placed at intervals along the edge of the quay4 ,the elevator is a wooden case1 #dj or #ej feet high1 in which an endless band furnished with buckets travels over two rollers placed at the top and bottom4 ,these are let down into the hold and scoop up the grain at the rate of from #ge to #aej tons per hour1 according to their size4 ,as soon as a bucket reaches the top roller it empties its charge into a spout1 which delivers the grain into a bin1 whence it is lifted again #cb feet by a second elevator to a bin from which it flows by gravity to a weighing hopper beneath2 and as soon as two tons has collected1 the contents are emptied automatically into a distributing hopper4 ,after all this1 the grain still has a long journey before it2 for it is now shot out on to an endless1 flat conveyer belt moving at a rate of #i to #aj feet per second4 ,it is carried horizontally by this for some distance along the quay1 and falls on to a second belt moving at right angles to the first1 which whisks it off to the receiving elevators of the storehouse4 ,once more it is lifted1 this time #acb feet1 to the top floor of the building1 and dropped on to a third belt1 which runs over a movable throwing-off carriage4 ,this can be placed at any point of the belt's travel1 to transfer the grain to any of the spouts leading to the #bej bins4 ,here it rests for a time4 ,when needed for the market it flows out at the bottom of a bin on to belts leading to delivery elevators1 from which it may be either passed back to a storage bin after being well aired1 or shot into wagons or vessels4 ,from first to last a single grain may have to travel three miles between the ship and the truck without being touched once by a human hand4 ,the vertical transport of grain is generally effected by an endless belt1 to which buckets are attached at short intervals4 ,the grain1 fed to the buckets either by hand or by mechanical means1 is scooped up1 whirled aloft1 and when it has passed the topmost point of its travel1 and just as the bucket is commencing the descent1 it flies by centrifugal force into a hopper which guides it to the travelling belt1 as already described4 ,of late years1 however1 much attention has been paid to pneumatic methods of elevating1 by which a cargo is transferred from ship to storehouse1 or from ship to ship1 through flexible tubes1 the motive power being either the pressure of atmospheric air rushing in to fill a vacuum1 or high-pressure air which blows the grain through the tube in much the same way as a steam injector forces water into a boiler4 ,sometimes both systems are used in combination4 ,we will first consider these methods separately4 ,,the ,,suction ,,pneumatic ,,grain-,,lifter is the invention of ,mr4 ,fred ,e4 ,duckham1 engineer of the ,millwall ,docks1 ,london4 ,the ships in which grain is brought to ,england often contain a mixed cargo as well2 and that the unloading of this may proceed simultaneously with the moving of the wheat it is necessary to keep the hatches clear4 ,as long as the grain is directly under a hatchway1 a bucket elevator can reach it2 but all that is not so conveniently situated must be brought within range of the buckets4 ,this means a large bill for labour1 even if machinery is employed to help the trimming4 ,mr4 ,duckham therefore designed an elevator which could easily reach any corner of a ship's interior4 ,the principal parts are a large cylindrical air-tight tank1 an engine to exhaust air from the same1 and long hoses1 armoured inside with a steel lining1 connected at one end to the tank1 and furnished at the other with a nozzle4 ,these hoses extend from the receiving tank to the grain1 which1 when the air has been exhausted to five or six pounds to the square inch1 flies up the tubes into the tank4 ,at the bottom of the tank are ingenious air-locks1 to allow the grain to pass into a bin below without admitting air to spoil the vacuum4 ,the locks are automatic1 and as soon as a certain quantity of grain has collected1 tip sideways1 closing the port through which it flowed1 and allowing it to drop through a hinged door4 ,two locks are attached together1 the one discharging while the other is filling4 ,an elevator of this kind will shift #aej tons or more an hour4 ,mr4 ,duckham claims for his invention that it has no limit in capacity4 ,it is practically independent of everything but its own steam power2 and the labour of one man suffices to keep its flexible suckers buried in grain4 ,no corner is inaccessible to the nozzle4 ,the pipes occupy only a very small part of the hatchway4 ,they can be set to work immediately a vessel comes alongside4 ,as many as a quarter of a million bushels are handled daily by one of these machines4 ,the pneumatic elevator is often installed on a floating base1 so that it may be moved about in a dock4 ,,the ,,pneumatic ,,blast ,,grain-,,lifter differs from the system just described in that the grain is driven through the pipes or hoses by air compressed to several pounds above atmospheric pressure4 ,a small tube attached to the main hose conveys compressed air to the nozzle through which grain enters the tube4 ,the nozzle consists of a short length of metal piping which is buried in the grain4 ,one half of it is encased by a jacket into which the compressed air rushes4 ,as the air escapes at high speed past the inner end of the piping into the main hose1 it causes a vacuum in the piping and draws in grain1 which is shot up the hose by the pressure behind it4 ,as already remarked1 the action of this pneumatic elevator is similar to that of a steam injector4 ,,the ,,combined ,,system ,under some conditions it is found convenient to employ both suction and blast in combination3 suction to draw the grain from a vessel's hold into elevators1 from which it is transferred to the warehouse by blast4 ,special boats are built for this work1 e4g4 the ,garryowen1 which has on board suction plant for transferring grain from a ship to barges1 and also blowing apparatus for elevating it into storehouses or into another ship4 ,the ,garryowen has the hull and engines of an ordinary screw steamer1 so that it can ply up and down the ,shannon and partly unload a vessel to reduce its draught sufficiently to allow it to reach ,limerick ,docks4 ,floating elevators of this kind are able to handle upwards of #aej tons of grain per hour4 ,,chapter ,,xvii ,,mechanical ,,transporters ,,and ,,conveyers ,,mechanical ,,conveyers--,,ropeways--,,cableways--,, telpherage--,,coaling ,,warships ,,at ,,sea ,a man carrying a sack of coal over a plank laid from the wharf to the ship's side1 a bricklayer's labourer moving slowly up a ladder with his hod of mortar--these illustrate the most primitive methods of shifting material from one spot to another4 ,when the wheelbarrow is used in the one case1 and a rope and pulley in the other1 an advance has been made1 but the effort is still great in proportion to the work accomplished2 and were such processes universal in the great industries connected with mining and manufacture1 the labour bill would be ruinous4 ,the development of methods of transportation has gone on simultaneously with the improvement of machinery of all kinds4 ,to be successful1 an industry must be conducted economically throughout4 ,thus1 to follow the history of wheat from the time that it is selected for sowing till it forms a loaf1 we see it mechanically placed in the ground1 mechanically reaped1 threshed1 and dressed1 mechanically hauled to the elevator1 mechanically transferred to the bins of the same1 mechanically shot into trucks or a ship1 mechanically raised into a flour-mill1 where it is cleaned1 ground1 weighed1 packed1 and trucked by machinery1 mechanically mixed with yeast and baked1 and possibly distributed by mechanically operated vehicles4 ,as a result we get a #b-lb4 loaf for less than three-pence4 ,anyone who thinks that the price is regulated merely by the amount of wheat grown is greatly mistaken1 for the cheapness of handling and transportation conduces at least equally to the cheapness of the finished article4 ,the same may be said of the metal articles with which every house is furnished4 ,a fender would be dearer than it is were not the iron ore cheaply transported from mine to rail1 from rail to the smelting furnace1 from the ground to the top of the furnace4 ,in short1 to whatever industry we look1 in which large quantities of raw or finished material have to be moved1 stored1 and distributed1 the mechanical conveyer has supplanted human labour to such an extent that in lack of such devices we can scarcely conceive how the industry could be conducted without either proving ruinous to the people who control it or enhancing prices enormously4 ,the types of elevators and conveyers now commonly used in all parts of the world are so numerous that in the following pages only some selected examples can be treated4 ,speaking broadly1 the mechanical transporter can be classified under two main heads--7#a7 those which handle materials continuously1 as in the case of belt conveyers1 pneumatic grain dischargers1 etc42 and 7#b7 those which work intermittently1 such as the telpher1 which carries skips on an aerial ropeway4 ,the first class are most useful for short distances2 the latter for longer distances1 or where the conditions are such that the material must be transported in large masses at a time by powerful grabs4 ,some transporters work only in a vertical direction2 others only horizontally2 while a third large section combine the two movements4 ,again1 while some are mere conveyers of material shot into or attached to them1 others scoop up their loads as they move4 ,the distinctions in detail are numerous1 and will be brought out in the chapters devoted to the various types4 ,,mechanical ,,conveyers ,we have already noticed band conveyers in connection with the transportation of grain4 ,they are also used for handling coal1 coke1 diamond dirt1 gold ore1 and other minerals1 and for moving filled sacks4 ,the belts are sometimes made of rubber or of balata faced with rubber on the upper surface1 which has to stand most of the wear and tear--sometimes of metal plates joined together by hinges at the ends4 ,a modification of the belt is the continuous trough1 with sloping or vertical sides4 ,this is built of open-ended sections jointed so that they may pass round the terminal rollers4 ,while travelling in a straight line the sides of the sections touch1 preventing any escape of the material carried1 but at the rollers the ends open in a ,v-shape4 ,another form of conveyer has a stationary trough through which the substance to be handled is pulled along by plates attached to cables or endless chains running on rollers4 ,or the moving agency may be plates dragged backwards and forwards periodically1 the plates hanging in one direction only1 like flap valves1 so as to pass over the material during the backward stroke1 and bite it during the forward stroke4 ,the vibrating conveyer is a trough which moves bodily backwards and forwards on hinged supports1 the oscillation gradually shaking its contents along4 ,as no dragging or pushing plates are here needed1 this form of conveyer is very suitable for materials which are liable to be injured by rough treatment4 ,,ropeways ,a certain person on asking what was the distance from ,x to ,y1 received the reply1 ,it is ten miles as the crow flies4 ,the country being mountainous1 the answer did not satisfy him1 and he said1 ,oh6 but you see1 ,i am not a crow4 ,engineers laying out a railway can sympathise with this gentleman1 for they know from sad experience that places only a few miles apart in a straight line often require a track many miles long to connect them if gradients are to be kept moderate4 ,now a locomotive1 a railway carriage1 or a goods truck is very heavy1 and must run on the firm bosom of ,mother ,earth4 ,but for comparatively light bodies a path may be made which much more nearly resembles the proverbial flight of the crow1 or1 as our ,american cousins would say1 a bee-line4 ,if you have travelled in ,norway and ,switzerland you probably have noticed here and there steel wire ropes spanning a torrent or hanging across a narrow valley4 ,over these ropes the peasants shoot their hay crops or wood faggots from the mountain-side to their homes1 or to a point near a road where the material can be transferred to carts4 ,adventurous folk even dare to entrust their own bodies to the seemingly frail steel thread1 using a brake to control the velocity of the descent4 ,the history of the modern ropeway and cableway dates from the 'thirties1 when the invention of wire rope supplied a flexible carrying agent of great strength in proportion to its weight1 and of sufficient hardness to resist much wear and tear1 and too inelastic to stretch under repeated stresses4 ,to prevent confusion1 we may at once state that a ropeway is an aerial track used only for the conveyance of material2 whereas a cableway hoists as well as conveys4 ,a further distinction--though it does not hold good in all cases--may be seen in the fact that1 while cableways are of a single span1 ropeways are carried for distances ranging up to twenty miles over towers or poles placed at convenient intervals4 ,ropeways fall into two main classes3 first1 those in which the rope supporting the weight of the thing carried moves2 secondly1 those in which the carrier rope is stationary1 and the skips1 or tubs1 etc41 are dragged along it by a second rope4 ,the moving rope system is best adapted for light loads1 not exceeding six hundredweight or so2 but over the second class bodies scaling five or six tons have often been moved4 ,in both systems the line may be single or double1 according to the amount of traffic which it has to accommodate4 ,the chief advantage of the double ropeway is that it permits a continuous service and an economy of power1 since in cases where material has to be delivered at a lower level than the point at which it is shipped1 the weight of the descending full trucks can be utilised to haul up ascending empty trucks4 ,spans of #b1jjj feet or two-fifths of a mile are not at all unusual in very rough country where the spots on which supports can be erected are few and far between2 but engineers naturally endeavour to make the span as short as possible1 in order to be able to use a small size of rope4 ,glancing at some interesting ropeways1 we may first notice that used in the construction of the new ,beachy ,head ,lighthouse1 recently erected on the foreshore below the head on which the original structure stands4 ,for the sake of convenience1 the workshops1 storage yards1 etc41 were placed on the cliffs1 #djj feet above the sea and some #hjj feet in a direct line from the site of the new lighthouse4 ,between the cliff summit and a staging in the sea were stretched two huge steel ropes1 the one1 six inches in circumference1 for the track over which the four-ton blocks of granite used in the building1 machinery1 tools1 etc41 should be lowered2 the other1 #e-a_/b inches in circumference1 for the return of the carriers and trucks containing workmen4 ,the ropes had a breaking strain of #abj and #ajj tons respectively2 that is to say1 if put in an hydraulic testing machine they would have withstood pulls equal to those exerted by masses of these weights hung on them4 ,their top ends were anchored in solid rock2 their lower ends to a mass of concrete built up in the chalk forming the sea-bottom4 ,when a granite block was attached to the carrier travelling on the rope1 its weight was gradually transferred to the rope by lowering the truck on which it had arrived until the latter was clear of the block4 ,as soon as the stone started on its journey the truck was lifted again to the level of the rails and trundled away4 ,a brakesman1 stationed at a point whence he could command the whole ropeway1 had under his hand the brake wheels regulating the movements of the trailing ropes for lowering and hauling on the two tracks4 ,another interesting ropeway is that at ,hong-,kong1 which transports the workmen in a sugar factory on the low1 fever-breeding levels to their homes in the hills where they may sleep secure from noxious microbes4 ,the carriers accommodate six men at a time1 and move at the rate of eight miles an hour4 ,the sensation of being hauled through mid-air must be an exhilarating one1 and some of us would not mind changing places with the workmen for a trip or two1 reassured by the fact that this ropeway has been in operation for several years without any accident4 ,in ,southern ,india1 in the ,anamalai ,hills1 a ropeway is used for delivering sawn timber from the forests to a point #a-a_/d miles below4 ,prior to the establishment of this ropeway the logs were sent down a circuitous mountain track on bullock carts4 ,its erection was a matter of great difficulty1 on account of the steep gradients and the dense and unhealthy forest through which a path had to be cut2 not to mention the dragging uphill of a cable which1 with the reel on which it was wound1 weighed four tons4 ,for this last operation the combined strength of nine elephants and a number of coolies had to be requisitioned1 since the friction of the rope dragging on the ground was enormous4 ,however1 the engineers soon had the cable stretched over its supports1 and the winding machinery in place at the top of the grade4 ,the single rope serves for both up and down traffic2 a central crossing station being provided at which the descending can pass the ascending carrier4 ,seven sleepers at a time are sent flying down the track at a rate of twenty miles an hour3 a load departing every half-hour4 ,the saving of labour1 time1 and expense is said to be very great1 and when the saw mills have a larger output the economy of working will be still more remarkable4 ,the longest passenger ropeway ever built is probably that over the ,chilkoot ,pass in ,alaska1 which was constructed in #ahig and #ahih to transport miners from ,dyea to ,crater ,lake on their way to the ,yukon goldfields4 ,from ,crater ,lake to the ,klondike the ,yukon ,river serves as a natural road1 but the climb to its head waters was a matter of great difficulty1 especially during the winter months1 and accompanied by much suffering4 ,but when the trestles had been erected for the fixed ropes1 two in number1 miners and their kits were hauled over the seven miles at little physical cost1 though naturally the charges for transportation ruled higher than in less rugged regions4 ,the opening of the ,white ,pass ,railway from ,skagway has largely abolished the need for this cable track1 which has nevertheless done very useful work4 ,the ,chilkoot ropeway has at least two spans of over #a1ejj feet4 ,as an engineering enterprise it claims our consideration1 since the conveyance of ropes1 timber1 engines1 etc41 into so inhospitable a region1 and the piecing of them together1 demanded great persistence on the part of the engineers and their employs4 ,,cableways ,for removing the over-burden of surface mines and dumping it in suitable places1 for excavating canals1 for dredging1 and for many other operations in which matter has to be moved comparatively short distances1 the cableway is largely employed4 ,we have already noticed that it differs from the ropeway in that it has to hoist and discharge its burdens as well as convey them4 ,the cableway generally consists of a single span between two towers1 which are either fixed or movable on rails according to the requirements of the work to be done4 ,in addition to the main cable which bears the weight1 and the rope which moves the skips along it1 the cableway has the fall rope1 which lowers the skip to the ground and raises it2 the dumping rope1 which discharges it2 and the button rope1 which pulls blocks off the horn of the skip truck at intervals as the latter moves1 to support the fall rope from the main cable4 ,if the fall rope sagged its weight would1 after a certain amount had been paid out1 overcome the weight of the skip1 and render it impossible to lower the skip to the filling point4 ,so a series of fall-rope carriers are1 at the commencement of a journey from one end of the cableway1 riding on an arm in front of the skip carriage4 ,the button-rope1 passing under a pulley on the top of the skip carriage1 is furnished at intervals with buttons of a size increasing towards the point at which the skip must be lowered4 ,the holes in the carriers are similarly graduated so as to pass over any button but the one intended to arrest them4 ,if we watched a skip travelling to the lowering point1 we should notice that the carriers were successively pulled off the skip carriage by the buttons1 and strung along over the main cable and under the fall rope4 ,when the skip has been lowered and filled the fall and hauling ropes are wound in2 the skip rises to the main cable1 and begins to travel towards the dumping point4 ,as long as the dumping rope is also hauled in at the same rate as the hauling rope it has no effect on the skip1 but when its rate of travel is increased by moving it on to a larger winding drum1 the skip is tipped or opened1 as the case may be1 without being arrested4 ,the skip may be filled by hand or made self-filling where circumstances permit4 ,the cableway is so economical in its working that it has greatly advanced the process of open-pit mining4 ,where ore lies near the surface it is desirable to remove the useless overlying matter 7called over-burden7 bodily1 and to convey it right away1 in preference to sinking shallow shafts with their attendant drawbacks of timbering and pumping4 ,an inclined railway is handicapped by the fact that it must occupy some of the surface to be uncovered1 while liable to blockage by the dbris of blasting operations4 ,the suspended cableway neither obstructs anything nor can be obstructed1 and is profitably employed when a ton of ore is laid bare for every four tons of over-burden removed4 ,in the case of the ,tilly ,foster ,mine1 ,new ,york1 where the removal of #cjj1jjj tons of rock exposed #fjj1jjj tons of ore from an excavation #dej ft4 long by #cjj ft4 wide1 the saving effected by the cableway was enormous4 ,again1 referring to the ,chicago ,drainage ,canal1 the records show that while labourers1 sledging and filling into cars1 averaged only #g to #h-a_/b cubic yards per man per day1 in filling into skips for the cable ways the labourers averaged from #ab to #ag cubic yards per day4#ai ,the first cableway erected by the ,lidgerwood ,manufacturing ,company for the prosecution of this engineering work handled #aj1hba cubic yards a month1 and proved so successful that nineteen similar plants were added4 ,the cableways are suspended in this instance from two towers moving on parallel tracks on each bank of the canal1 the towers being heavily ballasted on the outer sides of their bases to counteract the pull of the cable4 ,from time to time1 when a length had been cleared1 the towers were moved forward by engines hauling on fixed anchors4 ,the cableway is much used in the erection of masonry piers for bridges across rivers or valleys4 ,materials are conveyed by it rapidly and easily to points over the piers and lowered into position4 ,spans of over #a1ejj feet have been exceeded for such purposes2 and if need be1 spans of #b1jjj feet could be made to carry loads of twenty-five tons at a rate of twenty miles an hour4 ,,telpherage ,on most ropeways the skips or other conveyances are moved along the fixed ropes by trailing ropes working round drums driven by steam and controlled by brakes4 ,but the employment of electricity has provided a system called telpherage1 in which the vehicle carries its own motor1 fed by current from the rope on which it runs and from auxiliary cables suspended a short distance above the main rope4 ,telpher is a term derived from two ,greek words signifying a far carrier1 since the motor so named will move any distance so long as a track and current is supplied to it4 ,the carrier--for ore1 coal1 earth1 barrels1 sacks1 timber1 etc4--is suspended from the telpher by the usual hook-shaped support common to ropeways1 to enable the load to pass the arms of the posts or trestles bearing the rope4 ,the telpher usually has two motors1 one placed on each side of a two-wheeled carriage so as to balance2 but sometimes only a single motor is employed4 ,just above the running cable is the trolley cable1 from which the telpher picks up current through a hinged arm1 after the manner of an electric tram4 ,the carriers are controlled on steep grades by an electric braking device1 which acts automatically1 its effect varying with the speed at which the telpher runs4 ,the carrier wheels1 driven by the motors1 adhere to the cable without slipping on grades as severe as three in ten1 even when the surface has been moistened by rain4 ,in order to stop the telpher at any desired point1 the trolley wire is divided into a number of sections1 each controlled by a switch conveniently located4 ,by opening a switch the current is cut off from the corresponding section1 and the telpher will stop when it reaches this point4 ,it is again started by closing the switch4 ,at curves a section of the trolley wire 7i4e4 overhead cable for current7 is connected to the source of current through a 'resistance' which lowers the voltage 7pressure of the current7 across the motors at this point4 ,thus1 upon approaching a curve1 the telpher automatically slows down1 runs slowly around the curve until it passes the resistance section1 and is then automatically accelerated4#bj ,the telpher line is very useful 7for transporting material considerable distances7 in districts where it would not pay to construct a surface railway4 ,on plantations it serves admirably to shift grain1 fruits1 tobacco1 and other agricultural products4 ,then1 again1 a wide field is open to it for transmitting light articles1 such as castings and parts of machinery1 from one part of a foundry or manufactory to another1 or from factory to vessel or truck for shipment4 ,when coal has to be handled1 the buckets are dumped automatically into bins4 ,the telpher has much the same advantages over the steam-worked ropeway that an electric tram has over one moved by an endless cable4 ,its control is easier2 there is less friction2 and the speed is higher4 ,and in common with ropeways it can claim independence of obstructions on the ground1 and the ability to cross ravines with ease1 which in the case of a railway would have to be bridged at great expense4 ,,coaling ,,warships ,,at ,,sea ,the war between ,russia and ,japan has brought prominently before the public the necessity of being able to keep a war vessel well supplied with coal3 a task by no means easy when coaling stations are few and far between4 ,the voyage of ,admiral ,rojdestvensky from ,russia to ,eastern waters was marked by occasions on which he entered neutral ports to draw supplies for his furnaces1 though we know that colliers sailed with the warships to replenish their exhausted bunkers4 ,in the old days of sailing vessels1 their motive power1 even if fitful1 was inexhaustible4 ,but now that steam reigns supreme as the mover of the world's floating forts1 the problem of keeping the sea has become in one way very much more complicated4 ,the radius of a vessel's action is limited by the capacity of her coal bunkers4 ,her captain in war time would be perpetually perplexed by the question of fuel1 since movement is essential to naval success1 while any misjudged fast steaming in pursuit of the enemy might render his ship an inert mass1 incapable of motion1 because the coal supplies had given out2 or at least might compel him to return for supplies to the nearest port at a slow speed1 losing valuable time4 ,illustration3 ,a ,,temperley-,,miller ,,marine ,,cableway ,,coaling ,h4,m4,s4 ,,trafalgar ,,at ,,sea ,a carrier1 from which are slung the sacks of coal1 is hauled backwards and forwards by steel ropes stretching between the foremast of the transport and a mast rigged on the warship4 ,just as a competitor in a long-distance race takes his nourishment without halting1 so should a battleship be able to coal on the wing4 ,the task of transferring so many tons of the mineral from one ship's hold to that of another may seem easy enough to the inexperienced critic1 and under favourable conditions it might not be attended by great difficulty4 ,why1 someone may say1 you have only to bring the collier alongside the warship1 make her fast1 and heave out the coals4 ,in a perfect calm this might be feasible2 but let the slightest swell arise1 and then how the sides of the two craft would bump together1 with dire results to the weaker party6 ,actual tests have shown this4 ,at present broadside coaling is considered impracticable1 but the from bow to stern method has passed through its initial stages1 and after many failures has reached a point of considerable efficiency4 ,the difficulties in transferring coal from a collier to a warship by which she is being towed will be apparent after very little reflection4 ,in the first place1 there is the danger of the cableway and its load dipping into the water1 should the distance between the two vessels be suddenly diminished1 and the corresponding danger of the cable snapping should the pitching of the vessels increase the distance between the terminals of the cableway4 ,these difficulties have made it impossible to merely shoot coals down a rope attached high up a mast of the collier and to the deck of the warship4 ,what is evidently needed is some system which shall pay the cableway out or take it in automatically1 so as to counterbalance any lengthening or shortening movement of the vessels4 ,the ,lidgerwood ,manufacturing ,company of ,new ,york1 under the direction of ,mr4 ,spencer ,miller1 have brought out a cableway specially adapted for marine work4 ,the two vessels concerned are attached by a stout tow-line1 the collier1 of course1 being in the rear4 ,to carry the load1 a single endless wire rope1 #c_/h inch in diameter and #b1jjj feet long1 is employed4 ,it spans the distance between collier and ship twice1 giving an inward track for full sacks1 and an outward track for their return to the collier4 ,on one vessel are two winches1 the drums of which both turn in the same direction2 but while one drum is rigidly attached to its axle1 the other slips under a stress greater than that needed to keep the rope sufficiently taut4 ,since the rope passes round a pulley at the other terminal1 pressure placed at any point on the rope will tend to tighten both tracks1 while a slackening at any point would similarly ease them4 ,supposing1 then1 that the ships suddenly approach1 there will be a certain amount of slack at once wound in2 if1 on the other hand1 the ships draw apart1 the slipping drum will pay out rope sufficient to supply the need4 ,the constant slipping of this drum sets up great heat1 which is dissipated by currents of air4 ,as the sacks of coal arrive on the man-of-war they are automatically detached from the cable1 and fall down a chute into the hold4 ,in the ,temperley ,miller ,marine ,cableway the load is carried on a main cable kept taut by a friction drum1 and the hauling is done by an endless rope which has its own separate winches4 ,in actual tests made at sea in rough weather sixty tons per hour have been transferred1 the vessels moving at from four to eight miles an hour4 ,,footnotes3 #ai ,cassier's ,magazine4 #bj ,cassier's ,magazine4 ,,chapter ,,xviii ,,automatic ,,weighers ,scarcely less important than the rapid transference of materials from one place to another is the quick and accurate weighing of the same4 ,if a pneumatic grain elevator were used in conjunction with an ordinary set of scales such as are to be found at a corn dealer's there would be great delay1 and the advantage of the elevator would largely be lost4 ,similarly a mechanical transporter of coal or ore should automatically register the tonnage of the mineral handled1 to prevent undue waste of time4 ,there are in existence many types of automatic weighing machines1 the general principles of which vary with the nature of the commodity to be weighed4 ,finely divided substances1 such as grain1 seeds1 and sugar1 are usually handled by hopper weighers4 ,the grain1 etc41 is passed into a bin1 from the bottom of which it flows into a large pan4 ,when the proper unit of weight--a hundredweight or a ton--has nearly been attained1 the flow is automatically throttled1 so that it may be more exactly controlled1 and as soon as the full amount has passed1 the machine closes the hopper door and tips the pan over4 ,the latter delivers its contents and returns to its original position1 while the door above is simultaneously opened for the operation to be repeated4 ,a counting apparatus records the number of tips1 so that a glance suffices to learn how much material has passed through the weigher1 which may be locked up and allowed to look after itself for hours together4 ,the ,chronos automatic grain scale is built in many sizes for charges of from #ab to #c1cjj lbs4 of grain1 and tips five times a minute4 ,avery's grain weigher takes up to #e-a_/b tons at a time4 ,for materials of a lumpy nature1 such as coal and ore1 a different method is generally used4 ,the hopper process would not be absolutely accurate1 since the rate of feed cannot be exactly controlled when dust and large lumps weighing half a hundredweight or more are all jumbled together4 ,therefore instead of a pan which tips automatically as soon as it has received a fixed weight1 we find a bin which1 when a quantity roughly equal to the correct amount has been let in1 sinks on to a weigher and has its contents registered by an automatic counter1 which continuously adds up the total of a number of weighings and displays it on a dial4 ,so that if there be #aj lbs4 in excess of a ton at the first charge1 the dial records one ton1 and keeps the #aj lbs4 up its sleeve against the next weighing1 to which the excess is added4 ,avery's mineral scale works1 however1 on much the same principle as that for grain already noticed1 a special device being fitted to render the feed to the weighing pan as regular as possible4 ,his weigher is used to feed mechanical furnace stokers4 ,the quantity of coal used can thus be checked1 while an automatic apparatus prevents the stoker bunkers from being overfilled4 ,continuous weighers register the amount carried by a conveyer while in motion4 ,the recording apparatus comes into action at fixed intervals1 e4g4 as soon as the conveyer has moved ten feet4 ,the weighing mechanism is practically part of the conveyer1 and takes the weight of ten feet4 ,the steelyard is adjusted to exactly counterbalance the unloaded belt or skips of its length1 but rises in proportion to the load4 ,as soon as the conveyer has travelled ten feet the weight on the machine is immediately recorded1 and the steelyard returns to zero4 ,intermittent weighers record the weight of trucks or tubs passing over a railway or the cables of aerial track1 the weigher forming part of the track and coming into play as soon as a load is fully on it4 ,some machines not only weigh material1 but also stow and pack it4 ,we find a good instance in ,timewell's sacking apparatus1 which weighs corn1 chaff1 flour1 oatmeal1 rice1 coffee1 etc41 transfers it to sacks1 and sews the sack up automatically4 ,the amount of time saved by such a machine must be very great4 ,,note4--,the author desires to express his indebtedness to ,mr4 ,george ,f4 ,zimmer's ,the ,mechanical ,handling of ,material for some of the information contained in the above chapter2 and to the publishers1 ,messrs4 ,a4 ,crosby ,lockwood and ,son1 for permission to make use of the same4 ,,chapter ,,xix ,,transporter ,,bridges ,when the writer was in ,rouen1 in #ahih1 two lofty iron towers were being constructed by the ,seine3 the one on the ,quai du ,havre1 the other on the ,quai ,capelier1 which borders the river on the side of the suburb ,st4 ,sever4 ,the towers rose so far towards the sky that one had to throw one's head very far back to watch the workmen perched on the summit of the framework4 ,what were the towers for8 ,they seemed much too slender for the piers of an ordinary suspension bridge fit to carry heavy traffic4 ,an inquiry produced the information that they were the first instalment of a transbordeur1 or transporter bridge4 ,what is a bridge of this kind8 ,well1 it may best be described as a very lofty suspension bridge1 the girder of which is far above the water to allow the passage of masted ships4 ,the suspended girder serves only as the run-way for a truck from which a travelling car hangs by stout steel ropes1 the bottom of the car being but a few feet above the water4 ,the truck is carried across from tower to tower1 either by electric motors or by cables operated by steam-power4 ,the transporter bridge in a primitive form has existed for some centuries1 but its present design is of very modern growth4 ,with the increase of population has come an increased need for uninterrupted communication4 ,where rivers intervene they must be bridged1 and we see a steady growth in the number of bridges in ,london1 ,paris1 ,new ,york1 and other large towns4 ,unfortunately a bridge1 while joining land to land1 separates water from water1 and the dislocation of river traffic might not be compensated by the conveniences given to land traffic4 ,the ,forth1 ,brooklyn1 ,saltash1 and other bridges have1 therefore1 been built of such a height as to leave sufficient head-room under the girders for the masts of the tallest ships4 ,but what money they have cost6 ,and even the ,tower ,bridge1 with its hinged bascules1 or leaves1 and bridges with centres revolving horizontally1 devour large sums4 ,wanted1 therefore1 an efficient means of transport across a river which1 though not costly to install1 shall offer a good service and not impede river traffic4 ,thirty years ago ,mr4 ,charles ,smith1 a ,hartlepool engineer1 designed a bridge of the transporter type for crossing the ,tees at ,middlesbrough4 ,the bridge was not built1 because people feared that the towers would not stand the buffets of the north-easterly gales4 ,the idea promulgated by an ,englishman was taken up by foreign engineers1 who have erected bridges in ,spain1 ,tunis1 and ,france4 ,so successful has this type of ferry-bridge proved1 that it is now receiving recognition in the land of its birth1 and at the present time transporter bridges are nearing completion in ,wales and on the ,mersey4 ,illustration3 ,,the ,,latest ,,type ,,of ,,bridge ,the ,transporter ,bridge at ,bizerta1 ,tunis4 ,it has a span of #ejj feet1 and the suspension girder is #abj feet above high water1 so that the largest vessels may pass under it from the ,mediterranean to the inland lakes4 ,the car is seen near the bottom of the right-hand tower4 ,the first transbordeur built was that spanning the ,nervion1 a river flowing into the ,bay of ,biscay near ,bilbao1 a ,spanish town famous for the great deposits of iron ore close by4 ,a pair of towers rises on each bank to a height of #bdj feet1 and carry a suspended trussed girder #ecj feet long at a level of #aej feet above high-water mark4 ,the car1 giving accommodation for #bjj passengers 7it does not handle vehicles71 hangs on the end of cables #acj feet long1 and is propelled by a steam-engine situated in one of the towers4 ,motion is controlled by the car-conductor1 who is connected electrically with the engine-room4 ,the lofty towers are supported on the landward side by stout steel ropes firmly anchored in the ground4 ,these ropes are carried over the girder in the familiar curve of the suspension bridge1 and attached to it at regular intervals by vertical steel braces4 ,the cost of the bridge--#cb1jjj--;compares favourably with that of any alternative non-traffic-blocking scheme1 and the graceful1 airy lines of the erection are by no means a blot on the landscape4 ,the second transbordeur is that of ,rouen1 already referred to4 ,its span is rather less--#dfg feet--but the suspension girder lies higher by #ad feet4 ,the car is #db feet long by #cf broad1 and weighs1 with a full load1 #fj tons4 ,a passage1 which occupies #ee seconds1 costs one penny first class1 one halfpenny second class2 while a vehicle and horses pay #b-a_/b;d4 to #d;d41 according to weight4 ,the car is propelled by electricity1 under the control of a man in the conning-tower perched on the roof4 ,at ,bizerta we find the third flying-ferry1 which connects that town with ,tunis1 over a narrow channel between the ,mediterranean ,sea and two inland lakes4 ,it replaced a steam-ferry which had done duty for about ten years4 ,the lakes being an anchorage for war vessels1 it was imperative that any bridge over the straits should not interrupt free ingress and egress4 ,this bridge has a span of #ejj feet1 and like that at ,bilbao is worked by steam4 ,light as the structure appears1 it has withstood a cyclone which did great damage in the neighbourhood4 ,it is reported that the ,french ,government has decided to remove the bridge to some other port1 because its prominence would make it serve as a range-finder for an enemy's cannon in time of war4 ,its place would be taken either by a floating-bridge or by a submarine tunnel4 ,the ,nantes transporter over the ,loire differs from its fellows in one respect1 viz4 that it is built on the cantilever or balance principle4 ,instead of a single girder spanning the space between the towers1 it has three girders1 the two end ones being balanced on the towers and anchored at their landward extremities by vertical cables4 ,the gap between them is bridged by a third girder of bow shape1 which is stiff enough in itself to need no central support4 ,the motive power is electricity4 ,all these structures will soon be eclipsed by two ,english bridges3 the one over the ,usk at ,newport1 ,monmouthshire2 the other over the ,mersey and ,manchester ,ship ,canal at ,runcorn ,gap1 where the river narrows to #a1bjj feet4 ,the first of these has towers #bej feet high and #fhe feet apart4 ,the girders will give #agj feet head-room above high-water mark4 ,five hundred passengers will be able to travel at one time on the car1 besides a number of road vehicles1 and as the passage is calculated to take only one minute1 the average velocity will exceed eight miles an hour4 ,the cost has been set down at #fe1jjj1 or about one-thirtieth that of a suspension bridge1 and one-third that of a bascule bridge4 ,the bridge is being built by the ,french engineers responsible for the ,rouen transbordeur4 ,coming to the much more imposing ,runcorn bridge we find even these figures exceeded4 ,this span is #a1jjj feet in length4 ,the designer1 ,mr4 ,john ,j4 ,webster1 has already made a name with the ,great ,wheel which1 at ,earl's ,court1 ,london1 has given many thousands of pleasure-seekers an aerial trip above the roofs of the metropolis4 ,the following account by ,mr4 ,w4 ,g4 ,archer in the ,magazine of ,commerce describes this mammoth of its kind in some detail3-- ,the two main towers carrying the cables and the stiffening girders are built1 one on the south side of the ,ship ,canal1 and the other on the foreshore on the north bank of the river2 and the approaches consist of new roadways1 nearly flat1 built between stone and concrete retaining walls as far as the water's edge1 and a corrugated steel flooring1 upon which are laid the timber blocks on concrete1 resting on steel elliptical girders and cast-iron columns4 ,the roadway in front of the towers is widened out to #gj feet1 for marshalling the traffic1 and for providing space for waiting-rooms1 etc4 ,the towers are constructed wholly of steel1 rise #aij feet above high-water level1 and are bolted firmly to the cast-iron cylinders below4 ,each tower consists of four legs1 spaced #cj feet apart at the base1 and each pair of towers are #gj feet apart1 and are braced together with strong horizontal and diagonal frames4 ,each of the two main cables consists of #ai steel ropes bound together1 each rope being built up of #abg wires #jaf inches in diameter4 ,the ends of the cable backstays are anchored into the solid rock on each side of the river1 about #cj feet from the rock surface4 ,the weight of the main cables is about #bdc tons1 and from them are suspended two longitudinal stiffening girders1 #ah feet deep1 and placed #ce feet apart horizontally1 the underside of the girders being #hb feet above the level of high water4444 ,upon the lower flange of the stiffening girders are fixed the rails upon which runs the traveller1 from which is suspended the car4 ,the traveller is #gg feet long1 and is carried by sixteen wheels on each rail4 ,it is propelled by two electric motors of about #ce horse-power each4444 ,the car will be capable of holding at one time four large wagons and #cjj passengers1 the latter being protected from the weather by a glazed shelter4444 ,the time occupied by the car in crossing will be #b-a_/d minutes1 so1 allowing for the time spent in loading and unloading1 it will be capable of making nine or ten trips per hour4 ,this bridge1 when completed1 will have the largest span of any bridge in the ,united ,kingdom designed for carrying road traffic1 the clear space over the ,mersey and ,ship ,canal being #a1jjj feet4444 ,the total cost of the structure1 including ,parliamentary expenses1 will be about #aej1jjj4 ,mr4 ,archer adds that1 in spite of prophecies of disastrous collisions between transporter cars and passing ships1 there has up to date been no accident of any kind4 ,to those in search of a new sensation the experience of skimming swiftly a few feet above the water may be recommended4 ,,chapter ,,xx ,,boat ,,and ,,ship ,,raising ,,lifts ,in modern locomotion1 whether by land or water1 it becomes increasingly necessary to keep the way unobstructed where traffic is confined to the narrow limits of a pair of rails1 a road1 or a canal channel4 ,we widen our roads2 we double and quadruple our rails4 ,canals are1 as a rule1 not alterable except at immense cost2 and if1 in the first instance1 they were not built broad enough for the work that they are afterwards called upon to do1 much of their business must pass to rival methods of transportation4 ,modern canals1 such as the ,manchester and ,kiel canals1 were given generous proportions to start with1 as their purpose was to pass ocean-going ships1 and for many years it will not be necessary to enlarge them4 ,the ,suez ,canal has been widened in recent years1 by means of dredgers1 which easily scoop out the sandy soil through which it runs and deposit it on the banks4 ,but the ,corinth ,canal1 cut through solid rock1 cannot be thus economically expanded1 and as a result it has proved a commercial failure4 ,even if a canal be of full capacity in its channel-way there are points at which its traffic is throttled4 ,however gently the country it traverses may slope1 there must occur at intervals the necessity of making a lock for transferring vessels from one level to the other4 ,sometimes the ascent or descent is effected by a series of steps1 or flight of locks1 on account of the magnitude of the fall2 and in such cases the loss of time becomes a serious addition to the cost of transport4 ,in several instances engineers have got over the difficulty by ingenious hydraulic lifts1 which in a few minutes pass a boat through a perpendicular distance of many feet4 ,at ,anderton1 where the ,trent and ,mersey ,canal meets the ,weaver ,navigation1 barges up to #ajj tons displacement are raised fifty feet4 ,two troughs1 each weighing with their contents #bdj tons1 are carried by two cast-iron rams placed under their centres1 the cylinders of which are connected by piping4 ,when both troughs are full the pressure on the rams is equal1 and no movement results2 but if six inches of water be transferred from the one to the other1 the heavier at once forces up the lighter4 ,at ,fontinettes1 on the ,neufosse ,canal1 in ,france1 at ,la ,louvire1 in ,belgium1 and at ,peterborough1 in ,canada1 similar installations are found2 the last handling vessels of #djj tons through a rise of #fe feet4 ,fine engineering feats as these are1 they do not equal the canal-lift on the ,dortmund-,ems ,canal1 which puts ,dortmund in direct water communication with the ,elbe1 and opens the coal and iron deposits of the ,rhine and ,upper ,silesia to the busy manufacturing district lying between these two localities4 ,about ten miles from its eastern extremity the main reach of the canal forks off at ,heinrichenburg1 from the northward branch running to ,dortmund1 its level being on the average some #di feet lower than the branch4 ,for the transference of boats an up and down line of four locks each would have been needed2 and apart from the inevitable two hours' delay for locking1 this method would have entailed the loss of a great quantity of precious water4 ,mr4 ,r4 ,gerdau1 a prominent engineer of ,dsseldorf-,grafenburg1 therefore suggested an hydraulic lift1 which should accommodate boats of #gjj tons1 and pass them from the one level to the other in five minutes4 ,this scheme was approved1 and has recently been completed4 ,the principle of the lift is as follows3--,a trough1 #bcc feet long1 rests on five vertical supports1 themselves carried by as many hollow cylindrical floats moving up and down in deep wells full of water4 ,the buoyancy of the five floats is just equal to the combined weight of the trough and its load1 so that a comparatively small force causes the latter to rise or fall1 as required4 ,by letting off water from the trough--which is1 of course1 furnished with doors to seal its ends--it would be made to ascend2 while the addition of a few tons would cause a descent4 ,but this would mean waste of water2 and1 were the trough not otherwise governed1 a serious accident might happen if a float sprang a leak4 ,motion is therefore imparted to the trough by four huge vertical screws1 resting on solid masonry piers1 and turning in large collars attached to the trough near its corners4 ,all the screws work in unison through gearing1 as they are sufficiently stout to bear the whole load2 even were the floats removed1 no tilting or sudden fall is possible4 ,the screws are driven by an electric motor of #aej horse-power1 perched on the girders joining the tops of four steel towers which act as guides for the trough to move in1 while they absorb all wind-pressure4 ,under normal circumstances the trough rises or sinks at a speed of four inches per second4 ,the total mass in motion--trough1 water1 boat1 and floats--is #c1ajj tons4 ,our ideas of a float do not ordinarily rise above the small cork which we take with us when we go a-fishing1 or at the most above the buoy which bobs up and down to mark a fair-way4 ,these five floats--so called--belong to a very much larger class of creations4 ,each is #cj feet across inside and #df-a_/b feet high4 ,their wells1 #ach feet deep1 are lined with concrete nearly a yard thick1 to ensure absolute water-tightness1 inside the stout iron casings1 which rise #hb feet above the bottom4 ,in view of the immense weight which they have to carry1 the piers under the screw-spindles are extremely solid4 ,at its base each measures #ad feet by #ab feet #d inches1 and tapers upwards for #cf feet till these dimensions have contracted to #h feet #aj inches by #f feet #f inches4 ,the spindles1 #hj feet long and #aa inches in diameter1 must be four of the largest screws in existence4 ,to make it absolutely certain that they contained no flaws1 a #d-;inch central hole was drilled through them longitudinally--another considerable workshop feat4 ,if shafts of such length were left unsupported when the trough was at its highest point1 there would be danger of their bending and breaking2 and they are1 therefore1 provided with four sliding collars each1 connected each to its fellow by a rod4 ,when the trough has risen a fifth of its travel the first rod lifts the first collar1 which moves in the guide-pillars4 ,this in turn raises the second2 the second the third2 and so on4 ,so that by the time the trough is fully raised each spindle is kept in line by four intermediate supports4 ,the trough1 #bcc feet long by #cd-a_/b feet wide1 will receive a vessel #bbc feet long between perpendiculars4 ,it has a rectangular section1 and is built up of stout plates laid on strong cross-girders1 all carried by a single huge longitudinal girder resting on the float columns4 ,one of the most difficult problems inseparable from a structure of this kind is the provision of a water-tight joint between the trough and the upper and lower reaches of the canal4 ,at each end of the trough is a sliding door faced on its outer edges with indiarubber1 which the pressure of the water inside holds tightly against flanges when pressure on the outside is removed4 ,the termination of the canal reaches have similar doors2 but as it would be impossible to arrange things so accurately that the two sets of flanges should be water-tight1 a wedge1 shaped like a big ,u1 and faced on both sides with rubber1 is interposed4 ,the wedge at the lower reach gate is thickest at the bottom2 the upper wedge the reverse2 so that the trough in both cases jams it tight as it comes to rest4 ,the wedges can be raised or lowered in accordance with the fluctuations of the canals4 ,after thus briefly outlining the main constructional features of the lift1 let us watch a boat pass through from the lower to the upper level4 ,it is a steamer of #fjj tons burden1 quite a formidable craft to meet so far inland2 while some distance away it blows a warning whistle1 and the motor-man at his post moves a lever which sets the screw in motion4 ,the trough sinks until it has reached the proper level1 when the current is automatically broken1 and it sinks no further4 ,its travel is thus controllable to within #c_/af of an inch4 ,an interlocking arrangement makes it impossible to open the trough or reach gates until the trough has settled or risen to the level of the water outside4 ,on the other hand1 the motor driving the lifting screws cannot be started until the gates have been closed1 so that an accidental flooding of the countryside is amply provided against4 ,a man now turns the crank of a winch on the canal bank and unlocks the canal gate4 ,a second twist couples the gates between the canal and the trough together and starts the lifting-motors overhead1 which raise the twenty-eight ton mass twenty-three feet clear of the water-level4 ,the boat enters2 the doors are lowered and uncoupled2 the reach gate is locked4 ,the spindle-motor now starts2 up she goes1 and the process of coupling and raising gates is repeated before she is released into the upper reach4 ,from start to finish the transfer occupies about five minutes4 ,if a boat is not self-propelled1 electric capstans help it to enter and leave the trough4 ,such a vessel could not be passed through in less than twenty minutes4 ,putting on one side the ship dry docks1 which can raise a #ae1jjj ton vessel clear of the sea1 the ,dortmund hydraulic lift is the largest lift in the world1 and the novelty of its design will1 it is hoped1 render the above account acceptable to the reader4 ,before leaving the subject another canal lift may be noticed--that on the ,grand ,junction ,canal at ,foxton1 ,leicestershire--which has replaced a system of ten locks1 to raise barges through a height of #ge feet4 ,the new method is the invention of ,messrs4 ,g4 and ,c4 ,b4 ,j4 ,thomas4 ,in principle it consists of an inclined railway1 having eight rails1 four for the up and as many for the down traffic4 ,on each set of four rails runs a tank mounted on eight wheels1 which is connected with a similar tank on the other set by #g-;inch steel-wire ropes passing round winding drums at the top of the incline4 ,the tanks are thus balanced4 ,at the foot of the incline a barge which has to ascend is floated into whichever tank may be ready to receive it1 and the end gate is closed4 ,an engine is then started1 and the laden tank slides broadside on up the #cjj-;foot slope4 ,the summit being reached1 the tank gates are brought into register with those of the upper reach1 and as soon as they have been opened the boat floats out into the upper canal4 ,boats of #gj tons can be thus transferred in about twelve minutes1 at a cost of but a few pence each4 ,on a busy day #f1jjj tons are handled4 ,illustration3 ,by permission of ,mr4 ,gordon ,thomas4 ,a ,,boat ,,lift ,a canal barge lift which has superseded ten locks at ,foxton1 ,leicestershire4 ,two tanks1 balancing one another1 run on separate tracks up and down an incline4 ,at the bottom and top of the incline the tank is submerged so that a barge may float in or out4 ,a ,,ship-,,raising ,,lift ,the writer has treated one form of lift for raising ships out of the water--the floating dry dock--elsewhere1#ba so his remarks in this place will be confined to mechanism which1 having its foundations on ,mother ,earth1 heaves mighty vessels out of their proper element by the force of hydraulic pressure4 ,looking round for a good example of an hydraulic ship-lift1 we select that of the ,union ,ironworks1 ,san ,francisco4 ,some years ago the works were moved from the heart of the city to the edge of ,mission ,bay1 with the object of carrying on a large business in marine engineering and shipbuilding4 ,for such a purpose a dry dock1 which in a short time will lift a vessel clear of the water for cleaning or repairs1 is of great importance to both owners and workmen4 ,by the courtesy of the proprietors of ,cassier's ,magazine we are allowed to append the following account of this interesting lift4 ,the site available for a dock at the ,union ,ironworks was a mud-flat4 ,the depth of soft mud being from #hj to #ij feet1 would render the working of a graving dock 7i4e4 one dug out of the ground and pumped dry when the entrance doors have been closed7 very disagreeable2 as such docks1 where much mud is carried in with the water1 require a long time to be cleaned and to dry out4 ,plans were therefore prepared by ,mr4 ,george ,w4 ,dickie for an hydraulic dock1 including an automatic control1 which the designer felt confident would meet all the requirements of the situation1 and which1 after careful consideration1 the ,union ,ironworks decided to build4 ,work was begun in ,january1 #ahhf1 and the dock was opened for business on ,june #aeth1 #ahhg--;a very fine record4 ,this dock consists of a platform built of cross and longitudinal steel girders1 #fb feet wide and #ddj feet long1 having keel blocks and sliding bilge blocks upon which the ship to be lifted rests4 ,the lifting power is generated by a set of four steam-driven1 single-acting horizontal plunger pumps1 the diameter of the plungers being #c-a_/b inches and the stroke #cf inches4 ,forty strokes per minute is the regular speed4 ,there is a weighted accumulator1 or regulator1 connected with the pumps1 the throttle valve of the engines being controlled by the accumulator4#bb ,the load on the accumulator consists of a number of flat discs of metal1 the first one about #ad inches thick and the others about #d inches thick1 the diameter being about #d feet4 ,the first disc gives a pressure of #cjj lbs4 per square inch4 ,this is sufficient to lift the dock platform without a ship1 and is always kept on4 ,in lifting a ship1 as she comes out of the water and gets heavier on the platform1 additional discs are taken on by the accumulator ram as required4 ,the discs are suspended by pins on the side catching into links of a chain4 ,the engineer1 to take on another disc1 unhooks the throttle from the accumulator rod1 runs the engine a little above the normal speed1 the accumulator rises and takes the weight of the disc to be added2 the link carrying that disc is thus relieved and is withdrawn4 ,the engineer again hooks the accumulator rod to the engine throttle1 and the whole is self-acting again until another weight is required4 ,when all the discs are on the ram the full pressure of #a1ajj lbs4 per square inch is reached1 which enables a ship of #d1jjj tons weight to be raised4 ,there are eighteen hydraulic rams on each side of the dock4 ,these rams are each #cj inches in diameter and have a stroke of #af feet2 and as the platform rises #b feet for #a foot movement of the rams1 the total vertical movement of the platform is #cb feet4 ,when lowered to the lowest limit there are #bb feet of water over the keel blocks at high tide4 ,the foundations consist of seventy-two cylinders of iron1 which extend from the top girders to several feet below the mud line4 ,these cylinders are driven full of piles1 no pile being shorter than #ij feet4 ,the cylinders are to protect the piles from the teredo 7the timber-boring worm71 which is very destructive in ,san ,francisco ,harbour4 ,a heavy cast-iron cap completes each of the foundation piers1 and two heavy steel girders extend the full length of the dock on each side1 resting on the foundation piers and uniting them all longitudinally4 ,the hydraulic cylinders are carried by large castings resting on the girders1 each having a central opening to receive a cylinder1 which passes down between the piers4 ,there are thirty-six foundation piers1 and eighteen hydraulic cylinders on each side of the dock4 ,on the top of each hydraulic ram is a heavy sheave or pulley1 #f feet in diameter1 over which pass eight steel cables1 #b inches in diameter1 making in all #bhh cables4 ,one end of each cable is anchored in the bed-plates supporting the hydraulic cylinders1 while the other end is secured to the side girders of the platform4 ,each of the cables has been tested with a load of #hj tons1 so that the total test load for the ropes has been #ba1jjj tons4 ,in lifting a ship the load is never evenly distributed on the platform4 ,there is1 in fact1 often more than one ship on the platform at once4 ,some rams1 therefore1 may have a full load and others much less4 ,under these conditions1 to keep the platform a true plane1 irrespective of the irregular distribution of the load1 ,mr4 ,dickie designed a special valve gear to make the action of the dock perfectly automatic4 ,down each side of the dock a shaft is carried1 operated by a special engine in the power house4 ,at each hydraulic ram this shaft carries a worm1 gearing with a worm-wheel on a vertical screw extending the full height reached by the stroke of the ram4 ,this screw works in a nut on the end of a lever1 the other end of which is attached to the ram4 ,between the two points of support a rod1 working the valves--also carried by the ram--engages with the lever4 ,if at a given moment the screw-end is raised1 say1 six inches1 the lever opens the valve4 ,as the ram rises1 the lever1 having its other end similarly lifted by the rise1 gradually assumes a horizontal position1 and the valve closes4 ,to lift the dock the engine working the valve shaft is started1 and with it the operating screws4 ,these1 through the levers1 open the inlet valves4 ,the rams now begin to move up3 if any one has a light load it will move up ahead of the other1 but in doing so it lifts the other end of the lever and closes the valve4 ,in fact1 the screws are continually opening the valves1 while the motion of the rams is continually closing them1 so that no ram can move ahead of its screw1 and the speed of the screw determines the rate of movement of the lifting platform4 ,to lower the dock1 the engine operating the valve shaft is reversed1 and the screws and levers then control the outlet valves as they controlled the inlet valves in raising4 ,when the platform has reached the limit of its movement1 a line of locks on top of the foundation girders1 thirty-six on each side1 are pushed under the platform by an hydraulic cylinder1 and the platform is lowered on to them1 where it rests until the work is done on the ship2 then the platform is again lifted1 the locks are drawn back1 and the platform with its load is lowered until the ship floats out4 ,all the operations are automatic4 ,since the dock was opened well over a thousand ships have been lifted in it without any accident whatever2 the total register tonnage approaching #b1jjj1jjj4 ,the great favour in which the dock is held by shipowners and captains is partly due to the fact already mentioned1 that the ship is lifted above the level of tide water1 where the air can circulate freely under the bottom1 thus quickly taking up all the moisture1 and where the workmen can carry on operations with greater comfort4 ,when extensive repairs have to be undertaken on iron or steel vessels1 the fact that this dock forms part of an extensive shipbuilding plant1 and is located right in the yard1 enables such repairs to be executed with despatch and economy4 ,several large steamships have had the under-water portions of their hulls practically rebuilt in this dock4 ,the steamship ,columbia1 of the ,oregon ,line1 had practically a new bottom1 including the whole of the keel1 completed in twenty-six days4 ,this is possible1 because every facility is alongside the dock and the bottom of the vessel is on a level with the yard4 ,this being the only hydraulic dock controlled automatically 7in #ahig71 it has attracted a large amount of attention from engineering experts in this class of work4 ,english1 ,french1 ,german1 and ,russian engineers have visited the ,union ,iron ,works to study its working1 and their reports have done much to bring the facilities offered to shipping for repairs by the ,union ,iron ,works to the notice of shipowners all the world over4 ,,footnotes3 #ba ,the ,romance of ,modern ,engineering1 pp4 #chc foll4 #bb ,for explanation of the accumulator1 see the chapter on ,hydraulic ,tools 7p4 #ha74 ,,chapter ,,xxi ,a ,,self-,,moving ,,staircase ,at the ,american ,exhibition1 held in the ,crystal ,palace in #aijb1 there was shown a staircase which1 on payment of a penny1 transported any sufficiently daring person from the ground-floor to the gallery above4 ,all that the experimenters had to do was to step boldly on1 take hold of the balustrade1 which moved at an equal pace with the stairs1 and step off when the upper level was reached4 ,the escalator 7,latin scalae flight of stairs7 hails from the ,united ,states1 where it is proving a serious rival to the elevator4 ,in principle1 it is a continuously working lift1 the slow travel of which is more than compensated by the fact that it is always available4 ,the ordinary elevator is very useful in a large business or commercial house1 where it saves the legs of people who1 if they had to tramp up flight after flight of stairs1 would probably not spend so much money as they would be ready to part with if their vertical travel from one floor to another was entirely free of effort4 ,but the ordinary lift is1 like a railway1 intermittent4 ,we all know what it means to stand at the grille and watch the cage slide downwards on its journey of1 perhaps1 four floors1 when we want to go to a floor higher up4 ,rather than face the delay we use our legs4 ,theoretically1 therefore1 a large emporium should contain at least two lifts4 ,if the number be further increased1 the would-be passenger will have a still better chance of getting off at once4 ,thus at the station of the ,central ,london ,railway we have to wait but a very few seconds before a grille is thrown back and an attendant invites us to ,hurry up there1 please6 ,yet there is delay while the cage is being filled4 ,the actual journey occupies but a small fraction of the time which elapses between the moment when the first passenger enters the lift at the one end of the trip and the moment when the last person leaves it at the other end4 ,in a building where the lift stops every fifteen feet or so to take people on or put them off1 the waste of time is still more accentuated4 ,the escalator is always ready4 ,you step on and are transported one stage4 ,a second staircase takes you on at once if you desire it4 ,there is no delay4 ,furthermore1 the room occupied by a single escalator is much less than that occupied by the number of lifts required to give anything like an equally efficient service4 ,in large ,american stores1 then1 it is coming into favour1 and also on the ,manhattan ,elevated ,railway of ,new ,york4 ,when once the little nervousness accompanying the first use has worn off1 it eclipses the lift4 ,a writer in ,cassier's ,magazine says3 ,in one large retail store during the holiday season more than #f1jjj persons per hour have been carried upon the escalator for five hours of the day1 and the aggregate for an entire day is believed to be #ej1jjj4 ,in the same store on an ordinary day the passengers alighting at the second floor from the eight large lifts1 which run from the basement to the fifth floor1 were counted1 likewise the number at the escalator4 ,this latter was found to be #hei per cent4 of the number delivered by the eight lifts4 ,in another establishment1 in a very busy hour1 the number taken from the first floor by the escalator was four times the number taken from the first floor by the fourteen lifts1 which were running at their maximum capacity4 ,to the merchant this spells opportunity for business4 ,the experience at the ,twenty-third ,street and ,sixth ,avenue station of the ,manhattan ,elevated ,railway in ,new ,york1 during a recent shut-down of the escalator1 which has been in service for some time1 is interesting as showing the attitude of the public1 of which many millions have been carried by the installation during the several years of its operation4 ,the daily traffic receipts of this station for a period beginning several weeks before the shut-down and extending as many after1 for the years #aijc and #aijb1 and receipts of the adjacent stations for the same period were carefully plotted 444 and the loss area during the period of shut-down was determined4 ,the loss area was found to embrace #fd1fde fares4 ,it was1 furthermore1 daily a matter of observation that numbers of people1 finding that the escalator was not running1 refused to climb the stairs1 and turned away from the station4 ,in the case of a great store1 the escalator may be constructed as one continuous machine1 with landings at each floor1 and so arranged that steps which carry passengers up may perform a like service in carrying others down2 or separate machines may be installed in various locations affording the best opportunity for displaying merchandise to the customer who may be proceeding from the lower to the upper floor4 ,in the case of a six-storey building so equipped with escalator service in both directions1 or in all ten escalator flights1 it is obvious that the facilities are equal to an impossible number of elevators2 and as facility of access has a direct bearing upon opportunities for business1 it may well be argued that the relative value1 measured by rent1 of the main and upper floors is greatly changed4 ,each step in a staircase has two parts--the tread or horizontal board on which the foot is placed1 and the vertical riser which acts both as a support to the tread above and also prevents the foot from slipping under the tread4 ,in the escalator each tread is attached rigidly to its riser1 and the two together form an independent unit4 ,for the convenience of passengers in stepping on or off at the upper and lower landings1 the treads in these places are all in the same horizontal plane4 ,as they approach the incline the risers gradually appear1 and the treads separate vertically4 ,at the top of the incline the process is gradually reversed1 the risers disappearing until the treads once more form a horizontal belt4 ,the means of effecting this change is most ingenious4 ,each tread and its riser is carried on a couple of vertical triangular brackets1 one at each side of the staircase4 ,the base of the bracket is uppermost1 to engage with the tread1 and its apex has a hole through which passes a transverse bar1 which in its central part forms a pin in the link-chain by which power is transmitted to the escalator4 ,naturally1 the step would tip over4 ,this is prevented by a yoke attached to each end of the bar1 at right angles to it and parallel to the tread4 ,the yoke has at each extremity a small wheel running on its own rail--there being two rails for each side of the staircase4 ,since step1 brackets1 bar1 and yoke are all rigidly joined together1 the step is unable to leave the horizontal1 but its relation to the steps above and below is determined by the arrangement of the rails on which the yoke wheels run4 ,when these are in the same plane1 all the yokes1 and consequently the treads1 will also be in the same plane4 ,but at the incline1 where the inner rail gradually sinks lower than its fellow1 the front wheel of one tread is lower than the front wheel of the next1 and the risers appear4 ,it may be added that1 owing to the double track at each side of the staircase1 the back wheel of one tread does not interfere with the front wheel of that below2 and that on the level they come abreast without jostling1 as the yoke is bent4 ,the chain1 of which the step-bars form pins1 travels under the centre of the staircase4 ,it is made up of links eighteen inches long1 having1 in addition to the bars1 a number of steel cross-pins #a-a_/b inches in diameter1 their axes three inches apart1 so that the chain as a whole has a three-inch pitch4 ,the hubs of the links are bushed with bronze1 and have a graphite inlay1 which makes them self-lubricating4 ,every joint is turned to within #a_/a1jjj inch of absolute accuracy4 ,the tracks are of steel and hardwood1 insulated from the ironwork which supports them by sheets of rubber4 ,the wheels are so constructed as to be practically noiseless1 so that as a whole the escalator works very quietly4 ,it has been observed1 says the authority already quoted1 that beginners take pains to step upon a single tread1 and that after a little experience no attention whatever is given to the footing1 owing to the facility of adapting oneself to the situation4 ,the upper landing is somewhat longer1 thereby affording an interval for stepping off at either side of sufficient duration to meet the requirements of the aged and infirm4 ,the sole function of the travelling landing is to provide a time interval to meet the requirements of the slowest-acting passenger1 and not of the alert4 ,the terminal of the exit landing1 be it top or bottom 7for the escalator operates equally well for either ascent or descent71 is a barrier1 called the shunt1 of which the lower member travels horizontally in a plane oblique to the direction of movement of the steps1 and at a speed proportionately greater1 thereby imparting a right-angle resultant to the person or obstacle on the step which may come in contact with the shunt4 ,by reason of this resultant motion1 the person or obstacle is gently pushed off the end of the step upon the floor1 without shock or injury in the slightest degree4 ,the motion of the escalator is so smooth and constant that it does not interpose the least obstacle to the free movement of the passenger1 who may walk in either direction or assume any attitude to the same degree as upon a stationary staircase4 ,at ,cleveland1 ,u4,s4,a41 there has been erected a rolling roadway1 consisting of an inclined endless belt and platform made of planks eight feet long1 placed transversely across the roadway4 ,the timbers are fastened together in trucks of two planks each1 adjoining trucks being joined by heavy links to form a moving roadway1 which runs on #d1jjj small wheels4 ,at each end the roadway1 which is continuous1 passes round enormous rollers4 ,its total length is #dbj feet1 and the rise #fe feet4 ,four electric motors placed at regular intervals along its length1 and all controlled by one man at the head of the incline1 drive it at three miles an hour4 ,it can accommodate six wagons at a time4 ,,chapter ,,xxii ,,pneumatic ,,mail ,,tubes ,you put your money on the counter4 ,the shop assistant makes out a bill2 and you wonder what he will do with it next4 ,these large stores know nothing of an open till4 ,yet there are no cashiers' desks visible2 nor any overhead wires to whisk a carrier off to some corner where a young lady1 enthroned in a box1 controls all the pecuniary affairs of that department4 ,while you are wondering the assistant has wrapped the coin in the bill and put the two into a dumb-bell-shaped carrier1 which he drops into a hole4 ,a few seconds later1 flop6 and the carrier has returned into a basket under another opening4 ,there is something so mysterious about the operation that you ask questions1 and it is explained to you that there are pneumatic tubes running from every counter in the building to a central pay-desk on the first or second floor2 and that an engine somewhere in the basement is hard at work all day compressing air to shoot the carriers through their tubes4 ,certainly a great improvement on those croquet-ball receptacles which progressed with a deliberation maddening to anyone in a hurry along a wooden suspended railway6 ,now1 imagine tubes of this sort1 only of much larger diameter1 in some cases1 passing for miles under the streets and houses1 and you will have an idea of what the ,pneumatic ,mail ,despatch means3 the cash and bill being replaced by letters1 telegrams1 and possibly small parcels4 ,swift as the wind is a phrase often in our mouths1 when we wish to emphasise the celerity of an individual1 an animal1 or a machine in getting from one spot of the earth's surface to another4 ,mercury1 the messenger of uncertain-tempered ,jove1 was pictured with wings on his feet to convey1 symbolically1 the same notion of speed4 ,the modern human messenger is so poor a counterpart of the god1 and his feet are so far from being winged1 that for certain purposes we have fallen back on elemental air-currents1 not unrestrained like the breezes1 but confined to the narrow and certain paths of the metal tube4 ,the pneumatic despatch1 which at the present day is by no means universal1 has been tried in various forms for several decades4 ,its first public installation dates from #ahec1 when a tube three inches in diameter and #bbj yards long was laid in ,london to connect the ,international ,telegraph ,company with the ,stock ,exchange4 ,a vacuum was created artificially in front of the carrier1 which the ordinary pressure of the atmosphere forced through the tube4 ,soon after this the post-office authorities took the matter up1 as the pneumatic system promised to be useful for the transmission of letters2 but refused to face the initial expense of laying the tube lines4 ,when1 in #aheh1 ,mr4 ,c4 ,f4 ,varley introduced the high pressure method1 pneumatic despatch received an impetus comparable to that given to the steam-engine by the employment of high-pressure steam4 ,it was now possible to use a double line of tubes economically1 the air compressed for sending the carriers through the one line being pumped out of a chamber which sucked them back through the other4 ,tubes for postal work were soon installed in many large towns in ,great ,britain1 ,europe1 and the ,united ,states2 including the thirty-inch pneumatic railway between the ,north-,western ,district post office in ,eversholt ,street and ,euston ,station1 which for some months of #ahfc transported the mails between these two points4 ,the air was exhausted in front of the carriage by a large fan4 ,encouraged by its success1 the company built a much larger tube1 nearly #d-a_/b feet in diameter1 to connect ,euston ,station with the ,general ,post ,office4 ,this carried fourteen tons of post-office matter from one end to the other in a quarter of an hour4 ,there was an intermediate station in ,holborn1 where the engines for exhausting had been installed4 ,but owing to the difficulty of preventing air leakage round the carriages the undertaking proved a commercial failure1 and for years the very route of this pneumatic railway could not be found2 so quickly are failures forgotten6 ,the more useful small tube grew most vigorously in ,america and ,france4 ,in1 or about1 the year #ahge the ,western ,union ,telegraph ,company laid tubes in ,new ,york to despatch telegrams from one part of the city to the other1 because they found it quicker to send them this way than over the wires4 ,eighteen years later fifteen miles of tubes were installed in ,chicago to connect the main offices of the same company with the newspaper offices in the town1 and with various important public buildings4 ,messages which formerly took an hour or more in delivery are now flipped from end to end in a few seconds4 ,the ,philadelphia people meanwhile had been busy with a double line of six-inch tubes1 #c1jjj feet long1 laid by ,mr4 ,b4 ,c4 ,batcheller between the ,bourse and the ,general ,post ,office1 for the carriage of mails4 ,the first thing to pass through was a ,bible wrapped in the ,stars and ,stripes4 ,a #cj horse-power engine is kept busy exhausting and compressing the air needed for the service1 which amounts to about #hjj cubic feet per minute4 ,philadelphia can also boast an eight-inch service1 connecting the ,general ,post ,office with the ,union ,railway ,station1 a mile away4 ,one and a half minutes suffice for the transit of the large carriers packed tightly with letters and circulars1 nearly half a million of which are handled by these tubes daily4 ,new ,york is equally well served4 ,tubes run from the ,general ,post ,office to the ,produce ,exchange1 to ,brooklyn1 and to the ,grand ,central ,station4 ,the last is #c-a_/b miles distant2 but seven minutes only are needed for a tube journey which formerly occupied the mail vans for nearly three-quarters of an hour4 ,paris is the city of the petit bleu1 so important an institution in the gay capital4 ,here a network of tubes connects every post office in the urban area with a central bureau1 acting the part of a telephone exchange4 ,if you want to send an express message to a friend anywhere in ,paris1 you buy a petit bleu1 i4e4 a very thin letter-card not exceeding #a_/d oz4 in weight1 at the nearest post office1 and post it in a special box4 ,it whirls away to the exchange1 and is delivered from there if its destination be close at hand2 otherwise it makes a second journey to the office most conveniently situated for delivery4 ,everybody uses the voie pneumatique of ,paris1 so much cheaper than1 and quite as expeditious as1 the telegraph2 with the additional advantage that all messages are transmitted in the sender's own handwriting4 ,the system has been instituted for a quarter of a century1 and the ,parisians would feel lost without it4 ,london is by no means tubeless1 for it has over forty miles of #a-a_/b1 #b-a_/d1 and #c-;inch lines radiating from the postal nerve-centre of the metropolis1 of lengths ranging from #ajj to #b1jjj yards4 ,the tubes are in all cases composed of lead1 enclosed in a protecting iron piping4 ,to make a joint great care must be exercised1 so as to avoid any irregularity of bore4 ,when a length of piping is added to the line1 a chain is first passed through it1 which has at the end a bright steel mandrel just a shade larger than the pipe's internal diameter4 ,this is heated and pushed half-way into the pipe already laid2 and the new length is forced on to the other half till the ends touch4 ,a plumber's joint having been made1 the mandrel is drawn by the chain through the new length1 obliterating any dents or malformations in the interior4 ,the main lines are doubled--an up and a down track2 short branches have one tube only to work the inward and the outward despatches4 ,the carriers are made of gutta-percha covered with felt4 ,one end is closed by felt discs fitting the tube accurately to prevent the passage of air1 the other is open for the introduction of messages4 ,as they fly through the tube1 the carriers work an automatic signalling apparatus1 which tells how far they have progressed and when it will be safe to despatch the next carrier4 ,the ,london post-office system is worked by six large engines situated in the basement of the ,general ,post ,office4 ,so useful has the pneumatic tube proved that a ,bill has been before ,parliament for supplying ,london with a #ab-;inch network of tubes1 totalling #ajj miles of double line4 ,in a letter published in ,the ,times1 ,april #ai1 #aije1 the promoters of the scheme give a succinct account of their intentions1 and of the benefits which they expect to accrue from the scheme if brought to completion4 ,the ,batcheller system1 they write1 with which it is proposed to equip ,london1 is not a development of the miniature systems used for telegrams or single letters here or in ,paris1 ,berlin1 and other cities4 ,such systems deal with a felt carrier weighing a few ounces1 which is stopped by being blown into a box4 ,the ,batcheller system deals with a loaded steel carrier weighing seventy pounds travelling with a very high momentum4 ,the difference is fundamental4 ,in this sense pneumatic tubes are a recent invention1 and absolutely new to ,europe4 ,the ,batcheller system is the response to a pressing need4 ,careful observations show that more than #cj per cent4 of the street traffic is occupied with parcels and mails4 ,these form a distinct class1 differentiated from passengers on the one hand and from heavy goods on the other4 ,the ,batcheller system will do for parcels and mails what the underground electric railways do for passengers4 ,it has been in use for twelve years in ,america for mail purposes1 and where used has come to be regarded as indispensable4 ,the plan for ,london provides for nearly one hundred miles of double tubes with about twice that number of stations for receiving and delivery4 ,the system will cover practically the ,county of ,london1 and no point within that area can be more than one-quarter of a mile from a tube station4 ,beyond the ,county of ,london deliveries will be made by a carefully organised suburban motor-cart service4 ,thirty of the receiving stations are to be established in the large stores4 ,the diameter of the tube is to be of a size that will accommodate #hj per cent4 of the parcels1 as now wrapped1 and #ij per cent4 with slight adaptation4 ,the remaining #aj per cent4--furniture1 pianos1 and other heavy goods--are to be dealt with by a supplementary motor service4 ,if the tubes were enlarged their object would be partially defeated1 for with the increased size would go increased cost1 great surplus of capacity1 less frequent despatch1 and lower efficiency generally4 ,the unsuccessful ,euston ,tunnel of forty years ago--practically an underground railway--is an extreme illustration of this point1 though in that case there were grave mechanical defects as well4 ,from a mechanical point of view the system has been brought to such perfection that it is no more experimental than a locomotive or an electric tramcar4 ,the unique value of tube service is due to immediate despatch1 high velocity of transit1 immunity from traffic interruption1 and economy4 ,the greatest obstacle to rapid intercommunication is the delay resulting from accumulations due to time schedules4 ,the function of tube service is to abolish time schedules and all consequent delays4 ,the number of trades parcels annually delivered in ,london is estimated at more than #bjj1jjj1jjj4 ,a careful canvass has been made of #a1jjj shops only1 which represent a very small fraction of the total number in the county4 ,as a result it has been ascertained that these #a1jjj shops deliver no fewer than #fj1jjj1jjj parcels yearly1 a fact that seems to more than justify the foregoing estimate2 on the other hand1 it is known from official data that the parcel post in ,london is represented by less than #be1jjj1jjj1 or one-ninth of the total parcel traffic4 ,with a tube system in operation1 every parcel1 instead of waiting for the next delivery1 would leave the shop immediately4 ,after being despatched by the tube it would be delivered at a tube station within a quarter of a mile at least of its destination1 and thence by messenger4 ,the entire time consumed for an ordinary parcel would be not over an hour1 and for a special parcel fifteen to twenty minutes4 ,they require from three to six hours or longer at present4 ,the advantages of the tube system to the public would be manifold4 ,customers would find their purchases at home upon their return1 or1 if they preferred1 could do their shopping by telephone1 making their selections from goods sent on approval by tube4 ,the shopman would find himself relieved from a vast amount of confusion and annoyance1 less of his shop space given up to delivery1 and his expenses reduced4 ,small shops would be able to draw upon wholesale houses for goods not in stock1 while the customer waited4 ,such delay and confusion as are frequently occasioned by fogs would be reduced to a minimum4 ,while the success of the project is not dependent on ,post ,office support1 the ,post ,office should be one of the greatest gainers by it4 ,the time of delivery of local letters would be reduced from an average of three hours and six minutes to one hour4 ,express letters would be delivered more quickly than telegrams4 ,this has been demonstrated conclusively again and again in ,new ,york and other ,american cities where the tubes have been in operation for years4 ,the latest time of posting country letters would be deferred from one-half to one hour1 and incoming letters would be advanced by a similar period4 ,the parcels post would gain in precisely the same way1 but to an even larger extent4 ,if the ,post ,office choose to avail themselves of the opportunity1 every post office will become a tube station and every tube station a post office4 ,thus the same number of postmen covering but a tithe of the present distances could make deliveries without time schedules at intervals of a few minutes with a handful instead of a bagful of letters4 ,the sorting of mails would be performed at every station instead of at a few4 ,incoming country mails would be taken from the bags at the railway termini1 and the same bags refilled with outgoing country mails1 thus avoiding needless carriage to the ,post ,office and back4 ,no bags at all would be used for local mails1 the steel carriers themselves answering that purpose4 ,at every tube terminal a post-office clerk would be stationed1 so that the mails would never for an instant be out of post-office control4 ,its absolute security would be further ensured by a system of locking1 so that the carriers could only be opened by authorised persons at the station to which they were directed4 ,these safeguards offer a striking contrast to the present method that entrusts mail bags to the sole custody of van drivers in the employ of private contractors4 ,if the mails were handled by tube1 business men would be able to communicate with each other and receive replies several times in one day1 and country and foreign letters could always be answered upon the day of receipt4 ,the effect would be felt all over the ,empire4 ,would the laying of the tubes seriously impede traffic8 ,the promoters assure us that the inconvenience would not be comparable to that caused by laying a gas1 water1 or telephone system4 ,when one of those has been laid the annoyance1 they urge1 has only begun4 ,the streets must be periodically reopened for the purpose of making thousands of house connections1 extensions1 and repairs4 ,when a pneumatic tube is once down it is good for a generation at least4 ,it is not subject to recurrent alterations incidental to house connections and repairs4 ,in three ,american cities the tubes have been touched but three times in twelve years1 and in those cases the causes were a bursting water main and faulty adjacent electric installations4 ,the repairs were effected in a few hours4 ,from a general consideration of the scheme we may now turn to some mechanical details4 ,the pipes would be of #a foot internal diameter1 made in #ab-;foot lengths4 ,straight sections1 writes an engineering correspondent of ,the ,times1 would be of cast-iron1 bored1 counter-bored1 and turned to a slight taper at one end1 to fit a recess at the other end 7of the next tube71 to form the joints1 which could be caulked4 ,joints made in this way are estimated to permit of a deflection of #b inches from the straight1 so that the laying and bedding need not be exact4 ,bent sections are to be of seamless brass2 these are bored true before bending4 ,the permissible curvature is determined upon the basis of a maximum bend of #a foot radius for every #a inch of diameter2 the #a foot diameter of the ,london tubes would consequently be allowed a maximum curvature of #ab foot radius4 ,measured at the enlarged end1 the over-all diameter of each pipe is #ag inches1 and as two such pipes are to be laid side by side1 with #ah inches between centres1 the clear width will be #ce inches4 ,the trenches are therefore to be cut #cf inches wide1 and in order to have a comparatively free run for the sections1 it is proposed to cut the trenches #f feet deep4 ,when the hundred miles of piping have been laid1 the entire system will be tested to a pressure of #be lbs4 to the square inch1 or about two and a half times the working pressure4 ,engines of #aj1jjj h4p4 will be required to feed the lines with air1 for the propulsion of the carriers1 each #c feet #aj inches long1 and weighing #gj lbs4 ,in order to ensure the delivery of a carrier at its proper destination1 whether a terminus or an intermediate station1 ,mr4 ,batcheller has made a most ingenious provision4 ,on the front of a carrier is fixed a metal plate of a certain diameter4 ,at each station two electric wires project into the tube1 and as soon as a plate of sufficient diameter to short-circuit these wires arrives1 the current operates delivery mechanism1 and the carrier is switched off into the station box4 ,the despatcher1 knowing the exact size of disc for each station1 can therefore make certain that the carrier shall not go astray4 ,it may occur to the reader that1 should a carrier accidentally stick anywhere in the tubes1 it would be a matter of great difficulty to locate it4 ,evidently one could not feel for it with a long rod in half a mile of tubing--the distance between every two stations--with much hope of finding it4 ,but science has evolved a simple1 and at the same time quite reliable1 method of coping with the problem4 ,m4 ,bontemps is the inventor4 ,he located troubles in the ,paris tubes by firing a pistol1 and exactly measuring the time which elapsed between the report and its echo4 ,as the rate of sound travel is definitely known1 instruments of great delicacy enable the necessary calculations to be made with great accuracy4 ,when a breakdown occurred on the ,philadelphia tube line1 ,mr4 ,batcheller employed this method with great success1 for a street excavation1 made on the strength of rough measurements with the timing apparatus1 came within a few feet of the actual break in the pipe1 caused by a subsidence1 while the carriers themselves were found almost exactly at the point where the workmen had been told to begin digging4#bc ,there is no doubt that1 were such a system as that proposed established1 an enormous amount of time would be saved to the community4 ,a letter from ,charing ,cross to ,liverpool ,street1 says ,the ,world's ,work1 occupies by post three hours2 by tube transit it would occupy twenty to forty minutes1 or by an express system of tube transit ten to fifteen minutes4 ,express messages carried by the ,post ,office in ,london last year 7#aijc7 numbered about a million and a half1 but the cost sometimes seems very heavy4 ,to send a special message by hand from ,hampstead to ,fleet ,street1 for example1 costs #as4 #c;d41 and takes about an hour4 ,it is claimed that it could be sent by pneumatic tube at a cost of #c;d4 in from fifteen to twenty minutes1 and that for local service the tube would be far quicker than the telegraph1 and many times cheaper4 ,it has been calculated that from one-sixth to one-quarter of the wheeled traffic of ,london is occupied with the distribution of mails and parcels2 and if the tubes relieved the streets to this extent1 this fact alone would be a strong argument in their favour4 ,it is impossible to believe that tube transmission on a gigantic scale will not come4 ,hitherto its development has been hindered by mechanical difficulties4 ,but these have been mostly removed4 ,in the ,united ,states1 where the adage time is money is lived up to in a manner scarcely known on this side of the ,atlantic1 the device has been welcomed for public libraries1 warehouses1 railway depts1 factories--in short1 for all purposes where the employment of human messengers means delay and uncertainty4 ,twenty years ago ,berlier proposed to connect ,london and ,paris by tubes of a diameter equal to that of the pipes contemplated in the scheme now before ,parliament4 ,our descendants may see the tubes laid2 for when once a system of transportation has been proved efficient on a large scale its development soon assumes huge proportions4 ,and even the present generation may witness the tubes of our big cities lengthen their octopus arms till town and town are in direct communication4 ,after all it is merely a question of ,will it pay8 ,we have the means of uniting ,edinburgh and ,london by tube as effectually as by telephone or telegraph4 ,and since the general trend of modern commerce is to bring the article to the customer rather than to give the customer the trouble of going to select the article in situ--this applies1 of course1 to small portable things only--shopping from a distance will come into greater favour1 and the pneumatic tube will be recognised as a valuable ally4 ,we can imagine that ,mrs4 ,robinson of1 say1 ,reading1 will be glad to be spared the fatigue of a journey to ,regent ,street when a short conversation over the telephone wires is sufficient to bring to her door1 within an hour1 a selection of silver ware from which to choose a wedding present4 ,and her husband1 whose car has perhaps broken a rod at ,newbury1 will be equally glad of the quick delivery of a duplicate part from the makers4 ,these are only two possible instances1 which do not claim to be typical or particularly striking4 ,if you sit down and consider what an immense amount of time and expense could be saved to you in the course of a year by a lightning despatch1 you will soon come to the conclusion that the pneumatic tube has a great future before it4 ,,footnote3 #bc ,cassier's ,magazine1 xiii1 #def4 ,,chapter ,,xxiii ,,an ,,electric ,,postal ,,system ,far swifter than the movements of air are those of the electric current1 which travels many thousands of miles in a second of time4 ,thirty miles an hour is the speed proposed for the pneumatic tube system mentioned in our last chapter4 ,an ,italian1 ,count ,roberto ,taeggi ,piscicelli1 has elaborated an electric post which1 if realised1 will make such a velocity as that seem very slow motion indeed4 ,cable railways1 for the transmission of minerals1 are in very common use all over the world4 ,at ,hong-,kong and elsewhere they do good service for the transport of human beings4 ,the car or truck is hauled along a stout steel cable1 supported at intervals on strong poles of wood or metal1 by an endless rope wound off and on to a steam-driven drum at one end of the line1 or motion is imparted to it by a motor1 which picks up current as it goes from the cable itself and other wires with which contact is made4 ,count ,piscicelli's electric post is an adaptation of the electric cableway to the needs of parcel and letter distribution4 ,at present the mail service between towns is entirely dependent on the railway for considerable distances1 and on motors and horsed vehicles in cases where only a comparatively few miles intervene4 ,london and ,birmingham1 to take an instance1 are served by seven despatches each way every twenty-four hours4 ,a letter sent from ,london in the morning would1 under the most favourable conditions1 not bring an answer the same day--at least1 not during business hours4 ,so that urgent correspondence must be conducted over either the telephone or the telegraph wires4 ,count ,piscicelli proposes a network of light cableways--four lines on a single set of supports--between the great towns of ,britain4 ,each line--or rather track--consists of four wires1 two above and two below1 each pair on the same level4 ,the upper pair form the run-way for the two main wheels of the carrier2 the lower pair are for the trailing wheels4 ,three of the wires supply the three-phase current which drives the carrier2 the fourth operates the automatic switches installed every three or four miles for transforming the high-tension #e1jjj-volt current into low-tension #ejj-volt current in the section just being entered4 ,the carriers would be suitable for letters1 book-parcels1 and light packages4 ,the speed at which they would move--#aej miles per hour to begin with--would render possible a ten-minute service between1 say1 the towns already mentioned4 ,the inventor has hopes of increasing the speed to #bej m4p4h41 a velocity which would appear visionary had we not already before us the fact that an electric car1 weighing many tons1 has already been sent over the ,berlin-,zossen ,railway at #aca-a_/b miles per hour4 ,at any rate1 the electric post can reasonably be expected to outstrip the ordinary express train4 ,should such speeds as ,count ,piscicelli confidently discusses1 says ,the ,world's ,work1 be attained1 they would undoubtedly confer immense benefits upon the mercantile and agricultural community--upon the agricultural community because in this system is to be found that avenue of transmission to big centres of population of the products of la petite culture1 in which ,mr4 ,rider ,haggard1 for example1 in his invaluable book on ,rural ,england1 sees help for the farmer and for all connected with the cultivation of the soil4 ,count ,piscicelli proposes to obviate the delays at despatching and receiving towns by an inter-urban postal system1 in which the principal offices of any city would be connected with the head-office and with the principal railway termini4 ,from each of the sub-offices would radiate further lines1 along which post-collecting pillars are erected1 and over which lighter motors and collecting boxes 7similar to the despatch boxes7 travel4 ,the letter is put in through a slot and the stamp cancelled by an automatic apparatus with the name of the district1 number of the post1 and time of posting4 ,the letter then falls into a box at the foot of the column4 ,on the approach of a collecting-box the letter slot would be closed1 and by means of an electric motor the receptacle containing the letters lifted to the top of the column and its contents deposited in the collecting-box1 which travels alone past other post-collecting poles1 taking from each its toll1 and so on to the district office4 ,here1 in a mercantile centre1 a first sorting takes place1 local letters being retained for distribution by postmen1 and other boxes carry their respective loads to the different railway termini1 or central office4 ,were such an order of things established1 there would be a good excuse for the old country woman who sat watching the telegraph wire for the passage of a pair of boots she was sending to her son in far away ,lunnon6 ,,chapter ,,xxiv ,,agricultural ,,machinery ,,ploughs--,,drills ,,and ,,seeders--,,reaping ,,machines--,,threshing ,,machines--,,petrol-,,driven ,,field ,,machinery--,,electrical ,,farming ,,machinery ,agriculture is at once the oldest and most important of all national industries4 ,man being a graminivorous animal--witness his molar1 or grinding1 double teeth--has1 since the earliest times1 been obliged to observe the seasons1 planting his crops when the ground is moist1 and reaping them when the weather is warm and dry4 ,apart from the nomad races of the deserts and steppes1 who find their chief subsistence in the products of the date-palm and of their flocks and herds1 all nations cultivate a large portion of the country which they inhabit4 ,ancient monuments1 the oldest inscriptions and writings1 bear witness to the prime importance of the plough and reaping-hook2 and it may be reasonably assumed that the progress of civilisation is proved by the increased use of cereal foods1 and better methods of garnering and preparing them4 ,for thousands of years the sickle1 which ,greek and ,roman artists placed in the hand of their ,goddess of the ,harvest1 and the rude plough1 consisting of1 perhaps1 only a crooked bough with a pointed end1 were practically the only implements known to the husbandman besides his spade and mattock4 ,where labour is abundant and each householder has time to cultivate the little plot which suffices for the maintenance of his own family1 and while there is little inducement to take part in other than agricultural industries--tedious and time-wasting methods have held their own4 ,but in highly civilised communities carrying on manufactures of all sorts it is difficult for the farmer to secure an abundance of human help1 and yet it is recognised that a speedy preparation and sowing of the land1 and a prompt gathering and threshing of the harvest1 is all in favour of producing a successful and well-conditioned crop4 ,in ,england1 eighty years ago1 three men lived in the country for every one who lived in the town4 ,now the proportion has been reversed2 and that not in the ,british ,isles alone4 ,the world does not mean to starve2 but civilisation demands that as few people as possible should be devoted to procuring the staff of life for both man and beast4 ,we should reasonably expect1 therefore1 that the immense advance made in mechanical science during the last century should have left a deep mark on agricultural appliances4 ,such an expectation is more than justified2 for are there not many among us who have seen the sickle and the flail at work where now the self-binder and threshing machine perform the same duties in a fraction of the time formerly required8 ,the ploughman1 plodding sturdily down the furrow behind his clever team1 is indeed still a common sight2 but in the tilling season do we not hear the snort of the steam-engine1 as its steel rope tears a six-furrow plough through the mellow earth8 ,when the harvest comes we realise even more clearly how largely machinery has supplanted man2 while in the processes of separating the grain from its straw the human element plays an even smaller part4 ,it would not be too much to say that1 were we to revert next year to the practices of our grandfathers1 we should starve in the year following4 ,this chapter will be confined to a consideration of machinery operated by horse1 steam1 or other power1 which falls under four main headings1--ploughs1 drills1 reapers1 and threshers4 ,,ploughs ,the firm of ,messrs4 ,john ,fowler and ,company1 of ,leeds1 is most intimately connected with the introduction of the steam plough and cultivator4 ,their first type of outfit included one engine only1 the traversing of the plough across the field being effected by means of cables passing round a pulley on a low1 four-wheeled truck1 moved along the opposite edge of the field by ropes dragging on an anchor4 ,another method was to have the engine stationary at one corner of the field1 and an anchor at each of the three other corners1 the two at the ends of the furrow being moved for every journey of the plough4 ,in1 or about1 the year #ahfe this arrangement succumbed to the simple and1 as it now seems to us1 obvious improvement of introducing a second engine to progress vis--vis with the first1 and do its share of the pulling4 ,the modern eight-furrow steam plough will turn ten acres a day quite easily1 at a much lower cost than that of horse labour4 ,for tearing up land after a crop cultivators are sometimes used4 ,they have arrowhead-shaped coulters1 which cut very deep and bring large quantities of fresh earth to the surface4 ,the ground is now pulverised by harrows of various shapes1 according to the nature of the crop to be sown4 ,english farmers generally employ the spike harrow2 but ,yankee agriculturists make great use of the spring-tooth form1 which may best be described as an arrangement of very strong springs much resembling in outline the springs of house bells4 ,the shorter arm is attached to the frame1 while the longer and pointed arm tears the earth4 ,,drills ,,and ,,seeders ,in highly civilised countries the man carrying a basket from which he flings seeds broadcast is a very rare sight indeed4 ,the primitive method may have been effective--a good sower could cover an acre evenly with half a pint of turnip seed--but very slow4 ,we now use a long bin mounted on wheels1 which revolves discs inside the bin1 furnished with tiny spoons round the periphery to scoop small quantities of seed into tubes terminating in a coulter4 ,the farmer is thus certain of having evenly planted and parallel rows of grain1 which in the early spring1 when the sprouting begins1 make so pleasant an addition to the landscape4 ,the corn1 or maize1 crop of the ,united ,states is so important that it demands special sowing machinery1 which plants single grains at intervals of about eighteen inches4 ,a somewhat similar device is used for planting potatoes4 ,passing over the weeding machines1 which offer no features of particular interest1 we come to the ,,reaping ,,machines1 on which a vast amount of ingenuity has been expended4 ,at the beginning of the nineteenth century the ,royal ,agricultural ,society of ,great ,britain offered a prize for the introduction of a really useful machine which should replace the scythe and sickle4 ,several machines were brought out1 but they did not prove practical enough to attract much attention4 ,cyrus ,h4 ,mc,cormick invented in #ahca the reaper1 which1 with very many improvements added1 is to-day employed in all parts of the world4 ,the most noticeable point of this machine was the bar furnished with a row of triangular blades which passed very rapidly to and fro through slots in an equal number of sharp steel points1 against which they cut the grain4 ,the to-and-fro action of the cutter-blade was produced by a connecting-rod working on a crank rotated by the wheels carrying the machine4 ,illustration3 ,a ,,wheat-,,cutter ,a heading reaper being pushed over a wheat crop by six mules4 ,it cuts off the ears only1 leaving the straw standing4 ,the largest machines of this type used in ,california take swathes #ej feet broad4 ,the first ,mc,cormick reaper did wonders on a ,virginian farm2 other inventors were stimulated2 and in #ahcc there appeared the ,hussey reaper1 built on somewhat similar lines4 ,for twelve years or so these two machines competed against one another all over the ,united ,states2 and then ,mc,cormick added a raker attachment1 which1 when sufficient grain had accumulated on the platform1 enabled a second man on the machine to sweep it off to be tied up into a sheaf4 ,at the ,great ,exhibition held in ,london in #ahea1 the judges awarded a special medal to the inventor1 reporting that the whole expense of the ,exhibition would have been well recouped if only the reaper were introduced into ,england4 ,from ,france ,mc,cormick received the decoration of the ,legion of ,honour for having done more for the cause of agriculture than any man then living4 ,it would be reasonable to expect that1 after this public recognition1 the mechanical reaper would have been immediately valued at its true worth4 ,yet no man had more difficulty in introducing his machines than that pioneer inventor of agricultural implements4 ,farmers everywhere were slow to accept it1 and manufacturers were unwilling to undertake its manufacture4 ,even after the value of the machine had been demonstrated1 everyone seemed to fear that it would break down on rocky and uneven fields2 and the inventor had to demonstrate in person to the farmers the practicability of the reapers1 and then even guarantee them before the money could be obtained4 ,through all these trying discouragements the persistent inventor passed before he saw any reward for the work that he had spent half a lifetime in perfecting4 ,the ultimate triumph of the inventor may be sufficient reward for his labours and discouragements1 but those who would begrudge him the wealth that he subsequently made from his invention should consider some of the difficulties and obstacles he had to overcome in the beginning4#bd ,in #aheh an attachment was fitted to replace the second passenger on the machine4 ,four men followed behind to tie up the grain as it was shot off the machine4 ,inventors tried to abolish the need for these extra hands by means of a self-binding device4 ,a practical method1 employing wire1 appeared in #ahfj2 but so great was the trouble caused by stray pieces of the wire getting into threshing and other machinery through which the grain subsequently passed that farmers went back to hand work1 until the ,appleby patent of #ahgc replaced wire by twine4 ,words alone would convey little idea of how the corn is collected and encircled with twine2 how the knot is tied by an ingenious shuttle mechanism2 and how it is thrown out into a set of arms which collect sufficient sheaves to form a stook before it lets them fall4 ,so we would advise our readers to take the next chance of examining a modern self-binder1 and to persuade the man in charge to give as lucid an explanation as he can of the way in which things are done4 ,popular prejudice having once been conquered1 the success of the reapers was assured4 ,the year #ahgj saw #fj1jjj in use2 by #ahhe the output had increased to #bej1jjj2 and to-day the manufacture of agricultural labour-saving machines gives employment to over #bjj1jjj people2 an equal number being occupied in their transport and sale in all parts of the globe4 ,in ,california1 perhaps more than in any other country1 power agricultural machinery is seen at its best4 ,great traction-engines here take the place of human labour to an extraordinary extent4 ,the largest1 of #ej h4p4 and upwards1 with driving-wheels #fj inches in diameter and flanges of generous width1 travel over the uneven surface of the grain fields1 crossing ditches and low places1 and ascending the sides of steep hills1 with as much apparent ease as a locomotive rolls along its steel rails4 ,such powerful traction-engines1 or 'automobiles' as they are commonly called by the ,american farmers1 are capable of dragging behind them sixteen #aj-;inch ploughs1 four #f-;foot harrows1 and a drill and seeder4 ,the land is thus ploughed1 drilled1 and seeded all at one time4 ,from fifty to seventy-five acres of virgin soil can thus be ploughed and planted in a single day4 ,when the harvest comes the engines are again brought into service1 and the fields that would ordinarily defy the best efforts of an army of workmen are garnered quickly and easily4 ,the giant harvester is hitched to the traction-engine in place of the ploughs and harrows1 and cuts1 binds1 and stacks the golden wheat from seventy-five acres in a single day4 ,the cutters are #bf feet wide1 and they make a clear swathe across the field4 ,some of them thresh1 clean1 and sack the wheat as fast as it is cut and bound4 ,other traction-engines follow to gather up the sacked wheat1 and whole train-loads of it thus move across the field to the granaries or railways of the seaboard or interior4 ,for dead ripe crops the header is often used in ,california4 ,instead of being pulled it is pushed by mules1 and merely cuts off the heads1 leaving the straw to be trampled down by the animals since it has no value4 ,swathes as wide as #ej feet are thus treated1 the grain being threshed out while the machine moves4 ,one of the most beautiful1 and at the same time useful1 crops in the world is that of maize1 which feeds not only vast numbers of human beings1 but also countless flocks and herds1 the latter eating the green stalks as well as the ripened grain4 ,the ,united ,states alone produced no less than #b1ebc1fdh1cab bushels of this cereal in #aijb1 as against #ihg1jjj1jjj bushels of wheat1 and #fgj1jjj1jjj bushels of barley4 ,now1 maize has a very tough stalk1 often #aj feet high and an inch thick1 which cannot be cut with the ease of wheat or barley4 ,so a special machine has been devised to handle it4 ,the row of corn is picked up1 if fallen1 by chains furnished with projecting spikes working at an angle to the perpendicular1 so as to lift and simultaneously pull back the stalks1 which pass into a horizontal ,v-shaped frame4 ,this has a broad opening in front1 but narrows towards its rear end1 where stationary sickles fixed on either side give the stalk a drawing cut before it reaches the single knife moving to right and left in the angle of the ,v1 which severs the stalk completely4 ,the ,mc,cormick machine gathers the corn in vertical bundles1 and ties them up ready for the shockers4 ,,threshing ,,machines ,in principle these are simple enough4 ,the straw and grain is fed into a slot and pulled down between a toothed rotating drum and a fixed toothed concave4 ,these tear out the grain from the ear4 ,the former falls into the hopper of a winnowing and riddling machine1 which clears it from dust and husks1 and allows it to pass to a hopper4 ,an endless chain of buckets carries it to the delivery bins1 holding just one sackful each1 which when full discharge the grain through spouts into the receptacles waiting below their mouths4 ,an automatic counter records the number of sackfuls of corn that have been discharged1 so that dishonesty on the part of employs becomes practically an impossibility4 ,while the grain is thus treated1 oscillating rakes have arranged the straw and shaken it out behind in a form convenient for binding1 and the chaff has passed to its proper heap1 to be used as fuel for the engine or as food for cattle4 ,,petrol-,,driven ,,field ,,machinery ,on water1 rail1 and road the petrol engine has entered into rivalry with steam--very successfully too4 ,and now it bids fair to challenge both steam-engine and horse as the motive power for agricultural operations4 ,probably the best-known ,english petrol-driven farmer's help is that made by ,mr4 ,dan ,albone1 of ,biggleswade1 who in past times did much to introduce the safety bicycle to the public4 ,the ,ivel motor is not beautiful to look upon2 its sides are slab1 its outlines rather suggestive of an inverted punt4 ,but it is a willing and powerful worker2 requires no feeding in the early hours of the morning2 no careful brush down after the day's work2 no halts to ease wearied muscles4 ,in one tank is petrol1 in another lubricating oil1 in a third water to keep the cylinders cool4 ,a double-cylinder motor of #ah h4p4 transmits its energy through a large clutch and train of cogs to the road wheels1 made extra wide and well corrugated so that they shall not sink into soft ground or slip on hard4 ,there is a broad pulley-wheel peeping out from one side of the machine1 which is ready to drive chaff-cutters or threshers1 pump1 grind corn1 or turn a dynamo at a moment's notice4 ,illustration3 ,a ,,motor ,,plough ,the ,ivel ,agricultural ,motor pulling a three-furrow plough4 ,a motor thus harnessed will plough six acres a day at a total cost per acre of five shillings4 ,it is also available for reaping1 threshing1 chaff-cutting1 and other duties on a farm4 ,hitch the ,ivel on to a couple of reapers or a three-furrow plough1 and it soon shows its superiority to man's friend4 ,here are some records3-- ,eleven acres1 one rood1 thirteen poles of wet loam land ploughed in #ag-a_/b hours1 at a cost per acre of #es4 ,nineteen acres of wheat reaped and bound in #aj hours1 at a cost of #as4 #i;d4 per acre4 ,fifteen acres1 three roods of heavy grass cut in #c-a_/b hours1 cost1 #as4 per acre4 ,with horses the average cost of ploughing is about #ajs4 an acre2 of reaping #es4 ,so that the motor does at least twice the work for the same money4 ,we may quote a paragraph from the pen of ,home ,counties1 a well-known and perspicacious writer on agricultural topics4 ,it is because motor-farming is likely to result in a more thorough cultivation of the land and a more skilful and more enlightened practice of agriculture1 and not in a further extension of those deplorable land-scratching and acre-grasping methods of which so many pitiful examples may be seen on our clay soils1 that its beginnings are being sympathetically watched by many people who have the best interests of the rural districts and the prosperity of agriculture at heart4#be ,will our farmers give the same welcome to the agricultural motor that was formerly accorded to the mechanical reaper8 ,prophecy is risky1 but if1 before a decade has elapsed1 the horse has not been largely replaced by petrol on large farms and light land1 the writer of these lines will be much surprised4 ,,electrical ,,farming ,,machinery ,in ,france1 ,germany1 ,austria1 and the ,united ,states the electric motor has been turned to agricultural uses4 ,where water-power is available it is peculiarly suitable for stationary work1 such as threshing1 chaff-cutting1 root-slicing1 grinding1 etc4 ,the current can be easily distributed all over a large farm and harnessed to portable motors4 ,even ploughing has been done with electricity3 the energy being derived either from a steam-engine placed near by1 or from an overhead supply passing to the plough through trolley arms similar to those used on electric trams4 ,the great advances made recently in electrical power transmission1 and in the efficiency of the electric motor1 bring the day in sight when on large properties the fields will be girt about by cables and poles as permanent fixtures4 ,all the usual agricultural operations of ploughing1 drilling1 and reaping will then be independent of horses1 or of steam-engines panting laboriously on the headlands4 ,in fact1 the experiment has been tried with success in the ,united ,states4 ,whichever way we look1 ,giant ,steam is bowing before a superior power4 ,,footnotes3 #bd ,cassier's ,magazine4 #be ,the ,world's ,work1 vol4 iii4 #dii4 ,,chapter ,,xxv ,,dairy ,,machinery ,,milking ,,machines--,,cream ,,separators--,a ,,machine ,,for ,,drying ,,milk ,,milking ,,machines ,the farm labourer1 perched on a three-legged stool1 his head leaning against the soft flank of a cow as he squirts the milk in snowy jets into the frothing pail1 is1 like the blacksmith's forge throwing out its fiery spark-shower1 one of those sights which from childhood up exercise a mild fascination over the onlooker4 ,possibly he or she may be an interested person in more senses than one1 if the contents of the pail are ultimately to provide a refreshing drink1 for milk never looks so tempting as when it carries its natural froth4 ,modern methods of dairying demand the most scrupulous cleanliness in all processes4 ,pails1 pans1 and churns should be scoured until their shining surfaces suggest that on them the tiniest microbe could not find a footing4 ,buildings must be well aired1 scrubbed1 and treated occasionally with disinfectants4 ,even then danger may lurk unseen1 and the milk is therefore for certain purposes sterilised by heating it to a temperature approaching boiling-point and simultaneously agitating it mechanically to prevent the formation of a scum on the surface4 ,it is then poured into sealed bottles which bid defiance to exterior noxious germs4 ,the human hand1 even if washed frequently1 is a difficult thing to keep scientifically clean4 ,the milkman has to put his hand now on the cow's side1 now on his stool2 in short1 he is constantly touching surfaces which cannot be guaranteed germless4 ,he may1 therefore1 infect the teats1 which in turn infect the milk4 ,so that1 for health's sake as well as to minimise the labour and expense of milking1 various devices have been tried for mechanically extracting the fluid from the udder4 ,many of these have died quick deaths1 on account of their practical imperfections4 ,but one1 at least1 may be pronounced a success--the ,lawrence-,kennedy cow-milker1 which is worked by electricity1 and supplies another proof of the adaptability of the mysterious fluid to the service of man4 ,on the ,isle de la ,loge in the ,seine is a dairy farm which is most up-to-date in its employment of labour-saving appliances1 including that just mentioned4 ,here a turbine generates power to work vacuum pumps of large capacity4 ,the pumps are connected to tubes terminating in cone-shaped rubber caps that can be easily slipped on to the teat2 four caps branching out from a single suction chamber4 ,as soon as they have been adjusted1 the milkman--now shorn of a great part of his rights to that title--turns on the vacuum cock1 and the pulsator1 a device to imitate the periodic action of hand milking1 commences to work4 ,the number of pulsations per minute can be regulated to a nicety by adjusting screws4 ,on its way to the pail the milk passes through a glass tube1 so that the operator may see when the milking is completed4 ,this method eliminates the danger of hand contamination4 ,it also protects the milk entirely from the air1 and it has been stated that1 when thus extracted1 milk keeps sweet for a much longer time than under the old system4 ,the cows apparently do not object to machinery replacing man1 not even the ,jersey breed1 which are the most fidgety of all the tribe4 ,under the heading of economy the user scores heavily1 for a single attendant can adjust and watch a number of mechanical milkers1 whereas one man1 one cow must be the rule where the hand is used4 ,from the point of romance1 the world may lose2 the vacuum pump cannot vie with the pretty milkmaid of the songs4 ,practical people will1 however1 rest content with pure milk minus the beauty1 in preference to milk plus the microbe and the milkmaid1 who--especially when she is a man--is not always so very beautiful after all4 ,,cream ,,separators ,in the matter of separating the fatty from the watery elements of milk machinery also plays a part4 ,the custom of allowing the cream to rise in open pans suffices for small dairies where speed and thoroughness of separation are not of primary importance4 ,but when cream is required in wholesale quantities for the markets of large towns1 or for conversion into butter1 much greater expedition is needed4 ,the mechanical cream separator takes advantage of the laws of centrifugal force4 ,milk is poured into a bowl rotating at high speed on a vertical axis4 ,the heavier--watery--portions climb up the sides of the bowl in their endeavour to get as far away as possible from the centre of motion2 while the lighter particles of cream1 not having so much momentum1 are compelled to remain at the bottom4 ,by a simple mechanical arrangement1 the--very--skim milk is forced out of one tube1 and the cream out of another4 ,an efficient separator removes up to #ii per cent4 of the butter fat4 ,small sizes1 worked by hand1 treat from #aj to #ajj gallons of milk per hour2 while the large machines1 extensively used in creameries1 and turned by horse1 steam1 electric1 or other power1 have a capacity of #dej gallons per hour4 ,the saving effected by mechanical methods of separation is so great that dairy-farmers can now make a good profit on butter which formerly scarcely covered out-of-pocket expenses incurred in its manufacture4 ,a ,,machine ,,for ,,drying ,,milk ,milk contains #hg per cent4 of water and about #ab per cent4 of nutritive matter4 ,milk which has had the water evaporated from it becomes a highly concentrated food1 very valuable for many purposes which could not be served by the natural fluid4 ,until lately the process of separating the solid and liquid constituents was too costly to render the manufacture of dried milk a profitable industry4 ,but now there is on the market a drying apparatus1 manufactured by ,messrs4 ,james ,milnes and ,son1 of ,edinburgh1 which almost instantaneously drives off the water4 ,the machine used for this--the ,just-,hatmaker--process is simple4 ,it consists of two large metal drums1 #bh inches in diameter and #e feet long1 mounted horizontally in a framework with a space of about one-eighth of an inch between them4 ,high-pressure steam1 admitted to the drums through axial pipes1 raises their surfaces to a temperature of #bbj ,fahr4 ,the milk is allowed to flow in thin streams over the revolving drums1 the heat of which quickly evaporates the water4 ,a coating of solid matter gradually forms1 and this is scraped off by a knife and falls into a receptacle4 ,the milk is not boiled nor chemically altered in any way1 though completely sterilised by the heat4 ,this machine promises to revolutionise the milk trade1 as farmers will now be able to convert the very perishable product of their dairies into an easily handled and imperishable powder of great use for cooking and the manufacture of sweetmeats4 ,explorers and soldiers can have their milk supply reduced to tabloid form1 and a pound tin of the lozenges will temper their tea or coffee over many a camp fire far removed from the domestic cow4 ,,chapter ,,xxvi ,,sculpturing ,,machines ,the savage who1 with a flint point or bone splinter1 laboriously scratched rude figures on the walls of his cave dwelling1 did the best he was capable of to express the emotions which affect the splendidly equipped sculptor of to-day2 he wished to record permanently some shape in which for the time he was interested1 religiously or otherwise4 ,the sun1 moon and stars figure largely in primitive religions as objects of worship4 ,they could be easily suggested by a few strokes of a tool4 ,but when mortals turned from celestial to terrestrial bodies1 and to the worship of human or animal forms--the graven images of the ,bible--a much higher level of art was reached by the sculptor1 who endeavoured to give faithful representations in marble of the great men of the time and of the gods which his nation acknowledged4 ,the ,egyptians1 whose colossal monuments strew the banks of the ,nile1 worked in the most stubborn materials--basalt1 porphyry and granite--which would turn the edge of highly tempered steel1 and therefore raise wonder in our minds as to the nature of the tools which the subjects of the ,pharaohs must have possessed4 ,only one chisel1 of a bronze so soft that its edge turned at the first stroke against the rock under which it was found1 has so far come to light4 ,of steel tools there is no trace1 and we are left to the surmise that the ancients possessed some forgotten method of hardening other metals--including bronze--to a pitch quite unattainable to-day4 ,whatever were their implements1 they did magnificent work2 witness the splendid sculptures of vast proportions to be found in the ,british ,museum2 and the yet huger statues1 such as those of ,memnon and those at ,karnak1 which attract tourists yearly to ,egypt4 ,the ,egyptians admired magnitude2 the ,greeks perfection of outline4 ,the human form in its most ideal development1 so often found among a nation with whom athleticism was almost a religion1 inspired many of the great classical sculptors1 whose work never has been1 and probably never will be1 surpassed4 ,great honour awaited the winner in the ,olympian games2 but the most coveted prize of all was the permission given him--this after a succession of victories only--to erect a statue of himself in the sacred grove near the shrine of ,olympian ,jove4 ,happy the man who knew that succeeding generations would gaze upon a marble representation of some characteristic attitude assumed by him during his struggle for the laurel crown4 ,until recently the methods of sculpture have remained practically unaltered for thousands of years4 ,the artist first models his idea in clay or wax1 on a small scale4 ,he then1 if he designs a life-size or colossal statue1 erects a kind of iron skeleton to carry the clay of the full-sized model1 copied proportionately from the smaller one4 ,when this is finished1 a piece-mould is formed from it by applying wet lumps of plaster of ,paris all over the surface in such a manner that they can be removed piecemeal1 and fitted together to form a complete mould4 ,into this liquid plaster is run1 for a hollow cast of the whole figure1 which is smoothed and given its finishing touches by the master hand4 ,this cast has next to be reproduced in marble4 ,both the cast and the block of marble are set up on scale-stones1 revolving on vertical pivots4 ,an ingenious instrument1 called a pointing machine1 now comes into play4 ,it has two arms ending in fine metal points1 movable in ball-and-socket joints4 ,these arms are first applied to the model1 the lower being adjusted to touch a mark on the scale-stone1 the upper to just reach a mark on the figure4 ,the operator then clamps the arms and revolves the machine towards the block of marble1 the scale-stone of which has been marked similarly to its fellow4 ,the bottom arm is now set to rest on the corresponding mark of the scale-stone2 but the upper1 which can slide back telescopically1 is prevented from assuming its relative position by the unremoved portions of the block4 ,the workman therefore merely notices the point on the block at which the needle is directed1 and drills a hole into the marble on the line of the needle's axis1 to a depth sufficient to allow the arm to be fully extended4 ,this process is repeated1 in some cases many thousands of times1 until the block has been honeycombed with small holes4 ,the carver can now strike off the superfluous marble1 never going beyond the depth of a hole2 and a rough outline of the statue appears4 ,a more skilled workman follows him to shape the material to a close copy of the cast2 and the sculptor himself adds the finishing touches which stamp his personality on the completed work4 ,only a select few of the world's greatest sculptors have ventured to strike their statues direct from the marble1 without recourse to a preliminary model4 ,such a one was ,michelangelo1 who1 as though seized by a creative frenzy1 would hew and hack a block so furiously that the chips flew off like a shower1 continuing his attack for hours1 yet never making the single false stroke that in the case of other masters has ruined the work of months4 ,he truly was a genius1 and must have possessed an almost supernatural faculty of knowing when he had reached the exact depth at any point in the great block of marble from which his design gradually emerged4 ,the formation of artistic models will always require the master's hand2 but the reproduction of the cast in marble or stone can now be performed much more expeditiously than is possible with the pointing machine4 ,we have already two successful mechanisms which in an almost incredibly short time will eat a statue out of a block in faithful obedience to the movement of a pointer over the surface of a finished design4 ,they are the ,wenzel ,machine ,sculptor and ,signor ,augusto ,bontempi's ,meccaneglofo4 ,,the ,,wenzel ,,sculpturing ,,machine ,in the basement of a large ,london business house we found1 one dark ,november afternoon1 two men at work with curious-looking frameworks1 which they swayed backwards and forwards1 up and down1 to the accompaniment of a continuous clattering of metal upon stone4 ,approaching nearer1 we saw1 lying horizontally in the centre of the machine1 a small marble statue1 its feet clamped to a plate with deep notches in the circumference4 ,on either side1 at equal distances1 were two horizontal blocks of marble similarly attached to similar plates4 ,the workman had his eyes glued on a blunt-nosed pointer projecting from the middle of a balanced frame4 ,this he passed slowly over the surface of the statue1 and simultaneously two whirring drills also attached to the frame ate into the stone blocks just so far as the movement of the frame would permit4 ,the drills were driven by electric power and made some thousands of revolutions per minute1 throwing off the stone they bit away in the form of an exceedingly fine white dust4 ,it was most fascinating to watch the almost sentient performance of the drills4 ,just as a pencil in an artist's hands weaves line into line until they all suddenly spring into life and show their meaning1 so did the drills chase apparently arbitrary grooves which united1 spread1 and finally revealed the rough-hewn limb4 ,every now and then the machinist twisted the footplates round one notch1 and snicked the retaining bolts into them4 ,this exposed a fresh area of the statue and of the blocks to the pointer and the drills4 ,the large1 coarse drills used to clear away the superfluous material during the earlier stages of the work were replaced by finer points4 ,the low relief was scooped out1 the limbs moulded1 the delicate curves of cheek and the pencilling of eyebrows and lips traced1 and in a few hours the copies were ready for the usual smoothing and finishing at the hands of the human sculptor4 ,according to the capacity of the machine two1 four1 or six duplicates can be made at the cost of a little more power and time4 ,nor is it necessary to confine operations to stone and marble1 for we were shown some admirable examples of wooden statues copied from a delicate little bronze1 and1 were special drills provided1 the relations could be reversed1 bronze becoming passive to motions controlled by a wooden original4 ,sculpturing made easy would be a tempting legend to write over the ,wenzel machine4 ,but it would not represent the truth4 ,after all1 the mechanism only copies1 it cannot originate1 which is the function of the sculptor4 ,it stands to sculpturing in the same relation as the printer's process block to the artist's original sketch1 or the lithographic plates to the painter's coloured picture4 ,therefore prejudice against machine-made statues is as unreasonable as objection to the carefully-executed replica of a celebrated painting4 ,the sculptor himself has not produced it at first hand1 yet his personality has been stamped even on the copy1 for the machine can do nothing except what has already been done for it4 ,the machine merely displaces the old and imperfect pointing by hand1 substituting a method which is cheaper1 quicker1 and more accurate in its interpretation of the model4 ,it is obvious that1 apart from sculpture proper1 the industrial arts afford a wide field for this invention4 ,in architecture1 for instance1 carved wood and stonework for interiors and exteriors of buildings have been regarded hitherto as expensive luxuries1 yet in spite of their cost they are increasingly indulged in4 ,the architect now has at his disposal an economical method of carving which will enable him to utilise ornamental stonework to almost any degree4 ,sculptured friezes1 cornices1 and capitals1 which1 under the old rgime1 would represent months of highly paid hand labour1 may now be reproduced rapidly and in any quantity by the machine1 which could be adapted to work on the scaffolding itself4 ,what will become of the stonemasons8 ,won't they all be thrown out of work1 or at least a large number of them8 ,the best answer to these questions will be found in a consideration of industries in which machinery has replaced hand work4 ,has ,england1 as a cotton-spinning nation1 benefited because the power-loom was introduced8 ,does she employ more operatives than she would otherwise have done1 and are these better paid than the old hand weavers8 ,all these queries must have ,yes6 written against them4 ,in like manner1 if statuary and decoration becomes inexpensive1 twenty people will be able to afford what hitherto was within the reach of but one2 and an industry will arise beside which the output of the present-day monumental mason will appear very insignificant4 ,the sculpturing machine undoubtedly brings us one step nearer the universal ,house ,beautiful4 ,a complete list of the things which the versatile ,wenzel can perform would be tediously long4 ,let it therefore suffice to mention boot-lasts1 gun-stocks1 moulds1 engineering patterns1 numeral letters1 and other articles of irregular shape1 as some of the more prosaic productions which grow under the buzzing metal points4 ,some readers may be glad to hear that the ,wenzel promises another hobby for the individual who likes to use his hands1 since miniature machines are purchasable which treat subjects of a size not exceeding six inches in diameter4 ,no previous knowledge of carving is necessary1 and as soon as the elementary principles have been mastered the possessor of a small copier can take advantage of wet days to turn out statuettes1 busts1 and ornamental patterns for his own or friends' mantelpieces4 ,and surely a carefully finished copy in white marble of some dainty classic figure or group will be a gift well worth receiving6 ,the amateur photographer1 the fret-sawyer1 and the chip-carver will have to write ,ichabod over their workshops6 ,the ,wenzel has left its experimental stage far behind4 ,the ,german ,emperor1 after watching the creation of a miniature bust of ,beethoven1 expressed his delight in a machine that could call a musician from lifeless stone4 ,the whole of the interior decoration of the magnificent ,rathaus1 ,charlottenburg1 offers a splendid example of mechanical wood carving1 which tourists would do well to inspect4 ,we may now pass to ,,the ,,bontempi ,,sculpturing ,,machine1 for such is the translation of the formidable word ,meccaneglofo4 ,this machine is the invention of ,signor ,augusto ,bontempi1 a native of ,parma1 who commenced life as a soldier in the ,italian army1 and while still young has won distinction as a clever engineer4 ,his machine differs in most constructional details from the ,wenzel4 ,to begin with1 the pressure of the drills on the marble is imparted by water instead of by the hand2 secondly1 the block to be cut is arranged vertically instead of horizontally2 thirdly1 the index-pointer is not rigidly connected to the drill frame1 but merely controls the valves of hydraulic mechanism which guides the drills in any required direction4 ,the drills are rotated by electricity1 but all their other movements come from the pressure of water4 ,illustration3 ,a ,,small ,,wenzel ,,automatic ,,sculpturing ,,machine ,this cuts statuettes1 two at a time1 out of stone or wood1 the cutters being guided by a pointer passed over the surface of the model by the girl4 ,undoubtedly the most ingenious feature of the ,bontempi apparatus is the pointer's hydraulic valve1 which gives the drills a forward1 lateral1 or upward movement1 or a compound of two or three movements4 ,when the pointer is not touched all the valve orifices remain closed1 and the machine ceases to work4 ,should the operator pull the pointer forwards a water-way is opened1 and the liquid passes under great pressure to a cylinder which pushes the drill frame forward4 ,if the pointer be also pressed sideways1 a second channel opens and brings a second cylinder into action1 and the frame as a whole is moved correspondingly1 while an upward twist operates yet a third set of cylinders1 and the workman himself rises with the drills4 ,as soon as the sensitive tip of the pointer touches an object it telescopes1 and immediately closes the valves1 so that the drills bore no further in that direction4 ,the original and copies are turned about from time to time on their bases in a manner similar to that already described in treating the ,wenzel4 ,as many as twenty copies can be made on the largest machines4 ,quite recently there has been installed in ,southwark1 ,london1 a gigantic ,bontempi which stands #bg feet high1 and handles blocks #e feet #f inches square by #aj feet high1 and some #bj tons in weight4 ,owing to the huge masses to be worked only one copy can be made at a time2 though1 doubtless1 if circumstances warranted the expense1 a machine could be built to do double1 triple1 or quadruple duty4 ,the proprietors have discovered an abrasive to grind granite--ordinary steel chisels would be useless--and they expect a great demand for columns and monumental work in this stubborn material1 as their machines turn out finished stuff a dozen times faster than the mason4 ,an interesting story is told about the early days of ,signor ,bontempi's invention4 ,when he set up his experimental machine at ,florence1 the workmen1 following the example of the ,luddites1 rose in a body and threatened both him and his apparatus with destruction4 ,the police had to be called in to protect the inventor1 who thought it prudent to move his workshop to ,naples1 where the populace had broader-minded views4 ,the ,florentines are now sorry that they drove ,signor ,bontempi away1 for they find that instead of depressing the labour market1 the mechanical sculptor is a very good friend to both proprietor and employ4 ,,note4--,for information and illustrations the author has to thank ,mr4 ,w4 ,hanson ,boorne1 of the ,machine ,sculpture ,company1 ,aldermary ,house1 ,london1 ,e4,c41 and ,mr4 ,e4 ,w4 ,gaz1 secretary of the ,automatic ,sculpture ,syndicate1 ,sumner ,street1 ,southwark4 ,,chapter ,,xxvii ,,an ,,automatic ,,rifle ,while science works ceaselessly to cure the ills that human flesh is heir to1 invention as persistently devises weapons for man's destruction4 ,yesterday it was the discoveries of ,pasteur and the ,maxim gun2 to-day it is the ,finsen rays and the ,rexer automatic rifle4 ,though one cannot restrain a sigh on examining a new contrivance1 the sole function of which is to deal out death and desolation--sadly wondering why such ingenuity might not have been directed to the perfecting of a machine which would render life more easy and more pleasant2 yet from a book which deals with modern mechanisms we may not entirely exclude reference to a class of engines on which man has expended so much thought ever since gunpowder first entered the arena of human strife4 ,we therefore choose as our subject for this chapter a weapon hailing from ,denmark1 a country which1 though small in area1 contains many inventors of no mean repute4 ,in a ,london office1 within sight of the monument raised to ,england's great sailor hero1 the writer first made acquaintance with the ,rexer gun1 which1 venomous device that it is1 can spit forth death #cjj times a minute1 though it weighs only about #ah lbs4 ,its form is that of an ordinary rifle of somewhat clumsy build4 ,the eye at once picks out a pair of supports which project from a ring encircling it near the muzzle4 ,even a strong man would find #ah lbs4 too much to hold to his shoulder for any length of time2 so the ,rexer is primarily intended for stationary work4 ,the user lies prone1 rests the muzzle on its supports1 presses the butt to his shoulder1 and blazes away4 ,history repeats itself in the chronicles of firearms1 though it is a very long way from the old matchlock supported on a forked stick to the latest thing in rifles propped up by two steel legs4 ,machine-guns1 such as the ,maxim and ,hotchkiss1 weigh #fj lbs4 and upwards1 and have to be carried on a wheeled carriage1 drawn either by horses or by a number of men4 ,in very rough country they must be loaded on pack-horses or mules4 ,when required for action1 the gun1 its supports and appliances1 separated for packing1 must be hurriedly reassembled4 ,this means loss of valuable time4 ,the ,rexer rifle can be carried almost as easily as a ,lee-,metford or ,mauser1 and fires the ordinary small-bore ammunition4 ,wherever infantry or cavalry can go1 it can go too1 without entailing any appreciable amount of extra haulage4 ,before dealing with its actual use as a fighting arm we will notice the leading features of its construction4 ,the gun comprises the stock1 the casing and trigger-plate which enclose the breech mechanism1 the barrel1 and the perforated barrel cover1 to which are attached the forked legs on which the muzzle end is supported when firing1 and which fold up under the cover when not in use4 ,the power for working the mechanism is obtained from the recoil1 which1 when the gun is fired1 drives the barrel1 together with the breech and the other moving parts1 some two inches backwards1 thus compressing the powerful recoil-spring which lies behind the breech1 enclosed in the front part of the stock1 and which1 after the force of the recoil is spent1 expands1 and thus drives the barrel forward again into the firing position4 ,the recoil and return of the breech operate a set of levers and other working parts within the casing1 which1 by their combined actions following one another in fixed order1 open the breech1 eject the empty cartridge-case1 insert a new cartridge into the chamber1 and close the breech2 and when the gun is set for automatic action1 and the gunner keeps his finger pressed on the trigger1 the percussion arm strikes the hammer and the cartridge is fired2 the round of operations repeating itself till the magazine is emptied1 or until the gunner releases the trigger and thereby interrupts the firing4 ,a noticeable feature is the steel tube surrounding the barrel4 ,it is pierced with a number of openings to permit a circulation of air to cool the barrel1 which is furnished with fins similar to those on the cylinder of an air-cooled petrol motor to help dissipate the heat caused by the frequent explosions4 ,near the ends of the cover are the guides1 in which the barrel moves backwards and forwards under the influence of the recoil and the recoil-spring4 ,the supports are attached to the casing in such a way that the stock of the gun can be elevated or depressed and traversed through considerable angles without altering the position of the supports on the ground4 ,the rear end of the barrel cover is firmly fixed to the casing of the breech mechanism1 and forms with this and the stock the rigid part of the gun in which the moving portions work1 their motions being guided and controlled by cams and studs working in grooves and notches and on blocks attached to the rigid parts4 ,without the aid of special diagrams it is rather hard to explain the working of even a simple mechanism2 but the writer hopes that the following verbal description1 for which he has to thank the ,rexer ,company1 will at least go some way towards elucidating the action of the breech components4 ,inside the casing is the breech1 the front end of which is attached rigidly to the barrel1 the rear end being in contact with the recoil arm1 which is directly operated by the recoil spring lying in a recess in the stock4 ,in the breech is the breech-block1 which has three functions3 first to guide the new cartridges from the distributer1 which passes them from the magazine one by one into the casing1 to the firing position in the chamber 7i4e4 the expanded part of the bore at the rear end of the barrel72 secondly1 to hold the cartridge firmly fixed in the chamber1 and to act as an abutment or support to the back of the cartridge when it is fired1 and thus transmit the backward force of the explosion to the recoil spring2 thirdly1 to allow the spent cartridges to be discharged from the chamber by the extractor1 and to direct them by means of a guide curved downwards from the chamber1 so that they may be flung through an opening provided for that purpose in the trigger-plate in front of the trigger1 and out of the way of the gunner4 7,this opening is closed by a cover when the gun is not in use1 and opens automatically before the shot can be fired47 ,in order to effect this threefold object1 the breech-block is pivoted in the rear to the rear of the breech1 and has a vertical angular motion within it1 so that the fore end of the block can move into three different positions in relation to the chamber3 one1 below the chamber to guide the cartridge into it2 one1 directly in line with the chamber1 to back the cartridge2 and one1 above the chamber1 to allow the ejection of the spent cartridge-case by the extractor4 ,the cartridge is fired by a long pin through the breech-block1 struck behind by a hammer operated by a special spring4 ,the first function of the breech-block is1 as we have said1 to act as a guide for the cartridge into the chamber ready for firing1 after the fashion of the old ,martini-,henry breech-block4 ,the actual pushing forward of the cartridge is performed by a lever sliding on the top of the block4 ,after the explosion a small vertical lever jerks out the cartridge-case against the block1 and causes it to cannon downwards through the aperture in the trigger-plate already mentioned4 ,on the left-hand side of the breech casing is a small chamber1 open at the top and on the side next the breech4 ,to the top is clipped the magazine1 filled with twenty-five cartridges4 ,the magazine is shaped somewhat like a slice of melon1 only that the curved back and front are parallel4 ,the sides converge towards the inner edge4 ,it is closed at the lower end by a spring secured by a catch4 ,when a magazine is attached to the open top of the chamber the catch is released so as to put chamber and magazine in direct communication4 ,the cartridges would then be able to drop straight into the breech chamber through the side slot1 were the latter not protected by a curved horizontal shutter1 called the distributer4 ,its action is such that when a cartridge is being passed through into the breech casing1 the shutter closes1 and holds the remaining cartridges in the magazine2 and when the cartridge has passed it opens and lets the next into position in the side casing4 ,as soon as a cartridge enters the breech it is pushed forward into the chamber ready for firing by the feeder lever4 ,the magazine and the holder are so arranged that when the last cartridge has passed from the magazine to the distributer1 the motion of the moving parts of the gun is arrested till the magazine is removed1 when the motion is resumed so far as to push the remaining cartridge into the chamber and bring the breech-block into the firing position4 ,when another magazine has been fixed in the holder1 firing can be resumed by pulling the trigger2 but if another magazine is not fixed in the holder the last cartridge cannot be fired by pulling the trigger1 and only by pulling a handle which will be presently described4 ,this arrangement secures the continuance of the automatic firing being interrupted only by the very brief interval required for charging the apparatus4 ,the gun is fired1 as usual1 by pulling a trigger4 ,if a steady pull be kept on the trigger the whole contents of the magazine will be fired automatically 7the last cartridge excepted72 but if such continuous firing is not desired1 a few shots at a time may be fired automatically by alternately pulling and releasing the trigger4 ,if it is desired to fire shot by shot from the magazine1 a small swivel on the trigger-guard is moved so as to limit the movement of the trigger4 ,by moving this swivel out of the way1 automatic firing is resumed4 ,the gun may also be fired without a magazine by simply feeding cartridges by hand into the magazine holder4 ,in front of the trigger-guard is a safety catch1 and if this is set to safe the gun cannot be fired until the catch is moved to fire4 ,it is obvious that the recoil cannot come into action until a shot has been fired4 ,a handle is therefore provided on the right-hand side outside the casing1 by means of which the bolt forming the axis of the recoil and percussion arms may be turned so as to imitate the action of the recoil4 ,this handle must be turned to bring the first cartridge into the chamber1 but this having been done1 the handle returns to its normal position1 and need not be moved again4 ,we may now watch a gunner at work4 ,he chooses his position1 opens out the supports1 and pushes them into the ground so as to give the muzzle end a firm bearing4 ,he then takes a magazine from the box he carries with him1 and fixes it by a rapid motion into the magazine holder1 then1 resting his left hand on the stock to steady it1 he pulls over the handle with his right so as to bring the barrel and all the moving mechanism into the backward position4 ,he then releases the handle1 and the recoil spring comes into action and drives the breech forward1 when the controlling gear brings the front end of the breech-block into its downward position1 admits the first cartridge into the breech and pushes it forward by the cartridge-feeder into the barrel chamber4 ,the breech-block then rises to its central position at the back of the cartridge1 and the gun is ready for firing4 ,if automatic firing is required1 the gunner sets the swivel at the back of the trigger in the right position1 sights the object at which he has to fire1 and pulls the trigger1 thereby exploding the first cartridge4 ,the recoil then drives back the barrel and the breech4 ,the breech-block is moved into its highest position1 making room for the ejection of the empty cartridge-case1 which is then ejected by the extractor4 ,at the end of the recoil the block falls into its lowest position1 the cartridge-feeder having then arrived at the back of the breech-block4 ,the recoil-spring now drives the breech forward1 admits the new cartridge on to the breech-block and drives it forward by the feeder into the chamber4 ,the breech-block rises to its position behind the cartridge and is locked in that position4 ,the percussion arm is then released automatically1 strikes the hammer1 and fires the second cartridge1 the cycle of operations repeating itself till the last cartridge but one has been fired1 when the magazine is charged and the cycle of operations is again renewed and continued till the second set of cartridges has been fired4 ,the operations follow one another with such rapidity that the twenty-five cartridges contained in the magazine can be fired in less than two seconds4 ,at the same time1 the rate of firing remains under the control of the gunner1 who can interrupt it at any moment by simply releasing the trigger4 ,he can also alter his aim at any time and keep it directed on a moving object and fire at any suitable moment4 ,illustration3 ,,the ,,rexer ,,automatic ,,machine ,,gun ,it only weighs #ag-a_/b lb41 and can fire #cjj shots per minute4 ,the crescent-shaped clips hold #be cartridges each1 and as soon as one has been emptied another can be affixed in a moment4 ,in service it is not intended that every man should be armed with a ,rexer1 but only #c to #e per cent41 constituting a separate detachment which would act independently of the artillery and other machine-guns4 ,the latter would1 as at present1 cover the infantry's advance up to within some #ejj yards of the enemy1 but at this point would have to cease firing for fear of hitting their own men4 ,this period1 when the artillery can neither shoot over the heads of their infantry1 nor bring up the guns for fear of losing the teams1 affords the golden opportunity for the ,rexer1 which is advanced with the firing line4 ,if the fire of the detachment were concentrated on a part of the enemy's line1 that portion would be unable to reply while the attacking force rushed up to close quarters4 ,one hundred men armed with ,rexers would be as valuable as several hundred carrying the ordinary service weapon1 while they would be much more easily disposed1 advanced1 or withdrawn4 ,a squadron of cavalry would be accompanied by three troopers armed with ,rexers and by one leading a pack-horse laden with extra magazines4 ,each gunner would have on his horse #djj cartridges1 and the pack-horse #b1djj rounds1 distributed in leather cases over a specially designed saddle4 ,when a squadron1 not provided with machine-guns1 has to open a heavy fire1 a considerable proportion must remain behind the firing line to hold the horses of the firing party4 ,when1 on the other hand1 ,rexers are present1 only a few men would dismount1 leaving the main body ready to charge at the opportune moment2 and1 should the attack fail1 they could cover the retreat4 ,a use will also be found for the ,rexer in fortresses and on war vessels2 in fact1 everywhere where the machine-gun can take a part4 ,after exhaustive trials1 the ,danish ,government has adopted this weapon for both army and navy2 and it doubtless will presently be included in the armament of other governments4 ,there are signs that the most deadly arm of the future will be the automatic rifle4 ,perhaps a pattern even lighter than the ,rexer may appear4 ,if every unit of a large force could fire #cjj rounds a minute1 and ammunition were plentiful1 we could hardly imagine an assault in which the attacking party would not be wiped out1 even if similarly armed2 for with the perfection of firearms the man behind cover gets an ever-increasing advantage over his adversary advancing across the open4 ,a ,,ball-,,bearing ,,rifle ,rapidity of fire is only one of the desirable features in a firearm4 ,its range--or perhaps we had better say its muzzle velocity--is of almost equal importance4 ,the greater this is1 the flatter is the trajectory or curve described by the bullet1 and the more extended the point blank range and the danger zone4 ,take the case of two rifles capable of flinging a bullet one mile and two miles respectively4 ,riflemen seldom fire at objects further off than1 say1 #a1bjj yards2 so that you might think that1 given correct sighting in the weapon and a positive knowledge of the range1 both rifles would have equal chances of making a hit4 ,this is not the fact1 however1 for the more powerful rifle sends its bullet on a course much more nearly parallel to the ground than does the other4 ,therefore an object six feet high would evidently run greater risks of being hit somewhere by the two-mile rifle than by the one-mile4 ,thus1 if at #a1bjj yards the bullet had fallen to within six feet of the ground1 it might not actually strike earth till it had travelled #a1djj yards2 whereas with a lesser velocity and higher curve1 the point of impact might be only fifty yards behind4 ,evidently a six-foot man would be in danger anywhere in a belt #bjj yards broad were the high-velocity rifle in operation1 though the danger zone with the other weapon would be contracted to fifty yards4 ,at close quarters a flat trajectory is even more valuable1 since it diminishes the need for altering the sights4 ,if a rifle's point-blank range is up to #fjj yards1 you can fire at a man's head anywhere within that distance with a good chance of hitting him4 ,the farther he is away1 the lower he will be hit4 ,a high trajectory would necessitate an alteration of the sights for every fifty yards beyond1 say1 two hundred4 ,the velocity of a projectile is increased--7#a7 by increasing the weight of the driving charge2 7#b7 by decreasing the friction between the barrel and the projectile4 ,an ,american inventor1 ,mr4 ,orlan ,c4 ,cullen1 has adopted a means already well tried in mechanical engineering to decrease friction4 ,he has produced a rifle1 the barrel of which has in its walls eight spiral grooves of almost circular section1 a small arc of the circle being cut away so as to put the groove in continuous communication with the bore of the barrel4 ,these grooves are filled with steel balls1 one-tenth of an inch in diameter1 which are a good fit1 and on the slot side of the groove project a very tiny distance into the barrel4 ,the bullet--of hard steel--as it is driven through the barrel does not come into contact with the walls1 but runs over the balls1 which grip it with sufficient force to give it a spinning motion4 ,the inventor claims that there is no appreciable escape of gas round the bullet1 as the space between it and the barrel is so minute4 ,the ball races1 or grooves1 extend back to the powder chamber and forward to the muzzle4 ,their twist ceases a short distance from the muzzle to permit the insertion of recoil cushions1 which break the forces of the balls as they are dragged forward by the bullet4 ,mr4 ,cullen holds that a rifle built on this principle gives #dj per cent4 greater velocity than one with fixed rifling--to be exact1 has a point-blank range of #fej yards as compared with #dhj yards of the ,lee-,metford1 and will penetrate #aaf planks #a inch thick each4 ,the absence of friction brings absence of heat1 which in the case of machine-guns has always proved a difficulty4 ,it also minimises the recoil1 and reduces the weight of mountings for large guns4 ,whether these advantages sufficiently outweigh the disadvantages of complication and cleaning difficulties to render the weapon acceptable to military authorities remains to be seen4 ,we can only say that1 if the ball bearing proves as valuable in ballistics as it has in machinery1 then its adoption for firearms can be only a matter of time4 ,,plymouth3 ,w4 ,,brendon ,,and ,,son1 ,,ltd41 ,,printers4 99 99 99 99 99 ,transcriber's ,notes ,minor typographical errors have been corrected4 ,inconsistent accents1 punctuation1 and hyphenation are as in the original text unless noted below4 ,the following misprints and misspellings are noted or have been corrected in the text4 ,page #ch3 ,superscript #a changed to an inline fraction #a_/h 7#ej1jjj prick-marks #a_/h inch apart74 ,page #ee3 corp changed to corps 7a corps of inventors74 ,page #ade3 populsion changed to propulsion 7for its own propulsion74 ,page #agc3 searchlight changed to search-light to make the latter usage consistent throughout the book 7when a search-light alone74 ,page #bjf3 two changed to too 7the reversal being too sudden74 ,page #bdd3 ,according to the #aiaa ,encyclopdia ,britannica1 ,kleingert is the correct spelling of the name of the ,german who invented the first practical diving helmet4 ,more modern books1 however1 use a different spelling1 referring to 7,karl ,heinrich7 ,klingert4 ,page #bej3 ,saint ,goubin changed to ,saint ,gobain 7by ,saint ,gobain1 of ,paris74 ,page #bff3 overburden changed to over-burden to make the latter usage consistent throughout the book 7'removing the over-burden of surface mines'74 ,other changes to the text4 ,footnotes have been relabeled using numbers then collected together at the end of the chapter in which they appear4 ,this has the consequence that1 where the same reference is cited in more than one footnote in a chapter1 it can result in a sequence of footnotes with identical text4 ,that is not a transcription error4