,illustration3 ,the ,sun-,motor used on the ,pasadena ,ostrich-farm1 ,california4 ,it works a pump capable of delivering #a1djj gallons per minute4 ,see pp4 #baj1 #baa4 ,,the ,,romance ,,of ,,modern ,,invention ,,containing ,,interesting ,,descriptions ,,in ,,non-,,technical ,,language ,,of ,,wireless ,,telegraphy1 ,,liquid ,,air1 ,,modern ,,artillery1 ,,submarines1 ,,dirigible ,,torpedoes1 ,,solar ,,motors1 ,,airships1 c4 c4 ,,by ,,archibald ,,williams ,,author ,,of 8,,the ,,romance ,,of ,,modern ,,mechanism0 8,,the ,,romance ,,of ,,modern ,,engineering0 c4 c4 ,,with ,,twenty-,,five ,,illustrations ,,london ,,seeley ,,and ,,co4 ,,limited #ch ,,great ,,russell ,,street #aijg ,preface ,the object of this book is to set before young people in a bright and interesting way1 and without the use of technical language1 accounts of some of the latest phases of modern invention2 and also to introduce them to recent discoveries of which the full development is yet to be witnessed4 ,the author gratefully acknowledges the help given him as regards both literary matter and illustrations by3--,mr4 ,cuthbert ,hall 7the ,marconi ,wireless ,telegraphy ,co472 ,mr4 ,william ,sugg2 ,mr4 ,hans ,knudsen2 ,mr4 ,f4 ,c4 ,b4 ,cole2 ,mr4 ,e4 ,j4 ,ryves2 ,mr4 ,anton ,pollak2 the ,telautograph ,co42 the ,parsons ,steam ,turbine ,co42 the ,monotype ,co42 the ,biograph ,co42 the ,locomobile ,co42 the ,speedwell ,motor ,co4 ,september #aijb4 ,contents ,,wireless ,,telegraphy ,,high-,,speed ,,telegraphy ,,the ,,telephone--,,wireless ,,telephony ,,the ,,phonograph--,,the ,,hotographophone--,,the ,,telephonograph ,,the ,,telautograph ,,modern ,,artillery--,,rifles--,,machine ,,guns--,,heavy ,,ordnance--,,explosives--,,in ,,the ,,gun ,,factory ,,dirigible ,,torpedoes ,,submarine ,,boats ,,animated ,,pictures ,,the ,,great ,,paris ,,telescope ,,photographing ,,the ,,invisible--,,photography ,,in ,,the ,,dark ,,solar ,,motors ,,liquid ,,air ,,horseless ,,carriages ,,high-,,speed ,,railways ,,sea ,,expresses ,,mechanical ,,flight ,,type-,,setting ,,by ,,machinery ,,photography ,,in ,,colours ,,lighting ,list of ,illustrations ,,the ,,sun ,,motor ,,used ,,on ,,the ,,pasadena ,,ostrich-,,farm ,a ,,corner ,,of ,,mr4 ,,marconi',s ,,cabin ,,mr4 ,,marconi',s ,,travelling ,,station ,,the ,,poldhu ,,tower ,,guglielmo ,,marconi ,,high-,,speed ,,telegraphy3 ,a ,,receiving ,,instrument ,,high-,,speed ,,telegraphy4 ,,specimen ,,of ,,punched ,,tape ,a ,,unique ,,group ,,of ,,phonographs ,,the ,,telautograph3 ,,receiver ,,and ,,transmitter ,,the ,,telautograph1 ,,showing ,,the ,,principal ,,parts ,,the ,,telautograph1 ,,specimen ,,of ,,the ,,work ,,done ,,the ,,simms ,,armour-,,clad ,,motor ,,car ,,the 8,,holland0 ,,submarine ,,boat ,,an ,,interior ,,view ,,of ,,the 8,,holland0 ,,the 8,,holland0 ,,submarine ,,in ,,the ,,last ,,stages ,,of ,,submersion ,,the ,,great ,,paris ,,telescope ,,the ,,liquid ,,air ,,company',s ,,factory ,,at ,,pimlico ,m4 ,,serpollet ,,on ,,the 8,,easter ,,egg0 ,a ,,motor ,,car ,,driven ,,by ,,liquid ,,air ,,diagram ,,of ,,liquid ,,air ,,motor ,,car ,h4,m4,s4 ,,torpedo ,,destroyer 8,,viper0 ,,airship ,,of ,m4 ,,santos-,,dumont ,,rounding ,,the ,,eiffel ,,tower ,m4 ,,santos-,,dumont',s ,,airship ,,returning ,,to ,,longchamps ,,the ,,linotype ,,machine ,,the ,,monotype ,,casting ,,machine ,the ,romance of ,modern ,invention ,,wireless ,,telegraphy ,one day in #ahde a man named ,tawell1 dressed as a ,quaker1 stepped into a train at ,slough ,station on the ,great ,western ,railway1 and travelled to ,london4 ,when he arrived in ,london the innocent-looking ,quaker was arrested1 much to his amazement and dismay1 on the charge of having committed a foul murder in the neighbourhood of ,slough4 ,the news of the murder and a description of the murderer had been telegraphed from that place to ,paddington1 where a detective met the train and shadowed the miscreant until a convenient opportunity for arresting him occurred4 ,tawell was tried1 condemned1 and hung1 and the public for the first time generally realised the power for good dormant in the as yet little developed electric telegraph4 ,thirteen years later two vessels met in mid-,atlantic laden with cables which they joined and paid out in opposite directions1 till ,ireland and ,newfoundland were reached4 ,the first electric message passed on ,august #gth of that year from the ,new ,world to the ,old4 ,the telegraph had now become a world-power4 ,the third epoch-making event in its history is of recent date4 ,on ,december #ab1 #aija1 ,guglielmo ,marconi1 a young ,italian1 famous all over the world when but twenty-two years old1 suddenly sprang into yet greater fame4 ,at ,hospital ,point1 ,newfoundland1 he heard by means of a kite1 a long wire1 a delicate tube full of tiny particles of metal1 and a telephone ear-piece1 signals transmitted from far-off ,cornwall by his colleagues4 ,no wires connected ,poldhu1 the ,cornish station1 and ,hospital ,point4 ,the three short dot signals1 which in the ,morse code signify the letter ,s1 had been borne from place to place by the limitless1 mysterious ether1 that strange substance of which we now hear so much1 of which wise men declare we know so little4 ,marconi's great achievement1 which was of immense importance1 naturally astonished the world4 ,of course1 there were not wanting those who discredited the report4 ,others1 on the contrary1 were seized with panic and showed their readiness to believe that the ,atlantic had been spanned arially1 by selling off their shares in cable companies4 ,to use the language of the money-market1 there was a temporary 8slump0 in cable shares4 ,the world again woke up--this time to the fact that experiments of which it had heard faintly had at last culminated in a great triumph1 marvellous in itself1 and yet probably nothing in comparison with the revolution in the transmission of news that it heralded4 ,the subject of ,wireless ,telegraphy is so wide that to treat it fully in the compass of a single chapter is impossible4 ,at the same time it would be equally impossible to pass it over in a book written with the object of presenting to the reader the latest developments of scientific research4 ,indeed1 the attention that it has justly attracted entitle it1 not merely to a place1 but to a leading place2 and for this reason these first pages will be devoted to a short account of the history and theory of ,wireless ,telegraphy1 with some mention of the different systems by which signals have been sent through space4 ,on casting about for a point at which to begin1 the writer is tempted to attack the great topic of the ether1 to which experimenters in many branches of science are now devoting more and more attention1 hoping to find in it an explanation of and connection between many phenomena which at present are of uncertain origin4 ,what is ,ether8 ,in the first place1 its very existence is merely assumed1 like that of the atom and the molecule4 ,nobody can say that he has actually seen or had any experience of it4 ,the assumption that there is such a thing is justified only in so far as that assumption explains and reconciles phenomena of which we have experience1 and enables us to form theories which can be scientifically demonstrated correct4 ,what scientists now say is this3 that everything which we see and touch1 the air1 the infinity of space itself1 is permeated by a something1 so subtle that1 no matter how continuous a thing may seem1 it is but a concourse of atoms separated by this something1 the ,ether4 ,reasoning drove them to this conclusion4 ,it is obvious that an effect cannot come out of nothing4 ,put a clock under a bell-glass and you hear the ticking4 ,pump out the air and the ticking becomes inaudible4 ,what is now not in the glass that was there before8 ,the air4 ,reason1 therefore1 obliges us to conclude that air is the means whereby the ticking is audible to us4 ,no air1 no sound4 ,next1 put a lighted candle on the further side of the exhausted bell-glass4 ,we can see it clearly enough4 ,the absence of air does not affect light4 ,but can we believe that there is an absolute gap between us and the light8 ,no6 ,it is far easier to believe that the bell-glass is as full as the outside atmosphere of the something that communicates the sensation of light from the candle to the eye4 ,again1 suppose we measure a bar of iron very carefully while cold and then heat it4 ,we shall find that it has expanded a little4 ,the iron atoms1 we say1 have become more energetic than before1 repel each other and stand further apart4 ,what then is in the intervening spaces8 ,not air1 which cannot be forced through iron whether hot or cold4 ,no6 the ether3 which passes easily through crevices so small as to bar the way to the atoms of air4 ,illustration3 ,a ,corner of ,m4 ,marconi's cabin on board ,s4,s4 8,minneapolis10 showing instruments used in ,wireless ,telegraphy4 ,once more1 suppose that to one end of our iron bar we apply the negative 8pole0 of an electric battery1 and to the other end the positive pole4 ,we see that a current passes through the bar1 whether hot or cold1 which implies that it jumps across all the ether gaps1 or rather is conveyed by them from one atom to another4 ,the conclusion then is that ether is not merely omnipresent1 penetrating all things1 but the medium whereby heat1 light1 electricity1 perhaps even thought itself1 are transmitted from one point to another4 ,in what manner is the transmission effected8 ,we cannot imagine the ether behaving in a way void of all system4 ,the answer is1 by a wave motion4 ,the ether must be regarded as a very elastic solid4 ,the agitation of a portion of it by what we call heat1 light1 or electricity1 sets in motion adjoining particles1 until they are moving from side to side1 but not forwards2 the resultant movement resembling that of a snake tethered by the tail4 ,these ether waves vary immensely in length4 ,their qualities and effects upon our bodies or sensitive instruments depend upon their length4 ,by means of ingenious apparatus the lengths of various waves have been measured4 ,when the waves number #ejj billion per second1 and are but the #dj1jjjth of an inch long they affect our eyes and are named light--red light4 ,at double the number and half the length1 they give us the sensation of violet light4 ,when the number increases and the waves shorten further1 our bodies are 8blind0 to them2 we have no sense to detect their presence4 ,similarly1 a slower vibration than that of red light is imperceptible until we reach the comparatively slow pace of #ajj vibrations per second1 when we become aware of heat4 ,ether waves may be compared to the notes on a piano1 of which we are acquainted with some octaves only4 ,the gaps1 the unknown octaves1 are being discovered slowly but surely4 ,thus1 for example1 the famous ,x-rays have been assigned to the topmost octave2 electric waves to the notes between light and heat4 ,forty years ago ,professor ,clerk ,maxwell suggested that light and electricity were very closely connected1 probably differing only in their wave-length4 ,his theory has been justified by subsequent research4 ,the velocity of light 7#ahe1jjj miles per second7 and that of electric currents have been proved identical4 ,hertz1 a professor in the university of ,bonn1 also showed 7#ahhg-ahhi7 that the phenomena of light--reflection1 refraction1 and concentration of rays--can be repeated with electric currents4 ,we therefore take the word of scientists that the origin of the phenomena called light and electricity is the same--vibration of ether4 ,it at once occurs to the reader that their behaviour is so different that they might as well be considered of altogether different natures4 ,for instance1 interpose the very thinnest sheet of metal between a candle and the eye1 and the light is cut off4 ,but the sheet will very readily convey electricity4 ,on the contrary1 glass1 a substance that repels electricity1 is transparent1 i4e4 gives passage to light4 ,and again1 electricity can be conveyed round as many corners as you please1 whereas light will travel in straight lines only4 ,to clear away our doubts we have only to take the lighted candle and again hold up the metal screen4 ,light does not pass through1 but heat does4 ,substitute for the metal a very thin tank filled with a solution of alum1 and then light passes1 but heat is cut off4 ,so that heat and electricity both penetrate what is impenetrable to light2 while light forces a passage securely barred against both electricity and heat4 ,and we must remember that open space conveys all alike from the sun to the earth4 ,on meeting what we call solid matter1 ether waves are influenced1 not because ether is wanting in the solid matter1 but because the presence of something else than ether affects the intervening ether itself4 ,consequently glass1 to take an instance1 so affects ether that a very rapid succession of waves 7light7 are able to continue their way through its interstices1 whereas long electric waves are so hampered that they die out altogether4 ,metal on the other hand welcomes slow vibrations 7i4e4 long waves71 but speedily kills the rapid shakes of light4 ,in other words1 transparency is not confined to light alone4 ,all bodies are transparent to some variety of rays1 and many bodies to several varieties4 ,it may perhaps even be proved that there is no such thing as absolute resistance1 and that our inability to detect penetration is due to lack of sufficiently delicate instruments4 ,the cardinal points to be remembered are these3-- ,that the ether is a universal medium1 conveying all kinds and forms of energy4 ,that these forms of energy differ only in their rates of vibration4 ,that the rate of vibration determines what power of penetration the waves shall have through any given substance4 ,now1 it is generally true that whereas matter of any kind offers resistance to light--that is1 is not so perfect a conductor as the ether--many substances1 especially metals1 are more sensitive than ether to heat and electricity4 ,how quickly a spoon inserted into a hot cup of tea becomes uncomfortably hot1 though the hand can be held very close to the liquid without feeling more than a gentle warmth4 ,and we all have noticed that the very least air-gap in an electric circuit effectively breaks a current capable of traversing miles of wire4 ,if the current is so intense that it insists on passing the gap1 it leaps across with a report1 making a spark that is at once intensely bright and hot4 ,metal wires are to electricity what speaking tubes are to sound2 they are as it were electrical tubes through the air and ether4 ,but just as a person listening outside a speaking tube might faintly hear the sounds passing through it1 so an instrument gifted with an 8electric ear0 would detect the currents passing through the wire4 ,wireless telegraphy is possible because mankind has discovered instruments which act as electric ears or eyes1 catching and recording vibrations that had hitherto remained undetected4 ,the earliest known form of wireless telegraphy is transmission of messages by light4 ,a man on a hill lights a lamp or a fire4 ,this represents his instrument for agitating the ether into waves1 which proceed straight ahead with incredible velocity until they reach the receiver1 the eye of a man watching at a point from which the light is visible4 ,then came electric telegraphy4 ,at first a complete circuit 7two wires7 was used4 ,but in #ahch it was discovered that if instead of two wires only one was used1 the other being replaced by an earth connection1 not only was the effect equally powerful1 but even double of what it was with the metallic circuit4 ,thus the first step had been taken towards wireless electrical telegraphy4 ,the second was1 of course1 to abolish the other wire4 ,this was first effected by ,professor ,morse1 who1 in #ahdb1 sent signals across the ,susquehanna ,river without metallic connections of any sort4 ,along each bank of the river was stretched a wire three times as long as the river was broad4 ,in the one wire a battery and transmitter were inserted1 in the other a receiving instrument or galvanometer4 ,each wire terminated at each end in a large copper plate sunk in the water4 ,morse's conclusions were that provided the wires were long enough and the plates large enough messages could be transmitted for an indefinite distance2 the current passing from plate to plate1 though a large portion of it would be lost in the water4#a #a ,it is here proper to observe that the term wireless telegraphy1 as applied to electrical systems1 is misleading1 since it implies the absence of wires2 whereas in all systems wires are used4 ,but since it is generally understood that by wireless telegraphy is meant telegraphy without metal connections1 and because the more improved methods lessen more and more the amount of wire used1 the phrase has been allowed to stand4 ,about the same date a ,scotchman1 ,james ,bowman ,lindsay of ,dundee1 a man as rich in intellectual attainments as he was pecuniarily poor1 sent signals in a similar manner across the ,river ,tay4 ,in ,september1 #ahei1 ,lindsay read a paper before the ,british ,association at ,dundee1 in which he maintained that his experiments and calculations assured him that by running wires along the coasts of ,america and ,great ,britain1 by using a battery having an acting surface of #acj square feet and immersed sheets of #cjjj square feet1 and a coil weighing #cjj lbs41 he could send messages from ,britain to ,america4 ,want of money prevented the poor scholar of ,dundee from carrying out his experiments on a large enough scale to obtain public support4 ,he died in #ahfb1 leaving behind him the reputation of a man who in the face of the greatest difficulties made extraordinary electrical discoveries at the cost of unceasing labour2 and this in spite of the fact that he had undertaken and partly executed a gigantic dictionary in fifty different languages6 ,illustration3 ,m4 ,marconi's ,travelling ,station for ,wireless ,telegraphy4 ,the transmission of electrical signals through matter1 metal1 earth1 or water1 is effected by conduction1 or the leading of the currents in a circuit4 ,when we come to deal with arial transmission1 i4e4 where one or both wires are replaced by the ether1 then two methods are possible1 those of induction and ,hertzian waves4 ,to take the induction method first4 ,whenever a current is sent through a wire magnetism is set up in the ether surrounding the wire1 which becomes the core of a 8magnetic field40 ,the magnetic waves extend for an indefinite distance on all sides1 and on meeting a wire parallel to the electrified wire induce in it a dynamical current similar to that which caused them4 ,wherever electricity is present there is magnetism also1 and vice vers4 ,electricity--produces magnetism--produces electricity4 ,the invention of the ,bell telephone enabled telegraphers to take advantage of this law4 ,in #ahhe ,sir ,william ,preece1 now consulting electrical engineer to the ,general ,post-,office1 erected near ,newcastle two insulated squares of wire1 each side #ddj yards long4 ,the squares were horizontal1 parallel1 and a quarter of a mile apart4 ,on currents being sent through the one1 currents were detected in the other by means of a telephone1 which remained active even when the squares were separated by #ajjj yards4 ,sir ,william ,preece thus demonstrated that signals could be sent without even an earth connection1 i4e4 entirely through the ether4 ,in #ahhf he sent signals between two parallel telegraph wires #d-a_/b miles apart4 ,and in #ahib established a regular communication between ,flatholm1 an island fort in the ,bristol ,channel1 and ,lavernock1 a point on the ,welsh coast #c-a_/c miles distant4 ,the inductive method might have attained to greater successes had not a formidable rival appeared in the ,hertzian waves4 ,in #ahhg ,professor ,hertz discovered that if the discharge from a ,leyden jar were passed through wires containing an air-gap across which the discharge had to pass1 sparks would also pass across a gap in an almost complete circle or square of wire held at some distance from the jar4 ,this 8electric eye10 or detector1 could have its gap so regulated by means of a screw that at a certain width its effect would be most pronounced1 under which condition the detector1 or receiver1 was 8in tune0 with the exciter1 or transmitter4 ,hertz thus established three great facts1 that-- 7a7 ,a discharge of static 7i4e4 collected7 electricity across an air-gap produced strong electric waves in the ether on all sides4 7b7 ,that these waves could be caught4 7c7 ,that under certain conditions the catcher worked most effectively4 ,out of these three discoveries has sprung the latest phase of wireless telegraphy1 as exploited by ,signor ,marconi4 ,he1 in common with ,professors ,branly of ,paris1 ,popoff of ,cronstadt1 and ,slaby of ,charlottenburg1 besides many others1 have devoted their attention to the production of improved means of sending and receiving the ,hertzian waves4 ,their experiments have shown that two things are required in wireless telegraphy-- 7i47 ,that the waves shall have great penetrating power1 so as to pierce any obstacle4 7ii47 ,that they shall retain their energy1 so that a maximum of their original force shall reach the receiver4 ,the first condition is fulfilled best by waves of great length2 the second by those which1 like light1 are of greatest frequency4 ,for best telegraphic results a compromise must be effected between these extremes1 neither the thousand-mile long waves of an alternating dynamo nor the light waves of many thousands to an inch being of use4 ,the ,hertzian waves are estimated to be #bcj1jjj1jjj per second2 at which rate they would be #a-a_/b yards long4 ,they vary considerably1 however1 on both sides of this rate and dimension4 ,marconi's transmitter consists of three parts--a battery2 an induction coil1 terminating in a pair of brass balls1 one on each side of the air-gap2 and a ,morse transmitting-key4 ,upon the key being depressed1 a current from the battery passes through the coil and accumulates electricity on the brass balls until its tension causes it to leap from one to the other many millions of times in what is called a spark4 ,the longer the air-gap the greater must be the accumulation before the leap takes place1 and the greater the power of the vibrations set up4 ,marconi found that by connecting a kite or balloon covered with tinfoil by an aluminium wire with one of the balls1 the effect of the waves was greatly increased4 ,sometimes he replaced the kite or balloon by a conductor placed on poles two or three hundred feet high1 or by the mast of a ship4 ,we now turn to the receiver4 ,in #ahgi ,professor ,d4 ,e4 ,hughes observed that a microphone1 in connection with a telephone1 produced sounds in the latter even when the microphone was at a distance of several feet from coils through which a current was passing4 ,a microphone1 it may be explained1 is in its simplest form a loose connection in an electric circuit1 which causes the current to flow in fits and starts at very frequent intervals4 ,he discovered that a metal microphone stuck1 or cohered1 after a wave had influenced it1 but that a carbon microphone was self-restoring1 i4e4 regained its former position of loose contact as soon as a wave effect had ceased4 ,in #ahia ,professor ,branly of ,paris produced a 8coherer10 which was nothing more than a microphone under another name4 ,five years later ,marconi somewhat altered ,branly's contrivance1 and took out a patent for a coherer of his own4 ,it is a tiny glass tube1 about two inches long and a tenth of an inch in diameter inside4 ,a wire enters it at each end1 the wires terminating in two silver plugs fitting the bore of the tube4 ,a space of #a_/cb inch is left between the plugs1 and this space is filled with special filings1 a mixture of #if parts of nickel to #d of silver1 and the merest trace of mercury4 ,the tube is exhausted of almost all its air before being sealed4 ,this little gap filled with filings is1 except when struck by an electric wave1 to all practical purposes a non-conductor of electricity4 ,the metal particles touch each other so lightly that they offer great resistance to a current4 ,but when a ,hertzian wave flying through the ether strikes the coherer1 the particles suddenly press hard on one another1 and make a bridge through which a current can pass4 ,the current works a 8relay10 or circuit through which a stronger current passes1 opening and closing it as often as the coherer is influenced by a wave4 ,the relay actuates a tapper that gently taps the tube after each wave-influence1 causing the particles to decohere in readiness for the succeeding wave1 and also a ,morse instrument for recording words in dots and dashes on a long paper tape4 ,the coherer may be said to resemble an engine-driver1 and the 8relay0 an engine4 ,the driver is not sufficiently strong to himself move a train1 but he has strength enough to turn on steam and make the engine do the work4 ,the coherer is not suitable for use with currents of the intensity required to move a ,morse recorder1 but it easily switches a powerful current into another circuit4 ,want of space forbids a detailed account of ,marconi's successes with his improved instruments1 but the appended list will serve to show how he gradually increased the distance over which he sent signals through space4 ,in #ahif he came to ,england4 ,that year he signalled from a room in the ,general ,post-,office to a station on the roof #ajj yards distant4 ,shortly afterwards he covered #b miles on ,salisbury ,plain4 ,in ,may1 #ahig1 he sent signals from ,lavernock ,point to ,flatholm1 #c-a_/c miles4 ,this success occurred at a critical time1 for ,sir ,w4 ,preece had already1 as we have seen1 bridged the same gap by his induction method1 and for three days ,marconi failed to accomplish the feat with his apparatus1 so that it appeared as though the newer system were the less effective of the two4 ,but by carrying the transmitting instrument on to the beach below the cliff on which it had been standing1 and joining it by a wire to the pole already erected on the top of the cliff1 ,mr4 ,marconi1 thanks to a happy inspiration1 did just what was needed2 he got a greater length of wire to send off his waves from4 ,communication was at once established with ,flatholm1 and on the next day with ,brean ,down1 on the other side of the ,bristol ,channel1 and #h-b_/c miles distant4 ,then we have-- ,needles ,hotel to ,swanage #ag-a_/b miles4 ,salisbury to ,bath #cd ,french ,coast to ,harwich #ij ,isle of ,wight to ,the ,lizard #aif ,at ,sea 7#aija7 #cej ,dec4 #ag1 #aija1 ,england to ,america #bjii ,illustration3 ,poldhu ,towers1 the ,station put down by the ,marconi ,wireless ,telegraph ,company1 ,limited1 for carrying on a system of transatlantic wireless telegraphy between ,england and ,america4 ,from the four towers are suspended the rial wires which are carried into the buildings in the centre4 ,the towers are #bae feet in height1 and are made of wood4 ,a more pronounced1 though perhaps less sensational1 success than even this last occurred at the end of ,february1 #aijb4 ,mr4 ,marconi1 during a voyage to ,america on the s4s4 ,philadelphia remained in communication with ,poldhu1 ,cornwall1 until the vessel was #aeej miles distant1 receiving messages on a ,morse recorder for any one acquainted with the code to read4 ,signals arrived for a further #ejj miles1 but owing to his instruments not being of sufficient strength1 ,mr4 ,marconi could not reply4 ,when the transatlantic achievement was announced at the end of #aija1 there was a tendency in some quarters to decry the whole system4 ,the critics laid their fingers on two weak points4 ,in the first place1 they said1 the speed at which the messages could be transmitted was too slow to insure that the system would pay4 ,mr4 ,marconi replied that there had been a time when one word per minute was considered a good working rate across the ,atlantic cable2 whereas he had already sent twenty-two words per minute over very long distances4 ,a further increase of speed was only a matter of time4 ,the second objection raised centred on the lack of secrecy resulting from signals being let loose into space to strike any instrument within their range2 and also on the confusion that must arise when the ether was traversed by many sets of electric waves4 ,the young ,italian inventor had been throughout his experiments aware of these defects and sought means to remedy them4 ,in his earliest attempts we find him using parabolic metal screens to project his waves in any required direction and prevent their going in any other4 ,he also employed strips of metal in conjunction with the coherer1 the strips or 8wings0 being of such a size as to respond most readily to waves of a certain length4 ,the electric oscillations coming from the aerial wires carried on poles1 kites1 c41 were of great power1 but their energy dispersed very quickly into space in a series of rapidly diminishing vibrations4 ,this fact made them affect to a greater or less degree any receiver they might encounter on their wanderings4 ,if you go into a room where there is a piano and make a loud noise near the instrument a jangle of notes results4 ,but if you take a tuning-fork and after striking it place it near the strings1 only one string will respond1 i4e4 that of the same pitch as the fork4 ,what is required in wireless telegraphy is a system corresponding to the use of the tuning-fork4 ,unfortunately1 it has been discovered that the syntony or tuning of transmitter and receiver reduces the distance over which they are effective4 ,an electric 8noise0 is more far-reaching than an electric 8note40 ,mr4 ,marconi has1 however1 made considerable advances towards combining the sympathy and secrecy of the tuning system with the power of the 8noise0 system4 ,by means of delicately adjusted 8wings0 and coils he has brought it about that a series of waves having small individual strength1 but great regularity1 shall produce on the receiver a cumulative effect1 storing1 as it were1 electricity on the surface of the receiver 8wings0 until it is of sufficient power to overcome the resistance of the coherer4 ,that tuned wireless telegraphy is1 over moderate distances1 at least as secret as that through wires 7which can be tapped by induction7 is evident from the fact that during the ,america ,cup ,yacht ,races ,mr4 ,marconi sent daily to the ,new ,york ,herald messages of #djjj total words1 and kept them private in spite of all efforts to intercept them4 ,he claims to have as many as #bej 8tunes02 and1 indeed1 there seems to be no limit to their number1 so that the would-be 8tapper0 is in the position of a man trying to open a letter-lock of which he does not know the cipher-word4 ,he may discover the right tune1 but the chances are greatly against him4 ,we may be certain that the rapid advance in wireless telegraphy will not proceed much further before syntonic messages can be transmitted over hundreds if not thousands of miles4 ,it is hardly necessary to dwell upon the great prospect that the new telegraphy opens to mankind4 ,the advantages arising out of a ready means of communication1 freed from the shackles of expensive connecting wires and cables are1 in the main1 obvious enough4 ,we have only to imagine all the present network of wires replaced or supplemented by ether-waves1 which will be able to act between points 7e4g4 ships and ships1 ships and land1 moving and fixed objects generally7 which cannot be connected by metallic circuits4 ,already ocean voyages are being shortened as regards the time during which passengers are out of contact with the doings of the world4 ,the transatlantic journey has now a newsless period of but three days4 ,navies are being fitted out with instruments that may play as important a part as the big guns themselves in the next naval war4 ,a great maritime nation like our own should be especially thankful that the day is not far distant when our great empire will be connected by invisible electric links that no enemy may discover and cut4 ,the romantic side of wireless telegraphy has been admirably touched in some words uttered by ,professor ,ayrton in #ahii1 after the reading of a paper by ,mr4 ,marconi before the ,institution of ,electrical ,engineers4 8,if a person wished to call to a friend0 7said the ,professor71 8he would use a loud electro-magnetic voice1 audible only to him who had the electro-magnetic ear4 8#8,where are you8' he would say4 8,the reply would come--#8,i am at the bottom of a coal mine1' or #8,crossing the ,andes1' or #8,in the middle of the ,pacific4' ,or1 perhaps1 in spite of all the calling1 no reply would come1 and the person would then know his friend was dead4 ,let them think of what that meant2 of the calling which went on every day from room to room of a house1 and then imagine that calling extending from pole to pole2 not a noisy babble1 but a call audible to him who wanted to hear and absolutely silent to him who did not40 ,illustration3 ,guglielmo ,marconi4 ,when will ,professor ,ayrton's forecast come true8 ,who can say8 ,science is so full of surprises that the ordinary man wonders with a semi-fear what may be the next development2 and wise men like ,lord ,kelvin humbly confess that in comparison with what has yet to be learnt about the mysterious inner workings of ,nature their knowledge is but as ignorance4 ,,high-,,speed ,,telegraphy4 ,the wonderful developments of wireless telegraphy must not make us forget that some very interesting and startling improvements have been made in connection with the ordinary wire-circuit method3 notably in the matter of speed4 ,at certain seasons of the year or under special circumstances which can scarcely be foreseen1 a great rush takes place to transmit messages over the wires connecting important towns4 ,now1 the best telegraphists can with difficulty keep up a transmitting speed of even fifty words a minute for so long as half-an-hour4 ,the ,morse alphabet contains on the average three signals for each letter1 and the average length of a word is six letters4 ,fifty words would therefore contain between them #ijj signals1 or fifteen a second4 ,the strain of sending or noting so many for even a brief period is very wearisome to the operator4 ,means have been found of replacing the telegraph clerk1 so far as the actual signalling is concerned1 by mechanical devices4 ,in #ahdb ,alexander ,bain1 a watchmaker of ,thurso1 produced what is known as a 8chemical telegraph40 ,the words to be transmitted were set up in large metal type1 all capitals1 connected with the positive pole of a battery1 the negative pole of which was connected to earth4 ,a metal brush1 divided into five points1 each terminating a wire1 was passed over the metal type4 ,as often as a division of the brush touched metal it completed the electric circuit in the wire to which it was joined1 and sent a current to the receiving station1 where a similar brush was passing at similar speed over a strip of paper soaked in iodide of potassium4 ,the action of the electricity decomposed the solution1 turning it blue or violet4 ,the result was a series of letters divided longitudinally into five belts separated by white spaces representing the intervals between the contact points of the brush4 ,illustration3 ,the receiving instrument used by ,messrs4 ,pollak ,virag in their high-speed system of telegraphy4 ,this instrument is capable of receiving and photographically recording messages at the astonishing speed of #ej1jjj words an hour4 ,the ,bain ,chemical ,telegraph was able to transmit the enormous number of #aejj words per minute2 that is1 at ten times the rate of ordinary conversation6 ,but even when improvements had reduced the line wires from five to one1 the system1 on account of the method of composing the message to be sent1 was not found sufficiently practical to come into general use4 ,its place was taken by slower but preferable systems3 those of duplex and multiplex telegraphy4 ,when a message is sent over the wires1 the actual time of making the signals is more than is required for the current to pass from place to place4 ,this fact has been utilised by the inventors of methods whereby two or more messages may not only be sent the same way along the same wire1 but may also be sent in different directions4 ,messages are 8duplex0 when they travel across one another1 8multiplex0 when they travel together4 ,the principle whereby several instruments are able to use the same wire is that of distributing among the instruments the time during which they are in contact with the line4 ,let us suppose that four transmitters are sending messages simultaneously from ,london to ,edinburgh4 ,wires from all four instruments are led into a circular contact-maker1 divided into some hundreds of insulated segments connected in rotation with the four transmitters4 ,thus instrument ,a will be joined to segments #a1 #e1 #i1 #ac2 instrument ,b to segments #b1 #f1 #aj1 #ad2 instrument ,c with segments #c1 #g1 #aa1 #ae2 and so on4 ,along the top of the segments an arm1 connected with the telegraph line to ,edinburgh1 revolves at a uniform rate4 ,for about #a_/ejj of a second it unites a segment with an instrument4 ,if there are #aej segments on the 8distributor10 and the arm revolves three times a second1 each instrument will be put into contact with the line rather oftener than #aaj times per second4 ,and if the top speed of fifty words a minute is being worked to1 each of the fifteen signals occurring in each second will be on the average divided among seven moments of contact4 ,a similar apparatus at ,edinburgh receives the messages4 ,it is evident that for the system to work satisfactorily1 or even to escape dire confusion1 the revolving arms must run at a level speed in perfect unison with one another4 ,when the ,london arm is over segment #a1 the ,edinburgh arm must cover the same number4 ,the greatest difficulty in multiplex telegraphy has been to adjust the timing exactly4 ,paul la ,cour of ,copenhagen invented for driving the arms a device called the ,phonic ,wheel1 as its action was regulated by the vibrations of a tuning-fork4 ,the wheel1 made of soft iron1 and toothed on its circumference1 revolves at a short distance from the pole of a magnet4 ,as often as a current enters the magnet the latter attracts the nearest tooth of the wheel2 and if a regular series of currents pass through it the motion of the wheel will be uniform4 ,m4 la ,cour produced the regularity of current impulses in the motor magnet by means of a tuning-fork1 which is unable to vibrate more than a certain number of times a second1 and at each vibration closed a circuit sending current into the magnet4 ,to get two tuning-forks of the same note is an easy matter2 and consequently a uniformity of rotation at both ,london and ,edinburgh stations may be insured4 ,so sensitive is this 8interrupter0 system that as many as sixteen messages can be sent simultaneously1 which means that a single wire is conveying from #ejj to #hjj words a minute4 ,we can easily understand the huge saving that results from such a system2 the cost of instruments1 interrupter1 c41 being but small in proportion to that of a number of separate conductors4 ,the word-sending capacity of a line may be even further increased by the use of automatic transmitters able to work much faster in signal-making than the human brain and hand4 ,sir ,charles ,wheatstone's ,automatic ,transmitter has long been used in the ,post-,office establishments4 ,the messages to be sent are first of all punched on a long tape with three parallel rows of perforations4 ,the central row is merely for guiding the tape through the transmitting machine4 ,the positions of the holes in the two outside rows relatively to each other determine the character of the signal to be sent4 ,thus1 when three holes 7including the central one7 are abreast1 a ,morse 8dot0 is signified2 when the left-hand hole is one place behind the right hand1 a 8dash0 will be telegraphed4 ,in the case of a long communication the matter is divided among a number of clerks operating punching machines4 ,half-a-dozen operators could between them punch holes representing #bej to #cjj words a minute2 and the transmitter is capable of despatching as many in the same time1 while it has the additional advantage of being tireless4 ,the action of the transmitter is based upon the reversal of the direction or nature of current4 ,the punched tape is passed between an oscillating lever1 carrying two points1 and plates connected with the two poles of the battery4 ,as soon as a hole comes under a pin the pin drops through and makes a contact4 ,at the receiving end the wire is connected with a coil wound round the pole of a permanent bar-magnet4 ,such a magnet has what is known as a north pole and a south pole1 the one attractive and the other repulsive of steel or soft iron4 ,any bar of soft iron can be made temporarily into a magnet by twisting round it a few turns of a wire in circuit with the poles of a battery4 ,but which will be the north and which the south pole depends on the direction of the current4 ,if1 then1 a current passes in one direction round the north pole of a permanent magnet it will increase the magnet's attractive power1 but will decrease it if sent in the other direction4 ,the 8dot0 holes punched in the tape being abreast cause first a positive and then a negative current following at a very short interval2 but the 8dash0 holes not being opposite allow the positive current to occupy the wires for a longer period4 ,consequently the ,morse marker rests for correspondingly unequal periods on the recording 8tape10 giving out a series of dots and dashes1 as the inker is snatched quickly or more leisurely from the paper4 ,the ,wheatstone recorder has been worked up to #djj words a minute1 and when two machines are by the multiplex method acting together this rate is of course doubled4 ,as a speed machine it has1 however1 been completely put in the shade by a more recent invention of two ,hungarian electricians1 ,anton ,pollak and ,josef ,virag1 which combines the perforated strip method of transmission with the telephone and photography4 ,the message is sent off by means of a punched tape1 and is recorded by means of a telephonic diaphragm and light marking a sensitised paper4 ,in #ahih the inventors made trials of their system for the benefit of the ,united ,electrical ,company of ,buda-,pesth4 ,the ,hungarian capital was connected by two double lines of wire with a station #bjj miles distant1 where the two sets were joined so as to give a single circuit of #djj miles in length4 ,a series of tests in all weathers showed that the ,pollak-,virag system could transmit as many as #ajj1jjj words an hour over that distance4 ,from ,hungary the inventors went to the ,united ,states1 in which country of 8records0 no less than #aee1jjj words were despatched and received in the sixty minutes4 ,this average--#behj words per minute1 #dc per second--is truly remarkable6 ,even between ,new ,york and ,chicago1 separated by #iej odd miles1 the wires kept up an average of #ajjj per minute4 ,the apparatus that produces these marvellous results is of two types4 ,the one type records messages in the ,morse alphabet1 the other makes clearly-written longhand characters4 ,the former is the faster of the two1 but the legibility of the other more than compensates for the decrease of speed by one-half4 ,illustration3 ,specimens of the punched tape used for transmitting messages by the ,pollak-,virag system1 and of a message as it is delivered by the receiving machine4 ,the ,morse alphabet method closely resembles the ,wheatstone system4 ,the message is prepared for transmission by being punched on a tape4 ,but there is this difference in the position of the holes1 that whereas in the ,wheatstone method two holes are used for each dot and dash1 only one is required in the ,pollak-,virag4 ,if to the right of the central guiding line it signifies a 8dash10 if to the left1 a 8dot40 ,the 8reversal-of-current0 method1 already explained1 causes at the receiver end an increase or decrease in the power of a permanent magnet to attract or repel a diaphragm1 the centre of which is connected by a very fine metal bar with the centre of a tiny mirror hinged at one side on two points4 ,a very slight movement of the diaphragm produces an exaggerated movement of the mirror1 which1 as it tilts backwards and forwards1 reflects the light from an electric lamp on to a lens1 which concentrates the rays into a bright spot1 and focuses them on to a surface of sensitised paper4 ,in their earliest apparatus the inventors attached the paper to the circumference of a vertical cylinder1 which revolved at an even pace on an axle1 furnished at the lower end with a screw thread1 so that the portion of paper affected by the light occupied a spiral path from top to bottom of the cylinder4 ,in a later edition1 however1 an endless band of sensitised paper is employed1 and the lamp is screened from the mirror by a horizontal mantle in which is cut a helical slit making one complete turn of the cylinder in its length4 ,the mantle is rotated in unison with the machinery driving the sensitised band2 and as it revolves1 the spot at which the light from the filament can pass through the slit to the mirror is constantly shifting from right to left1 and the point at which the reflected light from the mirror strikes the sensitised paper from left to right4 ,at the moment when a line is finished1 the right extremity of the mantle begins to pass light again1 and the bright spot of light recommences its work at the left edge of the band1 which has now moved on a space4 ,the movements of the mirror backwards and forwards produce on the paper a zigzag tracing known as syphon-writing4 ,the record1 which is continuous from side to side of the band1 is a series of zigzag up-and-down strokes1 corresponding to the dots and dashes of the ,morse alphabet4 ,the apparatus for transmitting longhand characters is more complicated than that just described4 ,two telephones are now used1 and the punched tape has in it five rows of perforations4 ,if we take a copy-book and examine the letters1 we shall see that they all occupy one1 two1 or three bands of space4 ,for instance1 a1 between the lines1 occupies one band2 g1 two bands2 and f1 three4 ,in forming letters1 the movements of the fingers trace curves and straight lines1 the curves being the resultants of combined horizontal and vertical movements4 ,messrs4 ,pollak and ,virag1 in order to produce curves1 were obliged to add a second telephone1 furnished also with a metal bar joined to the mirror1 which rests on three points instead of on two4 ,one of these points is fixed1 the other two represent the ends of the two diaphragm bars1 which move the mirror vertically and horizontally respectively1 either separately or simultaneously4 ,a word about the punched paper before going further4 ,it contains1 as we have said1 five rows of perforations4 ,the top three of these are concerned only with the up-and-down strokes of the letters1 the bottom two with the cross strokes4 ,when a hole of one set is acting in unison with a hole of the other set a composite movement or curve results4 ,the topmost row of all sends through the wires a negative current of known strength2 this produces upward and return strokes in the upper zone of the letters3 for instance1 the upper part of a t4 ,the second row passes positive currents of equal strength with the negative1 and influences the up-and-down strokes of the centre zone1 e4g4 those of o2 the third row passes positive currents twice as strong as the negative1 and is responsible for double-length vertical strokes in the centre and lower zones1 e4g4 the stroke in p4 ,in order that the record shall not be a series of zigzags it is necessary that the return strokes in the vertical elements shall be on the same path as the out strokes2 and as the point of light is continuously tending to move from left to right of the paper there must at times be present a counteracting tendency counterbalancing it exactly1 so that the path of the light point is purely vertical4 ,at other times not merely must the horizontal movements balance each other1 but the right-to-left element must be stronger than the left-to-right1 so that strokes such as the left curve of an e may be possible4 ,to this end rows #d and #e of the perforations pass currents working the second telephone diaphragm1 which moves the mirror on a vertical axis so that it reflects the ray horizontally4 ,it will be noticed that the holes in rows #c1 #d1 #e vary in size to permit the passage of currents during periods of different length4 ,in this manner the little junction-hooks of such letters as r1 w1 v1 b are effected4 ,as fast as the sensitised paper strip is covered with the movements of the dancing spot of light it is passed on over rollers through developing and fixing chemical baths2 so that the receiving of messages is purely automatic4 ,the reader can judge for himself the results of this ingenious system as shown in a short section of a message transmitted by ,mr4 ,pollak4 ,the words shown actually occupied two seconds in transmission4 ,they are beautifully clear4 ,it is said that by the aid of a special 8multiplex0 device thirty sets of ,pollak-,virag apparatus can be used simultaneously on a line6 ,the reader will be able1 by the aid of a small calculation1 to arrive at some interesting figures as regards their united output4 ,,the ,,telephone4 ,a common enough sight in any large town is a great sheaf of fine wires running across the streets and over the houses4 ,if you traced their career in one direction you would find that they suddenly terminate1 or rather combine into cables1 and disappear into the recesses of a house1 which is the ,telephone ,exchange4 ,if you tracked them the other way your experience would be varied enough4 ,some wires would lead you into public institutions1 some into offices1 some into snug rooms in private houses4 ,at one time your journey would end in the town1 at another you would find yourself roaming far into the country1 through green fields and leafy lanes until at last you ran the wire to earth in some large mansion standing in a lordly park4 ,perhaps you might have to travel hundreds of miles1 having struck a 8trunk0 line connecting two important cities2 or you might even be called upon to turn fish and plunge beneath the sea for a while1 groping your way along a submarine cable4 ,in addition to the visible overhead wires that traverse a town there are many led underground through special conduits4 ,and many telephone wires never come out of doors at all1 their object being to furnish communication between the rooms of the same house4 ,the telephone and its friend1 the electric-bell1 are now a regular part of the equipment of any large premises4 ,the master of the house goes to his telephone when he wishes to address the cook or the steward1 or the head-gardener or the coachman4 ,it saves time and labour4 ,should he desire to speak to his town-offices he will1 unless connected direct1 8ring up0 the ,exchange1 into which1 as we have seen1 flow all the wires of the subscribers to the telephone system of that district4 ,the ringing-up is usually done by rapidly turning a handle which works an electric magnet and rings a bell in the ,exchange4 ,the operator there1 generally a girl1 demands the number of the person with whom the ringer wants to speak1 rings up that number1 and connects the wires of the two parties4 ,in some exchanges1 e4g4 the new ,post-,office telephone exchanges1 the place of electric-bells is taken by lamps1 to the great advantage of the operators1 whose ears are thus freed from perpetual jangling4 ,the action of unhooking the telephone receiver at the subscriber's end sends a current into a relay which closes the circuit of an electric lamp opposite the subscriber's number in the exchange4 ,similarly1 when the conversation is completed the action of hanging up the receiver again lights another lamp of a different colour1 given the exchange warning that the wires are free again4 ,in ,america1 the country of automatic appliances1 the operator is sometimes entirely dispensed with4 ,a subscriber is able1 by means of a mechanical contrivance1 to put himself in communication with any other subscriber unless that subscriber is engaged1 in which case a dial records the fact4 ,the popularity of the telephone may be judged from the fact that in #aija the ,national ,telephone ,company's system transmitted over #hjg millions of messages1 as compared with #hi millions of telegrams sent over the ,post ,office wires4 ,in ,america and ,germany1 however1 the telephone is even more universally employed than in ,england4 ,in the thinly populated prairies of ,west ,america the farm-houses are often connected with a central station many miles off1 from which they receive news of the outer world and are able to keep in touch with one another4 ,we are not1 perhaps1 as a nation sufficiently alive to the advantages of an efficient telephone system2 and on this account many districts remain telephoneless because sufficient subscribers cannot be found to guarantee use of a system if established4 ,it has been seriously urged that much of our country depopulation might be counteracted by a universal telephone service1 which would enable people to live at a distance from the towns and yet be in close contact with them4 ,at present1 for the sake of convenience and ease of 8getting at0 clients and customers1 many business men prefer to have their homes just outside the towns where their business is4 ,a cheap and efficient service open to every one would do away with a great deal of travelling that is necessary under existing circumstances1 and by making it less important to live near a town allow people to return to the country4 ,even ,norway has a good telephone system4 ,the telegraph is little used in the more thinly inhabited districts1 but the telephone may be found in most unexpected places1 in little villages hidden in the recesses of the fiords4 ,switzerland1 another mountainous country1 but very go-ahead in all electrical matters1 is noted for the cheapness of its telephone services4 ,at ,berne or ,geneva a subscriber pays #d the first year1 #b1 #abs4 the second year1 and but #a1 #abs4 the third4 ,contrast these charges with those of ,new ,york1 where #ae1 #ajs4 to #di1 #ajs4 is levied annually according to service4 ,the telephone as a public benefactor is seen at its best at ,buda-,pesth1 the twin-capital of ,hungary4 ,in #ahic1 one ,herr ,theodore ,buschgasch founded in that city a 8newspaper0--if so it may be called--worked entirely on the telephone4 ,the publishing office was a telephone exchange2 the wires and instruments took the place of printed matter4 ,the subscribers were to be informed entirely by ear of the news of the day4 ,the ,telefon ,hirmondo or 8,telephonic ,newsteller10 as the 8paper0 was named1 has more than six thousand subscribers1 who enjoy their telephones for the very small payment of eighteen florins1 or about a penny a day1 for twelve hours a day4 ,news is collected at the central office in the usual journalistic way by telephone1 telegraph1 and reporters4 ,it is printed by lithography on strips of paper six inches wide and two feet long4 ,these strips are handed to 8stentors10 or men with powerful and trained voices1 who read the contents to transmitting instruments in the offices1 whence it flies in all directions to the ears of the subscribers4 ,these last know exactly when to listen and what description of information they will hear1 for each has over his receiver a programme which is rigidly adhered to4 ,it must be explained at once that the ,telefon ,hirmondo is more than a mere newspaper1 for it adds to its practical use as a first-class journal that of entertainer1 lecturer1 preacher1 actor1 political speaker1 musician4 ,the ,telefon offices are connected by wire with the theatres1 churches1 and public halls1 drawing from them by means of special receivers the sounds that are going on there1 and transmitting them again over the wires to the thousands of subscribers4 ,the ,buda-,pesthian has therefore only to consult his programme to see when he will be in touch with his favourite actor or preacher4 ,the ladies know just when to expect the latest hints about the fashions of the day4 ,nor are the children forgotten1 for a special period is set aside weekly for their entertainment in the shape of lectures or concerts4 ,the advertising fiend1 too1 must have his say1 though he pays dearly for it4 ,on payment of a florin the stentors will shout the virtues of his wares for a space of twelve seconds4 ,the advertising periods are sandwiched in between items of news1 so that the subscriber is bound to hear the advertisements unless he is willing to risk missing some of the news if he hangs up his receiver until the 8puff0 is finished4 ,thanks to the ,telefon ,hirmondo the preacher1 actor1 or singer is obliged to calculate his popularity less by the condition of the seats in front of him than by the number of telephones in use while he is performing his part4 ,on the other hand1 the subscriber is spared a vast amount of walking1 waiting1 cab-hire1 and expense generally4 ,in fact1 if the principle is much further developed1 we shall begin to doubt whether a ,buda-,pesthian will be able to discover reasons for getting out of bed at all if the receiver hanging within reach of his hand is the entrance to so many places of delight4 ,will he become a very lazy person2 and what will be the effect on his entertainers when they find themselves facing benches that are used less every day8 ,will the sight of a row of telephone trumpets rouse the future ,liddon1 ,patti1 ,irving1 or ,gladstone to excel themselves8 ,it seems rather doubtful4 ,telephones cannot look interested or applaud4 ,what is inside the simple-looking receiver that hangs on the wall beside a small mahogany case1 or rests horizontally on a couple of crooks over the case8 ,in the older type of instrument the transmitter and receiver are separate1 the former fixed in front of the case1 the latter1 of course1 movable so that it can be applied to the ear4 ,but improved patterns have transmitter and receiver in a single movable handle1 so shaped that the earpiece is by the ear while the mouthpiece curves round opposite the mouth4 ,by pressing a small lever with the fingers the one or the other is brought into action when required4 ,the construction of the instrument1 of which we are at first a little afraid1 and with which we later on learn to become rather angry1 is in its general lines simple enough4 ,the first practical telephone1 constructed in #ahgf by ,graham ,bell1 a ,scotchman1 consisted of a long wooden or ebonite handle down the centre of which ran a permanent bar-magnet1 having at one end a small coil of fine insulated wire wound about it ,the ends of the wire coil are led through the handles to two terminals for connection with the line wires4 ,at a very short distance from the wire-wound pole of the magnet is firmly fixed by its edges a thin circular iron plate1 covered by a funnel-shaped mouthpiece4 ,the iron plate is1 when at rest1 concave1 its centre being attracted towards the pole of the magnet4 ,when any one speaks into the mouthpiece the sound waves agitate the diaphragm 7or plate71 causing its centre to move inwards and outwards4 ,the movements of the diaphragm affect the magnetism of the magnet1 sometimes strengthening it1 sometimes weakening it1 and consequently exciting electric currents of varying strength in the wire coil4 ,these currents passing through the line wires to a similar telephone excite the coil in it1 and in turn affect the magnetism of the distant magnet1 which attracts or releases the diaphragm near its pole1 causing undulations of the air exactly resembling those set up by the speaker's words4 ,to render the telephone powerful enough to make conversation possible over long distances it was found advisable to substitute for the one telephone a special transmitter1 and to insert in the circuit a battery giving a much stronger current than could possibly be excited by the magnet in the telephone at the speaker's end4 ,edison in #ahgg invented a special transmitter made of carbon4 ,he discovered that the harder two faces of carbon are pressed together the more readily will they allow current to pass2 the reason probably being that the points of contact increase in number and afford more bridges for the current4 ,accordingly his transmitter contains a small disc of lampblack 7a form of carbon7 connected to the diaphragm1 and another carbon or platinum disc against which the first is driven with varying force by the vibrations of the voice4 ,the ,edison transmitter is therefore in idea only a modification of the microphone4 ,it acts as a regulator of current1 in distinction to the ,bell telephone1 which is only an exciter of current4 ,modern forms of telephones unite the ,edison transmitter with the ,bell receiver4 ,the latter is extremely sensitive to electric currents1 detecting them even when of the minutest power4 ,we have seen that ,marconi used a telephone in his famous transatlantic experiments to distinguish the signals sent from ,cornwall4 ,a telephone may be used with an 8earth return0 instead of a second wire2 but as this exposes it to stray currents by induction from other wires carried on the same poles or from the earth itself1 it is now usual to use two wires1 completing the metallic circuit4 ,even so a subscriber is liable to overhear conversations on wires neighbouring his own2 the writer has lively recollections of first receiving news of the relief of ,ladysmith in this manner4 ,owing to the self-induction of wires in submarine cables and the consequent difficulty of forcing currents through them1 the telephone is at present not used in connection with submarine lines of more than a very moderate length4 ,england has1 however1 been connected with ,france by a telephone cable from ,st4 ,margaret's ,bay to ,sangatte1 #bc miles2 and ,scotland with ,ireland1 ,stranraer to ,donaghadee1 #bf miles4 ,the former cable enables speech between ,london and ,marseilles1 a distance of #ijj miles2 and the latter makes it possible to speak from ,london to ,dublin vi ,glasgow4 ,the longest direct line in existence is that between ,new ,york and ,chicago1 the complete circuit of which uses #aijj miles of stout copper wire1 raised above the ground on poles #ce feet high4 ,the efficiency of the telephone on a well laid system is so great that it makes very little difference whether the persons talking with one another are #ej or #ejj miles apart4 ,there is no reason why a ,cape-to-,cairo telephone should not put the two extremities of ,africa in clear vocal communication4 ,we may even live to see the day when a ,london business man will be able to talk with his agent in ,sydney1 ,melbourne1 or ,wellington4 ,a step towards this last achievement has been taken by ,m4 ,germain1 a ,french electrician1 who has patented a telephone which can be used with stronger currents than are possible in ordinary telephones2 thereby1 of course1 increasing the range of speech on submarine cables4 ,the telephone that we generally use has a transmitter which permits but a small portion of the battery power to pass into the wires1 owing to the resistance of the carbon diaphragm4 ,the weakness of the current is to a great extent compensated by the exceedingly delicate nature of the receiver4 ,m4 ,germain has reversed the conditions with a transmitter that allows a very high percentage of the current to flow into the wires1 and a comparatively insensitive receiver4 ,the result is a 8loud-speaking telephone0--not a novelty1 for ,edison invented one as long ago as #ahgg--which is capable of reproducing speech in a wonderfully powerful fashion4 ,m4 ,germain1 with the help of special tubular receivers1 has actually sent messages through a line having the same resistance as that of the ,london-,paris line1 so audibly that the words could be heard fifteen yards from the receiver in the open air6 ,the ,telephone ,,wireless ,,telephony4 ,in days when wireless telegraphy is occupying such a great deal of the world's attention1 it is not likely to cause much astonishment in the reader to learn that wireless transmission of speech over considerable distances is an accomplished fact4 ,we have already mentioned 7see 8,wireless ,telegraphy07 that by means of parallel systems of wires ,sir ,william ,preece bridged a large air-gap1 and induced in the one sounds imparted to the other4 ,since then two other methods have been introduced2 and as a preface to the mention of the first we may say a few words about ,graham ,bell's ,photophone4 ,in this instrument light is made to do the work of a metal connection between speaker and listener4 ,professor ,bell1 in arranging the ,photophone1 used a mouthpiece as in his electric telephone1 but instead of a diaphragm working in front of a magnet to set up electric impulses along a wire he employed a mirror of very thin glass1 silvered on one side4 ,the effect of sound on this mirror was to cause rapid alterations of its shape from concave to convex1 and consequent variations of its reflecting power4 ,a strong beam of light was concentrated on the centre of the mirror through a lens1 and reflected by the mirror at an angle through another lens in the direction of the receiving instrument4 ,the receiver consisted of a parabolic reflector to catch the rays and focus them on a selenium cell connected by an electric circuit with an ordinary telephone earpiece4 ,on delivering a message into the mouthpiece the speaker would1 by agitating the mirror1 send a succession of light waves of varying intensity towards the distant selenium cell4 ,selenium has the peculiar property of offering less resistance to electrical currents when light is thrown upon it than when it is in darkness3 and the more intense is the light the less is the obstruction it affords4 ,the light-waves from the mirror1 therefore1 constantly alter its capacity as a conductor1 allowing currents to pass through the telephone with varying power4 ,in this way ,professor ,bell bridged #hjj yards of space2 over which he sent1 besides articulate words1 musical notes1 using for the latter purpose a revolving perforated disc to interrupt a constant beam of light a certain number of times per second4 ,as the speed of the disc increased the rate of the light-flashes increased also1 and produced in the selenium cell the same number of passages to the electric current1 converted into a musical note by the receiver4 ,so that by means of mechanical apparatus a 8playful sunbeam0 could literally be compelled to play a tune4 ,from the ,photophone we pass to another method of sound transmission by light1 with which is connected the name of ,mr4 ,hammond ,v4 ,hayes of ,boston1 ,massachusetts4 ,it is embodied in the ,radiophone1 or the ,ray-speaker1 for it makes strong rays of light carry the human voice4 ,luminous bodies give off heat4 ,as the light increases1 so as a general rule does the heat also4 ,at present we are unable to create strong light without having recourse to heat to help us1 since we do not know how to cause other vibrations of sufficient rapidity to yield the sensation of light4 ,but we can produce heat directly1 and heat will set atoms in motion1 and the ether too1 giving us light1 but taking as reward a great deal of the energy exerted4 ,now1 the electric arc of a searchlight produces a large amount of light and heat4 ,the light is felt by the eye at a distance of many miles1 but the body is not sensitive enough to be aware of the heat emanating from the same source4 ,mr4 ,hayes has1 however1 found the heat accompanying a searchlight beam quite sufficient to affect a mechanical 8nerve0 in a far-away telephone receiver4 ,the transmitting apparatus is a searchlight1 through the back of which run four pairs of wires connected with a telephone mouthpiece after passing through a switch and resistance-box or regulator4 ,the receiver is a concave mirror1 in the focus of which is a tapering glass bulb1 half filled with carbonised filament very sensitive to heat4 ,the tapering end of the bulb projects through the back of the mirror into an ear tube4 ,if a message is to be transmitted the would-be speaker turns his searchlight in the direction of the person with whom he wishes to converse1 and makes the proper signals4 ,on seeing them the other presents his mirror to the beam and listens4 ,the speaker's voice takes control of the searchlight beam4 ,the louder the sound the more brilliantly glows the electric arc2 the stronger becomes the beam1 the greater is the amount of heat passed on to the mirror and gathered on the sensitive bulb4 ,the filament inside expands4 ,the tapering point communicates the fact to the earpiece4 ,this operation being repeated many times a second the earpiece fills with sound1 in which all the modulations of the far-distant voice are easily distinguishable4 ,two sets of the apparatus above described are necessary for a conversation1 the functions of the searchlight and the bulb not being reversible4 ,but inasmuch as all large steamers carry searchlights the necessary installation may be completed at a small expense4 ,mr4 ,hayes' invention promises to be a rival to wireless telegraphy over comparatively short distances4 ,it can be relied upon in all weathers1 and is a fast method of communication4 ,like the photophone it illustrates the inter-relationship of the phenomena of ,sound1 ,light1 and ,heat1 and the readiness with which they may be combined to attain an end4 ,next we turn from air to earth1 and to the consideration of the work of ,mr4 ,a4 ,f4 ,collins of ,philadelphia4 ,this electrician merely makes use of the currents flowing in all directions through the earth1 and those excited by an electric battery connected with earth4 ,the outfit requisite for sending wireless spoken messages consists of a couple of convenient stands1 as many storage batteries1 sets of coils1 and receiving and transmitting instruments4 ,the action of the transmitter is to send from the battery a series of currents through the coils1 which transmit them1 greatly intensified1 to the earth by means of a wire connected with a buried wire-screen4 ,the electric disturbances set up in the earth travel in all directions1 and strike a similar screen buried beneath the receiving instrument1 where the currents affect the delicate diaphragm of the telephone earpiece4 ,the system is1 in fact1 upon all fours with ,mr4 ,marconi's1 the distinguishing feature being that the ether of the atmosphere is used in the latter case1 that of the earth in the former4 ,the intensity coils are common to both2 the buried screens are the counterpart of the arial kites or balloons2 the telephone transmitter corresponds to the telegraphic transmitting key2 the earpiece to the coherer and relay4 ,no doubt in time ,mr4 ,collins will 8tune0 his instruments1 so obtaining below ground the same sympathetic electric vibrations which ,mr4 ,marconi1 ,professor ,lodge1 or others have employed to clothe their arial messages in secrecy4 ,,the ,,phonograph4 ,even if ,thomas ,edison had not done wonders with electric lighting1 telephones1 electric torpedoes1 new processes for separating iron from its ore1 telegraphy1 animated photography1 and other things too numerous to mention1 he would still have made for himself an enduring name as the inventor of the ,phonograph4 ,he has fitly been called the 8,wizard of the ,west0 from his genius for conjuring up out of what would appear to the multitude most unpromising materials startling scientific marvels1 among which none is more truly wizard-like than the instrument that is as receptive of sound as the human ear1 and of illimitable reproducing power4 ,by virtue of its elfishly human characteristic1 articulate speech1 it occupies1 and always will occupy1 a very high position as a mechanical wonder4 ,when listening to a telephone we are aware of the fact that the sounds are immediate reproductions of a living person's voice1 speaking at the moment and at a definite distance from us2 but the phonographic utterances are those of a voice perhaps stilled for ever1 and the difference adds romance to the speaking machine4 ,the ,phonograph was born in #ahgf4 ,as we may imagine1 its appearance created a stir4 ,a contributor to the ,times wrote in #ahgg3 8,not many weeks have passed since we were startled by the announcement that we could converse audibly with each other1 although hundreds of miles apart1 by means of so many miles of wire with a little electric magnet at each end4 8,another wonder is now promised us--an invention purely mechanical in its nature1 by means of which words spoken by the human voice can be1 so to speak1 stored up and reproduced at will over and over again hundreds1 it may be thousands1 of times4 ,what will be thought of a piece of mechanism by means of which a message of any length can be spoken on to a plate of metal--that plate sent by post to any part of the world and the message absolutely respoken in the very voice of the sender1 purely by mechanical agency8 ,what1 too1 shall be said of a mere machine1 by means of which the old familiar voice of one who is no longer with us on earth can be heard speaking to us in the very tones and measure to which our ears were once accustomed80 ,the first ,edison machine was the climax of research in the realm of sound4 ,as long ago as #ahef a ,mr4 ,leo ,scott made an instrument which received the formidable name of ,phonautograph1 on account of its capacity to register mechanically the vibrations set up in the atmosphere by the human voice or by musical instruments4 ,a large metal cone like the mouth of an ear-trumpet had stretched across its smaller end a membrane1 to which was attached a very delicate tracing-point working on the surface of a revolving cylinder covered with blackened paper4 ,any sound entering the trumpet agitated the membrane1 which in turn moved the stylus and produced a line on the cylinder corresponding to the vibration4 ,scott's apparatus could only record4 ,it was1 so to speak1 the first half of the phonograph4 ,edison1 twenty years later1 added the active half4 ,his machine1 as briefly described in the ,times1 was simple2 so very simple that many scientists must have wondered how they failed to invent it themselves4 ,a metal cylinder grooved with a continuous square-section thread of many turns to the inch was mounted horizontally on a long axle cut at one end with a screw-thread of the same 8pitch0 as that on the cylinder4 ,the axle1 working in upright supports1 and furnished with a heavy flywheel to render the rate of revolution fairly uniform1 was turned by a handle4 ,over the grooved cylinder was stretched a thin sheet of tinfoil1 and on this rested lightly a steel tracing-point1 mounted at the end of a spring and separated from a vibrating diaphragm by a small pad of rubber tubing4 ,a large mouthpiece to concentrate sound on to the diaphragm completed the apparatus4 ,to make a record with this machine the cylinder was moved along until the tracing-point touched one extremity of the foil4 ,the person speaking into the mouthpiece turned the handle to bring a fresh surface of foil continuously under the point1 which1 owing to the thread on the axle and the groove on the cylinder being of the same pitch1 was always over the groove1 and burnished the foil down into it to a greater or less depth according to the strength of the impulses received from the diaphragm4 ,illustration3 ,a unique group of ,phonographs4 #a4 ,the oldest phonograph in existence1 now in ,south ,kensington ,museum4 #b4 ,tinfoil instrument4 #c4 ,a cheaper form of the same4 #d4 ,a 8spectacle-form0 graphophone4 #e4 ,an exactly similar instrument1 half-size scale4 #f4 ,a doll fitted with phonograph4 ,the record being finished1 the point was lifted off the foil1 the cylinder turned back to its original position1 and the point allowed to run again over the depressions it had made in the metal sheet4 ,the latter now became the active part1 imparting to the air by means of the diaphragm vibrations similar in duration and quality to those that affected it when the record was being made4 ,it is interesting to notice that the phonograph principle was originally employed by ,edison as a telephone 8relay40 ,his attention had been drawn to the telephone recently produced by ,graham ,bell1 and to the evil effects of current leakage in long lines4 ,he saw that the amount of current wasted increased out of proportion to the length of the lines--even more than in the proportion of the squares of their lengths--and he hoped that a great saving of current would be effected if a long line were divided into sections and the sound vibrations were passed from one to the other by mechanical means4 ,he used as the connecting link between two sections a strip of moistened paper1 which a needle1 attached to a receiver1 indented with minute depressions1 that handed on the message to another telephone4 ,the phonograph proper1 as a recording machine1 was an after-thought4 ,edison's first apparatus1 besides being heavy and clumsy1 had in practice faults which made it fall short of the description given in the ,times4 ,its tone was harsh4 ,the records1 so far from enduring a thousand repetitions1 were worn out by a dozen4 ,to these defects must be added a considerable difficulty in adjusting a record made on one machine to the cylinder of another machine4 ,edison1 being busy with his telephone and electric lamp work1 put aside the phonograph for a time4 ,graham ,bell1 his brother1 ,chichester ,bell1 and ,charles ,sumner ,tainter1 developed and improved his crude ideas4 ,they introduced the ,graphophone1 using easily removable cylinder records4 ,for the tinfoil was substituted a thin coating of a special wax preparation on light paper cylinders4 ,clockwork-driven motors replaced the hand motion1 and the new machines were altogether more handy and effective4 ,as soon as he had time ,edison again entered the field4 ,he conceived the solid wax cylinder1 and patented a small shaving apparatus by means of which a record could be pared away and a fresh surface be presented for a new record4 ,the phonograph or graphophone of to-day is a familiar enough sight2 but inasmuch as our readers may be less intimately acquainted with its construction and action than with its effects1 a few words will now be added about its most striking features4 ,in the first place1 the record remains stationary while the trumpet1 diaphragm and stylus pass over it4 ,the reverse was the case with the tinfoil instrument4 ,the record is cut by means of a tiny sapphire point having a circular concave end very sharp at the edges1 to gouge minute depressions into the wax4 ,the point is agitated by a delicate combination of weights and levers connecting it with a diaphragm of ,french glass #a_/adj inch thick4 ,the reproducing point is a sapphire ball of a diameter equal to that of the gouge4 ,it passes over the depressions1 falling into them in turn and communicating its movements to a diaphragm1 and so tenderly does it treat the records that a hundred repetitions do not inflict noticeable damage4 ,it is a curious instance of the manner in which man unconsciously copies nature that the parts of the reproducing attachment of a phonograph contains parts corresponding in function exactly to those bones of the ear known as the ,hammer1 ,anvil1 and ,stirrup4 ,to understand the inner working of the phonograph the reader must be acquainted with the theory of sound4 ,all sound is the result of impulses transmitted by a moving body usually reaching the ear through the medium of the air4 ,the quantity of the sound1 or loudness1 depends on the violence of the impulse2 the tone1 or note1 on the number of impulses in a given time 7usually fixed as one second72 and the quality1 or timbre1 as musicians say1 on the existence of minor vibrations within the main ones4 ,if we were to examine the surface of a phonograph record 7or phonogram7 under a powerful magnifying glass we should see a series of scoops cut by the gouge in the wax1 some longer and deeper than others1 long and short1 deep and shallow1 alternating and recurring in regular groups4 ,the depth1 length1 and grouping of the cuts decides the nature of the resultant note when the reproducing sapphire point passes over the record--at a rate of about ten inches a second4 ,the study of a tracing made on properly prepared paper by a point agitated by a diaphragm would enable us to understand easily the cause of that mysterious variation in timbre which betrays at once what kind of instrument has emitted a note of known pitch4 ,for instance1 let us take middle ,c1 which is the result of a certain number of atmospheric blows per second on the drum of the ear4 ,the same note may come from a piano1 a violin1 a banjo1 a man's larynx1 an organ1 or a cornet2 but we at once detect its source4 ,it is scarcely imaginable that a piano and a cornet should be mistaken for one another4 ,now1 if the tracing instrument had been at work while the notes were made successively it would have recorded a wavy line1 each wave of exactly the same length as its fellows1 but varying in its outline according to the character of the note's origin4 ,we should notice that the waves were themselves wavy in section1 being jagged like the teeth of a saw1 and that the small secondary waves differed in size4 ,the minor waves are the harmonics of the main note4 ,some musical instruments are richer in these harmonics than others4 ,the fact that these delicate variations are recorded as minute indentations in the wax and reproduced is a striking proof of the phonograph's mechanical perfection4 ,furthermore1 the phonograph registers not only these composite notes1 but also chords or simultaneous combinations of notes1 each of which may proceed from a different instrument4 ,in its action it here resembles a man who by constant practice is able to add up the pounds1 shillings1 and pence columns in his ledger at the same time1 one wave system overlapping and blending with another4 ,the phonograph is not equally sympathetic with all classes of sounds4 ,banjo duets make good records1 but the guitar gives a poor result4 ,similarly1 the cornet is peculiarly effective1 but the bass drum disappointing4 ,the deep chest notes of a man come from the trumpet with startling truth1 but the top notes on which the soprano prides herself are often sadly 8tinny40 ,the phonograph1 therefore1 even in its most perfect form is not the equal of the exquisitely sensitive human ear2 and this may partially be accounted for by the fact that the diaphragm in both recorder and reproducer has its own fundamental note which is not in harmony with all other notes1 whereas the ear1 like the eye1 adapts itself to any vibration4 ,yet the phonograph has an almost limitless rpertoire4 ,it can justly be claimed for it that it is many musical instruments rolled into one4 ,it will reproduce clearly and faithfully an orchestra1 an instrumental soloist1 the words of a singer1 a stump orator1 or a stage favourite4 ,consequently we find it every where--at entertainments1 in the drawing-room1 and even tempting us at the railway station or other places of public resort to part with our superfluous pence4 ,at the ,london ,hippodrome it discourses to audiences of several thousand persons1 and in the nursery it delights the possessors of ingeniously-constructed dolls which1 on a button being pressed and concealed machinery being brought into action1 repeat some well-known childish melody4 ,it must not be supposed that the phonograph is nothing more than a superior kind of scientific toy4 ,more serious duties than those of mere entertainment have been found for it4 ,at the last ,presidential ,election in the ,states the phonograph was often called upon to harangue large meetings in the interests of the rival candidates1 who were perhaps at the time wearing out their voices hundreds of miles away with the same words4 ,since the pronunciation of a foreign language is acquired by constant imitation of sounds1 the phonograph1 instructed by an expert1 has been used to repeat words and phrases to a class of students until the difficulties they contain have been thoroughly mastered4 ,the sight of such a class hanging on the lips--or more properly the trumpet--of a phonograph gifted with the true ,parisian accent may be common enough in the future4 ,as a mechanical secretary and substitute for the shorthand writer the phonograph has certainly passed the experimental stage4 ,its daily use by some of the largest business establishments in the world testify to its value in commercial life4 ,many firms1 especially ,american1 have invested heavily in establishing phonograph establishments to save labour and final expense4 ,the manager1 on arriving at his office in the morning1 reads his letters1 and as the contents of each is mastered1 dictates an answer to a phonograph cylinder which is presently removed to the typewriting room1 where an assistant1 placing it upon her phonograph and fixing the tubes to her ears1 types what is required4 ,it is interesting to learn that at ,ottawa1 the seat of the ,canadian ,government1 phonographs are used for reporting the parliamentary proceedings and debates4 ,there is therefore a prospect that1 though the talking-machine may lose its novelty as an entertainer1 its practical usefulness will be largely increased4 ,and while considering the future of the instrument1 the thought suggests itself whether we shall be taking full advantage of ,mr4 ,edison's notable invention if we neglect to make records of all kinds of intelligible sounds which have more than a passing interest4 ,if the records were made in an imperishable substance they might remain effective for centuries1 due care being taken of them in special depositories owned by the nation4 ,to understand what their value would be to future generations we have only to imagine ourselves listening to the long-stilled thunder of ,earl ,chatham1 to the golden eloquence of ,burke1 or the passionate declamations of ,mrs4 ,siddons4 ,and in the narrower circle of family interests how valuable a part of family heirlooms would be the phonograms containing a vocal message to posterity from ,grandfather this1 or ,great-aunt that1 whose portraits in the drawing-room album do little more than call attention to the changes in dress since the time when their subjects faced the camera6 ,record-,making and ,manufacture4--,phonographic records are of two shapes1 the cylindrical and the flat1 the latter cut with a volute groove continuously diminishing in diameter from the circumference to the centre4 ,flat records are used in the ,gramophone--a reproducing machine only4 ,their manufacture is effected by first of all making a record on a sheet of zinc coated with a very thin film of wax1 from which the sharp steel point moved by the recording diaphragm removes small portions1 baring the zinc underneath4 ,the plate is then flooded with an acid solution1 which eats into the bared patches1 but does not affect the parts still covered with wax4 ,the etching complete1 the wax is removed entirely1 and a cast or electrotype negative record made from the zinc plate4 ,the indentations of the original are in this represented by excrescences of like size2 and when the negative block is pressed hard down on to a properly prepared disc of vulcanite or celluloid1 the latter is indented in a manner that reproduces exactly the tones received on the 8master0 record4 ,cylindrical records are made in two ways1 by moulding or by copying4 ,the second process is extremely simple4 ,the 8master0 cylinder is placed on a machine which also rotates a blank cylinder at a short distance from and parallel to the first4 ,over the 8master0 record passes a reproducing point1 which is connected by delicate levers to a cutting point resting on the 8blank10 so that every movement of the one produces a corresponding movement of the other4 ,this method1 though accurate in its results1 is comparatively slow4 ,the moulding process is therefore becoming the more general of the two4 ,edison has recently introduced a most beautiful process for obtaining negative moulds from wax positives4 ,owing to its shape1 a zinc cylinder could not be treated like a flat disc1 as1 the negative made1 it could not be detached without cutting4 ,edison1 therefore1 with characteristic perseverance1 sought a way of electrotyping the wax1 which1 being a non-conductor of electricity1 would not receive a deposit of metal4 ,the problem was how to deposit on it4 ,any one who has seen a ,crookes' tube such as is used for ,x-ray work may have noticed on the glass a black deposit which arises from the flinging off from the negative pole of minute particles of platinum4 ,edison took advantage of this repellent action2 and by enclosing his wax records in a vacuum between two gold poles was able to coat them with an infinitesimally thin skin of pure gold1 on which silver or nickel could be easily deposited4 ,the deposit being sufficiently thick the wax was melted out and the surface of the electrotype carefully cleaned4 ,to make castings it was necessary only to pour in wax1 which on cooling would shrink sufficiently to be withdrawn4 ,the delicacy of the process may be deduced from the fact that some of the sibilants1 or hissing sounds of the voice1 are computed to be represented by depressions less than a millionth of an inch in depth1 and yet they are most distinctly reproduced6 ,cylinder records are made in two sizes1 #b-a_/b and #e inches in diameter respectively4 ,the larger size gives the most satisfactory renderings1 as the indentations are on a larger scale and therefore less worn by the reproducing point4 ,one hundred turns to the inch is the standard pitch of the thread2 but in some records the number is doubled4 ,phonographs1 ,graphophones1 and ,gramophones are manufactured almost entirely in ,america1 where large factories1 equipped with most perfect plant and tools1 work day and night to cope with the orders that flow in freely from all sides4 ,one factory alone turns out a thousand machines a day1 ranging in value from a few shillings to forty pounds each4 ,records are made in ,england on a large scale2 and now that the ,edison-,bell firm has introduced the unbreakable celluloid form their price will decrease4 ,by means of the ,edison electrotyping process a customer can change his record without changing his cylinder4 ,he takes the cylinder to the factory1 where it is heated1 placed in the mould1 and subjected to great pressure which drives the soft celluloid into the mould depressions2 and behold6 in a few moments 8,auld ,lang ,syne0 has become 8,home1 ,sweet ,home10 or whatever air is desired4 ,thus altering records is very little more difficult than getting a fresh book at the circulating library4 ,,the ,,photographophone4 ,this instrument is a phonograph working entirely by means of light and electricity4 ,the flame of an electric lamp is brought under the influence of sound vibrations which cause its brilliancy to vary at every alteration of pitch or quality4 ,the light of the flame is concentrated through a lens on to a travelling photographic sensitive film1 which1 on development in the ordinary way1 is found to be covered with dark and bright stripes proportionate in tone to the strength of the light at different moments4 ,the film is then passed between a lamp and a selenium plate connected with an electric circuit and a telephone4 ,the resistance of the selenium to the current varies according to the power of the light thrown upon it4 ,when a dark portion of the film intercepts the light of the lamp the selenium plate offers high resistance2 when the light finds its way through a clear part of the film the resistance weakens4 ,thus the telephone is submitted to a series of changes affecting the 8receiver40 ,as in the making of the record speech-vibrations affect light1 and the light affects a sensitive film2 so in its reproduction the film affects a sensitive selenium plate1 giving back to a telephone exactly what it received from the sound vibrations4 ,one great advantage of ,mr4 ,ruhmer's method is that from a single film any number of records can be printed by photography2 another1 that1 as with the ,telegraphone 7see below71 the same film passed before a series of lamps successively is able to operate a corresponding number of telephones4 ,the inventor is not content with his success4 ,he hopes to record not merely sounds but even pictures by means of light and a selenium plate4 ,,the ,,telephonograph4 ,having dealt with the phonograph and the telephone separately1 we may briefly consider one or two ingenious combinations of the two instruments4 ,the word ,telephonograph signifies an apparatus for recording sounds sent from a distance4 ,it takes the place of the human listener at the telephone receiver4 ,let us suppose that a ,reading subscriber wishes to converse along the wires with a friend in ,london1 but that on ringing up his number he discovers that the friend is absent from his home or office4 ,he is left with the alternative of either waiting till his friend returns1 which may cause a serious loss of time1 or of dictating his message1 a slow and laborious process4 ,this with the ordinary telephonic apparatus4 ,but if the ,london friend be the possessor of a ,telephonograph1 the person answering the call-bell can1 if desired to do so1 switch the wires into connection with it and start the machinery2 and in a very short time the message will be stored up for reproduction when the absent friend returns4 ,the ,telephonograph is the invention of ,mr4 ,j4 ,e4 ,o4 ,kumberg4 ,the message is spoken into the telephone transmitter in the ordinary way1 and the vibrations set up by the voice are caused to act upon a recording stylus by the impact of the sound waves at the further end of the wires4 ,in this manner a phonogram is produced on the wax cylinder in the house or office of the person addressed1 and it may be read off at leisure4 ,a very sensitive transmitter is employed1 and if desired the apparatus can be so arranged that by means of a double-channel tube the words spoken are simultaneously conveyed to the telephone and to an ordinary phonograph1 which insures that a record shall be kept of any message sent4 ,the ,telegraphone1 produced by ,mr4 ,valdemar ,poulsen1 performs the same functions as the telephonograph1 but differs from it in being entirely electrical4 ,it contains no waxen cylinder1 no cutting-point2 their places are taken respectively by a steel wire wound on a cylindrical drum 7each turn carefully insulated from its neighbours7 and by a very small electro-magnet1 which has two delicate points that pass along the wire1 one on either side1 resting lightly upon it4 ,as the drum rotates1 the whole of the wire passes gradually between the two points1 into which a series of electric shocks is sent by the action of the speaker's voice at the further end of the wires4 ,the shocks magnetise the portion of steel wire which acts as a temporary bridge between the two points4 ,at the close of three and a half minutes the magnet has worked from one end of the wire coil to the other2 it is then automatically lifted and carried back to the starting-point in readiness for reproduction of the sounds4 ,this is accomplished by disconnecting the telegraphone from the telephone wires and switching it on to an ordinary telephonic earpiece or receiver4 ,as soon as the cylinder commences to revolve a second time1 the magnet is influenced by the series of magnetic 8fields0 in the wires1 and as often as it touches a magnetised spot imparts an impulse to the diaphragm of the receiver1 which vibrates at the rate and with the same force as the vibrations originally set up in the distant transmitter4 ,the result is a clear and accurate reproduction of the message1 even though hours and even days may have elapsed since its arrival4 ,as the magnetic effects on the wire coil retain their power for a considerable period1 the message may be reproduced many times4 ,as soon as the wire-covered drum is required for fresh impressions1 the old one is wiped out by passing a permanent magnet along the wire to neutralise the magnetism of the last message4 ,mr4 ,poulsen has made an instrument of a different type to be employed for the reception of an unusually lengthy communication4 ,instead of a wire coil on a cylinder1 a ribbon of very thin flat steel spring is wound from one reel on to another across the poles of two electro-magnets1 which touch the lower side only of the strip4 ,the first magnet is traversed by a continuous current to efface the previous record2 the second magnetises the strip in obedience to impulses from the telephone wires4 ,the message complete1 the strip is run back1 and the magnets connected with receivers1 which give out loud and intelligent speech as the strip again traverses them4 ,the ,poulsen machine makes the transmission of the same message simultaneously through several telephones an easy matter1 as the strip can be passed over a series of electro-magnets each connected with a telephone4 ,,the ,,telautograph4 ,it is a curious experience to watch for the first time the movements of a tiny ,telautograph pen as it works behind a glass window in a japanned case4 ,the pen1 though connected only with two delicate wires1 appears instinct with human reason4 ,it writes in a flowing hand1 just as a man writes4 ,at the end of a word it crosses the t's and dots the i's4 ,at the end of a line it dips itself in an inkpot4 ,it punctuates its sentences correctly4 ,it illustrates its words with sketches4 ,it uses shorthand as readily as longhand4 ,it can form letters of all shapes and sizes4 ,and yet there is no visible reason why it should do what it does4 ,the japanned case hides the guiding agency1 whatever it may be4 ,our ears cannot detect any mechanical motion4 ,the writing seems at first sight as mysterious as that which appeared on the wall to warn ,king ,belshazzar4 ,in reality it is the outcome of a vast amount of patience and mechanical ingenuity culminating in a wonderful instrument called the ,telautograph4 ,the ,telautograph is so named because by its aid we can send our autographs1 i4e4 our own particular handwriting1 electrically over an indefinite length of wire1 as easily as a telegraph clerk transmits messages in the ,morse alphabet4 ,whatever the human hand does on one telautograph at one end of the wires1 that will be reproduced by a similar machine at the other end1 though the latter be hundreds of miles away4 ,illustration3 ,by kind permission of ,the ,telautograph ,co4 ,the ,telautograph4 ,the upper portion is the ,receiver1 the lower 7with cover removed7 is the ,transmitter4 ,the instrument stands about eighteen inches high1 and its base is as many inches square4 ,it falls into two parts1 the receiver and the transmitter4 ,the receiver is vertical and forms the upright and back portion of the telautograph4 ,at one side of it hangs an ordinary telephone attachment4 ,the transmitter1 a sloping desk placed conveniently for the hand1 is the front and horizontal portion4 ,the receiver of one station is connected with the transmitter of another station2 there being ordinarily no direct communication between the two parts of the same instrument4 ,an attempt will be made to explain1 with the help of a simple diagram1 the manner in which the telautograph performs its duties4 ,these duties are threefold4 ,in the first place1 it must reproduce whatever is written on the transmitter4 ,secondly1 it must reproduce only what is written1 not all the movements of the hand4 ,thirdly1 it must supply the recording pen with fresh paper to write on1 and with fresh ink to write with4 ,in our diagram we must imagine that all the coverings of the telautograph have been cleared away to lay bare the most essential parts of the mechanism4 ,for the sake of simplicity not all the coils1 wires1 and magnets having functions of their own are represented1 and the drawing is not to scale4 ,but what is shown will enable the reader to grasp the general principles which work the machine4 ,turning first of all to the transmitter1 we have ,p1 a little platform hinged at the back end1 and moving up and down very slightly in front1 according as pressure is put on to or taken off it by the pencil4 ,across it a roll of paper is shifted by means of the lever ,s1 which has other uses as well4 ,to the right of ,p is an electric bell-push1 ,e1 and on the left ,k1 another small button4 ,the pencil is at the junction of two small bars ,,cc'1 which are hinged at their other end to the levers ,,aa'4 ,any motion of the pencil is transmitted by ,,cc' to ,,aa'1 and by them to the arms ,,ll'1 the extremities of which1 two very small brushes ,,zz'1 sweep along the quadrants ,,rr'4 ,this is the first point to observe1 that the position of the pencil decides on which sections of the quadrants these little brushes rest1 and consequently how much current is to be sent to the distant station4 ,the quadrants are known technically as rheostats1 or current-controllers4 ,each quadrant is divided into #dif parts1 separated from each other by insulating materials1 so that current can pass from one to the other only by means of some connecting wire4 ,in our illustration only thirteen divisions are given1 for the sake of clearness4 ,the dark lines represent the insulation4 ,,ww' are the very fine wire loops connecting each division of the quadrant with its neighbours4 ,if then a current from the battery ,b enters the rheostat at division #a it will have to pass through all these wires before it can reach division #ac4 ,the current always enters at #a1 but the point of departure from the rheostat depends entirely upon the position of the brushes ,z or ,z'4 ,if ,z happens to be on ,no4 #f the current will pass through five loops of wire1 along the arm ,l1 and so through the main wire to the receiving station2 if on ,no4 #ac1 through twelve loops4 ,illustration3 ,,the ,,telautograph ,before going any further we must have clear ideas on the subject of electrical resistance1 upon which the whole system of the telautograph is built up4 ,electricity resembles water in its objection to flow through small passages4 ,it is much harder to pump water through a half-inch pipe than through a one-inch pipe1 and the longer the pipe is1 whatever its bore1 the more work is required4 ,so then1 two things affect resistance--size of pipe or wire1 and length of pipe or wire4 ,the wires ,,ww' are very fine1 and offer very high resistance to a current2 so high that by the time the current from battery ,b has passed through all the wire loops only one-fifteenth or less of the original force is left to traverse the long-distance wire4 ,the rheostats act independently of one another4 ,as the pencil moves over the transmitting paper1 a succession of currents of varying intensity is sent off by each rheostat to the receiving station4 ,the receiver1 to which we must now pay attention1 has two arms ,,dd'1 and two rods ,,ff'1 corresponding in size with ,,aa' and ,,cc' of the transmitter4 ,the arms ,,dd' are moved up and down by the coils ,,tt' which turn on centres in circular spaces at the bend of the magnets ,,mm'4 ,the position of these coils relatively to the magnets depend on the strength of the currents coming from the transmitting station4 ,each coil strains at a small spiral spring until it has reached the position in which its electric force is balanced by the retarding influence of the spring4 ,one of the cleverest things in the telautograph is the adjustment of these coils so that they shall follow faithfully the motions of the rods ,,ll' in the transmitter4 ,illustration3 ,by kind permission of ,the ,telautograph ,co4 ,an example of the work done by the ,telautograph4 ,the upper sketch shows a design drawn on the transmitter2 the lower is the same design as reproduced by the receiving instrument1 many miles distant4 ,we are now able to trace the actions of sending a message4 ,the sender first presses the button ,e to call the attention of some one at the receiving station to the fact that a message is coming1 either on the telephone or on the paper4 ,it should be remarked1 by-the-bye1 that the same wires serve for both telephone and telautograph1 the unhooking of the telephone throwing the telautograph out of connection for the time4 ,he then presses the lever ,s towards the left1 bringing his transmitter into connection with the distant receiver1 and also moving a fresh length of paper on to the platform ,p4 ,with his pencil he writes his message1 pressing firmly on the paper1 so that the platform may bear down against an electric contact1 ,x4 ,as the pencil moves about the paper the arms ,,cc' are constantly changing their angles1 and the brushes ,,zz' are passing along the segments of the rheostats4 ,currents flow in varying intensity away to the coils ,,tt' and work the arms ,,dd'1 the wires ,,ff'1 and the pen1 a tiny glass tube4 ,in the perfectly regulated telautograph the arms ,,aa' and the arms ,,dd' will move in unison1 and consequently the position of the pen must be the same from moment to moment as that of the pencil4 ,mr4 ,foster ,ritchie1 the clever inventor of this telautograph1 had to provide for many things besides mere slavish imitation of movement4 ,as has been stated above1 the pen must record only those movements of the pencil which are essential4 ,evidently1 if while the pencil returns to dot an i a long line were registered by the pen corresponding to the path of the pencil1 confusion would soon ensue on the receiver2 and instead of a neatly-written message we should have an illegible and puzzling maze of lines4 ,mr4 ,ritchie has therefore taken ingenious precautions against any such mishap4 ,the platen ,p on being depressed by the pencil touches a contact1 ,x1 which closes an electric circuit through the long-distance wires and excites a magnet at the receiving end4 ,that attracts a little arm and breaks another circuit1 allowing the bar ,y to fall close to the paper4 ,the wires ,,ff' and the pen are now able to rest on the paper and trace characters4 ,but as soon as the platen ,p rises1 on the removal of the pencil from the transmitting paper1 the contact at ,x is broken1 the magnet at the receiver ceases to act1 the arm it attracted falls back and sets up a circuit which causes the bar to spring up again and lift the pen4 ,so that unless you are actually pressing the paper with your pencil1 the pen is not marking1 though it may be moving4 ,as soon as a line is finished a fresh surface of paper is required at both ends4 ,the operator pushes the lever ,s sideways1 and effects the change mechanically at his end4 ,at the same time a circuit is formed which excites certain magnets at the receiver and causes the shifting forward there also of the paper1 and also breaks the writing current1 so that the pen returns for a moment to its normal position of rest in the inkpot4 ,it may be asked3 ,if the wires are passing currents to work the writing apparatus1 how can they simultaneously affect the lifting-bar1 ,y8 ,the answer is that currents of two different kinds are used1 a direct current for writing1 a vibratory current for depressing the lifting-bar4 ,the direct current passes from the battery ,b through the rheostats ,,rr' along the wires1 through the coils working the arms ,,dd' and into the earth at the far end2 but the vibratory current1 changing its direction many times a second and so neutralising itself1 passes up one wire and back down the other through the lifting-bar connection without interfering with the direct current4 ,the message finished1 the operator depresses with the point of his pencil the little push-key1 ,k1 and connects his receiver with the distant transmitter in readiness for an answer4 ,the working speed of the telautograph is that of the writer4 ,if shorthand be employed1 messages can be transmitted at the rate of over #ajj words per minute4 ,as regards the range of transmission1 successful tests have been made by the postal authorities between ,paris and ,london1 and also between ,paris and ,lyons4 ,in the latter case the messages were sent from ,paris to ,lyons and back directly to ,paris1 the lines being connected at ,lyons1 to give a total distance of over #fej miles4 ,there is no reason why much greater length of line should not be employed4 ,the telautograph in its earlier and imperfect form was the work of ,professor ,elisha ,gray1 who invented the telephone almost simultaneously with ,professor ,graham ,bell4 ,his telautograph worked on what is known as the step-by-step principle1 and was defective in that its speed was very limited4 ,if the operator wrote too fast the receiving pen lagged behind the transmitting pencil1 and confusion resulted4 ,accordingly this method1 though ingenious1 was abandoned1 and ,mr4 ,ritchie in his experiments looked about for some preferable system1 which should be simpler and at the same time much speedier in its action4 ,after four years of hard work he has brought the rheostat system1 explained above1 to a pitch of perfection which will be at once appreciated by any one who has seen the writing done by the instrument4 ,the advantages of the ,telautograph over the ordinary telegraphy may be briefly summed up as follows3-- ,anybody who can write can use it2 the need of skilled operators is abolished4 ,a record is automatically kept of every message sent4 ,the person to whom the message is sent need not be present at the receiver4 ,he will find the message written out on his return4 ,the instrument is silent and so insures secrecy4 ,an ordinary telegraph may be read by sound2 but not the telautograph4 ,it is impossible to tap the wires unless1 as is most unlikely1 the intercepting party has an instrument in exact accord with the transmitter4 ,it can be used on the same wires as the ordinary telephone1 and since a telephone is combined with it1 the subscriber has a double means of communication4 ,for some items of business the telephone may be used as preferable2 but in certain cases1 the telautograph4 ,a telephone message may be heard by other subscribers2 it is impossible to prove the authenticity of such a message unless witnesses have been present at the transmitting end2 and the message itself may be misunderstood by reason of bad articulation4 ,but the telautograph preserves secrecy while preventing any misunderstanding4 ,anything written by it is for all practical purposes as valid as a letter4 ,we must not forget its extreme usefulness for transmitting sketches4 ,a very simple diagram often explains a thing better than pages of letter-press4 ,the telautograph may help in the detection of criminals1 a pictorial presentment of whom can by its means be despatched all over the country in a very short time4 ,and in warfare an instrument flashing back from the advance-guard plans of the country and of the enemy's positions might on occasion prove of the greatest importance4 ,,modern ,,artillery4 ,the vast subject of artillery in its modern form1 including under this head for convenience' sake not only heavy ordnance but machine-guns and small-arms1 can of necessity only be dealt with most briefly in this chapter4 ,it may therefore be well to take a general survey and to define beforehand any words or phrases which are used technically in describing the various operations4 ,the employment of firearms dates from a long-distant past1 and it is interesting to note that many an improvement introduced during the last century is but the revival of a former invention which only lack of accuracy in tools and appliances had hitherto prevented from being brought into practical usage4 ,so far back as #adih the art of rifling cannon in straight grooves was known1 and a ,british patent was taken out in #afce by ,rotsipan4 ,the grooves were first made spiral or screwed by ,koster of ,birmingham about #afbj4 ,berlin possesses a rifled cannon with thirteen grooves dated #affd4 ,but the first recorded uses of such weapons in actual warfare was during ,louis ,napoleon's ,italian campaign in #ahei1 and two years later by ,general ,james of the ,united ,states ,army4 ,the system of breech-loading1 again1 is as old as the sixteenth century1 and we find a ,british patent of #agda2 while the first ,united ,states patent was given in #ahaa for a flint-lock weapon4 ,magazine guns of ,american production appeared in #ahdi and #ahfj1 but these were really an adaptation of the old matchlock revolvers1 said to belong to the period #adhj-aejj4 ,there is one in the ,tower of ,london credited to the fifteenth century1 and a ,british patent of #agah describes a well-constructed revolver carried on a tripod and of the dimensions of a modern machine-gun4 ,the inventor gravely explains that he has provided round chambers for round bullets to shoot ,christians1 and square chambers with square missiles for use against the ,turks6 ,the word 8ordnance0 is applied to heavy guns of all kinds1 and includes guns mounted on fortresses1 naval guns1 siege artillery1 and that for use in the field4 ,these guns are all mounted on stands or carriages1 and may be divided into three classes3-- 7i47 ,cannon1 or heavy guns4 7ii47 ,howitzers1 for field1 mountain1 or siege use1 which are lighter and shorter than cannon1 and designed to throw hollow projectiles with comparatively small charges4 7iii47 ,mortars1 for throwing shells at a great elevation4 ,the modern long-range guns and improved howitzers have1 however1 virtually superseded mortars4 ,machine-guns of various forms are comparatively small and light1 transportable by hand1 and filling a place between cannon and small-arms1 the latter term embracing the soldier's personal armament of rifle and pistol or revolver1 which are carried in the hand4 ,a group of guns of the like design are generally given the name of their first inventor1 or the place of manufacture3 such as the ,armstrong gun1 the ,vickers-,maxim1 the ,martini-,henry rifle1 or the ,enfield4 ,the indifferent use of several expressions in describing the same weapon is1 however1 rather confusing4 ,one particular gun may be thus referred to3--by its weight in tons or cwt41 as 8the #ce-ton gun02 by the weight of its projectile1 as 8a #fh-pounder02 by its calibre1 that is1 size of bore1 as 8the #d-;inch gun40 ,of these the heavier breech-loading 7,b4-,l47 and quick-firing 7,q4-,f47 guns are generally known by the size of bore2 small ,q4-,f4's1 field-guns1 c41 by the weight of projectile4 ,it is therefore desirable to enter these particulars together when making any list of service ordnance for future reference4 ,no individual gun1 whether large or small1 is a single whole1 but consists of several pieces fastened together by many clever devices4 ,the principal parts of a cannon are3-- 7#a7 ,the chase1 or main tube into which the projectile is loaded2 terminating at one end in the muzzle4 7#b7 ,the breech-piece1 consisting of 7a7 the chamber1 which is bored out for a larger diameter than the chase to contain the firing-charge4 7b7 ,the breech-plug1 which is closed before the charge is exploded and screwed tightly into place1 sealing every aperture by means of a special device called the 8obturator10 in order to prevent any gases passing out round it instead of helping to force the projectile forwards towards the muzzle4 ,the whole length of inside tube is termed the barrel1 as in a machine-gun1 rifle1 or sporting-piece1 but in the two latter weapons the breech-opening is closed by sliding or springing back the breech-block or bolt into firing position4 ,old weapons as a rule were smooth-bored 7,s4-,b471 firing a round missile between which and the barrel a considerable amount of the gases generated by the explosion escaped and caused loss of power1 this escape of gas being known as windage4 ,in all modern weapons we use conical projectiles1 fitted near the base with a soft copper driving-band1 the diameter of which is somewhat larger than that of the bore of the gun1 and cut a number of spiral grooves in the barrel4 ,the enormous pressure generated by the explosion of the charge forces the projectile down the bore of the gun and out of the muzzle4 ,the body of the projectile1 made of steel or iron1 being smaller in diameter than the bore1 easily passes through1 but the driving-band being of greater diameter1 and being composed of soft copper1 can only pass down the bore with the projectile by flowing into the grooves1 thus preventing any escape of gas1 and being forced to follow their twist4 ,it therefore rotates rapidly upon its own longitudinal axis while passing down the barrel1 and on leaving the muzzle two kinds of velocity have been imparted to it2--first1 a velocity of motion through the air2 secondly1 a velocity of rotation round its axis which causes it to fly steadily onward in the required direction1 i4e4 a prolongation of the axis of the gun4 ,thus extreme velocity and penetrating power1 as well as correctness of aim1 are acquired4 ,the path of a projectile through the air is called its trajectory1 and if uninterrupted its flight would continue on indefinitely in a perfectly straight line4 ,but immediately a shot has been hurled from the gun by the explosion in its rear two other natural forces begin to act upon it3-- ,gravitation1 which tends to bring it to earth4 ,air-resistance1 which gradually checks its speed4 7,theoretically1 a bullet dropped perpendicularly from the muzzle of a perfectly horizontal rifle would reach the ground at the same moment as another bullet fired from the muzzle horizontally1 the action of gravity being the same in both cases47 ,its direct1 even course is therefore deflected till it forms a curve1 and sooner or later it returns to earth1 still retaining a part of its velocity4 ,to counteract the attraction of gravity the shot is thrown upwards by elevating the muzzle1 care being taken to direct the gun's action to the same height above the object as the force of gravitation would draw the projectile down during the time of flight4 ,the gunner is enabled to give the proper inclination to his piece by means of the sights2 one of these1 near the muzzle1 being generally fixed1 while that next the breech is adjustable by sliding up an upright bar which is so graduated that the proper elevation for any required range is given4 ,the greater the velocity the flatter is the trajectory1 and the more dangerous to the enemy4 ,assuming the average height of a man to be six feet1 all the distance intervening between the point where a bullet has dropped to within six feet of the earth1 and the point where it actually strikes is dangerous to any one in that interval1 which is called the 8danger zone40 ,a higher initial velocity is gained by using stronger firing charges1 and a more extended flight by making the projectile longer in proportion to its diameter4 ,the reason why a shell from a cannon travels further than a rifle bullet1 both having the same muzzle velocity1 is easily explained4 ,a rifle bullet is1 let us assume1 three times as long as it is thick2 a cannon shell the same4 ,if the shell have ten times the diameter of the bullet1 its 8nose0 will have #aj #aj #ajj times the area of the bullet's nose2 but its mass will be #aj #aj #aj #ajjj times that of the bullet4 ,in other words1 when two bodies are proportional in all their dimensions their air-resistance varies as the square of their diameters1 but their mass and consequently their momentum varies as the cube of their diameters4 ,the shell therefore starts with a great advantage over the bullet1 and may be compared to a 8crew0 of cyclists on a multicycle all cutting the same path through the air2 whereas the bullet resembles a single rider1 who has to overcome as much air-resistance as the front man of the 8crew0 but has not the weight of other riders behind to help him4 ,as regards the effect of rifling1 it is to keep the bullet from turning head over heels as it flies through the air1 and to maintain it always point forwards4 ,every boy knows that a top 8sleeps0 best when it is spinning fast4 ,its horizontal rotation overcomes a tendency to vertical movement towards the ground4 ,in like manner a rifle bullet1 spinning vertically1 overcomes an inclination of its atoms to move out of their horizontal path4 ,professor ,john ,perry1 ,f4,r4,s41 has illustrated this gyroscopic effect1 as it is called1 of a whirling body with a heavy flywheel in a case1 held by a man standing on a pivoted table4 ,however much the man may try to turn the top from its original direction he will fail as long as its velocity of rotation is high4 ,he may move the top relatively to his body1 but the table will turn so as to keep the centre line of the top always pointing in the same direction4 ,,rifles4 ,up to the middle of last century our soldiers were armed with the flint-lock musket known as 8,brown ,bess10 a smooth-bore barrel #c_/d-;inch in diameter1 thirty-nine inches long1 weighing with its bayonet over eleven pounds4 ,the round leaden bullet weighed an ounce1 and had to be wrapped in a 8patch0 or bit of oily rag to make it fit the barrel and prevent windage2 it was then pushed home with a ramrod on to the powder-charge1 which was ignited by a spark passing from the flint into a priming of powder4 ,how little its accuracy of aim could be depended upon1 however1 is proved by the word of command when advancing upon an enemy1 8,wait till you see the whites of their eyes1 boys1 before you fire60 ,in the year #afhj each troop of ,life ,guards was supplied with eight rifled carbines1 a modest allowance1 possibly intended to be used merely by those acting as scouts4 ,after this we hear nothing of them until in #ahjj the #ieth ,regiment received a #bj-;bore muzzle-loading rifle1 exchanged about #ahce for the ,brunswick rifle firing a spherical bullet1 an improvement that more than doubled its effective range4 ,the companies so armed became known as the ,rifle ,brigade4 ,at last1 in #ahdb1 the old flint-lock was superseded for the whole army by the original percussion musket1 a smooth-bore whose charge was exploded by a percussion cap made of copper4 ,that this copper had some commercial value was shown by the rush of 8roughs0 to ,aldershot and elsewhere upon a field-day to collect the split fragments which strewed the ground after the troops had withdrawn4 ,soon afterward the barrel was rifled and an elongated bullet brought into use4 ,this missile was pointed in front1 and had a hollowed base so contrived that it expanded immediately the pressure of exploding gases was brought to bear on it1 and thus filled up the grooves1 preventing any windage4 ,the one adopted by our army in the year #aheb was the production of ,m4 ,mini1 a ,frenchman1 though an expanding bullet of ,english invention had been brought forward several years before4 ,meanwhile the ,prussians had their famous needle-gun1 a breech-loading rifled weapon fired by a needle attached to a sliding bolt2 as the bolt is shot forward the needle pierces the charge and ignites the fulminate by friction4 ,this rifle was used in the ,prusso-,austrian war of #ahff some twenty years after its first inception1 and the ,french promptly countered it by arming their troops with the ,chassept rifle1 an improved edition of the same principle4 ,a piece which could be charged and fired in any position from five to seven times as fast as the muzzle-loader1 which the soldier had to load standing1 naturally caused a revolution in the infantry armament of other nations4 ,the ,english ,government1 as usual the last to make a change1 decided in #ahfd upon using breech-loading rifles4 ,till a more perfect weapon could be obtained the ,enfields were at a small outlay converted into breech-loaders after the plans of ,mr4 ,snider1 and were henceforward known as ,snider-,enfields4 ,eventually--as the result of open competition--the ,martini-,henry rifle was produced by combining ,henry's system of rifling with ,martini's mechanism for breech-loading4 ,this weapon had seven grooves with one turn in twenty-two inches1 and weighed with bayonet #aj lb4 #d oz4 ,it fired with great accuracy1 the trajectory having a rise of only eight feet at considerable distances1 so that the bullet would not pass over the head of a cavalry man4 ,twenty rounds could be fired in fifty-three seconds4 ,now in the latter years of the century all these weapons have been superseded by magazine rifles1 i4e4 rifles which can be fired several times without recourse to the ammunition pouch4 ,they differ from the revolver in having only one firing chamber1 into which the cartridges are one by one brought by a simple action of the breech mechanism1 which also extracts the empty cartridge-case4 ,the bore of these rifles is smaller and the rifling sharper2 they therefore shoot straighter and harder than the large bore1 and owing to the use of new explosives the recoil is less4 ,the ,french ,lebel magazine rifle was the pioneer of all now used by ,european nations1 though a somewhat similar weapon was familiar to the ,americans since #ahdi1 being first used during the ,civil ,war4 ,the ,henry rifle1 as it was called1 afterwards became the ,winchester4 ,the ,german army rifle is the ,mauser1 so familiar to us in the hands of the ,boers during the ,south ,african ,war--loading five cartridges at once in a case or 8clip0 which falls out when emptied4 ,the same rifle has been adopted by ,turkey1 and was used by the ,spaniards in the late ,spanish-,american ,war4 ,the ,austrian ,mannlicher1 adopted by several continental nations1 and the ,krag-,jorgensen now used in the north of ,europe and as the ,united ,states army weapon1 resemble the ,mauser in most particulars4 ,each of these loads the magazine in one movement with a clip4 ,the ,hotchkiss magazine rifle has its magazine in the stock1 holding five extra cartridges pushed successively into loading position by a spiral spring4 ,our forces are now armed principally with the ,lee-,enfield1 which is taking the place of the ,lee-,metford issued a few years ago4 ,these are small-bore rifles of 4#cjc inch calibre1 having a detachable box1 which is loaded with ten cartridges 7,lee-,metford eight7 passed up in turn by a spring into the breech1 whence1 when the bolt is closed1 they are pushed into the firing-chamber4 ,the empty case is ejected by pulling back the bolt1 and at the same time another cartridge is pressed up from the magazine and the whole process repeated4 ,when the cut-off is used the rifle may be loaded and fired singly1 be the magazine full or empty4 ,the ,lee-,enfield has five grooves 7,lee-,metford ten71 making one complete turn from right to left in every ten inches4 ,it weighs #i lb4 #d oz41 and the barrel is #cj4aig inches long4 ,the range averages #cejj yards4 ,we are now falling into line with other powers by adopting the 8clip0 form instead of the box for loading4 ,the sealed pattern of the new service weapon is thus provided1 and has also been made somewhat lighter and shorter while preserving the same velocity4 ,we are promised an even more rapid firing rifle than any of these1 one in which the recoil is used to work the breech and lock so that it is a veritable automatic gun4 ,indeed1 several continental nations have made trial of such weapons and reported favourably upon them4 ,one lately tried in ,italy works by means of gas generated by the explosion passing through a small hole to move a piston-rod4 ,it is claimed that the magazine can hold as many as fifty cartridges and fire up to thirty rounds a minute2 but the barrel became so hot after doing this that the trial had to be stopped4 ,the principal result of automatic action would probably be excessive waste of cartridges by wild firing in the excitement of an engagement4 ,it is to-day as true as formerly that it takes on the average a man's weight of lead to kill him in battle4 ,to our neighbours across the ,channel the credit also belongs of introducing smokeless powder1 now universally used2 that of the ,lee-,metford being 8cordite40 ,to prevent the bullets flattening on impact they are coated with a hard metal such as nickel and its alloys4 ,if the nose is soft1 or split beforehand1 a terribly enlarged and lacerated wound is produced2 so the ,geneva ,convention humanely prohibited the use of such missiles in warfare4 ,before quitting this part of our subject it is as well to add a few words about pistols4 ,these have passed through much the same process of evolution as the rifle1 and have now culminated in the many-shotted revolver4 ,during the period #adhj-aejj the match-lock revolver is said to have been brought into use2 and one attributed to this date may be seen in the ,tower of ,london4 ,two hundred years ago1 ,richards1 a ,london gunsmith1 converted the ancient wheel-lock into the flint-lock2 he also rifled his barrel and loaded it at the breech4 ,the ,richards weapon was double-barrelled1 and unscrewed for loading at the point where the powder-chamber ended2 the ball was placed in this chamber in close contact with the powder1 and the barrel rescrewed4 ,the bullet being a soft leaden ball1 was forced1 when the charge was fired1 through the rifled barrel with great accuracy of aim4 ,the percussion cap did not oust the flint-lock till less than a century ago1 when many single-barrelled pistols1 such as the famous ,derringer1 were produced2 these in their turn were replaced by the revolver which ,colt introduced in #ahcf-ahej4 ,smith and ,wesson in the early sixties improved upon it by a device for extracting the empty cartridges automatically4 ,livermore and ,russell of the ,united ,states invented the 8clip10 containing several cartridges2 but the equally well-known ,winchester has its cartridges arranged in a tube below the barrel1 whence a helical spring feeds them to the breech as fast as they are needed4 ,at the present time each ,war ,department has its own special service weapon4 ,the ,german ,mauser magazine-pistol for officer's use fires ten shots in ten seconds1 a slight pressure of the trigger setting the full machinery in motion2 the pressure of gas at each explosion does all the rest of the work--extracts and ejects the cartridge case1 cocks the hammer1 and presses springs which reload and close the weapon1 all in a fraction of a second4 ,the ,mannlicher is of the same automatic type1 but its barrel moves to the front1 leaving space for a fresh cartridge to come up from the magazine below1 while in the ,mauser the breech moves to the rear during recoil4 ,the range is half a mile4 ,the cartridges are made up in sets of ten in a case1 which can be inserted in one movement4 ,,machine-,,guns4 ,intermediate between hand-borne weapons and artillery1 and partaking of the nature of both1 come the machine-guns firing small projectiles with extraordinary rapidity4 ,since the ,united ,states made trial of ,dr4 ,gatling's miniature battery in the ,civil ,war 7#ahfb-ahfe71 invention has been busy evolving more and more perfect types1 till the most modern machine-gun is a marvel of ingenuity and effectiveness4 ,the ,gatling machine-gun1 which has been much improved in late years by the ,accles system of 8feed10 and is not yet completely out of date1 consists of a circular series of ten barrels--each with its own lock--mounted on a central shaft and revolved by a suitable gear4 ,the cartridges are successively fed by automatic actions into the barrels1 and the hammers are so arranged that the entire operation of loading1 closing the breech1 firing and withdrawing the empty cartridge-cases 7which is known as their 8longitudinal reciprocating motion07 is carried on while the locks are kept in constant revolution1 along with the barrels and breech1 by means of a hand-crank4 ,one man places a feed-case filled with cartridges into the hopper1 another turns the crank4 ,as the gun is rotated the cartridges drop one by one from the feed-cases into the grooves of the carrier1 and its lock loads and fires each in turn4 ,while the gun revolves further the lock1 drawing back1 extracts and drops the empty case2 it is then ready for the next cartridge4 ,in action five cartridges are always going through some process of loading1 while five empty shells are in different stages of ejection4 ,the latest type1 fitted with an electro-motor1 will fire at the rate of one thousand rounds per minute1 and eighty rounds have actually been fired within ten seconds6 ,it is not1 however1 safe to work these machine-guns so fast1 as the cartridges are apt to be occasionally pulled through unfired and then explode among the men's legs4 ,the automatic guns1 on the contrary1 as they only work by the explosion1 are free from any risk of such accidents4 ,the feed-drums contain #ajd cartridges1 and can be replaced almost instantly4 ,one drumful can be discharged in #e-a_/d seconds4 ,the small-sized ,gatling has a drum-feed of #djj cartridges in sixteen sections of twenty-five each passed up without interruption4 ,the gun is mounted for use so that it can be pointed at any angle1 and through a wide lateral range1 without moving the carriage4 ,the ,gardner4--,the ,gatling1 as originally made1 was for a time superseded by the ,gardner1 which differed from it in having the barrels 7four or fewer in number7 fixed in the same horizontal plane4 ,this was worked by a rotatory handle on the side of the gun4 ,the cartridges slid down a feed-case in a column to the barrel1 where they were fired by a spring acting on a hammer4 ,the ,nordenfelt4--,mr4 ,nordenfelt's machine-gun follows this precedent2 its barrels--#aj1 #e1 #d1 #b1 or #a in number--also being arranged horizontally in a strong1 rigid frame4 ,each barrel has its own breech-plug1 striker1 spring1 and extractor1 and each fires independently of the rest1 so that all are not out of action together4 ,the gun has a swivelled mount easily elevated and trained1 and the steel frames take up the force of the discharge4 ,in rapid firing one gunner can work the firing-handle while another lays and alters the direction4 ,the firing is operated by a lever working backwards and forwards by hand1 and the gun can be discharged at the rate of #fjj rounds per minute4 ,the ,hotchkiss4--,the ,hotchkiss gun1 or revolving cannon1 is on a fresh system1 that of intermittent rotation of the barrels without any rotation of breech or mechanism4 ,there is only one loading piston1 one spring striker1 and one extractor for all the barrels4 ,the shock of discharge is received against a massive fixed breech1 which distributes it to the whole body4 ,like the ,nordenfelt1 however1 it can be dismounted and put together again without the need of tools4 ,the above pattern throws #a lb4 projectiles4 ,the ,maxim4--,differing from all these comes the ,maxim gun1 so much in evidence now with both land and sea service4 ,it is made up of two portions3-- 7#a7 ,fixed3 a barrel-casing1 which is also a water-jacket1 and breech-casing4 7#b7 ,recoiling3 a barrel and two side plates which carry lock and crank4 ,this recoiling portion works inside the fixed4 ,the gun is supplied with ammunition by a belt holding #bej cartridges passing through a feed-block on the top4 ,its mechanism is worked automatically2 first by the explosion of the charge1 which causes the barrel to recoil backwards and extends a strong spring which1 on reasserting itself1 carries it forwards again4 ,the recoiling part moves back about an inch1 and this recoil is utilised by bringing into play mechanism which extracts the empty cartridge-case1 and on the spring carrying the barrel forward again moves a fresh one into position4 ,under the barrel casing is the ejector tube through which the empty cartridge-cases are ejected from the gun4 ,the rate of fire of the ,maxim gun is #fjj rounds per minute4 ,deliberate fire means about #gj rounds per minute2 rapid fire will explode #dej rounds in the same time4 ,as the barrel becomes very hot in use the barrel-casing contains seven pints of water to keep it cool4 ,about #bjjj rounds can be fired at short intervals2 but in continuous firing the water boils after some #fjj rounds1 and needs replenishing after about #ajjj4 ,a valved tube allows steam1 but not water to escape4 ,the operator works this gun by pressing a firing-lever or button4 ,after starting the machine he merely sits behind the shield1 which protects him from the enemy1 directing it1 as it keeps on firing automatically so long as the bands of cartridges are supplied and a finger held on the trigger or button4 ,by setting free a couple of levers with his left hand1 and pressing his shoulder against the padded shoulder-piece1 he is able to elevate or depress1 or train the barrel horizontally1 without in any way interfering with the hail of missiles4 ,we use two sizes1 one with 4#de bore for the ,navy1 which takes an all-lead bullet weighing #dhj grains1 and the other with 4#cjc bore1 the ordinary nickel-coated rifle bullet for the ,army4 ,but as the ,maxim gun can be adapted to every rifle-calibre ammunition it is patronised by all governments4 ,the gun itself weighs #ef lbs41 and is mounted for use in various ways3 on a tripod1 a field stand1 or a field carriage with wheels4 ,this carriage has sixteen boxes of ammunition1 each containing a belt of #bej cartridges1 making #djjj rounds altogether4 ,its total weight is about half a ton1 so that it can be drawn by one horse1 and it is built for the roughest cross-country work4 ,a little machine1 which can be fixed to the wheel1 recharges the belts with cartridges by the working of a handle4 ,for ships the ,maxim is usually mounted on the ordinary naval cone mount1 or it can be clamped to the bulwark of the deck or the military 8top0 on the mast4 ,but there is a most ingenious form of parapet mounting1 known as the garrison mount1 which turns the ,maxim into a 8disappearing gun10 and can be used equally well for fortress walls or improvised entrenchments4 ,the gun is placed over two little wheels on which it can be run along by means of a handle pushed behind in something the fashion of a lawn-mower4 ,arrived at its destination1 the handle1 which is really a rack1 is turned downwards1 and on twisting one of the wheels the gun climbs it by means of a pinion-cog till it points over the wall1 to which hooks at the end of two projecting bars firmly fix it1 the broadened end of the handle being held by its weight to the ground4 ,it is locked while in use1 but a few turns of the wheel cause it to sink out of sight in as many seconds4 ,the rifle-calibre guns may also be used as very light horse artillery to accompany cavalry by being mounted on a 8galloping carriage0 drawn by a couple of horses1 and with two seats for the operators4 ,the carriage conveys #cjjj rounds1 and the steel-plated seats turn up and form shields during action4 ,it is interesting to notice that an extra light form of the gun is made which may be carried strapped on an infantryman's back and fired from a tripod4 ,two of these mounted on a double tricycle can be propelled at a good pace along a fairly level road1 and the riders dismounting have1 in a few moments1 a valuable little battery at their disposal4 ,the ,pom-pom1 of which we have heard so much in the late war1 is a large edition of the ,maxim automatic system with some differences in the system4 ,its calibre is #a-a_/b inches4 ,instead of bullets it emits explosive shells #a lb4 in weight1 fitted with percussion fuses which burst them into about twelve or fourteen pieces4 ,the effective range is up to #bjjj yards1 and it will carry to #djjj yards4 ,an improved ,pom-pom recently brought out hurls a #a-a_/d lb4 shell with effect at a mark #cjjj yards away1 and as far as #fjjj yards before its energy is entirely exhausted4 ,the muzzle velocity of this weapon is #bcej feet a second as against the #ahjj feet of the older pattern4 ,they both fire #cjj rounds a minute4 ,the ,colt automatic gun is an ,american invention whose automatic action is due to explosion of the charge1 not to recoil4 ,the force by which the motions of firing1 extracting1 and loading are performed is derived from the powder-gases1 a portion of which--passing through a small vent in the muzzle--acts by means of a lever on the mechanism of the gun4 ,this is also in two parts3 7a7 barrel1 attached to 7b7 breech-casing1 in which gear for charging1 firing1 and ejecting is contained4 ,the barrel1 made of a strong alloy of nickel1 has its cartridges fed in by means of belts coiled in boxes attached to the breech-casing1 the boxes moving with the latter so that the movements of the gun do not affect it4 ,these boxes contain #bej cartridges each and are easily replaced4 ,the feed-belt is inserted1 and the lever thrown down and moved backward--once by hand--as far as it will go2 this opens the breech and passes the first cartridge from the belt to the carrier4 ,the lever is then released and the spring causes it to fly forward1 close the vent1 and transfer the cartridge from the carrier to the barrel1 also compressing the mainspring and opening and closing the breech4 ,on pulling the trigger the shot is fired1 and after the bullet has passed the little vent1 but is not yet out of the muzzle1 the force of the expanding gas1 acting through the vent on the piston1 sets a gas-lever in operation which acts on the breech mechanism1 opens breech1 ejects cartridge-case1 and feeds another cartridge into the carrier4 ,the gas-lever returning forces the cartridge home in the barrel and closes and locks the breech4 ,the hammer of the gun acts as the piston of an air-pump1 forcing a strong jet of air into the chamber1 and through the barrel1 thus removing all unburnt powder1 and thoroughly cleansing it4 ,the metal employed is strong enough to resist the heaviest charge of nitro-powder1 and the accuracy of its aim is not disturbed by the vibrations of rapid fire4 ,it does not heat fast1 so has no need of a water-jacket1 any surplus heat being removed by a system of radiation4 ,the bore is made of any rifle calibre for any small-arm ammunition1 and is fitted with a safety-lock4 ,for our own pieces we use the ,lee-,metford cartridges4 ,four hundred shots per minute can be fired4 ,the gun consists altogether of ninety-four pieces1 but the working-pieces1 i4e4 those only which need be separated for cleaning1 c41 when in the hands of the artilleryman1 are less than twenty4 ,it can be handled in action by one man1 the operation resembling that of firing a pistol4 ,the machine weighs #dj lbs41 and for use by cavalry or infantry can be mounted on the ,dundonald ,galloping ,carriage4 ,the ammunition-box1 containing #bjjj rounds ready for use1 carries the gun on its upper side1 and is mounted on a strong steel axle4 ,a pole with a slotted end is inserted into a revolving funnel on the bend of the shaft1 the limbering-up being completed by an automatic bolt and plug4 ,the gun-carriage itself is of steel1 with hickory wheels and hickory and steel shafts1 detachable at will4 ,the simple harness suits any saddled cavalry horse1 and the shafts work in sockets behind the rider's legs4 ,its whole weight with full load of ammunition is under four hundredweight4 ,,heavy ,,ordnance4 ,as with rifles and the smaller forms of artillery1 so also with heavy ordnance1 the changes and improvements within the last fifty years have been greater than those made during the course of all the previous centuries4 ,these changes have affected alike not only the materials from which a weapon is manufactured1 the relative size of calibre and length of bore1 the fashion of mounting and firing1 but also the form and weight of the projectile1 the velocity with which it is thrown1 and even the substances used in expelling it from the gun4 ,compare for a moment the old cast-iron muzzle-loaders1 stubby of stature1 which ,wellington's bronzed veterans served with round cannon balls1 well packed in greasy clouts to make them fit tight1 or with shell and grape shot1 throughout the hard-fought day of ,waterloo1 from a distance which the chroniclers measure by paces1 so near stood the opposing ranks to one another4 ,or stand in imagination upon one of ,nelson's stately men-o'-war and watch the grimy guns' crews1 eight or ten to each1 straining on the ropes4 ,see the still smoking piece hauled inboard1 its bore swabbed out to clean and cool it1 then recharged by the muzzle2 home go powder1 wad1 and the castor full of balls or the chain shot to splinter the enemy's masts1 rammed well down ere the gun is again run out through the port-hole4 ,now the gunner snatches the flaming lintstock and1 signal given1 applies it to the powder grains sprinkled in the touch-hole4 ,a salvo of fifty starboard guns goes off in one terrific broadside1 crashing across the ,frenchman's decks at such close quarters that in two or three places they are set on fire by the burning wads4 ,next comes a cry of 8,boarders60 and the ships are grappled as the boarding-party scrambles over the bulwarks to the enemy's deck1 a brisk musket-fire from the crowded rigging protecting their advance2 meanwhile the larboard guns1 with their simultaneous discharge1 are greeting a new adversary4 ,such was war a century ago4 ,compare with it the late ,south ,african ,campaign where the range of guns was estimated in miles1 and after a combat lasting from morn to eve1 the ,british general could report3 8,i do not think we have seen a gun or a ,boer all day40 ,the days of hand-to-hand fighting have passed1 the mle in the ranks may be seen no more2 in a few years the bayonet may be relegated to the limbo of the coat-of-mail or the cast-iron culverin4 ,yet the modern battle-scene bristles with the most death-dealing weapons which the ingenuity of man has ever constructed4 ,the hand-drawn machine-gun discharges in a couple of minutes as many missiles as a regiment of ,wellington's infantry1 with a speed and precision undreamt of by him4 ,the quick-firing long-range naval guns now in vogue could annihilate a fleet or destroy a port without approaching close enough to catch a glimpse of the personnel of their opponents4 ,the deadly torpedo guards our waterways more effectually than a squadron of ships4 ,all resources of civilisation have been drawn upon1 every triumph of engineering secured1 to forge such weapons as shall strike the hardest and destroy the most pitilessly4 ,but strange and unexpected the result6 ,where we counted our battle-slain by thousands we now mourn over the death of hundreds2 where whole regiments were mown down our ambulances gather wounded in scattered units4 ,here is the bright side of modern war4 ,the muzzle-loading gun has had its day1 a very long day and a successful one4 ,again and again it has reasserted itself and ousted its rivals1 but at last all difficulties of construction have been surmounted and the breech-loader has 8come to stay40 ,however1 our services still contain a large number of muzzle-loading guns1 many of them built at quite a recent period1 and adapted as far as possible to modern requirements4 ,so to these we will first turn our attention4 ,the earliest guns were made of cast-iron1 but this being prone to burst with a large charge1 bronze1 brass1 and other tougher materials were for a long time employed4 ,most elaborately chased and ornamented specimens of these old weapons are to be seen in the ,tower1 and many other collections4 ,in the utilitarian days of the past century cheapness and speed in manufacture were more sought after than show4 ,iron was worked in many new ways to resist the pressure of explosion4 ,armstrong of ,elswick conceived the idea of building up a barrel of coiled iron by joining a series of short welded cylinders together1 and closing them by a solid forged breech-piece4 ,over all1 again1 wrought-iron coils were shrunk4 ,subsequently he tried a solid forged-iron barrel bored out to form a tube4 ,neither make proving very satisfactory1 steel tubes were next used1 but were too expensive and uncertain at that stage of manufacture4 ,again coiled iron was called into requisition1 and ,mr4 ,frazer of the ,royal ,gun ,factory introduced a system of double and triple coils which was found very successful1 especially when a thin steel inner tube was substituted for the iron one 7#ahfi74 ,all these weapons were rifled1 so that there was of necessity a corresponding difference in the projectile employed4 ,conical shells being used1 studs were now placed on the body of the shell to fit into the rifling grooves1 which were made few in number and deeply cut4 ,this was apt to weaken the bore of the gun2 but on the other hand many studs to fit into several shallow grooves weakened the cover of the shells4 ,various modifications were tried1 and finally a gas-check which expands into the grooves was placed at the base of the shell4 ,the muzzle-loader having thus been turned into a very efficient modern weapon the next problem to be solved was how to throw a projectile with sufficient force to penetrate the iron and steel armour-plates then being generally applied to war-ships4 8,build larger guns0 was the conclusion arrived at1 and presently the arsenals of the ,powers were turning out mammoth weapons up to #ajj tons1 and even #aaj tons in weight with a calibre of #af inches and more for their huge shells4 ,then was the mighty #ce-ton 8,woolwich ,infant0 born 7#ahgb71 and its younger but still bigger brothers1 #ha tons1 #af-;inch bore1 followed by the ,elswick #ajj-ton giants1 some of which were mounted on our defences in the ,mediterranean4 ,but the fearful concussion of such enormous guns when fixed in action on board ship injured the superstruction1 and even destroyed the boats1 and the great improvements made in steel both for guns and armour soon led to a fresh revolution4 ,henceforward instead of mounting a few very heavy guns we have preferred to trust to the weight of metal projected by an increased number of smaller size1 but much higher velocity4 ,and these guns are the quick-firing breech-loaders4 ,the heaviest of our up-to-date ordnance is of moderate calibre1 the largest breech-loaders being #ab-;inch1 #aj-;inch1 and #i4b-;inch guns4 ,but the elaborateness of its manufacture is such that one big gun takes nearly as long to 8build up0 as the ship for which it is destined4 ,each weapon has to pass through about sixteen different processes3-- 7#a7 ,the solid 7or hollow7 ingot is forged4 7#b7 ,annealed1 to get rid of strains4 7#c7 ,it is placed horizontally on a lathe and rough-turned4 7#d7 ,rough-bored in a lathe4 7#e7 ,hardened4 ,heated to a high temperature and plunged1 while hot1 into a bath of rape oil kept cold by a water-bath4 ,it cools slowly for seven to eight hours1 being moved about at intervals by a crane4 ,this makes the steel more elastic and tenacious4 7#f7 ,annealed1 i4e4 reheated to #ijj ,fahr4 and slowly cooled4 ,siemens' pyrometer is used in these operations4 7#g7 ,tested by pieces cut off4 7#h7 ,turned and bored for the second time4 7#i7 ,carefully turned again for shrinkage4 ,outer coil expanded till large enough to fit easily over inner4 ,inside1 set up vertically in a pit1 has outside lowered on to it1 water and gas being applied to make all shrink evenly4 ,other projections1 hoops1 rings1 c41 also shrunk on4 7#aj7 ,finish--bored and chambered4 7#aa7 ,broached1 or very fine bored1 perhaps lapped with lead and emery4 7#ab7 ,rifled horizontally in a machine4 7#ac7 ,prepared for breech fittings4 7#ad7 ,taken to the ,proof ,butts for trial4 7#ae7 ,drilled for sockets1 sights1 c4 ,lined and engraved4 ,breech fittings1 locks1 electric firing gear1 c41 added4 ,small adjustments made by filing4 7#af7 ,browned or painted4 ,when worn the bore can be lined with a new steel tube4 ,these lengthy operations completed1 our gun has still to be mounted upon its field-carriage1 naval cone1 or disappearing mounting1 any of which are complicated and delicately-adjusted pieces of mechanism1 the product of much time and labour1 which we have no space here to describe4 ,some account of the principal parts of these guns has already been given1 but the method by which the breech is closed remains to be dealt with4 ,it will be noticed that though guns now barely reach half the weight of the monster muzzle-loaders1 they are even more effective4 ,thus the #df-ton 7#ab-;inch7 gun hurls an #hej-lb4 projectile with a velocity of #bgej foot-seconds1 and uses a comparatively small charge4 ,the famous 8#ha-ton0 needed a very big charge for its #agjj-lb4 shell1 and had little more than half the velocity and no such power of penetration4 ,this change has been brought about by using a slower-burning explosive very powerful in its effects2 enlarging the chamber to give it sufficient air space1 and lengthening the chase of the gun so that every particle of the powder-gas may be brought into action before the shot leaves the muzzle4 ,this system and the substitution of steel for the many layers of welded iron1 makes our modern guns long and slim in comparison with the older ones4 ,to resist the pressure of the explosion against the breech end1 a tightly-fitting breech-plug must be employed4 ,the most modern and ingenious is the ,welin plug1 invented by a ,swedish engineer4 ,the ordinary interrupted screw breech-plug has three parts of its circumference plane and the other three parts 8threaded10 or grooved1 to screw into corresponding grooves in the breech2 thus only half of the circumference is engaged by the screw4 ,mr4 ,welin has cut steps on the plug1 three of which would be threaded to one plane segment1 each locking with its counterpart in the breech4 ,in this case there are three segments engaged to each one left plane1 and the strength of the screw is almost irresistible4 ,the plug1 which is hinged at the side1 has therefore been shortened by one-third1 and is light enough to swing clear with one touch of the handwheel that first rotates and unlocks it4 ,the method of firing is this3 ,the projectile lifted 7by hydraulic power on a ship7 into the loading tray is swung to the mouth of the breech and pushed into the bore4 ,a driving-band attached near its base is so notched at the edges that it jams the shell closely and prevents it slipping back if loaded at a high angle of elevation4 ,the powder charge being placed in the chamber the breech-plug is now swung-to and turned till it locks close4 ,the vent-axial or inner part of this breech-plug 7next to the charge71 which is called from its shape the 8mushroom-head10 encloses between its head and the screw-plug the de ,bange obturator1 a flat canvas pad of many layers soaked with mutton fat tightly packed between discs of tin4 ,when the charge explodes1 the mushroom-head--forced back upon the pad--compresses it till its edges bulge against the tube and prevent any escape of gas breechwards4 ,the electric spark which fires the charge is passed in from outside by means of a minute and ingenious apparatus fitted into a little vent or tube in the mushroom-head4 ,as the electric circuit cannot be completed till the breech-plug is screwed quite home there is now no more fear of a premature explosion than of double loading4 ,if the electric gear is disordered the gun can be fired equally well and safely by a percussion tube4 ,this description is of a typical large gun1 and may be applied to all calibres and also to the larger quick-firers4 ,the mechanism as the breech is swung open again withdraws the empty cartridge4 ,so valuable has de ,bange's obturator proved1 however1 that guns up to the #f-;inch calibre now have the powder charge thrown into the chamber in bags1 thus saving the weight of the metal tubes hitherto necessary4 ,of course several types of breech-loading guns are used in the ,service1 but the above are the most modern4 ,the favourite mode of construction at the present time is the wire-wound barrel1 the building up of which is completed by covering the many layers of wire with an outer tube or jacket expanded by heat before it is slipped on in order that it may fit closely when cold4 ,a previous make1 without wire1 is strengthened by rings or hoops also shrunk on hot4 ,the quick-firers proper are of many sizes1 #h-;inch1 #g4e-;inch1 #f-;inch1 #d4g-;inch1 #d-;inch1 and #c-;inch 7#ab-pounders74 ,the naval type is as a rule longer and lighter than those made for the rough usage of field campaigning and have a much greater range4 ,there are also smaller quick-firers1 #c-pounders and #f-pounders with bore something over #a-;inch and #b-;inch 7,nordenfelt1 ,hotchkiss1 ,vickers-,maxim74 ,some of the high velocity #ab-pounders being employed as garrison guns along with #f-;inch and #d4g-;inch1 and the large calibre howitzers4 ,we still use howitzer batteries of #e-;inch bore in the field and in the siege-train1 all being short1 rifled1 breech-loading weapons1 as they throw a heavy shell with smallish charges at a high angle of elevation1 but cover a relatively short distance4 ,a new pattern of #h-;inch calibre is now under consideration4 ,it is interesting to contrast the potencies of some of these guns1 all of which use cordite charges4 ---------------------------------------- ----------------------- ,calibre4 ,charge4 ,weight of ,muzzle ,velocity ,number of ,shot4 in ,rounds per ,foot ,seconds4 ,minute4 ---------------------------------------- ----------------------- #ab inch #bjg lbs4 #hej lbs4 #bgej #a #h 0 #eb 0 #baj 0 #bgej #e #f 0 #be 0 #ajj 0 #bgge #h #d4g 0 #i 0 #de 0 #bfjj #ab #c 0 #b lbs4 #i oz4 #ab4e 0 #bfjj #bj ---------------------------------------- ----------------------- ,illustration3 ,the ,simms armour-clad motor-car for coast defence4 ,maxim guns and ,pom-pom in action4 ,in the armament of our fine ,navy guns are roughly distributed as follows3--#ha-ton1 #ac-a_/b-;inch1 and superseded patterns of machine-guns such as ,gatling's1 ,gardner's1 and ,nordenfelt's1 besides a few surviving muzzle-loaders1 c41 are carried only by the oldest battleships4 ,the first-class battleships are chiefly supplied with four #ab-;inch guns in barbettes1 twelve #f-;inch as secondary batteries1 and a number of smaller quick-firers on the upper decks and in the fighting tops1 also for use in the boats1 to which are added several ,maxims4 ,the first-class cruisers have #i4b as their largest calibre1 with a lessened proportion of #f-;inch1 c4 ,some of the newest bear only #g-a_/b or #f-;inch guns as their heaviest ordnance2 like the second-class cruisers which1 however1 add several #d4g#8s between these and their small quick-firers4 ,vessels of inferior size usually carry nothing more powerful than the #d4g4 ,all are now armed with torpedo tubes4 ,these same useful little quick-firers and machine-guns have been the lethal weapons which made the armoured trains so formidable4 ,indeed1 there seems no limit to their value both for offence and defence1 for the battle chariot of the ancient ,briton has its modern successor in the ,simms' motor war car lately exhibited at the ,crystal ,palace4 ,this armour-plated movable fort is intended primarily for coast defence1 but can work off beaten tracks over almost any sort of country4 ,it is propelled at the rate of nine miles an hour by a #af-;horse-power motor1 carrying all its own fuel1 two pom-poms1 two small ,maxims1 and #aj1jjj rounds of ammunition1 besides the necessary complement of men and searchlights for night use1 c41 c4 ,the searchlight1 by the way1 has taken the place of all former inventions thrown from guns1 such as ground-light balls1 or parachute lights with a time-fuse which burst in the air and remained suspended1 betraying the enemy's proceedings4 ,in like manner the linked chain and 8double-headed0 shot1 the 8canister0--iron balls packed in thin iron or tin cylinders which would travel about #cej yards--the 8carcasses0 filled with inflammable composition for firing ships and villages1 are as much out of date as the solid round shot or cannon-ball4 ,young ,shrapnell's invention a century ago of the form of shell that bears his name1 a number of balls arranged in a case containing also a small bursting-charge fired either by percussion or by a time-fuse1 has practically replaced them all4 ,thrown with great precision of aim its effective range is now up to #ejjj yards4 ,a #ae-pounder shrapnell shell1 for instance1 contains #aib bullets1 and covers several hundred yards with the scattered missiles flying with extreme velocity4 ,common shell1 from #b-a_/b to #c calibres long1 contains an explosive only4 ,another variety is segment shell1 made of pieces built up in a ring with a bursting charge in the centre which presently shatters it4 ,the ,palliser shell has a marvellous penetrating power when used against iron plates4 ,but1 mirabile dictu6 experiments tried within the past few months prove that a soft cap added externally enables a projectile to pierce with ease armour which had previously defied every attack4 ,,explosives4 ,half a century ago gunpowder was still the one driving power which started the projectile on its flight4 ,it is composed of some #ge parts of saltpetre or nitrate of potash1 #ae parts of carefully prepared charcoal1 and #aj parts of sulphur4 ,this composition imprisons a large amount of oxygen for combustion and is found to act most successfully when formed into rather large prismatic grains4 ,on the abolition of the old flint-lock its place was taken by a detonating substance enclosed in a copper cap1 and some time later inventors came forward with new and more powerful explosives to supersede the use of gunpowder4 ,by treating cotton with nitric and sulphuric acid reaction gun-cotton was produced2 and a year later glycerine treated in the same manner became known to commerce as nitro-glycerine4 ,this liquid form being inconvenient to handle1 some inert granular substance such as infusorial earth was used to absorb the nitro-glycerine1 and dynamite was the result4 ,the explosion of gun-cotton was found to be too sudden and rapid for rifles or cannon2 it was liable to burst the piece instead of blowing out the charge4 ,in order to lessen the rapidity of its ignition ordinary cotton was mixed with it1 or its threads were twisted round some inert substance4 ,when repeating-rifles and machine-guns came into general use a smokeless powder became necessary4 ,such powders as a rule contain nitro-cellulose 7gun-cotton7 or nitro-glycerine1 or both4 ,these are combined into a plastic1 gluey composition1 which is then made up into sticks or pellets of various shapes1 and usually of large size to lessen the extreme rapidity of their combustion4 ,substances such as tan1 paraffin1 starch1 bran1 peat1 c41 c41 and many mineral salts1 are used in forming low explosives from high ones4 ,to secure complete combustion some of the larger pellets are made with a central hole1 or even pierced by many holes1 so that the fire penetrates the entire mass and carries off all its explosive qualities4 ,our cordite consists of nitro-glycerine dissolving di-nitro cellulose by the acid of a volatile solvent and a mineral jelly or oil4 ,this compound is semi-fluid1 and being passed like macaroni through round holes in a metal plate it forms strings or cords of varying size according to the diameter of the holes4 ,hence the name1 cordite4 ,many experiments in search of more powerful explosives resulted in an almost universal adoption of picric acid as the base4 ,this acid is itself produced by the action of nitric acid upon carbolic acid1 and each nation has its own fashion of preparing it for artillery4 ,the ,french began with mlinite in #ahhe1 this being a mixture of picric acid and gun-cotton4 ,the composition of lyddite 7named from its place of manufacture1 ,lydd1 in ,kent7 is a jealously-guarded ,british secret4 ,this substance was first used in #e-;inch howitzers during the late ,soudan campaign1 playing a part in the bombardment of ,omdurman4 ,the effect of the #ej-lb4 lyddite shells upon the ,south ,african kopjes is described as astounding4 ,when the yellow cloud had cleared away trees were seen uprooted1 rocks pulverised1 the very face of the earth had changed4 ,several attempts have been made to utilise dynamite for shells1 some of the guns employing compressed air as their motive power4 ,the ,united ,states some years ago went to great expense in setting up for this purpose heavy pneumatic plant1 which has recently been disposed of as too cumbrous4 ,dudley's 8,arial ,torpedo0 gun discharged a #ac-lb4 shell containing explosive gelatine1 gun-cotton1 and fulminate of mercury by igniting the small cordite charge in a parallel tube1 through a vent in which the partially cooled gases acted on the projectile in the barrel4 ,this was rotated in the air by inclined blades on a tailpiece1 as the barrel could not be rifled for fear of the heat set up by friction4 ,some guns actuated on much the same principle are said to have been used with effect in the ,hispano-,american war4 ,mr4 ,hudson ,maxim with his explosive 8maximite0 claims to throw half a ton of dynamite about a mile1 and a one-ton shell to half that distance4 ,but even these inventors are outstripped by ,professor ,birkeland1 who undertakes to hurl a projectile weighing two tons from an iron tube coiled with copper wire down which an electric current is passed2 thus doing away entirely with the need of a firing-charge4 ,,in ,,the ,,gun ,,factory4 ,let us pay a visit to one of our gun factories and get some idea of the multiform activities necessary to the turning out complete of a single piece of ordnance or a complicated machine-gun4 ,we enter the enormous workshop1 glazed as to roof and sides1 full of the varied buzz and whirr and clank of the machinery4 ,up and down the long bays stand row upon row of lathes1 turning1 milling1 polishing1 boring1 rifling--all moving automatically1 and with a precision which leaves nothing to be desired4 ,the silent attendants seem to have nothing in their own hands1 they simply watch that the cutting does not go too far1 and with a touch of the guiding handles regulate the pace or occasionally insert a fresh tool4 ,the bits used in these processes are self-cleaning1 so the machinery is never clogged2 and on the ground lie little heaps of brass chips cut away by the minute milling tools2 or in other places it is bestrewn with shavings of brass and steel which great chisels peel off as easily as a carpenter shaves a deal board4 ,here an enormous steel ingot1 forged solid1 heated again and again in a huge furnace and beaten by steam-hammers1 or pressed by hydraulic power between each heating till it is brought to the desired size and shape1 is having its centre bored through by a special drill which takes out a solid core4 ,this operation is termed 8trepanning10 and is applied to guns not exceeding eight inches2 those of larger calibre being rough-bored on a lathe1 and mandrils placed in them during the subsequent forgings4 ,the tremendous heat generated during the boring processes--we may recall how ,benjamin ,thompson made water boil by the experimental boring of a cannon--is kept down by streams of soapy water continually pumped through and over the metal4 ,we notice this flow of lubricating fluid in all directions1 from oil dropping slowly on to the small brass-milling machines to this fountain-play of water which makes a pleasant undertone amidst the jangle of the machines4 ,but these machines are less noisy than we anticipated2 in their actual working they emit scarcely the slightest sound4 ,what strikes us more than the supreme exactness with which each does its portion of the work1 is the great deliberateness of its proceeding4 ,all the hurry and bustle is above us1 caused by the driving-bands from the engine1 which keeps the whole machinery of the shed in motion4 ,suddenly1 with harsh creakings1 a great overhead crane comes jarring along the bay1 drops a chain1 grips up a gun-barrel1 and1 handling this mass of many tons' weight as easily as we should lift a walking-stick1 swings it off to undergo another process of manufacture4 ,we pass on to the next lathe where a still larger forging is being turned externally1 supported on specially devised running gear1 many different cutters acting upon it at the same time1 so that it is gradually assuming the tapering1 banded appearance familiar to us in the completed state4 ,we turn1 fairly bewildered1 from one stage of manufacture to another4 ,here is a gun whose bore is being 8chambered0 to the size necessary for containing the firing charge4 ,further along we examine a more finished weapon in process of preparation to receive the breech-plug and other fittings4 ,still another we notice which has been 8fine-bored0 to a beautifully smooth surface but is being improved yet more by 8lapping0 with lead and emery powder4 ,in the next shed a marvellous machine is rifling the interior of a barrel with a dexterity absolutely uncanny1 for the tool which does the rifling has to be rotated in order to give the proper 8twist0 at the same moment as it is advancing lengthwise down the bore4 ,the grooves are not made simultaneously but as a rule one at a time1 the distance between them being kept by measurements on a prepared disc4 ,now we have reached the apparatus for the wire-wound guns1 a principle representing the ne plus ultra of strength and durability hitherto evolved4 ,the rough-bored gun is placed upon a lathe which revolves slowly1 drawing on to it from a reel mounted at one side a continuous layer of steel ribbon about a quarter of an inch wide4 ,on a #ab-;inch gun there is wound some #aag miles of this wire6 fourteen layers of it at the muzzle end and seventy-five at the breech end4 ,heavy weights regulate the tension of the wire1 which varies for each layer1 the outermost being at the lowest tension1 which will resist a pressure of over #ajj tons to the square inch4 ,we next enter the division in which the gun cradles and mounts are prepared1 where we see some of the heaviest work carried out by electric dynamos1 the workman sitting on a raised platform to keep careful watch over his business4 ,passing through this with interested but cursory inspection of the cone mountings for quick-firing naval guns1 some ingenious elevating and training gear and a field carriage whose hydraulic buffers merit closer examination1 we come to the shell department where all kinds of projectiles are manufactured4 ,shrapnel in its various forms1 armour-piercing shells1 forged steel or cast-iron1 and small brass cartridges for the machine-guns may be found here2 and the beautifully delicate workmanship of the fuse arrangements attracts our admiration4 ,but we may not linger2 the plant for the machine-guns themselves claim our attention4 ,owing to the complexity and minute mechanism of these weapons almost a hundred different machines are needed1 some of the milling machines taking a large selection of cutters upon one spindle4 ,indeed1 in many parts of the works one notices the men changing their tools for others of different size or application4 ,some of the boring machines work two barrels at the same time1 others can drill three barrels or polish a couple simultaneously4 ,but there are hundreds of minute operations which need to be done separately1 down to the boring of screw holes and cutting the groove on a screw-head4 ,many labourers are employed upon the lock alone4 ,and every portion is gauged correctly to the most infinitesimal fraction1 being turned out by the thousand1 that every separate item may be interchangeable among weapons of the same make4 ,look at the barrel which came grey and dull from its first turning now as it is dealt with changing into bright silver4 ,here it is adjusted upon the hydraulic rifling machine which will prepare it to carry the small-arm bullet 74#cjc inch74 ,that one of larger calibre is rifled to fire a small shell4 ,further on1 the barrels and their jackets are being fitted together and the different parts assembled and screwed up4 ,we have not time to follow the perfect implement to its mounting1 nor to do more than glance at those howitzers and the breech mechanism of the #f-;inch quick-firers near which our guide indicates piles of flat cases to keep the de ,bange obturators from warping while out of use4 ,for the afternoon is waning and the foundry still unvisited4 ,to reach it we pass through the smith's shop and pause awhile to watch a supply of spanners being roughly stamped by an immense machine out of metal plates and having their edges tidied off before they can be further perfected4 ,a steam-hammer is busily engaged in driving mandrils of increasing size through the centre of a red-hot forging4 ,the heat from the forges is tremendous1 and though it is tempered by a spray of falling water we are glad to escape into the next shed4 ,here we find skilled workmen carefully preparing moulds by taking in sand the exact impression of a wooden dummy4 ,fortunately we arrive just as a series of casts deeply sunk in the ground are about to be made4 ,two brawny labourers bear forward an enormous iron crucible1 red-hot from the furnace1 filled with seething liquid--manganese bronze1 we are told--which1 when an iron bar is dipped into it1 throws up tongues of beautiful greenish-golden flame4 ,the smith stirs and clears off the scum as coolly as a cook skims her broth6 ,now it is ready1 the crucible is again lifted and its contents poured into a large funnel from which it flows into the moulds beneath and fills them to the level of the floor4 ,at each one a helper armed with an iron bar takes his stand and stirs again to work up all dross and air-bubbles to the surface before the metal sets--a scene worthy of a painter's brush4 ,and so we leave them4 ,,dirigible ,,torpedoes4 ,the history of warlike inventions is the history of a continual see-saw between the discovery of a new means of defence and the discovery of a fresh means of attack4 ,at one time a shield is devised to repel a javelin2 at another a machine to hurl the javelin with increased violence against the shield2 then the shield is reinforced by complete coats of mail1 and so on4 ,the ball of invention has rolled steadily on into our own times1 gathering size as it rolls1 and bringing more and more startling revolutions in the art of war4 ,to-day it is a battle between the forces of nature1 controllable by man in the shape of 8high explosives10 and the resisting power of metals tempered to extreme toughness4 ,at present it looks as if1 on the sea at least1 the attack were stronger than the defence4 ,our warships may be cased in the hardest metal several inches thick until they become floating forts1 almost impregnable to the heaviest shells4 ,they may be provided with terrible engines able to give blow for blow1 and be manned with the stoutest hearts in the world4 ,and yet1 were a sea-fight in progress1 a blow1 crushing and resistless1 might at any time come upon the vessel from a quarter whence1 even though suspected1 its coming might escape notice--below the waterline4 ,were it possible to case an ironclad from deck to keel in foot-thick plating1 the metal would crumple like a biscuit-box under the terrible impact of the torpedo4 ,this destructive weapon is an object of awe not so much from what it has done as from what it can do4 ,the instances of a torpedo shivering a vessel in actual warfare are but few4 ,yet its moral effect must be immense4 ,even though it may miss its mark1 the very fact of its possible presence will1 especially at night-time1 tend to keep the commanding minds of a fleet very much on the stretch1 and to destroy their efficiency4 ,a torpedo knows no half measures4 ,it is either entirely successful or utterly useless4 ,its construction entails great expense1 but inasmuch as it can1 if directed aright1 send a million of the enemy's money and a regiment of men to the bottom1 the discharge of a torpedo is1 after all1 but the setting of a sprat to catch a whale4 ,the aim of inventors has been to endow the dirigible torpedo1 fit for use in the open sea1 with such qualities that when once launched on its murderous course it can pursue its course in the required direction without external help4 ,the difficulties to be overcome in arriving at a serviceable weapon have been very great owing to the complexity of the problem4 ,a torpedo cannot be fired through water like a cannon shell through air4 ,water1 though yielding1 is incompressible1 and offers to a moving body a resistance increasing with the speed of that body4 ,therefore the torpedo must contain its own motive power and its own steering apparatus1 and be in effect a miniature submarine vessel complete in itself4 ,to be out of sight and danger it must travel beneath the surface and yet not sink to the bottom2 to be effective it must possess great speed1 a considerable sphere of action1 and be able to counteract any chance currents it may meet on its way4 ,among purely automobile torpedoes the ,whitehead is easily first4 ,after thirty years it still holds the lead for open sea work4 ,it is a very marvel of ingenious adaptation of means to an end1 and as it has fulfilled most successfully the conditions set forth above for an effective projectile it will be interesting to examine in some detail this most valuable weapon4 ,in #ahgc one ,captain ,lupuis of the ,austrian navy experimented with a small fireship which he directed along the surface of the sea by means of ropes and guiding lines4 ,this fireship was to be loaded with explosives which should ignite immediately on coming into collision with the vessel aimed at4 ,the ,austrian ,government declared his scheme unworkable in its crude form1 and the ,captain looked about for some one to help him throw what he felt to be a sound idea into a practical shape4 ,he found the man he wanted in ,mr4 ,whitehead1 who was at that time manager of an engineering establishment at ,fiume4 ,mr4 ,whitehead fell in enthusiastically with his proposition1 at once discarded the complicated system of guiding ropes1 and set to work to solve the problem on his own lines4 ,at the end of two years1 during which he worked in secret1 aided only by a trusted mechanic and a boy1 his son1 he constructed the first torpedo of the type that bears his name4 ,it was made of steel1 was fourteen inches in diameter1 weighed #cjj lbs41 and carried eighteen pounds of dynamite as explosive charge4 ,but its powers were limited4 ,it could attain a rate of but six knots an hour under favourable conditions1 and then for a short distance only4 ,its conduct was uncertain4 ,sometimes it would run along the surface1 at others make plunges for the bottom4 ,however1 the ,british ,government1 recognising the importance of ,mr4 ,whitehead's work1 encouraged him to perfect his instrument1 and paid him a large sum for the patent rights4 ,pattern succeeded pattern1 until comparative perfection was reached4 ,described briefly1 the ,whitehead torpedo is cigar-shaped1 blunt-nosed and tapering gradually towards the tail1 so following the lines of a fish4 ,its length is twelve times its diameter1 which varies in different patterns from fourteen to nineteen inches4 ,at the fore end is the striker1 and at the tail are a couple of three-bladed screws working on one shaft in opposite directions1 to economise power and obviate any tendency of the torpedo to travel in a curve2 and two sets of rudders1 the one horizontal1 the other vertical4 ,the latest form of the torpedo has a speed of twenty-nine knots and a range of over a thousand yards4 ,the torpedo is divided into five compartments by watertight steel bulkheads4 ,at the front is the explosive head1 containing wet gun-cotton1 or some other explosive4 ,the 8war head10 as it is called1 is detachable1 and for practice purposes its place is taken by a dummy-head filled with wood to make the balance correct4 ,next comes the air chamber1 filled with highly-compressed air to drive the engines2 after it the balance chamber1 containing the apparatus for keeping the torpedo at its proper depth2 then the engine-room2 and1 last of all1 the buoyancy chamber1 which is air-tight and prevents the torpedo from sinking at the end of its run4 ,to examine the compartments in order3-- ,in the very front of the torpedo is the pistol and primer-charge for igniting the gun-cotton4 ,especial care has been taken over this part of the mechanism1 to prevent the torpedo being as dangerous to friends as to foes4 ,the pistol consists of a steel plug sliding in a metal tube1 at the back end of which is the fulminating charge4 ,until the plug is driven right in against this charge there can be no explosion4 ,three precautions are taken against this happening prematurely4 ,in the first place1 there is on the forward end of the plug a thread cut1 up which a screw-fan travels as soon as it strikes the water4 ,until the torpedo has run forty-five feet the fan has not reached the end of its travel1 and the plug consequently cannot be driven home4 ,even when the plug is quite free only a heavy blow will drive it in1 as a little copper pin has to be sheared through by the impact4 ,and before the screw can unwind at all1 a safety-pin must be withdrawn at the moment of firing4 ,so that a torpedo is harmless until it has passed outside the zone of danger to the discharging vessel4 ,the detonating charge is thirty-eight grains of fulminate of mercury1 and the primer-charge consists of six one-ounce discs of dry gun-cotton contained in a copper cylinder1 the front end of which is connected with the striker-tube of the pistol4 ,the fulminate1 on receiving a blow1 expands #bejj times1 giving a violent shock to the gun-cotton discs1 which in turn explode and impart a shock to the main charge1 #bjj lbs4 of gun-cotton4 ,the air chamber is made of the finest compressed steel1 or of phosphor-bronze1 a third of an inch thick4 ,when ready for action this chamber has to bear a pressure of #acej lbs4 to the square inch4 ,so severe is the compression that in the largest-sized torpedoes the air in this chamber weighs no less than #fc lbs4 ,the air is forced in by very powerful pumps of a special design4 ,aft of this chamber is that containing the stop-valve and steering-gear4 ,the stop-valve is a species of air-tap sealing the air chamber until the torpedo is to be discharged4 ,the valve is so arranged that it is impossible to insert the torpedo into the firing-tube before the valve has been opened1 and so brought the air chamber into communication with the starting-valve1 which does not admit air to the engines till after the projectile has left the tube4 ,the steering apparatus is undoubtedly the most ingenious of the many clever contrivances packed into a ,whitehead torpedo4 ,its function is to keep the torpedo on an even keel at a depth determined before the discharge4 ,this is effected by means of two agencies1 a swinging weight1 and a valve which is driven in by water pressure as the torpedo sinks4 ,when the torpedo points head downwards the weight swings forward1 and by means of connecting levers brings the horizontal rudders up4 ,as the torpedo rises the weight becomes vertical and the rudder horizontal4 ,this device only insures that the torpedo shall travel horizontally4 ,the valve makes it keep its proper depth by working in conjunction with the pendulum4 ,the principle1 which is too complicated for full description1 is1 put briefly1 a tendency of the valve to correct the pendulum whenever the latter swings too far4 ,lest the pendulum should be violently shaken by the discharge there is a special controlling gear which keeps the rudders fixed until the torpedo has proceeded a certain distance1 when the steering mechanism is released4 ,the steering-gear does not work directly on the rudder4 ,mr4 ,whitehead found in his earlier experiments that the pull exerted by the weight and valve was not sufficient to move the rudders against the pressure of the screws4 ,he therefore introduced a beautiful little auxiliary engine1 called the servo-motor1 which is to the torpedo what the steam steering-gear is to a ship4 ,the servo-motor1 situated in the engine-room1 is only four inches long1 but the power it exerts by means of compressed air is so great that a pressure of half an ounce exerted by the steering-gear produces a pull of #afj lbs4 on the rudders4 ,the engines consist of three single-action cylinders1 their cranks working at an angle of #abj to one another1 so that there is no 8dead0 or stopping point in their action4 ,they are very small1 but1 thanks to the huge pressure in the air chamber1 develop nearly thirty-one horse-power4 ,lest they should 8race10 or revolve too quickly1 while passing from the tube to the water and do themselves serious damage1 they are provided with a 8delay action valve10 which is opened by the impact of the torpedo against the water4 ,further1 lest the air should be admitted to the cylinders at a very high pressure gradually decreasing to zero1 a 8reducing valve0 or governor is added to keep the engines running at a constant speed4 ,whitehead torpedoes are fired from tubes above or below the waterline4 ,deck tubes have the advantage of being more easily aimed1 but when loaded they are a source of danger1 as any stray bullet or shell from an enemy's ship might explode the torpedo with dire results4 ,there is therefore an increasing preference for submerged tubes4 ,an ingenious device is used for aiming the torpedo1 which makes allowances for the speed of the ship from which it is fired1 the speed of the ship aimed at1 and the speed of the torpedo itself4 ,when the moment for firing arrives1 the officer in charge presses an electric button1 which sets in motion an electric magnet fixed to the side of the tube4 ,the magnet releases a heavy ball which falls and turns the 8firing rod40 ,compressed air or a powder discharge is brought to bear on the rear end of the torpedo1 which1 if submerged1 darts out from the vessel's side along a guiding bar1 from which it is released at both ends simultaneously1 thus avoiding the great deflection towards the stern which would occur were a broadside torpedo not held at the nose till the tail is clear4 ,this guiding apparatus enables a torpedo to leave the side of a vessel travelling at high speed almost at right angles to the vessel's path4 ,it will be easily understood that a ,whitehead torpedo is a costly projectile1 and that its value--#ejj or more--makes the authorities very careful of its welfare4 ,during practice with 8blank0 torpedoes a 8,holmes light0 is attached4 ,this light is a canister full of calcium phosphide to which water penetrates through numerous holes1 causing gas to be thrown off and rise to the surface1 where1 on meeting with the oxygen of the air1 it bursts into flame and gives off dense volumes of heavy smoke1 disclosing the position of the torpedo by night or day4 ,at ,portsmouth are storehouses containing upwards of a thousand torpedoes4 ,every torpedo is at intervals taken to pieces1 examined1 tested1 and put together again after full particulars have been taken down on paper4 ,each steel 8baby0 is kept bright and clean1 coated with a thin layer of oil1 lest a single spot of rust should mar its beauty4 ,an interesting passage from ,lieutenant ,g4 ,e4 ,armstrong's book on 8,torpedoes and ,torpedo ,vessels0 will illustrate the scrupulous exactness observed in all things relating to the torpedo depts3 8,as an example of the care with which the stores are kept it may be mentioned that a particular tiny pattern of brass screw which forms part of the torpedo's mechanism and which is valued at about twopence-halfpenny per gross1 is never allowed to be a single number wrong4 ,on one occasion1 when the stocktaking took place1 it was found that instead of #ejjj little screws being accounted for by the man who was told off to count them1 there were only #diig4 ,several foolscap letters were written and exchanged over these three small screws1 though their value was not more than a small fraction of a farthing40 ,the classic instance of the effectiveness of this type of torpedo is the battle of the ,yalu1 fought between the ,japanese and ,chinese fleets in #ahid4 ,the ,japanese had been pounding their adversaries for hours with their big guns without producing decisive results4 ,so they determined upon a torpedo attack1 which was delivered early in the morning under cover of darkness1 and resulted in the destruction of a cruiser1 the ,ting ,yuen4 ,the next night a second incursion of the ,japanese destroyers wrecked another cruiser1 the ,lai ,yuen1 which sunk within five minutes of being struck2 sank the ,wei ,yuen1 an old wooden vessel used as a training-school2 and blew a large steam launch out of the water on to an adjacent wharf4 ,these hits 8below the belt0 were too much for the ,chinese1 who soon afterwards surrendered to their more scientific and better equipped foes4 ,if a general naval war broke out to-day most nations would undoubtedly pin their faith to the ,whitehead torpedo for use in the open sea1 now that its accuracy has been largely increased by the gyroscope1 a heavy flywheel attachment revolving rapidly at right angles to the path of the torpedo1 and rendering a change of direction almost impossible4 ,for harbour defence the ,brennan or its ,american rival1 the ,sims-,edison1 might be employed4 ,they are both torpedoes dirigible from a fixed base by means of connecting wires4 ,the presence of these wires constitutes an obstacle to their being of service in a fleet action4 ,the ,brennan is used by our naval authorities4 ,it is the invention of a ,melbourne watchmaker4 ,being a comparatively poor man1 ,mr4 ,brennan applied to the ,colonial ,government for grants to aid him in the manufacture and development of his torpedo1 and he was supplied with sufficient money to perfect it4 ,in #ahha he was requested by our ,admiralty to bring his invention to ,england1 where it was experimented upon1 and pronounced so efficient for harbour and creek defence that at the advice of the ,royal ,engineers ,mr4 ,brennan was paid large sums for his patents and services4 ,the ,brennan torpedo derives its motive power from a very powerful engine on shore1 capable of developing #ajj horse-power1 with which it is connected by stout piano wires4 ,one end of these wires is wound on two reels inside the torpedo1 each working a screw2 the other end is attached to two winding drums driven at high velocity by the engine on shore4 ,as the drums wind in the wire the reels in the torpedo revolve2 consequently1 the harder the torpedo is pulled back the faster it moves forward1 liked a trained trotting mare4 ,the steering of the torpedo is effected by alterations in the relative speeds of the drums1 and consequently of the screws4 ,the drums run loose on the engine axle1 and are thrown in or out of gear by means of a friction-brake1 so that their speed can be regulated without altering the pace of the engines4 ,any increase in the speed of one drum causes a corresponding decrease in the speed of the other4 ,the torpedo can be steered easily to right or left within an arc of forty degrees on each side of straight ahead2 but when once launched it cannot be retrieved except by means of a boat4 ,its path is marked by a ,holmes light1 described above4 ,it has a #bjj-lb4 gun-cotton charge1 and is fitted with an apparatus for maintaining a proper depth very similar to that used in the ,whitehead torpedo4 ,the ,sims-,edison torpedo differs from the ,brennan in its greater obedience to orders and in its motive power being electrically transmitted through a single connecting cable4 ,it is over thirty feet in length and two feet in diameter4 ,attached to the torpedo proper by rods is a large copper float1 furnished with balls to show the operator the path of the torpedo4 ,the torpedo itself is in four parts3 the explosive head2 the magazine of electric cables1 which is paid out as the torpedo travels2 the motor room2 and the compartment containing the steering-gear4 ,the projectile has a high speed and long range--over four thousand yards4 ,it can twist and turn in any direction1 and1 if need be1 be called to heel4 ,like the ,brennan1 it has the disadvantage of a long trailing wire1 which could easily become entangled2 and it might be put out of action by any damage inflicted on its float by the enemy's guns4 ,but it is likely to prove a very effective harbour-guard if brought to the test4 ,in passing to the ,orling-,armstrong torpedo we enter the latest phase of torpedo construction4 ,seeing the disadvantages arising from wires1 electricians have sought a means of controlling torpedoes without any tangible connection4 ,wireless telegraphy showed that such a means was not beyond the bounds of possibility4 ,mr4 ,axel ,orling1 a ,swede1 working in concert with ,mr4 ,j4 ,t4 ,armstrong1 has lately proved that a torpedo can be steered by waves of energy transmitted along rays of light1 or perhaps it would be more correct to say along shafts of a form of ,x-rays4 ,mr4 ,orling claims for his torpedo that it is capable of a speed of twenty-two knots or more an hour2 that it can be called to heel1 and steered to right or left at will2 that as long as it is in sight it is controllable by rays invisible to the enemy2 that not merely one1 but a number of torpedoes can be directed by the same beams of light2 that1 as it is submerged1 it would1 even if detected1 be a bad mark for the enemy's guns4 ,the torpedo carries a shaft which projects above the water1 and bears on its upper end a white disc to receive the rays and transmit them to internal motors to be transmuted into driving power4 ,the rod also carries at night an electric light1 shaded on the enemy's side1 but rendering the whereabouts of the torpedo very visible to the steerer4 ,mr4 ,orling's torpedo acts throughout in a cruelly calculating manner4 ,before its attack a ship would derive small advantage from a crinoline of steel netting2 for the large torpedo conceals in its head a smaller torpedo1 which1 as soon as the netting is struck1 darts out and blasts an opening through which its longer brother1 after a momentary delay1 can easily follow4 ,the netting penetrated1 the torpedo has yet to strike twice before exploding4 ,on the first impact1 a pin1 projecting from the nose1 is driven in to reverse the engines1 and at the same time a certain nut commences to travel along a screw4 ,the nut having worked its way to the end of the thread1 the head of the torpedo fills slowly through a valve1 giving it a downward slant in front4 ,the engines are again reversed and the nut again travels1 this time bringing the head of the torpedo up1 so as to strike the vessel at a very effective angle from below4 ,this torpedo has passed beyond the experimental stage4 ,it is reported that by command of the ,swedish ,government1 to whom ,mr4 ,orling offered his invention1 and of the ,king1 who takes a keen interest in the ideas of his young countryman1 a number of experiments were some time ago carried out in the ,swedish rivers4 ,torpedoes were sent #b-a_/b miles1 directed as desired1 and made to rise or sink--all this without any tangible connection4 ,the ,government was sufficiently satisfied with the result to take up the patents1 as furnishing a cheap means of defending their coasts4 ,mr4 ,orling has described what he imagines would happen in case of an attack on a position protected by his ingenious creations4 8,suppose that ,i had twelve torpedoes hidden away under ten feet of water in a convenient little cove1 and that ,i was directed to annihilate a hostile fleet just appearing above the horizon4 ,before me1 on a little table perhaps1 ,i should have my apparatus2 twelve buttons would be under my fingers4 ,against each button there would be a description of the torpedo to which it was connected2 it would tell me its power of destruction1 and the power of its machinery1 and for what distance it would go4 ,on each button1 also1 would be indicated the time that ,i must press it to release the torpedoes4 ,well now1 ,i perceive a large vessel in the van of the approaching fleet4 ,i put my fingers on the button which is connected with my largest and most formidable weapon4 ,i press the button--perhaps for twelve seconds4 ,the torpedo is pushed forward from its fastenings by a special spring1 a small pin is extracted from it1 and immediately the motive machinery is set in motion1 and underneath the water goes my little agent of destruction1 and there is nothing to tell the ship of its doom4 ,i place my hand on another button1 and according to the time ,i press it ,i steer the torpedo2 the rudder answers to the rays1 and the rays answer to the will of my mind40#b #b ,pearson's ,magazine4 ,if this torpedo acts fully up to its author's expectations1 naval warfare1 at least as at present conducted1 will be impossible4 ,there appears to be no reason why this torpedo should not be worked from shipboard2 and we cannot imagine that hostile ships possessing such truly infernal machines would care to approach within miles of one another1 especially if the submarine be reinforced by the arial torpedo1 different patterns of which are in course of construction by ,mr4 ,orling and ,major ,unge1 a brother ,swede4 ,the ,orling type will be worked by the new rays1 strong enough to project it through space4 ,major ,unge's will depend for its motive power upon a succession of impulses obtained by the ignition of a slow-burning gas1 passing through a turbine in the rear of the torpedo4 ,the inventor hopes for a range of at least six miles4 ,what defence would be possible against such missiles8 ,liable to be shattered from below1 or shivered from above1 the warship will be placed at an ever-increasing disadvantage4 ,its size will only render it an easier mark2 its strength1 bought at the expense of weight1 will be but the means of insuring a quicker descent to the sea's bottom4 ,is it not probable that sea-fights will become more and more matters of a few terrible1 quickly-delivered blows8 ,human inventions will hold the balance more and more evenly between nations of unequal size1 first on sea1 then on land1 until at last1 as we may hope1 even the hottest heads and bravest hearts will shrink from courting what will be less war than sheer annihilation1 and war1 man's worst enemy1 will be itself annihilated4 ,,submarine ,,boats4 ,the introduction of torpedoes for use against an enemy's ships below the waterline has led by natural stages to the evolution of a vessel which may approach unsuspected close enough to the object of attack to discharge its missile effectively4 ,before the searchlight was adopted a night surprise gave due concealment to small craft2 but now that the gloom of midnight can be in an instant flooded with the brilliance of day a more subtle mode of attack becomes necessary4 ,hence the genesis of the submarine or submersible boat1 so constructed as to disappear beneath the sea at a safe distance from the doomed ship1 and when its torpedo has been sped to retrace its invisible course until outside the radius of destruction4 ,to this end many so-called submarine boats have been invented and experimented with during recent years4 ,the idea is an ancient one revived1 as indeed are the large proportion of our boasted modern discoveries4 ,aristotle describes a vessel of this kind 7a diving-bell rather than a boat1 however71 used in the siege of ,tyre more than two thousand years ago2 and also refers to the divers being provided with an air-tube1 8like the trunk of an elephant10 by means of which they drew a fresh supply of air from above the surface--a contrivance adopted in more than one of our modern submarines4 ,alexander the ,great is said to have employed divers in warfare2 ,pliny speaks of an ingenious diving apparatus1 and ,bacon refers to air-tubes used by divers4 ,we even find traces of weapons of offence being employed4 ,calluvius is credited with the invention of a submarine gun for projecting ,greek fire4 ,the ,bishop of ,upsala in the sixteenth century gives a somewhat elaborate description of certain leather skiffs or boats used to scuttle ships by attacking them from beneath1 two of which he claims to have personally examined4 ,in #afbi we read that the ,barbary corsairs fixed submarine torpedoes to the enemy's keel by means of divers4 ,as early as #aegi an ,english gunner named ,william ,bourne patented a submarine boat of his own invention fitted with leather joints1 so contrived as to be made smaller or larger by the action of screws1 ballasted with water1 and having an air-pipe as mast4 ,the ,campbell-,ash submarine tried in #ahhe was on much the same principle4 ,cornelius van ,drebbel1 an ingenious ,dutchman who settled in ,england before #afjj1 produced certain submersible vessels and obtained for them the patronage of two kings4 ,he claims to have discovered a means of re-oxygenating the foul air and so enabling his craft to remain a long time below water2 whether this was done by chemical treatment1 compressed air1 or by surface tubes no record remains4 ,drebbel's success was such that he was allowed to experiment in the ,thames1 and ,james ,i4 accompanied him on one of his sub-aquatic journeys4 ,in #afbf ,charles ,i4 gave him an order to make 8boates to go under water10 as well as 8water mines1 water petards10 c41 presumably for the campaign against ,france1 but we do not hear of these weapons of destruction being actually used upon this occasion4 ,illustration3 ,the 8,holland0 ,submarine ,boat4 ,these early craft seem to have been generally moved by oars working in air-tight leather sockets2 but one constructed at ,rotterdam about #afed was furnished with a paddle-wheel4 ,coming now nearer to our own times1 we find that an ,american called ,bushnell had a like inspiration in #aggc1 when he invented his famous 8,turtles10 small1 upright boats in which one man could sit1 submerge himself by means of leather bottles with the mouths projecting outside1 propel himself with a small set of oars and steer with an elementary rudder4 ,an unsuccessful attempt was made to blow up the ,english fleet with one of these 8,turtles0 carrying a torpedo1 but the current proved too strong1 and the missile exploded at a harmless distance1 the operator being finally rescued from an unpremeditated sea-trip6 ,bushnell was the author of the removable safety-keel now uniformly adopted4 ,soon afterwards another ,new ,englander took up the running1 ,fulton--one of the cleverest and least appreciated engineers of the early years of the nineteenth century4 ,his ,nautilus1 built in the ,french dockyards1 was in many respects the pattern for our own modern submarines4 ,the cigar-shaped copper hull1 supported by iron ribs1 was twenty-four feet four inches long1 with a greatest diameter of seven feet4 ,propulsion came from a wheel1 rotated by a hand winch1 in the centre of the stern2 forward was a small conning-tower1 and the boat was steered by a rudder4 ,there was a detachable keel below2 and fitted into groves on the top were a collapsible mast and sail for use on the surface of the water4 ,an anchor was also carried externally4 ,in spite of the imperfect materials at his disposal ,fulton had much success4 ,at ,brest he took a crew of three men twenty-five feet down1 and on another day blew up an old hulk4 ,in the ,seine two men went down for twenty minutes and steered back to their starting-point under water4 ,he also put in air at high pressure and remained submerged for hours4 ,but ,france1 ,england1 and his own country in turn rejected his invention2 and1 completely discouraged1 he bent his energies to designing boat engines instead4 ,in #ahba ,captain ,johnson1 also an ,american1 made a submersible vessel #ajj feet long1 designed to fetch ,napoleon from ,st4 ,helena1 travelling for the most part upon the surface4 ,this expedition never came off4 ,two later inventions1 by ,castera and ,payerne1 in #ahbg and #ahdf respectively1 were intended for more peaceful objects4 ,being furnished with diving-chambers1 the occupants could retrieve things from the bottom of the sea2 ,castera providing his boat with an air-tube to the surface4 ,bauer1 another inventor1 lived for some years in ,england under the patronage of ,prince ,albert1 who supplied him with funds for his experiments4 ,with ,brunel's help he built a vessel which was indiscreetly modified by the naval authorities1 and finally sank and drowned its crew4 ,going then to ,russia he constructed sundry submarines for the navy2 but was in the end thrown over1 and1 like ,fulton1 had to turn himself to other employment4 ,the fact is that up to this period the cry for a practical submarine to use in warfare had not yet arisen1 or these inventions would have met with a far different reception4 ,within the last half century all has changed4 ,america and ,france now rival each other in construction1 while the other nations of ,europe look on with intelligent interest1 and in turn make their contributions towards solving the problem of under-wave propulsion4 ,america led the way during the ,civil ,war blockades in #ahfd1 when the ,housatonic was sunk in ,charleston harbour1 and damage done to other ships4 ,but these experimental torpedo-boats were clumsy contrivances compared with their modern successors1 for they could only carry their destructive weapon at the end of a spar projecting from the bows--to be exploded upon contact with the obstacle1 and probably involve the aggressor in a common ruin4 ,so nothing more was done till the perfecting of the ,whitehead torpedo 7see ,dirigible ,torpedoes7 gave the required impetus to fresh enterprise4 ,france1 experimenting in the same direction1 produced in #ahhi ,goubet's submarine1 patent of a private inventor1 who has also been patronised by other navies4 ,these are very small boats1 the first1 #af-a_/b feet long1 carrying a crew of two or three men4 ,goubet ,no4 #b1 built in #ahii1 is #bf-a_/d feet long1 composed of several layers of gun-metal united by strong screw-bolts1 and so able to resist very great pressure4 ,they are egg-or spindle-shaped1 supplied with compressed air1 able to sink and rise by rearrangement of water-ballast4 ,reservoirs in the hull are gradually filled for submersion with water1 which is easily expelled when it is desired to rise again4 ,if this system goes wrong a false keel of thirty-six hundredweight can be detached and the boat springs up to the surface4 ,the propulsive force is electricity1 which works the driving-screw at the rear1 and the automobile torpedo is discharged from its tube by compressed air4 8,by the aid of an optical tube1 which a pneumatic telescopic apparatus enables the operator to thrust above the surface and pull down in a moment1 the captain of the ,goubet can1 when near the surface1 see what is going on all round him4 ,this telescope has a system of prisms and lenses which cause the image of the sea-surface to be deflected down to the eye of the observer below4 8,fresh air for the crew is provided by reservoirs of oxygen1 and accumulations of foul air can be expelled by means of a small pump4 ,enough fresh air can be compressed into the reservoirs to last the crew for a week or more40 ,the ,gymnote1 laid down in #ahih1 is more than double the size of the ,goubet2 it is cigar-shaped1 #bi feet long by #f feet diameter1 with a displacement of thirty tons4 ,the motive power is also electricity stored in accumulators for use during submersion1 and the speed expected--but not realised--was to be ten knots4 ,five years later this type was improved upon in the ,gustave ,zd1 the largest submarine ever yet designed4 ,this boat1 built of phosphor-bronze1 with a single screw1 measures #aca feet in length and has a displacement of #bff tons2 she can contain a crew of nine officers and men1 carries three torpedoes--though with one torpedo tube instead of two--has a lightly armoured conning-tower1 and is said to give a surface speed of thirteen knots and to make eight knots when submerged4 ,at a trial of her powers made in the presence of ,m4 ,lockroy1 ,minister of ,marine1 she affixed an unloaded torpedo to the battleship ,magenta and got away unobserved4 ,the whole performance of the boat on that occasion was declared to be most successful4 ,but its cost proved excessive considering the small radius of action obtainable1 and a smaller vessel of the same type1 the ,morse 7#aah #i feet71 is now the official size for that particular class4 ,in #ahif a competition was held and won by the submersible ,narval of ,m4 ,laubeuf1 a craft shaped much like the ordinary torpedo-boat4 ,on the surface or awash the ,narval works by means of a ,brul engine burning oil fuel to heat its boilers2 but when submerged for attack with funnel shut down is driven by electric accumulators4 ,she displaces #ajj odd tons and is provided with four ,dzewiecki torpedo tubes4 ,her radius of action1 steaming awash1 is calculated at some #bej miles1 or seventy miles when proceeding under water at five knots an hour4 ,this is the parent of another class of boats designed for offensive tactics1 while the ,morse type is adapted chiefly for coast and harbour defence4 ,the ,french navy includes altogether thirty submarine craft1 though several of these are only projected at present1 and none have yet been put to the practical tests of actual warfare--the torpedoes used in experimenting being1 of course1 blank4 ,meanwhile in ,america experiments have also been proceeding since #ahhg1 when ,mr4 ,holland of ,new ,york produced the vessel that bears his name4 ,this1 considerably modified1 has now been adopted as model by our ,navy ,department1 which is building some half-dozen on very similar lines4 ,though it is not easy to get any definite particulars concerning ,french submarines ,americans are less reticent1 and we have graphic accounts of the ,holland and her offspring from those who have visited her4 ,these vessels1 though cigar-shaped liked most others1 in some respects resemble the ,narval1 being intended for long runs on the surface1 when they burn oil in a four-cylinder gasolene engine of #afj horse-power4 ,under water they are propelled by an electric waterproof motor of seventy horse-power1 and proceed at a pace of seven knots per hour4 ,there is a superstructure for deck1 with a funnel for the engine and a small conning-tower protected by #d-;inch armour4 ,the armament carried comprises five #ah-;inch ,whitehead torpedoes1 #aa feet #h inches long4 ,one hundred and twenty tons is the displacement1 including tank capacity for #hej gallons of gasolene2 the full length is #fc feet #d inches1 with a beam of #aa feet #i inches4 ,illustration3 ,an interior view of the 8,holland40 ,the large pendulum on the right actuates mechanism to keep the ,submarine at the required depth below the surface4 ,the original ,holland boat is thus described by an adventurous correspondent who took a trip in her#c3 8,the ,holland is fifty-three feet long1 and in its widest part it is #aj-a_/d feet in diameter4 ,it has a displacement of seventy-four tons1 and what is called a reserve buoyancy of #b-a_/b tons which tends to make it come to the surface4 #c ,pearson's ,magazine4 8,the frames of the boat are exact circles of steel4 ,they are set a little more than a foot apart4 ,they diminish gradually in diameter from the centre of the boat to the bow and stern4 ,on the top of the boat a flat superstructure is built to afford a walking platform1 and under this are spaces for exhaust pipes and for the external outfit of the boat1 such as ropes and a small anchor4 ,the steel plates which cover the frame are from one-half to three-eighths of an inch in thickness4 8,from what may be called the centre of the boat a turret extends upwards through the superstructure for about eighteen inches4 ,it is two feet in diameter1 and is the only means of entrance to the boat4 ,it is the place from which the boat is operated4 ,at the stern is an ordinary three-bladed propeller and an ordinary rudder1 and in addition there are two horizontal rudders--8diving-rudders0 they are called--which look like the feet of a duck spread out behind as it swims along the water4 8,from the bow two-thirds of the way to the stern there is a flooring1 beneath which are the storage batteries1 the tank for the gasolene1 and the tanks which are filled with water for submerging2 in the last one-third of the boat the flooring drops away1 and the space is occupied by the propelling machinery4 8,there are about a dozen openings in the boat1 the chief being three ,kingston valves1 by means of which the submerging tanks are filled or emptied4 ,others admit water to pressure gauges1 which regulate or show the depth of the vessel under water4 ,there are twelve deadlights in the top and sides of the craft4 ,to remain under water the boat must be kept in motion1 unless an anchor is used4 8,it can be steered to the surface by the diving rudders1 or sent flying to the top through emptying the storage tanks4 ,if it strikes bottom1 or gets stuck in the mud1 it can blow itself loose by means of its compressed air4 ,it cannot be sunk unless pierced above the flooring4 ,it has a speed capacity of from eight to ten knots either on the surface or under water4 8,it can go #aejj miles on the surface without renewing its supply of gasolene4 ,it can go fully forty knots under water without coming to the surface1 and there is enough compressed air in the tanks to supply a crew with fresh air for thirty hours1 if the air is not used for any other purpose1 such as emptying the submerging tanks4 ,it can dive to a depth of twenty feet in eight seconds4 8,the interior is simply packed with machinery4 ,as you climb down the turret you are confronted with it at once4 ,there is a diminutive compass which must be avoided carefully by the feet4 ,a pressure gauge is directly in front of the operator's eye as he stands in position4 ,there are speaking-tubes to various parts of the boat1 and a signal-bell to the engine-room4 8,as the operator's hands hang by his sides1 he touches a wheel on the port side1 by turning which he steers the little vessel1 and one on the starboard side1 by turning which he controls the diving machinery4 ,after the top is clamped down the operator can look out through plate-glass windows1 about one inch wide and three inches long1 which encircle the turret4 8,so long as the boat is running on the surface these are valuable1 giving a complete view of the surroundings if the water is smooth4 ,after the boat goes beneath the surface1 these windows are useless2 it is impossible to see through the water4 ,steering must be done by compass2 until recently considered an impossible task in a submarine boat4 ,a tiny electric light in the turret shows the operator the direction in which he is going1 and reveals the markings on the depth gauges4 ,if the boat should pass under an object1 such as a ship1 a perceptible shadow would be noticed through the deadlights1 but that is all4 ,the ability to see fishes swimming about in the water is a pleasant fiction4 8,the only clear space in the body of the boat is directly in front of the bench on which the man in the turret is standing4 ,it is where the eighteen-inch torpedo-tube1 and the eight and five-eighths inch arial gun are loaded4 8,along the sides of this open space are six compressed-air tanks1 containing thirty cubic feet of air at a pressure of #bjjj lbs4 to a square inch4 ,near by is a smaller tank1 containing three cubic feet of air at a fifty pounds pressure4 ,a still smaller tank contains two cubic feet of air at a ten pounds pressure4 ,these smaller tanks supply the compressed air which1 with the smokeless powder1 is used in discharging the projectiles from the boat4 8,directly behind the turret1 up against the roof on the port side1 is the little engine by which the vessel is steered2 it is worked by compressed air4 ,fastened to the roof on the starboard side is the diving-engine1 with discs that look as large as dinner-plates stood on end4 ,these discs are diaphragms on which the water-pressure exerts an influence1 counteracting certain springs which are set to keep the diving rudders at a given pitch1 and thus insuring an immersion of an exact depth during a run4 8,at one side is a cubic steel box--the air compressor2 and directly in the centre of this part of the boat is a long pendulum1 just as there is in the ordinary torpedo1 which1 by swinging backwards and forwards as the boat dives and rises1 checks a tendency to go too far down1 or to come up at too sharp an angle4 ,on the floor are the levers which1 when raised and moved in certain directions1 fill or empty the submerging tanks4 ,on every hand are valves and wheels and pipes in such apparent confusion as to turn a layman's head4 8,there are also pumps in the boat1 a ventilating apparatus1 and a sounding contrivance1 by means of which the channel is picked out when running under water4 ,this sounding contrivance consists of a heavy weight attached to a piano wire passing from a reel out through a stuffing-box in the bottom4 ,there are also valves which release fresh air to the crew1 although in ordinary runs of from one-half to one hour this is not necessary1 the fresh air received from the various exhausts in the boat being sufficient to supply all necessities in that length of time40 ,another submersible of somewhat different design is the production of the ,swedish inventor1 ,mr4 ,nordenfelt4 ,this boat is #i-a_/b metres in length1 and has a displacement of sixty tons4 ,like the ,goubet it sinks only in a horizontal position1 while the ,holland plunges downward at a slight angle4 ,on the surface a steam-engine of #ajj horse-power propels it1 and when the funnel is closed down and the vessel submerges itself1 the screws are still driven by superheated steam from the large reservoir of water boiling at high pressure which maintains a constant supply1 three circulation pumps keeping this in touch with the boiler4 ,the plunge is accomplished by means of two protected screws1 and when they cease to move the reserve buoyancy of the boat brings it back to the surface4 ,it is steered by a rudder which a pendulum regulates4 ,the most modern of these boats is of ,english manufacture1 built at ,barrow1 and tried in ,southampton ,water4 ,the vessels hitherto described should be termed submersible rather than submarine1 as they are designed to usually proceed on the surface1 and submerge themselves only for action when in sight of the enemy4 ,american ingenuity has produced an absolutely unique craft to which the name submarine may with real appropriateness be applied1 for1 sinking in water #ajj feet deep1 it can remain below and run upon three wheels along the bottom of the sea4 ,this is the ,argonaut1 invented by ,mr4 ,simon ,lake of ,baltimore1 and its main portion consists of a steel framework of cylindrical form which is surmounted by a flat1 hollow steel deck4 ,during submersion the deck is filled with water and thus saved from being crushed by outside pressure as well as helping to sink the craft4 ,when moving on the surface it has the appearance of an ordinary ship1 with its two light masts1 a small conning-tower on which is the steering-wheel1 bowsprit1 ventilators1 a derrick1 suction-pump1 and two anchors4 ,a gasolene engine of special design is used for both surface and submerged cruising under ordinary circumstances1 but in time of war storage batteries are available4 ,an electric dynamo supplies light to the whole interior1 including a #djjj candle-power searchlight in the extreme bow which illuminates the pathway while under water4 ,on the boat being stopped and the order given to submerge1 the crew first throw out sounding lines to make sure of the depth4 ,they then close down external openings1 and retreat into the boat through the conning-tower1 within which the helmsman takes his stand1 continuing to steer as easily as when outside4 ,the valves which fill the deck and submersion tanks are opened1 and the ,argonaut drops gently to the floor of the ocean4 ,the two apparent masts are in reality #c-;inch iron pipes which rise thirty feet or more above the deck1 and so long as no greater depth is attained1 they supply the occupants with fresh air and let exhausted gases escape1 but close automatically when the water reaches their top4 ,once upon the bottom of the sea this versatile submarine begins its journey as a tricycle4 ,it is furnished with a driving-wheel on either side1 each of which is #f-a_/b feet in diameter and weighs #ejjj lbs42 and is guided by a third wheel weighing #bjjj lbs4 journalled in the rudder4 ,on a hard bottom or against a strong tide the wheels are most effective owing to their weight1 but in passing through soft sand or mud the screw propeller pushes the boat along1 the driving-wheels running 8loose40 ,in this way she can travel through even waist-deep mud1 the screw working more strongly than on the surface1 because it has such a weight of water to help it1 and she moves more easily uphill4 ,in construction the ,argonaut is shaped something like a huge cigar1 her strong steel frames1 spaced twenty inches apart1 being clad with steel plates #c_/h-;inch thick double riveted over them4 ,great strength is necessary to resist the pressure of superincumbent water1 which at a depth of #ajj feet amounts to #dd lbs4 per square inch4 ,originally she was built #cf feet long1 but was subsequently lengthened by some #bj odd feet1 and has #i feet beam4 ,she weighs fifty-seven tons when submerged4 ,a false section of keel1 #djjj lbs4 in weight1 can on emergency be instantly released from inside2 and two downhaul weights1 each of #ajjj lbs41 are used as an extra precaution for safety when sinking in deep water4 ,the interior is divided into various compartments1 the living quarters consisting of the cabin1 galley1 operating chamber and engine-room4 ,there are also a division containing stores and telephone1 the intermediate1 and the divers' room4 ,the 8operating0 room contains the levers1 handwheels1 and other mechanism by which the boat's movements are governed4 ,a water gauge shows her exact depth below the surface2 a dial on either side indicates any inclination from the horizontal4 ,certain levers open the valves which admit water to the ballast-tanks in the hold2 another releases the false keel2 there is a cyclometer to register the wheel travelling1 and other gauges mark the pressure of steam1 speed of engines1 c4 ,a compass in the conning-tower enables the navigator to steer a true course whether above or below the surface4 ,this conning-tower1 only six feet high1 rises above the centre of the living quarters1 and is of steel with small windows in the upper part4 ,encircling it to about three-quarters of its height is a reservoir for gasolene1 which feeds into a smaller tank within the boat for consumption4 ,the compressed air is stored in two ,mannesmann steel reservoirs which have been tested to a pressure of #djjj lbs4 per square inch4 ,this renews the air-supply for the crew when the ,argonaut is long below1 and also enables the diving operations to be carried on4 ,the maximum speed at which the ,argonaut travels submerged is five knots an hour1 and when she has arrived at her destination--say a sunken coal steamer--the working party pass into the 8intermediate0 chamber1 whose air-tight doors are then closed4 ,a current of compressed air is then turned on until the air is equal in pressure to that in the divers' room4 ,the doors of this close over india rubber to be air and water-tight2 one communicates with the 8intermediate10 the other is a trap which opens downwards into the sea4 ,through three windows in the prow those remaining in the room can watch operations outside within a radius varying according to the clearness of the water4 ,the divers assume their suits1 to the helmets of which a telephone is attached1 so arranged that they are able to talk to each other as well as to those in the boat4 ,they are also provided with electric lamps1 and a brilliant flood of light streams upon them from the bows of the vessel4 ,the derrick can be used with ease under water1 and the powerful suction-pump will 8retrieve0 coal from a submerged vessel into a barge above at the rate of sixty tons per hour4 ,it will thus be seen how valuable a boat of this kind may be for salvage operations1 as well as for surveying the bottom of harbours1 river mouths1 sea coasts1 and so on4 ,in war time it can lay or examine submarine mines for harbour defence1 or1 if employed offensively1 can enter the enemy's harbour with no chance of detection1 and there destroy his mines or blow up his ships with perfect impunity4 ,to return the ,argonaut to the surface it is only necessary to force compressed air into the space below the deck and the four tanks in the hold4 ,her buoyancy being thus gradually restored she rises slowly and steadily till she is again afloat upon the water1 and steams for land4 ,we have now glanced briefly at some of the most interesting attempts--out of many dozens--to produce a practicable submarine vessel in bygone days2 and have inquired more closely into the construction of several modern designs2 among these the ,holland has received especial attention1 as that is the model adopted by our ,admiralty1 and our own new boats only differ in detail from their ,american prototype4 ,but before quitting this subject it will be well to consider what is required from the navigating engineer1 and how far present invention has supplied the demand4 ,illustration3 ,the 8,holland0 ,submarine in the last stages of submersion4 ,the perfect submarine of fiction was introduced by ,jules ,verne1 whose ,nautilus remains a masterpiece of scientific imagination4 ,this marvellous vessel ploughed the seas with equal power and safety1 whether on the surface or deeply sunk beneath the waves1 bearing the pressure of many atmospheres4 ,it would rest upon the ocean floor while its inmates1 clad in diving suits1 issued forth to stroll amid aquatic forests and scale marine mountains4 ,it gathered fabulous treasures from pearl beds and sunken galleons2 and could ram and sink an offending ship a thousand times its size without dinting or loosening a plate on its own hull4 ,no weather deflected its compass1 no movement disturbed its equilibrium4 ,its crew followed peacefully and cheerfully in their spacious cabins a daily round of duties which electric power and automatic gear reduced to a minimum4 ,save for the misadventure of a shortened air-supply when exploring the ,polar pack1 and the clash of human passions1 ,captain ,nemo's guests would have voyaged in a floating paradise4 ,compare with this entrancing creation the most practical vessels of actual experiment4 ,they are small1 blind craft1 groping their way perilously when below the surface1 the steel and electrical machinery sadly interfering with any trustworthy working of their compass1 and the best form of periscope hitherto introduced forming a very imperfect substitute for ordinary vision4 ,their speed1 never very fast upon the surface1 is reduced by submersion to that of the oldest and slowest gunboats4 ,their radius of action is also circumscribed--that is1 they cannot carry supplies sufficient to go a long distance1 deal with a hostile fleet1 and then return to headquarters without replenishment4 ,furthermore1 there arise the nice questions of buoyancy combined with stability when afloat1 of sinking quickly out of sight1 and of keeping a correct balance under water4 ,the equilibrium of such small vessels navigating between the surface and the bottom is extremely sensitive2 even the movements to and fro of the crew are enough to imperil them4 ,to meet this difficulty the big water-ballast tanks1 engines and accumulators are necessarily arranged at the bottom of the hull1 and a pendulum working a helm automatically is introduced to keep it longitudinally stable4 ,to sink the boat1 which is done by changing the angle of the propeller in the ,goubet and some others1 and by means of horizontal rudders and vanes in the ,nordenfelt and ,holland1 it must first be most accurately balanced1 bow and stern exactly in trim4 ,then the boat must be put into precise equilibrium with the water--i4e4 must weigh just the amount of water displaced4 ,for this its specific gravity must be nearly the same as that of the water 7whether salt or fresh71 and a small accident might upset all calculations4 ,collision1 even with a large fish1 could destroy the steering-gear1 and a dent in the side would also tend to plunge it at once to destruction4 ,did it escape these dangers and succeed in steering an accurate course to its goal1 we have up to now little practical proof that the mere act of discharging its torpedo--though the weight of the missile is intended to be automatically replaced immediately it drops from the tube--may not suffice to send the vessel either to bottom or top of the sea4 ,in the latter case it would be within the danger zone of its alarmed enemy and at his mercy1 its slow speed 7even if uninjured7 leaving it little chance of successful flight4 ,but whatever the final result1 one thing is certain1 that--untried as it is--the possible contingency of a submarine attack is likely to shake the morale of an aggressive fleet4 8,when the first submarine torpedo-boat goes into action10 says ,mr4 ,holland1 8she will bring us face to face with the most perplexing problem ever met in warfare4 ,she will present the unique spectacle1 when used in attack1 of a weapon against which there is no defence4444 ,you can send nothing against the submarine boat1 not even itself4444 ,you cannot see under water1 hence you cannot fight under water4 ,hence you cannot defend yourself against an attack under water except by running away40 ,this inventor is1 however1 an enthusiast about the future awaiting the submarine as a social factor4 ,his boat has been tested by long voyages on and below water with complete success4 ,the ,argonaut also upon one occasion travelled a thousand miles with five persons1 and proved herself 8habitable1 seaworthy1 and under perfect control40 ,mr4 ,holland confidently anticipates in the near future a ,channel service of submerged boats run by automatic steering-gear upon cables stretched from coast to coast1 and eloquently sums up its advantages4 ,the passage would be always practicable1 for ordinary interruptions such as fog and storms cannot affect the sea depths4 ,an even temperature would prevail summer and winter1 the well-warmed and lighted boats being also free from smoke and spray4 ,no nauseating smells would proceed from the evenly-working electric engines4 ,no motion cause sea-sickness1 no collision be apprehended--as each line would run on its own cable1 and at its own specified depth1 a telephone keeping it in communication with shore4 ,in like manner a service might be plied over lake bottoms1 or across the bed of wide rivers whose surface is bound in ice4 ,such is the submarine boat as hitherto conceived for peace or war--a daring project for the coming generation to justify4 ,,animated ,,pictures4 ,has it ever occurred to the reader to ask himself why rain appears to fall in streaks though it arrives at earth in drops8 ,or why the glowing end of a charred stick produces fiery lines if waved about in the darkness8 ,common sense tells us the drop and the burning point cannot be in two places at one and the same time4 ,and yet apparently we are able to see both in many positions simultaneously4 ,this seeming paradox is due to 8persistence of vision10 a phenomenon that has attracted the notice of scientific men for many centuries4 ,persistence may be briefly explained thus3-- ,the eye is extremely sensitive to light1 and will1 as is proved by the visibility of the electric spark1 lasting for less than the millionth part of a second1 receive impressions with marvellous rapidity4 ,but it cannot get rid of these impressions at the same speed4 ,the duration of a visual impression has been calculated as one-tenth to one-twenty-first of a second4 ,the electric spark1 therefore1 appears to last much longer than it really does4 ,hence it is obvious that if a series of impressions follow one another more rapidly than the eye can free itself of them1 the impressions will overlap1 and one of four results will follow4 7a7 ,apparently uninterrupted presence of an image if the same image be repeatedly represented4 7b7 ,confusion1 if the images be all different and disconnected4 7c7 ,combination1 if the images of two or a very few objects be presented in regular rotation4 7d7 ,motion1 if the objects be similar in all but one part1 which occupies a slightly different portion in each presentation4 ,in connection with 7c7 an interesting story is told of ,sir ,j4 ,herschel by ,charles ,babbage3--#d #d ,quoted from ,mr4 ,henry ,v4 ,hopwood's 8,living ,pictures10 to which book the author is indebted for much of his information in this chapter4 8,one day ,herschel1 sitting with me after dinner1 amusing himself by spinning a pear upon the table1 suddenly asked whether ,i could show him the two sides of a shilling at the same moment4 ,i took out of my pocket a shilling1 and holding it up before the looking-glass1 pointed out my method4 #8,no1' said my friend1 #8that won't do2' then spinning my shilling upon the table1 he pointed out his method of seeing both sides at once4 ,the next day ,i mentioned the anecdote to the late ,dr4 ,fitton1 who a few days after brought me a beautiful illustration of the principle4 ,it consisted of a round disc of card suspended between two pieces of sewing silk4 ,these threads being held between the finger and thumb of each hand1 were then made to turn quickly1 when the disc of card1 of course1 revolved also4 ,upon one side of this disc of card was painted a bird1 upon the other side an empty bird-cage4 ,on turning the thread rapidly the bird appeared to have got inside the cage4 ,we soon made numerous applications1 as a rat on one side and a trap on the other1 c4 ,it was shown to ,captain ,kater1 ,dr4 ,wollaston1 and many of our friends1 and was1 after the lapse of a short time1 forgotten4 ,some months after1 during dinner at the ,royal ,society ,club1 ,sir ,joseph ,banks being in the chair1 ,i heard ,mr4 ,barrow1 then secretary to the ,admiralty1 talking very loudly about a wonderful invention of ,dr4 ,paris1 the object of which ,i could not quite understand4 ,it was called the ,thaumatrope1 and was said to be sold at the ,royal ,institution1 in ,albemarle ,street4 ,suspecting that it had some connection with our unnamed toy ,i went next morning and purchased for seven shillings and sixpence a thaumatrope1 which ,i afterwards sent down to ,slough to the late ,lady ,herschel4 ,it was precisely the thing which her son and ,dr4 ,fitton had contributed to invent1 which amused all their friends for a time1 and had then been forgotten40 ,the thaumatrope1 then1 did nothing more than illustrate the power of the eye to weld together a couple of alternating impressions4 ,the toys to which we shall next pass represent the same principle working in a different direction towards the production of the living picture4 ,now1 when we see a man running 7to take an instance7 we see the same body and the same legs continuously1 but in different positions1 which merge insensibly the one into the other4 ,no method of reproducing that impression of motion is possible if only one drawing1 diagram1 or photograph be employed4 ,a man represented with as many legs as a centipede would not give us any impression of running or movement2 and a blur showing the positions taken successively by his legs would be equally futile4 ,therefore we are driven back to a series of pictures1 slightly different from one another2 and in order that the pictures may not be blurred a screen must be interposed before the eye while the change from picture to picture is made4 ,the shorter the period of change1 and the greater the number of pictures presented to illustrate a single motion1 the more realistic is the effect4 ,these are the general principles which have to be observed in all mechanism for the production of an illusory effect of motion4 ,the persistence of vision has led to the invention of many optical toys1 the names of which1 in common with the names of most apparatus connected with the living picture1 are remarkable for their length4 ,of these toys we will select three for special notice4 ,in #ahcc ,plateau of ,ghent invented the phenakistoscope1 8the thing that gives one a false impression of reality0--to interpret this formidable word4 ,the phenakistoscope is a disc of card or metal round the edge of which are drawn a succession of pictures showing a man or animal in progressive positions4 ,between every two pictures a narrow slit is cut4 ,the disc is mounted on an axle and revolved before a mirror1 so that a person looking through the slits see one picture after another reflected in the mirror4 ,the zoetrope1 or ,wheel of ,life1 which appeared first in #ahfj1 is a modification of the same idea4 ,in this instrument the pictures are arranged on the inner side of a hollow cylinder revolving on a vertical axis1 its sides being perforated with slits above the pictures4 ,as the slit in both cases caused distortion ,m4 ,reynaud1 a ,frenchman1 produced in #ahgg the praxinoscope1 which differed from the zoetrope in that the pictures were not seen directly through slits1 but were reflected by mirrors set half-way between the pictures and the axis of the cylinder1 a mirror for every picture4 ,only at the moment when the mirror is at right angles to the line of sight would the picture be visible4 ,m4 ,reynaud also devised a special lantern for projecting praxinoscope pictures on to a screen4 ,these and other somewhat similar contrivances1 though ingenious1 had very distinct limitations4 ,they depended for their success upon the inventiveness and accuracy of the artist1 who was confined in his choice of subject2 and could1 owing to the construction of the apparatus1 only represent a small series of actions1 indefinitely repeated by the machine4 ,and as a complete action had to be crowded into a few pictures1 the changes of position were necessarily abrupt4 ,to make the living picture a success two things were needed2 some method of securing a very rapid series of many pictures1 and a machine for reproducing the series1 whatever its length4 ,the method was found in photography1 with the advance of which the living picture's progress is so closely related1 that it will be worth while to notice briefly the various improvements of photographic processes4 ,the old-fashioned ,daguerreotype process1 discovered in #ahci1 required an exposure of half-an-hour4 ,the introduction of wet collodion reduced this tax on a sitter's patience to ten seconds4 ,in #ahgh the dry plate process had still further shortened the exposure to one second2 and since that date the silver-salt emulsions used in photography have had their sensitiveness to light so much increased1 that clear pictures can now be made in one-thousandth of a second1 a period minute enough to arrest the most rapid movements of animals4 ,by #ahgh1 therefore1 instantaneous photography was ready to aid the living picture4 ,previously to that year series of photographs had been taken from posed models1 without however extending the choice of subjects to any great extent4 ,but between #ahgj and #ahhj two men1 ,marey and ,muybridge1 began work with the camera on the movements of horses4 ,marey endeavoured to produce a series of pictures round the edge of one plate with a single lens and repeated exposures4#e ,muybridge1 on the other hand1 used a series of cameras4 ,he erected a long white background parallel to which were stationed the cameras at equal distances4 ,the shutters of the cameras were connected to threads laid across the interval between the background and the cameras in such a manner that a horse driven along the track snapped them at regular intervals1 and brought about successive exposures4 ,muybridge's method was carried on by ,anschtz1 a ,german1 who in #ahii brought out his electrical ,tachyscope1 or 8quick-seer40 ,having secured his negatives he printed off transparent positives on glass1 and arranged these last round the circumference of a large disc rotating in front of a screen1 having in it a hole the size of the transparencies4 ,as each picture came opposite the hole a ,geissler tube was momentarily lit up behind it by electrical contact1 giving a fleeting view of one phase of a horse's motion4 #e ,a very interesting article in the ,may1 #aijb1 issue of ,pearson's ,magazine deals with the latest work of ,professor ,marey in the field of the photographic representation of the movements of men1 birds1 and quadrupeds4 ,the introduction of the ribbon film in or about #ahhh opened much greater possibilities to the living picture than would ever have existed had the glass plate been retained4 ,it was now comparatively easy to take a long series of pictures2 and accordingly we find ,messrs4 ,friese-,greene and ,evans exhibiting in #ahij a camera capable of securing three hundred exposures in half a minute1 or ten per second4 ,the next apparatus to be specially mentioned is ,edison's ,kinetoscope1 which he first exhibited in ,england in #ahid4 ,as early as #ahhg ,mr4 ,edison had tried to produce animated pictures in a manner analogous to the making of a sound-record on a phonograph 7see p4 #ef74 ,he wrapped round a cylinder a sheet of sensitized celluloid which was covered1 after numerous exposures1 by a spiral line of tiny negatives4 ,the positives made from these were illuminated in turn by flashes of electric light4 ,this method was1 however1 entirely abandoned in the perfected kinetoscope1 an instrument for viewing pictures the size of a postage stamp1 carried on a continuously moving celluloid film between the eye of the observer and a small electric lamp4 ,the pictures passed the point of inspection at the rate of forty-six per second 7a rate hitherto never approached71 and as each picture was properly centred a slit in a rapidly revolving shutter made it visible for a very small fraction of a second4 ,holes punched at regular intervals along each side of the film engaged with studs on a wheel1 and insured a regular motion of the pictures4 ,this principle of a perforated film has been used by nearly all subsequent manufacturers of animatographs4 ,to secure forty-six negatives per second ,edison invented a special exposure device4 ,each negative would have but one-forty-sixth of a second to itself1 and that must include the time during which the fresh surface of film was being brought into position before the lens4 ,he therefore introduced an intermittent gearing1 which jerked the film forwards forty-six times per second1 but allowed it to remain stationary for nine-tenths of the period allotted to each picture4 ,during the time of movement the lens was covered by the shutter4 ,this principle of exposure has also been largely adopted by other inventors4 ,by its means weak negatives are avoided1 while pictures projected on to a screen gain greatly in brilliancy and steadiness4 ,the capabilities of a long flexible film-band having been shown by ,edison1 he was not long without imitators4 ,phantoscopes1 ,bioscopes1 ,photoscopes1 and many other instruments followed in quick succession4 ,in #ahie ,messrs4 ,lumire scored a great success with their ,cinematograph1 which they exhibited at ,marseilles and ,paris2 throwing the living picture as we now know it on to a screen for a large company to see4 ,this camera-lantern opens the era of commercial animated-photography4 ,the number of patents taken out since #ahie in connection with living-picture machines is sufficient proof that inventors have either found in this particular branch of photography a peculiar fascination1 or have anticipated from it a substantial profit4 ,a company known as the ,mutoscope and ,biograph ,company has been formed for the sole object of working the manufacture and exhibition of the living picture on a great commercial scale4 ,the present company is ,american1 but there are subsidiary allied companies in many parts of the world1 including the ,british ,isles1 ,france1 ,italy1 ,belgium1 ,germany1 ,austria1 ,india1 ,australia1 ,south ,africa4 ,the part that the company has played in the development of animated photography will be easily understood from the short account that follows4 ,the company controls three machines1 the ,mutograph1 or camera for making negatives2 the ,biograph1 or lantern for throwing pictures on to the screen2 and the ,mutoscope1 a familiar apparatus in which the same pictures may be seen in a different fashion on the payment of a penny4 ,externally the ,mutograph is remarkable for its size1 which makes it a giant of its kind4 ,the complete apparatus weighs1 with its accumulators1 several hundreds of pounds4 ,it takes a very large picture1 as animatograph pictures go--two by two-and-a-half inches1 which1 besides giving increased detail1 require less severe magnification than is usual with other films4 ,the camera can make up to a hundred exposures per second1 in which time twenty-two feet of film will have passed before the lens4 ,the film is so heavy that were it arrested bodily during each exposure and then jerked forward again1 it might be injured4 ,the mechanism of the mutograph1 driven at regular speed1 by an electric motor1 has been so arranged as to halt only that part of the film which is being exposed1 the rest moving forward continuously4 ,the exposed portion1 together with the next surface1 which has accumulated in a loop behind it1 is dragged on by two rollers that are in contact with the film during part only of their revolutions4 ,thus the jerky motion is confined to but a few inches of the film1 and even at the highest speeds the camera is peculiarly free from vibration4 ,an exposed mutograph film is wound for development round a skeleton reel1 three feet in diameter and seven long1 which rotates in a shallow trough containing the developing solution4 ,development complete1 the reel is lifted from its supports and suspended over a succession of other troughs for washing1 fixing1 and final washing4 ,when dry the negative film is passed through a special printing frame in contact with another film1 which receives the positive image for the biograph4 ,the difficulty of handling such films will be appreciated to a certain extent even by those whose experience is confined to the snaky behaviour of a short ,kodak reel during development4 ,the ,mutoscope ,company's organisation is as perfect as its machinery4 ,it has representatives in all parts of the world4 ,wherever stirring events are taking place1 whether in peace or war1 a mutograph operator will soon be on the spot with his heavy apparatus to secure pictures for world-wide exhibition4 ,it need hardly be said that great obstacles1 human and physical1 have often to be overcome before a film can be exposed2 and considerable personal danger encountered4 ,we read that an operator1 despatched to ,cuba during the ,spanish-,american ,war was left three days and nights without food or water to guard his precious instruments1 the party that had landed him having suddenly put to sea on sighting a ,spanish cruiser4 ,another is reported to have had a narrow escape from being captured at sea by the ,spaniards after a hot chase4 ,it is also on record that a mutograph set up in ,atlantic ,city to take a procession of fire-engines was charged and shattered by one of the engines2 that the operators were flung into the crowd3 and that nevertheless the box containing the exposed films was uninjured1 and on development yielded a very sensational series of pictures lasting to the moment of collision4 ,the ,mutoscope ,company owns several thousand series of views1 none probably more valuable than those of his ,holiness the ,pope1 who graciously gave ,mr4 ,w4 ,k4 ,dickson five special sittings1 during which no less than #ag1jjj negatives were made1 each one of great interest to millions of people throughout the world4 ,the company spares neither time nor money in its endeavour to supply the public with what will prove acceptable4 ,a year's output runs into a couple of hundred miles of film4 ,as much as #gjj feet is sometimes expended on a single series1 which may be worth anything up to #ajjj4 ,the energy displayed by the operators is often marvellous4 ,to take instances4 ,the ,derby of #ahih was run at #c4bj ,p4,m4 ,at ten o'clock the race was run again by ,biograph on the great sheet at the ,palace ,theatre4 ,on the home-coming of ,lord ,kitchener from the ,soudan ,campaign1 a series of photographs was taken at ,dover in the afternoon and exhibited the same evening6 ,or again1 to consider a wider sphere of action1 the ,jubilee ,procession of #ahig was watched in ,new ,york ten days after the event2 two days later in ,chicago2 and in three more the films were attracting large audiences in ,san ,francisco1 #ejjj miles from the actual scene of the procession6 ,one may easily weary of a series of single views passed slowly through a magic-lantern at a lecture or entertainment4 ,but when the ,biograph is flashing its records at lightning speed there is no cause for dullness4 ,it is impossible to escape from the fascination of movement4 ,a single photograph gives the impression of mere resemblance to the original2 but a series1 each reinforcing the signification of the last1 breathes life into the dead image1 and deludes us into the belief that we see1 not the representation of a thing1 but the thing itself4 ,the bill of fare provided by the ,biograph ,company is varied enough to suit the most fastidious taste4 ,now it is the great ,naval ,review off ,spithead1 or ,president ,faure shooting pheasants on his preserves near ,paris4 ,a moment's pause and then the magnificent ,falls of ,niagara foam across the sheet2 ,maxim guns fire harmlessly2 panoramic scenes taken from locomotives running at high velocity unfold themselves to the delighted spectators1 who feel as if they really were speeding over open country1 among towering rocks1 or plunging into the darkness of a tunnel4 ,here is an express approaching with all the quiver and fuss of real motion1 so faithfully rendered that it seems as if a catastrophe were imminent2 when1 snap6 we are transported a hundred miles to watch it glide into a station4 ,the doors open1 passengers step out and shake hands with friends1 porters bustle about after luggage1 doors are slammed again1 the guard waves his flag1 and the carriages move slowly out of the picture4 ,then our attention is switched away to the #aj-;inch disappearing gun1 landing and firing at ,sandy ,hook4 ,and next1 as though to show that nothing is beneath the notice of the biograph1 we are perhaps introduced to a family of small pigs feeding from a trough with porcine earnestness and want of manners4 ,it must not be thought that the ,living ,picture caters for mere entertainment only4 ,it serves some very practical and useful ends4 ,by its aid the movements of machinery and the human muscles may be studied in detail1 to aid a mechanical or medical education4 ,it furnishes art schools with all the poses of a living model4 ,less serious pursuits1 such as dancing1 boxing1 wrestling and all athletic sports and exercise1 will find a use for it4 ,as an advertising medium it stands unrivalled1 and we shall owe it a deep debt of gratitude if it ultimately supplants the flaring posters that disfigure our towns and desecrate our landscapes4 ,not so long since1 the directors of the ,norddeutscher-,lloyd ,steamship ,company hired the biograph at the ,palace ,theatre1 ,london1 to demonstrate to anybody who cared to witness a very interesting exhibition that their line of vessels should always be used for a journey between ,england and ,america4 ,the ,living ,picture has even been impressed into the service of the ,british ,empire to promote emigration to the ,colonies4 ,three years ago ,mr4 ,freer exhibited at the ,imperial ,institute and in other places in ,england a series of films representing the #ahig harvest in ,manitoba4 ,would-be emigrants were able to satisfy themselves that the great ,canadian plains were fruitful not only on paper4 ,for could they not see with their own eyes the stately procession of automatic 8binders0 reaping1 binding1 and delivering sheaves of wheat1 and puffing engines threshing out the grain ready for market8 ,a far preferable method this to the bogus descriptions of land companies such as lured poor ,chuzzlewit and ,mark ,tapley into the deadly swamps of 8,eden40 ,again1 what more calculated to recruit boys for our warships than the fine ,polytechnic exhibition known as 8,our ,navy08 ,what words1 spoken or printed1 could have the effect of a series of vivid scenes truthfully rendered1 of drills on board ship1 the manning and firing of big guns1 the limbering-up of smaller guns1 the discharge of torpedoes1 the headlong rush of the 8destroyers08 ,the ,mutoscope1 to which reference has been made above1 may be found in most places of public entertainment1 in refreshment bars1 on piers1 in exhibitions1 on promenades4 ,a penny dropped into a slot releases a handle1 the turning of which brings a series of pictures under inspection4 ,the pictures1 enlarged from mutograph films1 are mounted in consecutive order round a cylinder1 standing out like the leaves of a book4 ,when the cylinder is revolved by means of the handle the picture cards are snapped past the eye1 giving an effect similar to the lifelike projections on a biograph screen4 ,from #ijj to #ajjj pictures are mounted on a cylinder4 ,the advantages of the mutoscope--its convenient size1 its simplicity1 and the ease with which its contents may be changed to illustrate the topics and events of the day--have made the animated photograph extremely popular4 ,it does for vision what the phonograph does for sound4 ,in a short time we shall doubtless be provided with handy machines combining the two functions and giving us double value for our penny4 ,the real importance and value of animated photography will be more easily estimated a few years hence than to-day1 when it is still more or less of a novelty4 ,the multiplication of illustrated newspapers and magazines points to a general desire for pictorial matter to help down the daily1 weekly1 or monthly budget of news1 even if the illustrations be imaginative products of ,fleet ,street rather than faithful to fact4 ,the reliable living picture 7we expect the 8set-scene07 which 8holds up a mirror to nature10 will be a companion rather than a rival of journalism1 following hard on the description in print of an event that has taken place under the eye of the recording camera4 ,the zest with which we have watched during the last two years biographic views of the embarkation and disembarkation of troops1 of the transport of big guns through drifts and difficult country1 and of the other circumstances of war1 is largely due to the descriptions we have already read of the things that we see on the screen4 ,and1 on the other hand1 the impression left by a series of animated views will dwell in our memories long after the contents of the newspaper columns have become confused and jumbled4 ,it is therefore especially to be hoped that photographic records will be kept of historic events1 such as the ,jubilee1 the ,queen's ,funeral1 ,king ,edward's ,coronation1 so that future generations may1 by the turning of a handle1 be brought face to face with the great doings of a bygone age4 ,,the ,,great ,,paris ,,telescope ,a telescope so powerful that it brings the moon apparently to within thirty-five miles of the earth2 so long that many a cricketer could not throw a ball from one end of it to the other2 so heavy that it would by itself make a respectable load for a goods train2 so expensive that astronomically-inclined millionaires might well hesitate to order a similar one for their private use4 ,such is the huge ,paris telescope that in #aijj delighted thousands of visitors in the ,french ,exposition1 where1 among the many wonderful sights to be seen on all sides1 it probably attracted more notice than any other exhibit4 ,this triumph of scientific engineering and dogged perseverance in the face of great difficulties owes its being to a suggestion made in #ahid to a group of ,french astronomers by ,m4 ,deloncle4 ,he proposed to bring astronomy to the front at the coming ,exposition1 and to effect this by building a refracting telescope that in size and power should completely eclipse all existing instruments and add a new chapter to the 8story of the heavens40 ,to the mind unversed in astronomy the telescope appeals by the magnitude of its dimensions1 in the same way as do the ,forth ,bridge1 the ,eiffel ,tower1 the ,big ,wheel1 the statue of ,liberty near ,new ,york harbour1 the ,pyramids1 and most human-made 8biggest on records40 ,at the time of ,m4 ,deloncle's proposal the largest refracting telescope was the ,yerkes' at ,william's ,bay1 ,wisconsin1 with an object-glass forty inches in diameter2 and next to it the #cf-;inch ,lick instrument on ,mount ,hamilton1 ,california1 built by ,messrs4 ,alvan ,clark of ,cambridgeport1 ,massachusetts4 ,among reflecting telescopes the prior place is still held by ,lord ,rosse's1 set up on the lawn of ,birr ,castle half a century ago4 ,its speculum1 or mirror1 weighing three tons1 lies at the lower end of a tube six feet across and sixty feet long4 ,this huge reflector1 being mounted in meridian1 moves only in a vertical direction4 ,a refracting telescope is one of the ordinary pocket type1 having an object-lens at one end and an eyepiece at the other4 ,a reflector1 on the other hand1 has no object-lens1 its place being taken by a mirror that gathers the rays entering the tube and reflects them back into the eyepiece1 which is situated nearer the mouth end of the tube than the mirror itself4 ,each system has its peculiar disadvantages4 ,in reflectors the image is more or less distorted by 8spherical aberration40 ,in refractors the image is approximately perfect in shape1 but liable to 8chromatic aberration10 a phenomenon especially noticeable in cheap telescopes and field-glasses1 which often show objects fringed with some of the colours of the spectrum4 ,this defect arises from the different refrangibility of different light rays4 ,thus1 violet rays come to a focus at a shorter distance from the lens than red rays1 and when one set is in focus to the eye the other must be out of focus4 ,in carefully-made and expensive instruments compound lenses are used1 which by the employment of different kinds of glass bring all the colours to practically the same focus1 and so do away with chromatic aberration4 ,to reduce colour troubles to a minimum ,m4 ,deloncle proposed that the object-lens should have a focal distance of about two hundred feet1 since a long focus is more easily corrected than a short one1 and a diameter of over fifty-nine inches4 ,the need for so huge a lens arises out of the optical principles of a refractor4 ,the rays from an object--a star1 for instance--strike the object-glass at the near end1 and are bent by it into a converging beam1 till they all meet at the focus4 ,behind the focus they again separate1 and are caught by the eyepiece1 which reduces them to a parallel beam small enough to enter the pupil4 ,we thus see that though the unaided eye gathers only the few rays that fall directly from the object on to the pupil1 when helped by the telescope it receives the concentrated rays falling on the whole area of the object-glass2 and it would be sensible of a greatly increased brightness had not this light to be redistributed over the image1 which is the object magnified by the eyepiece4 ,assuming the aperture of the pupil to be one-tenth of an inch1 and the object to be magnified a hundred times1 the object-lens should have a hundred times the diameter of the pupil to render the image as bright as the object itself4 ,if the lens be five instead of ten inches across1 a great loss of light results1 as in the high powers of a microscope1 and the image loses in distinctness what it gains in size4 ,as ,m4 ,deloncle meant his telescope to beat all records in respect of magnification1 he had no choice but to make a lens that should give proportionate illumination1 and itself be of unprecedented size4 ,at first ,m4 ,deloncle met with considerable opposition and ridicule4 ,such a scheme as his was declared to be beyond accomplishment4 ,but in spite of many prophecies of ultimate failure he set to work1 entrusting the construction of the various portions of his colossal telescope to well-tried experts4 ,to ,m4 ,gautier was given the task of making all the mechanical parts of the apparatus2 to ,m4 ,mantois the casting of the giant lenses2 to ,m4 ,despret the casting of the huge mirror1 to which reference will be made immediately4 ,the first difficulty to be encountered arose from the sheer size of the instrument4 ,it was evidently impossible to mount such a leviathan in the ordinary way4 ,a tube1 #ahj feet long1 could not be made rigid enough to move about and yet permit careful observation of the stars4 ,even supposing that it were satisfactorily mounted on an 8equatorial foot0 like smaller glasses1 how could it be protected from wind and weather8 ,to cover it1 a mighty dome1 two hundred feet or more in diameter1 would be required2 a dome exceeding by over seventy feet the cupola of ,st4 ,peter's1 ,rome2 and this dome must revolve easily on its base at a pace of about fifty feet an hour1 so that the telescope might follow the motion of the heavenly bodies4 ,the constructors therefore decided to abandon any idea of making a telescope that could be moved about and pointed in any desired direction4 ,the alternative course open to them was to fix the telescope itself rigidly in position1 and to bring the stars within its field by means of a mirror mounted on a massive iron frame--the two together technically called a siderostat4 ,the mirror and its support would be driven by clockwork at the proper sidereal rate4 ,the siderostat principle had been employed as early as the eighteenth century1 and perfected in recent years by ,lon ,foucault1 so that in having recourse to it the builders of the telescope were not committing themselves to any untried device4 ,in days when the handling of masses of iron1 and the erection of huge metal constructions have become matters of everyday engineering life1 no peculiar difficulty presented itself in connection with the metal-work of the telescope4 ,the greatest possible care was of course observed in every particular4 ,all joints and bearings were adjusted with an extraordinary accuracy2 and all the cylindrical moving parts of the siderostat verified till they did not vary from perfect cylindricity by so much as one twenty-five-thousandth of an inch6 ,the tube of the telescope1 #ahj feet long1 consisted of twenty-four sections1 fifty-nine inches in diameter1 bolted together and supported on seven massive iron pillars4 ,it weighed twenty-one tons4 ,the siderostat1 twenty-seven feet high1 and as many in length1 weighed forty-five tons4 ,the lower portion1 which was fixed firmly on a bed of concrete1 had on the top a tank filled with quicksilver1 in which the mirror and its frame floated4 ,the quicksilver supported nine-tenths of the weight1 the rest being taken by the levers used to move the mirror4 ,though the total weight of the mirror and frame was thirteen tons1 the quicksilver offered so little resistance that a pull of a few pounds sufficed to rotate the entire mass4 ,the real romance of the construction of this huge telescope centres on the making of the lenses and mirror4 ,first-class lenses for all photographic and optical purposes command a very high price on account of the care and labour that has to be expended on their production2 the value of the glass being trifling by comparison4 ,few1 if any1 trades require greater mechanical skill than that of lensmaking2 the larger the lens the greater the difficulties it presents1 first in the casting1 then in the grinding1 last of all in the polishing4 ,the presence of a single air-bubble in the molten glass1 the slightest irregularity of surface in the polishing may utterly destroy the value of a lens otherwise worth several thousands of pounds4 ,illustration3 ,reproduced by the permission of ,proprietors of 8,knowledge40 ,general view1 of the ,great ,paris ,telescope1 showing the eye-end4 ,the tube is #ahj feet long1 and #ei inches in diameter4 ,it weighs #ba tons4 ,the object-glass of the great telescope was cast by ,m4 ,mantois1 famous as the manufacturer of large lenses4 ,the glass used was boiled and reboiled many times to get rid of all bubbles4 ,then it was run into a mould and allowed to cool very gradually4 ,a whole month elapsed before the breaking of a mould1 when the lens often proved to be cracked on the surface1 owing to the exterior having cooled faster than the interior and parted company with it4 ,at last1 however1 a perfect cast resulted4 ,m4 ,despret undertook the even more formidable task of casting the mirror at his works at ,jeumont1 ,north ,france4 ,a special furnace and oven1 capable of containing over fifteen tons of molten glass1 had to be constructed4 ,the mirror1 #f-a_/b feet in diameter and eleven inches thick1 absorbed #c-c_/d tons of liquid glass2 and so great was the difficulty of cooling it gradually1 that out of the twenty casts eighteen were failures4 ,the rough lenses and mirror having been ground to approximate correctness in the ordinary way1 there arose the question of polishing1 which is generally done by one of the most sensitive and perfect instruments existing-the human hand4 ,in this case1 owing to the enormous size of the objects to be treated1 hand work would not do4 ,the mere hot touch of a workman would raise on the glass a tiny protuberance1 which would be worn level with the rest of the surface by the polisher1 and on the cooling of the part would leave a depression1 only #a-ge1jjj of an inch deep1 perhaps1 but sufficient to produce distortion1 and require that the lens should be ground down again1 and the whole surface polished afresh4 ,m4 ,gautier therefore polished by machinery4 ,it proved a very difficult process altogether1 on account of frictional heating1 the rise of temperature in the polishing room1 and the presence of dust4 ,to insure success it was found necessary to warm all the polishing machinery1 and to keep it at a fixed temperature4 ,at the end of almost a year the polishing was finished1 after the lenses and mirror had been subjected to the most searching tests1 able to detect irregularities not exceeding #a-bej1jjj of an inch4 ,m4 ,gautier applied to the mirror ,m4 ,foucault's test1 which is worth mentioning4 ,a point of light thrown by the mirror is focused through a telescope4 ,the eyepiece is then moved inwards and outwards so as to throw the point out of focus4 ,if the point becomes a luminous circle surrounded by concentric rings1 the surface throwing the light point is perfectly plane or smooth4 ,if1 however1 a pushing-in shows a vertical flattening of the point1 and a pulling-out a horizontal flattening1 that part is concave2 if the reverse happens1 convexity is the cause4 ,for the removal of the mirror from ,jeumont to ,paris a special train was engaged1 and precautions were taken rivalling those by which travelling ,royalty is guarded4 ,the train ran at night without stopping1 and at a constant pace1 so that the vibration of the glass atoms might not vary4 ,on arriving at ,paris1 the mirror was transferred to a ponderous waggon1 and escorted by a body of men to the ,exposition buildings4 ,the huge object-lens received equally careful treatment4 ,the telescope was housed at the ,exhibition in a long gallery pointing due north and south1 the siderostat at the north end4 ,at the other1 the eyepiece1 end1 a large amphitheatre accommodated the public assembled to watch the projection of stellar or lunar images on to a screen thirty feet high1 while a lecturer explained what was visible from time to time4 ,the images of the sun and moon as they appeared at the primary focus in the eyepiece measured from twenty-one to twenty-two inches in diameter1 and the screen projections were magnified from these about thirty times superficially4 ,the eyepiece section consisted of a short tube1 of the same breadth as the main tube1 resting on four wheels that travelled along rails4 ,special gearing moved this truck-like construction backwards and forwards to bring a sharp focus into the eyepiece or on to a photographic plate4 ,focusing was thus easy enough when once the desired object came in view2 but the observer being unable to control the siderostat1 #bej feet distant1 had to telephone directions to an assistant stationed near the mirror whenever he wished to examine an object not in the field of vision4 ,by the courtesy of the proprietors of the ,strand ,magazine we are allowed to quote ,m4 ,deloncle's own words describing his emotions on his first view through the giant telescope3-- 8,as is invariably the case1 whenever an innovation that sets at nought old-established theories is brought forward1 the prophecies of failure were many and loud1 and ,i had more than a suspicion that my success would cause less satisfaction to others than to myself4 ,better than any one else ,i myself was cognisant of the unpropitious conditions in which my instrument had to work4 ,the proximity of the river1 the dust raised by hundreds of thousands of trampling feet1 the trepidation of the soil1 the working of the machinery1 the changes of temperature1 the glare from the thousands of electric lamps in close proximity--each of these circumstances1 and many others of a more technical nature1 which it would be tedious to enumerate1 but which were no less important1 would have been more than sufficient to make any astronomer despair of success even in observatories where all the surroundings are chosen with the utmost care4 8,in regions pure of calm and serene air large new instruments take months1 more often years1 to regulate properly4 8,in spite of everything1 however1 ,i still felt confident4 ,our calculations had been gone over again and again1 and ,i could see nothing that in my opinion warranted the worst apprehensions of my kind critics4 8,it was with ill-restrained impatience that ,i waited for the first night when the moon should show herself in a suitable position for being observed2 but the night arrived in due course4 8,everything was in readiness4 ,the movable portion of the roof of the building had been slid back1 and the mirror of the siderostat stood bared to the sky4 8,in the dark1 square chamber at the other end of the instrument1 #bjj feet away1 into which the eyepiece of the instrument opened1 ,i had taken my station with two or three friends4 ,an attendant at the telephone stood waiting at my elbow to transmit my orders to his colleague in charge of the levers that regulated the siderostat and its mirror4 8,the moon had risen now1 and her silvery glory shone and sparkled in the mirror4 8#8,a right declension1' ,i ordered4 8,the telephone bell rang in reply4 #8,slowly1 still slower2 now to the left--enough2 again a right declension--slower2 stop now--very1 very slowly4' 8,on the ground-glass before our eyes the moon's image crept up from one corner until it had overspread the glass completely4 ,and there we stood in the centre of ,paris1 examining the surface of our satellite with all its craters and valleys and bleak desolation4 8,i had won the day40 ,,photographing ,,the ,,invisible4 ,most of us are able to recognise when we see them shadowgraphs taken by the aid of the now famous ,x-rays4 ,they generally represent some part of the structure of men1 beasts1 birds1 or fishes4 ,very dark patches show the position of the bones1 large and small2 lighter patches the more solid muscles clinging to the bony framework2 and outside these again are shadowy tracts corresponding to the thinnest and most transparent portions of the fleshy envelope4 ,in an age fruitful as this in scientific marvels1 it often takes some considerable time for the public to grasp the full importance of a fresh discovery4 ,but when1 in #ahif1 it was announced that ,professor ,rntgen of ,wrzburg had actually taken photographs of the internal organs of still living creatures1 and penetrated metal and other opaque substances with a new kind of ray1 great interest was manifested throughout the civilised world4 ,on the one hand the 8new photography0 seemed to upset popular ideas of opacity2 on the other it savoured strongly of the black art1 and1 by its easy excursions through the human body1 seemed likely to revolutionise medical and surgical methods4 ,at first many strange ideas about the ,x-rays got afloat1 attributing to them powers which would have surprised even their modest discoverer4 ,it was also thought that the records were made in a camera after the ordinary manner of photography1 but as a matter of fact ,rntgen used neither lens nor camera1 the operation being similar to that of casting a shadow on a wall by means of a lamp4 ,in ,x-radiography a specially constructed electrically-lit glass tube takes the place of the lamp1 and for the wall is substituted a sensitised plate4 ,the object to be radiographed is merely inserted between them1 its various parts offering varying resistance to the rays1 so that the plate is affected unequally1 and after exposure may be developed and printed from it the usual way4 ,photographs obtained by using ,x-rays are therefore properly called shadowgraphs or skiagraphs4 ,the discovery that has made ,professor ,rntgen famous is1 like many great discoveries1 based upon the labours of other men in the same field4 ,geissler1 whose vacuum tubes are so well known for their striking colour effects1 had already noticed that electric discharges sent through very much rarefied air or gases produced beautiful glows4 ,sir ,william ,crookes1 following the same line of research1 and reducing with a ,sprengel air-pump the internal pressure of the tubes to #a_/ajjjjj of an atmosphere1 found that a luminous glow streamed from the cathode1 or negative pole1 in a straight line1 heating and rendering phosphorescent anything that it met4 ,crookes regarded the glow as composed of 8radiant matter10 and explained its existence as follows4 ,the airy particles inside the tube1 being few in number1 are able to move about with far greater freedom than in the tightly packed atmosphere outside the tube4 ,a particle1 on reaching the cathode1 is repelled violently by it in a straight line1 to 8bombard0 another particle1 the walls of the tube1 or any object set up in its path1 the sudden arrest of motion being converted into light and heat4 ,by means of special tubes he proved that the 8radiant matter0 could turn little vanes1 and that the flow continued even when the terminals of the shocking-coil were outside the glass1 thus meeting the contention of ,puluj that the radiant matter was nothing more than small particles of platinum torn from the terminals4 ,he also showed that1 when intercepted1 radiant matter cast a shadow1 the intercepting object receiving the energy of the bombardment2 but that when the obstruction was removed the hitherto sheltered part of the glass wall of the tube glowed with a brighter phosphorescence than the part which had become 8tired0 by prolonged bombardment4 ,experiments further revealed the fact that the shaft of 8,cathode rays0 could be deflected by a magnet from their course1 and that they affected an ordinary photographic plate exposed to them4 ,in #ahid ,lenard1 a ,hungarian1 and pupil of the famous ,hertz1 fitted a ,crookes' tube with a 8window0 of aluminium in its side replacing a part of the glass1 and saw that the course of the rays could be traced through the outside air4 ,from this it was evident that something else than matter must be present in the shaft of energy sent from the negative terminal of the tube1 as there was no direct communication between the interior and the exterior of the tube to account for the external phosphorescence4 ,whatever was the nature of the rays he succeeded in making them penetrate and impress themselves on a sensitised plate enclosed in a metal box4 ,then in #ahif came ,rntgen's great discovery that the rays from a ,crookes' tube1 after traversing the glass1 could pierce opaque matter4 ,he covered the tube with thick cardboard1 but found that it would still cast the shadows of books1 cards1 wood1 metals1 the human hand1 c41 on to a photographic plate even at the distance of some feet4 ,the rays would also pass through the wood1 metal1 or bones in course of time2 but certain bodies1 notably metals1 offered a much greater resistance than others1 such as wood1 leather1 and paper4 ,professor ,rntgen crowned his efforts by showing that a skeleton could be 8shadow-graphed0 while its owner was still alive4 ,naturally everybody wished to know not only what the rays could do1 but what they were4 ,rntgen1 not being able to identify them with any known rays1 took refuge in the algebraical symbol of the unknown quantity and dubbed them ,x-rays4 ,he discovered this much1 however1 that they were invisible to the eye under ordinary conditions2 that they travelled in straight lines only1 passing through a prism1 water1 or other refracting bodies without turning aside from their path2 and that a magnet exerted no power over them4 ,this last fact was sufficient of itself to prevent their confusion with the radiant matter 8cathode rays0 of the tube4 ,rntgen thought1 nevertheless1 that they might be the cathode rays transmuted in some manner by their passage through the glass1 so as to resemble in their motion sound-waves1 i4e4 moving straight forward and not swaying from side to side in a series of zig-zags4 ,the existence of such ether waves had for some time before been suspected by ,lord ,kelvin4 ,other authorities have other theories4 ,we may mention the view that ,x represents the ultra-violet rays of the spectrum1 caused by vibrations of such extreme rapidity as to be imperceptible to the human eye1 just as sounds of extremely high pitch are inaudible to the ear4 ,this theory is to a certain extent upheld by the behaviour of the photographic plate1 which is least affected by the colours of the spectrum at the red end and most by those at the violet end4 ,a photographer is able to use red or orange light in his dark room because his plates cannot 8see0 them1 though he can2 whereas the reverse would be the case with ,x-rays4 ,this ultra-violet theory claims for ,x-rays a rate of ether vibration of trillions of waves per second4 ,an alternative theory is to relegate the rays to the gap in the scale of ether-waves between heatwaves and light-waves4 ,but this does not explain any more satisfactorily than the other the peculiar phenomenon of non-refraction4 ,the apparatus employed in ,x-photography consists of a ,crookes' tube of a special type1 a powerful shocking or induction coil1 a fluorescent screen and photographic plates and appliances for developing1 c41 besides a supply of high-pressure electricity derived from the main1 a small dynamo or batteries4 ,a ,crookes' tube is four to five inches in diameter1 globular in its middle portion1 but tapering away towards each end4 ,through one extremity is led a platinum wire1 terminating in a saucer-shaped platinum plate an inch or so across4 ,at the focus of this1 the negative terminal1 is fixed a platinum plate at an angle to the path of the rays so as to deflect them through the side of the tube4 ,the positive terminal penetrates the glass at one side4 ,the tube contains1 as we have seen1 a very tiny residue of air4 ,if this were entirely exhausted the action of the tube would cease2 so that some tubes are so arranged that when rarefaction becomes too high the passage of an electrical current through small bars of chemicals1 whose ends project through the sides of the tube1 liberates gas from the bars in sufficient quantity to render the tube active again4 ,when the ,ruhmkorff induction coil is joined to the electric circuit a series of violent discharges of great rapidity occur between the tube terminals1 resembling in their power the discharge of a ,leyden jar1 though for want of a dense atmosphere the brilliant spark has been replaced by a glow and brush-light in the tube4 ,the coil is of large dimensions1 capable of passing a spark across an air-gap of ten to twelve inches4 ,it will perhaps increase the reader's respect for ,x-rays to learn that a coil of proper size contains upwards of thirteen miles of wire2 though indeed this quantity is nothing in comparison with the #aej miles wound on the huge inductorium formerly exhibited at the ,london ,polytechnic4 ,if we were invited to an ,x-ray demonstration we should find the operator and his apparatus in a darkened room4 ,he turns on the current and the darkness is broken by a velvety glow surrounding the negative terminal1 which gradually extends until the whole tube becomes clothed in a green phosphorescence4 ,a sharply-defined line athwart the tube separates the shadowed part behind the receiving plate at the negative focus--now intensely hot--from that on which the reflected rays fall directly4 ,one of us is now invited to extend a hand close to the tube4 ,the operator then holds on the near side of the hand his fluorescent screen1 which is nothing more than a framework supporting a paper smeared on one side with platino-cyanide of barium1 a chemical that1 in common with several others1 was discovered by ,salvioni of ,perugia to be sensitive to the rays and able to make them visible to the human eye4 ,the value of the screen to the ,x-radiographer is that of the ground-glass plate to the ordinary photographer1 as it allows him to see exactly what things are before the sensitised plate is brought into position1 and in fact largely obviates the necessity for making a permanent record4 ,the screen shows clearly and in full detail all the bones of the hand--so clearly that one is almost irresistibly drawn to peep behind to see if a real hand is there4 ,one of us now extends an arm and the screen shows us the ulna and the radius working round each other1 now both visible1 now one obscuring the other4 ,on presenting the body to the course of the rays a remarkable shadow is cast on to the screen4 ,the spinal column and the ribs2 the action of the heart and lungs are seen quite distinctly4 ,a deep breath causes the movement of a dark mass--the liver4 ,there is no privacy in presence of the rays4 ,the enlarged heart1 the diseased lung1 the ulcerated liver betrays itself at once4 ,in a second of time the phosphorescent screen reveals what might baulk medical examination for months4 ,if a photographic slide containing a dry-plate be substituted for the focusing-screen1 the rays soon penetrate any covering in which the plate may be wrapped to protect it from ordinary light rays4 ,the process of taking a shadowgraph may therefore be conducted in broad daylight1 which is under certain conditions a great advantage1 though the sensitiveness of plates exposed to ,rntgen rays entails special care being taken of them when they are not in use4 ,in the early days of ,x-radiography an exposure of some minutes was necessary to secure a negative1 but now1 thanks to the improvements in the tubes1 a few seconds is often sufficient4 ,the discovery of the ,x-rays is a great discovery1 because it has done much to promote the noblest possible cause1 the alleviation of human suffering4 ,not everybody will appreciate a more rapid mode of telegraphy1 or a new method of spinning yarn1 but the dullest intellect will give due credit to a scientific process that helps to save life and limb4 ,who among us is not liable to break an arm or leg1 or suffer from internal injuries invisible to the eye8 ,who among us therefore should not be thankful on reflecting that1 in event of such a mishap1 the ,x-rays will be at hand to show just what the trouble is1 how to deal with it1 and how far the healing advances day by day8 ,the ,x-ray apparatus is now as necessary for the proper equipment of a hospital as a camera for that of a photographic studio4 ,it is especially welcome in the hospitals which accompany an army into the field4 ,since ,may #ahif many a wounded soldier has had reason to bless the patient work that led to the discovery at ,wrzburg4 ,the ,greek war1 the war in ,cuba1 the ,tirah campaign1 the ,egyptian campaign1 and the war in ,south ,africa1 have given a quick succession of fine opportunities for putting the new photography to the test4 ,there is now small excuse for the useless and agonising probings that once added to the dangers and horrors of the military hospital4 ,even if the ,x-ray equipment1 by reason of its weight1 cannot conveniently be kept at the front of a rapidly moving army1 it can be set up in the 8advanced0 or 8base0 hospitals1 whither the wounded are sent after a first rough dressing of their injuries4 ,the medical staff there subject their patients to the searching rays1 are able to record the exact position of a bullet or shell-fragment1 and the damage it has done2 and by promptly removing the intruder to greatly lessen its power to harm4 ,the ,rntgen ray has added to the surgeon's armoury a powerful weapon4 ,its possibilities are not yet fully known1 but there can be no doubt that it marks a new epoch in surgical work4 ,and for this reason ,professor ,rntgen deserves to rank with ,harvey1 the discoverer of the blood's circulation2 with ,jenner1 the father of vaccination2 and with ,sir ,james ,young ,simpson1 the first doctor to use chloroform as an ansthetic4 ,,photography ,,in ,,the ,,dark4 ,strange as it seems to take photographs with invisible rays1 it is still stranger to be able to affect sensitised plates without apparently the presence of any kind of rays4 ,professor ,w4 ,j4 ,russell1 ,vice-,president of the ,royal ,society of ,london1 has discovered that many substances have the power of impressing their outlines automatically on a sensitive film1 if the substance be placed in a dark cupboard in contact with1 or very close to a dry-plate4 ,after some hours1 or it may be days1 development of the plate will reveal a distinct impression of the body in question4 ,dr4 ,russell experimented with wood1 metal1 leaves1 drawings1 printed matter1 lace4 ,zinc proved to be an unusually active agent4 ,a plate of the metal1 highly polished and then ruled with patterns1 had at the end of a few days imparted a record of every scratch and mark to the plate4 ,and not only will zinc impress itself1 but it affects substances which are not themselves active1 throwing shadowgraphs on to the plate4 ,this was demonstrated with samples of lace1 laid between a plate and a small sheet of bright zinc2 also with a skeleton leaf4 ,it is curious that while the interposition of thin films of celluloid1 gutta-percha1 vegetable parchment1 and gold-beater's skin--all inactive--between the zinc and the plate has no obstructive effect1 a plate of thin glass counteracts the action of the zinc4 ,besides zinc1 nickel1 aluminium1 pewter1 lead1 and tin among the metals influence a sensitised plate4 ,another totally different substance1 printer's ink1 has a similar power2 or at least some printer's ink1 for ,professor ,russell found that different samples varied greatly in their effects4 ,what is especially curious1 the printed matter on both sides of a piece of newspaper appeared on the plate1 and that the effect proceeded from the ink and not from any rays passing from beyond it is proved by the fact that the type came out dark in the development1 whereas if it had been a case of shadowgraphy1 the ink by intercepting rays would have produced white letters4 ,professor ,russell has also shown that modern writing ink is incapable of producing an impression unaided1 but that on the other hand paper written on a hundred years ago or a printed book centuries old will1 with the help of zinc1 yield a picture in which even faded and uncertain characters appear quite distinctly4 ,this opens the way to a practical use of the discovery1 in the deciphering of old and partly obliterated manuscripts4 ,a very interesting experiment may be made with that useful possession--a five-pound note4 ,place the note printed side next to the plate1 and the printing appears dark2 but insert the note between a zinc sheet and the plate1 its back being this time towards the sensitised surface1 and the printing appears white2 and the zinc1 after contact with the printed side1 will itself yield a picture of the inscription as though it had absorbed some virtue from the note6 ,as explanation of this paradoxical dark photography--or whatever it is--two theories may be advanced4 ,the one--favoured by ,professor ,russell--is that all 8active0 substances give off vapours able to act on a photographic plate4 ,in support of this may be urged the fact that the interposition of glass prevents the making of dark pictures4 ,but on the other hand it must be remembered that celluloid and sheet-gelatine1 also air-tight substances1 are able to store up light and to give it out again4 ,it is well known among photographers that to allow sunlight to fall on the inside of a camera is apt to have a 8fogging0 effect on a plate that is exposed in the camera afterwards1 though the greatest care be taken to keep all external light from the plate4 ,but here the glass again presents a difficulty1 for if this were a case of reflected light1 glass would evidently be less obstructive than opaque vegetable parchment or gutta-percha4 ,,solar ,,motors4 ,one day ,george ,stephenson and a friend stood watching a train drawn by one of his locomotives4 8,what moves that train80 asked ,stephenson4 8,the engine10 replied his friend4 8,and what moves the engine80 8,the steam40 8,and what produces the steam80 8,coal40 8,and what produces coal80 ,this last query nonplussed his friend1 and ,stephenson himself replied1 8,the sun40 ,the 8bottled sunshine0 that drove the locomotive was stored up millions of years ago in the dense forests then covering the face of the globe4 ,every day vegetation was built by the sunbeams1 and in the course of ages this growth was crushed into fossil form by the pressure of high-piled rock and dbris4 ,to-day we cast 8black diamonds0 into our grates and furnaces1 to call out the warmth and power that is a legacy from a period long prior to the advent of fire-loving man1 often forgetful of its real source4 ,we see the influence of the sun more directly in the motions of wind and water4 ,had not the sun's action deposited snow and rain on the uplands of the world1 there would be no roaring waterfall1 no rushing torrent1 no smooth-flowing stream4 ,but for the sun heating the atmosphere unequally1 there would not be that rushing of cool air to replace hot which we know as wind4 ,we press ,sol into our service when we burn fuel2 our wind-mills and water-mills make him our slave4 ,of late years many prophets have arisen to warn us that we must not be too lavish of our coal2 that the time is not so far distant1 reckoning by centuries1 when the coal-seams of the world will be worked out and leave our descendants destitute of what plays so important a part in modern life4 ,now1 though waste is unpardonable1 and the care for posterity praiseworthy1 there really seems to be no good reason why we should alarm ourselves about the welfare of the people of the far future4 ,even if coal fails1 the winds and the rivers will be there1 and the huge unharnessed energy of the tides1 and the sun himself is ready to answer appeals for help1 if rightly shaped4 ,he does not demand the prayers of ,persian fire-worshippers1 but rather the scientific gathering of his good gifts4 ,place your hand on a roof lying square to the summer sun1 and you will find it too hot for the touch4 ,concentrate a beam of sunshine through a small burning-glass4 ,how fierce is the small glowing focal spot that makes us draw our hands suddenly away6 ,suppose now a large glass many feet across bending several square yards of sun rays to a point1 and at that point a boiler4 ,the boiler would develop steam1 and the steam might be led into cylinders and forced to drudge for us4 ,do many of us realise the enormous energy of a hot summer's day8 ,the heat falling in the tropics on a single square foot of the earth's surface has been estimated as the equivalent of one-third of a horse-power4 ,the force of ,niagara itself would on this basis be matched by the sunshine streaming on to a square mile or so4 ,a steamship might be propelled by the heat that scorches its decks4 ,for many centuries inventors have tried to utilise this huge waste power4 ,we all know how1 according to the story1 ,archimedes burnt up the ,roman ships besieging his native town1 ,syracuse1 by concentrating on them the sun heat cast from hundreds of mirrors4 ,this story is less probable than interesting as a proof that the ancients were aware of the sun's power4 ,the first genuine solar machine was the work of ,ericsson1 the builder of the ,monitor4 ,he focused sun heat on a boiler1 which gave the equivalent of one horse-power for every hundred square feet of mirrors employed4 ,this was not what engineers would call a 8high efficiency10 a great deal of heat being wasted1 but it led the way to further improvements4 ,in ,america1 especially in the dry1 arid regions1 where fuel is scarce and the sun shines pitilessly day after day1 all the year round1 sun-catchers of various types have been erected and worked successfully4 ,dr4 ,william ,calver1 of ,washington1 has built in the barren wastes of ,arizona huge frames of mirrors1 travelling on circular rails1 so that they may be brought to face the sun at all hours between sunrise and sunset4 ,dr4 ,calver employs no less than #afjj mirrors4 ,as each of these mirrors develops #aj-ae degrees of heat it is obvious1 after an appeal to simple arithmetic1 that the united efforts of these reflectors should produce the tremendous temperature #af1jjj-bd1jjj degrees1 which1 expressed comparatively1 means the paltry #ij degrees in the shade beneath which we grow restive multiplied hundreds of times4 ,hitherto the greatest known heat had been that of the arc of the electric lamp1 in which the incandescent particles between pole and pole attain #fjjj degrees ,fahrenheit4 ,the combined effect of the burning mirrors is irresistible4 ,they can1 we are told1 in a few moments reduce ,russian iron to the consistency of warmed wax1 though it mocks the heat of many blast-furnaces4 ,they will bake bricks twenty times as rapidly as any kiln1 and the bricks produced are not the friable blocks which a mason chips easily with his trowel1 but bodies so hard as to scratch case-hardened steel4 ,there are at work in ,california sun-motors of another design4 ,the reader must imagine a huge conical lamp-shade turned over on to its smaller end1 its inner surface lined with nearly #ahjj mirrors #b feet long and #c inches broad1 the whole supported on a light iron framework1 and he will have a good idea of the apparatus used on the ,pasadena ostrich farm4 ,the machine is arranged in meridian1 that is1 at right angles to the path of the sun1 which it follows all day long by the agency of clockwork4 ,in the focus of the mirrors is a boiler1 #ac feet #f inches long1 coated with black1 heat-absorbing substances4 ,this boiler holds over #ajj gallons of water1 and being fed automatically will raise steam untended all the day through4 ,the steam is led by pipes to an engine working a pump1 capable of delivering #adjj gallons per minute4 ,the cheapness of the apparatus in proportion to its utility is so marked that1 in regions where sunshine is almost perpetual1 the solar motor will in time become as common as are windmills and factory chimneys elsewhere4 ,if the heat falling on a few square yards of mirror lifts nearly #ajj1jjj gallons of water an hour1 there is indeed hope for the ,sahara1 the ,persian ,desert1 ,arabia1 ,mongolia1 ,mexico1 ,australia4 ,that is to say1 if the water under the earth be in these parts as plentiful as the sunshine above it4 ,the effect of water on the most unpromising soil is marvellous4 ,already in ,algeria the ,french have reclaimed thousands of square miles by scientific irrigation4 ,in ,australia huge artesian wells have made habitable for man and beast millions of acres that were before desert4 ,it is only a just retribution that the sun should be harnessed and compelled to draw water for tracts to which he has so long denied it4 ,the sun-motor is only just entering on its useful career1 and at present we can but dream of the great effects it may have on future civilisation4 ,yet its principle is so simple1 so scientific1 and so obvious1 that it is easy to imagine it at no far distant date a dangerous rival to ,king ,coal himself4 ,to quarry coal from the bowels of the earth and transform it into heat1 is to traverse two sides of a triangle1 the third being to use the sunshine of the passing hour4 ,,liquid ,,air4 ,among common phenomena few are more interesting than the changes undergone by the substance called water4 ,its usual form is a liquid4 ,under the influence of frost it becomes hard as iron1 brittle as glass4 ,at the touch of fire it passes into unsubstantial vapour4 ,this transformation illustrates the great principle that the form of every substance in the universe is a question of heat4 ,a metal transported from the earth to the sun would first melt and then vaporise2 while what we here know only as vapours would in the moon turn into liquids4 ,we notice that1 as regards bulk1 the most striking change is from liquid to gaseous form4 ,in steam the atoms and molecules of water are endowed with enormous repulsive vigour4 ,each atom suddenly shows a huge distaste for the company of its neighbours1 drives them off1 and endeavours to occupy the largest possible amount of private space4 ,now1 though we are accustomed to see water-atoms thus stirred into an activity which gives us the giant steam as servant1 it has probably fallen to the lot of but few of us to encounter certain gaseous substances so utterly deprived of their self-assertiveness as to collapse into a liquid mass1 in which shape they are quite strangers to us4 ,what gaseous body do we know better than the air we breathe8 and what should we less expect to be reducible to the consistency of water8 ,yet science has lately brought prominently into notice that strange child of pressure and cold1 ,liquid ,air2 of which great things are prophesied1 and about which many strange facts may be told4 ,very likely our readers have sometimes noticed a porter uncoupling the air-tube between two railway carriages4 ,he first turns off the tap at each end of the tube1 and then by a twist disconnects a joint in the centre4 ,at the moment of disconnection what appears to be a small cloud of steam issues from the joint4 ,this is1 however1 the result of cold1 not heat1 the tube being full of highly-compressed air1 which by its sudden expansion develops cold sufficient to freeze any particles of moisture in the surrounding air4 ,keep this in mind1 and also what happens when you inflate your cycle-tyre4 ,the air-pump grows hotter and hotter as inflation proceeds3 until at last1 if of metal1 it becomes uncomfortably warm4 ,the heat is caused by the forcing together of air-molecules1 and inasmuch as all force produces heat1 your strength is transformed into warmth4 ,in these two operations1 compression and expansion1 we have the key to the creation of liquid air--the great power1 as some say1 of to-morrow4 ,illustration3 ,by kind permission of ,the ,liquid ,air ,co4 ,a view of the ,liquid ,air ,co4's factory at ,pimlico4 ,on the left are the three compressors1 squeezing the air at pressures of #ij1 #ejj and #b1bjj lbs4 to the square inch respectively4 ,on the right is the reservoir in which the liquid is stored4 ,suppose we take a volume of air and squeeze it into #a_/ajj of its original space4 ,the combativeness of the air-atoms is immensely increased4 ,they pound each other frantically1 and become very hot in the process4 ,now1 by cooling the vessel in which they are1 we rob them of their energy4 ,they become quiet1 but they are much closer than before4 ,then imagine that all of a sudden we let them loose again4 ,the life is gone out of them1 their heat has departed1 and on separating they shiver grievously4 ,in other words1 the heat contained by the #a_/ajj volume is suddenly compelled to 8spread itself thin0 over the whole volume3 result--intense cold4 ,and if this air be brought to bear upon a second vessel filled likewise with compressed air1 the cold will be even more intense1 until at last the air-atoms lose all their strength and collapse into a liquid4 ,liquid air is no new thing4 ,who first made it is uncertain4 ,the credit has been claimed for several people1 among them ,olzewski1 a ,pole1 and ,pictet1 a ,swiss4 ,as a mere laboratory experiment the manufacture of liquid air in small quantities has been known for twenty years or more4 ,the earlier process was one of terrific compression alone1 actually forcing the air molecules by sheer strength into such close contact that their antagonism to one another was temporarily overcome4 ,so expensive was the process that the first ounce of liquid air is estimated to have cost over #fjj6 ,in order to make liquid air an article of commerce the most important condition was a wholesale decrease in cost of production4 ,in #aheg ,c4 ,w4 ,siemens took out a patent for making the liquid on what is known as the regenerative principle1 whereby the compressed air is chilled by expanding a part of it4 ,professor ,dewar--a scientist well known for his researches in the field of liquid gases--had in #ahib produced liquid air by a modification of the principle at comparatively small cost2 and other inventors have since then still further reduced the expense1 until at the present day there appears to be a prospect of liquid air becoming cheap enough to prove a dangerous rival to steam and electricity4 ,a company1 known as the ,liquid ,air1 ,power and ,automobile ,company1 has established large plants in ,america and ,england for the manufacture of the liquid on a commercial scale4 ,the writer paid a visit to their depot in ,gillingham ,street1 ,london1 where he was shown the process by ,mr4 ,hans ,knudsen1 the inventor of much of the machinery there used4 ,the reader will doubtless like to learn the 8plain1 unvarnished truth0 about the creation of this peculiar liquid1 and to hear of the freaks in which it indulges--if indeed those may be called freaks which are but obedience to the unchanging laws of ,nature4 ,on entering the factory the first thing that strikes the eye and ear is the monstrous fifty horse-power gas-engine1 pounding away with an energy that shakes the whole building4 ,from its ponderous flywheels great leather belts pass to the compressors1 three in number1 by which the air1 drawn from outside the building through special purifiers1 is subjected to an increasing pressure4 ,three dials on the wall show exactly what is going on inside the compressors4 ,the first stands at #ij lbs4 to the square inch1 the second at #ejj1 and the third at #bbjj1 or rather less than a ton pressure on the area of a penny6 ,the pistons of the low-pressure compressor is ten inches in diameter1 but that of the high pressure only two inches1 or #a_/be of the area1 so great is the resistance to be overcome in the last stage of compression4 ,now1 if the cycle-pump heats our hands1 it will be easily understood that the temperature of the compressors is very high4 ,they are water-jacketed like the cylinders of a gas-engine1 so that a circulating stream of cold water may absorb some of the heat4 ,the compressed air is passed through spiral tubes winding through large tanks of water which fairly boils from the fierceness of the heat of compression4 ,when the air has been sufficiently cooled it is allowed to pass into a small chamber1 expanding as it goes1 and from the small into a larger chamber1 where the cold of expansion becomes so acute that the air-molecules collapse into liquid1 which collects in a special receptacle4 ,arrangements are made whereby any vapour rising from the liquid passes through a space outside the expansion chambers1 so that it helps to cool the incoming air and is not wasted4 ,the liquid-air tank is inside a great wooden case1 carefully protected from the heat of the atmosphere by non-conducting substances4 ,a tap being turned1 a rush of vapour shoots out1 soon followed by a clear1 bluish liquid1 which is the air we breathe in a fresh guise4 ,a quantity of it is collected in a saucepan4 ,it simmers at first1 and presently boils like water on a fire4 ,the air-heat is by comparison so great that the liquid cannot resist it1 and strives to regain its former condition4 ,you may dip your finger into the saucepan--if you withdraw it again quickly--without hurt4 ,the cushion of air that your finger takes in with it protects you against harm--for a moment4 ,but if you held it in the liquid for a couple of seconds you would be minus a digit4 ,pour a little over your coat sleeve4 ,it flows harmlessly to the ground1 where it suddenly expands into a cloud of chilly vapour4 ,put some in a test tube and cork it up4 ,the cork soon flies out with a report--the pressure of the boiling air drives it4 ,now watch the boiling process4 ,the nitrogen being more volatile--as it boils at a lower temperature than oxygen--passes off first1 leaving the pure1 blue oxygen4 ,the temperature of this liquid is over #cab degrees below zero 7as far below the temperature of the air we breathe as the temperature of molten lead is above it674 ,a tumbler of liquid oxygen dipped into water is soon covered with a coating of ice1 which can be detached from the tumbler and itself used as a cup to hold the liquid4 ,if a bit of steel wire be now twisted round a lighted match and the whole dipped into the cup1 the steel flares fiercely and fuses into small pellets2 which means that an operation requiring #cjjj degrees ,fahrenheit has been accomplished in a liquid #cjj degrees below zero6 ,liquid air has curious effects upon certain substances4 ,it makes iron so brittle that a ladle immersed for a few moments may be crushed in the hands2 but1 curiously enough1 it has a toughening effect on copper and brass4 ,meat1 eggs1 fruit1 and all bodies containing water become hard as steel and as breakable as glass4 ,mercury is by it congealed to the consistency of iron2 even alcohol1 that can brave the utmost ,arctic cold1 succumbs to it4 ,the writer was present when some thermometers1 manufactured by ,messrs4 ,negretti and ,zambra1 were tested with liquid air4 ,the spirit in the tubes rapidly descended to #bej degrees below zero1 then sank slowly1 and at about #bfj degrees froze and burst the bulb4 ,the measuring of such extreme temperatures is a very difficult matter in consequence of the inability of spirit to withstand them1 and special apparatus1 registering cold by the shrinkage of metal1 must be used for testing some liquid gases1 notably liquid hydrogen1 which is so much colder than liquid air that it actually freezes it into a solid ice form6 ,for handling and transporting liquid gases glass receptacles with a double skin from which all air has been exhausted are employed4 ,the surrounding vacuum is so perfect an insulator that a 8,dewar bulb0 full of liquid air scarcely cools the hand1 though the intervening space is less than an inch4 ,this fact is hard to square with the assertion of scientific men that our atmosphere extends but a hundred or two miles from the earth's surface1 and that the recesses of space are a vacuum4 ,if it were so1 how would heat reach us from the sun1 ninety-two millions of miles away8 ,one use at least for liquid air is sufficiently obvious4 ,as a refrigerating agent it is unequalled4 ,bulk for bulk its effect is of course far greater than that of ice2 and it has this advantage over other freezing compounds1 that whereas slow freezing has a destructive effect upon the tissues of meat and fruit1 the instantaneous action of liquid air has no bad results when the thing frozen is thawed out again4 ,the ,liquid ,air ,company therefore proposes erecting depts at large ports for supplying ships1 to preserve the food1 cool the cabins in the tropics1 and1 we hope1 to alleviate some of the horrors of the stokehold4 ,liquid air is already used in medical and surgical science4 ,in surgery it is substituted for ansthetics1 deadening any part of the body on which an operation has to be performed4 ,in fever hospitals1 too1 its cooling influence will be welcomed2 and liquid oxygen takes the places of compressed oxygen for reviving the flickering flame of life4 ,it will also prove invaluable for divers and submarine boats4 ,in combination with oil and charcoal liquid air1 under the name of 8oxyliquit10 becomes a powerful blasting agent4 ,cartridges of paper filled with the oil and charcoal are provided with a firing primer4 ,when everything is ready for the blasting the cartridges are dropped into a vessel full of liquid air1 saturated1 placed in position1 and exploded4 ,mr4 ,knudsen assured the writer that oxyliquit is twice as powerful as nitro-glycerine1 and its cost but one-third of that of the other explosive4 ,it is also safer to handle1 for in case of a misfire the cartridge becomes harmless in a few minutes1 after the liquid air has evaporated4 ,but the greatest use will be found for liquid air when it exerts its force less violently4 ,it is the result of power2 its condition is abnormal2 and its return to its ordinary state is accompanied by a great development of energy4 ,if it be placed in a closed vessel it is capable of exerting a pressure of #ab1jjj lbs4 to the square inch4 ,its return to atmospheric condition may be regulated by exposing it more or less to the heat of the atmosphere4 ,so long as it remains liquid it represents so much stored force1 like the electricity stored in accumulators4 ,the ,liquid ,air ,company have at their ,gillingham ,street dept a neat little motor car worked by liquid air4 ,a copper reservoir1 carefully protected1 is filled with the liquid1 which is by mechanical means squirted into coils1 in which it rapidly expands1 and from them passes to the cylinders4 ,a charge of eighteen gallons will move the car forty miles at an average pace of twelve miles an hour1 without any of the noise1 dirt1 smell1 or vapour inseparable from the employment of steam or petroleum4 ,the speed of the car is regulated by the amount of liquid injected into the expansion coils4 ,we now come to the question of cost--the unromantic balance in which new discoveries are weighed and many found wanting4 ,the storage of liquid air is feasible for long periods4 7,a large vacuum bulb filled and exposed to the atmosphere had some of the liquid still unevaporated at the end of twenty-two days47 ,but will it be too costly for ordinary practical purposes now served by steam and electricity8 ,the managers of the ,liquid ,air ,company1 while deprecating extravagant prophecies about the future of their commodity1 are nevertheless confident that it has 8come to stay40 ,with the small #ej horse-power plant its production costs upwards of one shilling a gallon1 but with much larger plant of #ajjj horse-power they calculate that the expenses will be covered and a profit left if they retail it at but one penny the gallon4 ,this great reduction in cost arises from the economising of 8waste energy40 ,in the first place the power of expansion previous to the liquefaction of the compressed air will be utilised to work motors4 ,secondly1 the heat of the cooling tanks will be turned to account1 and even the 8exhaust0 of a motor would be cold enough for ordinary refrigerating4 ,it is1 of course1 impossible to get more out of a thing than has been put into it2 and liquid air will therefore not develop even as much power as was required to form it4 ,but its handiness and cleanliness strongly recommend it for many purposes1 as we have seen2 and as soon as it is turned out in large quantities new uses will be found for it4 ,perhaps the day will come when liquid-air motors will replace the petrol car1 and in every village we shall see hung out the sign1 8,liquid air sold here40 ,as the ,french say1 8,qui vivra verra40 ,,horseless ,,carriages4 ,a body of enterprising ,manchester merchants1 in the year #aged1 put on the road a 8flying coach10 which1 according to their special advertisement1 would1 8however incredible it may appear1 actually1 barring accidents1 arrive in ,london in four and a half days after leaving ,manchester40 ,according to the ,lord ,chancellor of the time such swift travelling was considered dangerous as well as wonderful--the condition of the roads might well make it so--and also injurious to health4 8,i was gravely advised10 he says1 8to stay a day in ,york on my journey between ,edinburgh and ,london1 as several passengers who had gone through without stopping had died of apoplexy from the rapidity of the motion40 ,as the coach took a fortnight to pass from the ,scotch to the ,english capital1 at an average pace of between three and four miles an hour1 it is probable that the ,chancellor's advisers would be very seriously indisposed by the mere sight of a motor-car whirling along in its attendant cloud of dust1 could they be resuscitated for the purpose4 ,and we1 on the other hand1 should prefer to get out and walk to 8flying0 at the safe speed of their mail coaches4 ,illustration3 ,by kind permission of ,the ,speedwell ,motor ,co4 ,m4 ,serpollet on the 8,easter ,egg10 which at ,nice covered a kilometre in the record time of #bi-d_/e secs4 7over #ge miles per hour74 ,this car is run with steam4 ,the improvement of highroads1 and road-making generally1 accelerated the rate of posting4 ,in the first quarter of the nineteenth century an average of ten or even twelve miles an hour was maintained on the ,bath ,road4 ,but that pace was considered inadequate when the era of the 8iron horse0 commenced1 and the decay of stage-driving followed hard upon the growth of railways4 ,what should have been the natural successor of the stage-coach was driven from the road by ill-advised legislation1 which gave the railroads a monopoly of swift transport1 which has but lately been removed4 ,the history of the steam-coach1 steam-carriage1 automobile1 motor-car--to give it its successive names--is in a manner unique1 showing as it does1 instead of steady development of a practical means of locomotion1 a sudden and decisive check to an invention worthy of far better treatment than it received4 ,the compiler of even a short survey of the automobile's career is obliged to divide his account into two main portions1 linked together by a few solitary engineering achievements4 ,the first period 7#ahjj-ahcf71 will1 without any desire to arrogate for ,england more than her due or to belittle the efforts of any other nations1 be termed the ,english period1 since in it ,england took the lead1 and produced by far the greatest number of steam-carriages4 ,the second 7#ahgj to the present day7 may1 with equal justice1 be styled the ,continental period1 as witnessing the great developments made in automobilism by ,french1 ,german1 ,belgian1 and ,american engineers3 ,england1 for reasons that will be presently noticed1 being until quite recently too heavily handicapped to take a part in the advance4 ,historical4--,it is impossible to discover who made the first self-moving carriage4 ,in the sixteenth century one ,johann ,haustach1 a ,nuremberg watchmaker1 produced a vehicle that derived its motive power from coiled springs1 and was in fact a large edition of our modern clockwork toys4 ,about the same time the ,dutch1 and among them especially one ,simon ,stevin1 fitted carriages with sails1 and there are records of a steam-carriage as early as the same century4 ,but the first practical1 and at least semi-successful1 automobile driven by internal force was undoubtedly that of a ,frenchman1 ,nicholas ,joseph ,cugnot1 who justly merits the title of father of automobilism4 ,his machine1 which is to-day one of the most treasured exhibits in the ,paris ,museum of ,arts and ,crafts1 consisted of a large carriage1 having in front a pivoted platform bearing the machinery1 and resting on a solid wheel1 which propelled as well as steered the vehicle4 ,the boiler1 of stout riveted copper plates1 had below it an enclosed furnace1 from which the flames passed upwards through the water through a funnel4 ,a couple of cylinders1 provided with a simple reversing gear1 worked a ratchet that communicated motion to the driving-wheel4 ,this carriage did not travel beyond a very slow walking pace1 and ,cugnot therefore added certain improvements1 after which 7#aggj7 it reached the still very moderate speed of four miles an hour1 and distinguished itself by charging and knocking down a wall1 a feat that is said to have for a time deterred engineers from developing a seemingly dangerous mode of progression4 ,ten years later ,dallery built a steam car1 and ran it in the streets of ,amiens--we are not told with what success2 and before any further advance had been made with the automobile the ,french ,revolution put a stop to all inventions of a peaceful character among our neighbours4 ,in ,england1 however1 steam had already been recognised as the coming power4 ,richard ,trevethick1 afterwards to become famous as a railroad engineer1 built a steam motor in #ahjb1 and actually drove it from ,cambourne to ,plymouth1 a distance of ninety miles4 ,but instead of following up this success1 he forsook steam-carriages for the construction of locomotives1 leaving his idea to be expanded by other men1 who were convinced that a vehicle which could be driven over existing roads was preferable to one that was helpless when separated from smooth metal rails4 ,between the years #ahjj and #ahcf many steam vehicles for road traffic appeared from time to time1 some1 such as ,david ,gordon's 7propelled by metal legs pressing upon the ground71 strangely unpractical1 but the majority showing a steady improvement in mechanical design4 ,as it will be impossible1 without writing a small book1 to name all the ,english constructors of this period1 we must rest content with the mention of the leading pioneers of the new locomotion4 ,sir ,goldsworthy ,gurney1 an eminent chemist1 did for mechanical road propulsion what ,george ,stephenson was doing for railway development4 ,he boldly spent large sums on experimental vehicles1 which took the form of six-wheeled coaches4 ,the earliest of these were fitted with legs as well as driving-wheels1 since he thought that in difficult country wheels alone would not have sufficient grip4 7,a similar fallacy was responsible for the cogged wheels on the first railways47 ,but in the later types legs were abandoned as unnecessary4 ,his coaches easily climbed the steepest hills round ,london1 including ,highgate ,hill1 though a thoughtful mathematician had proved by calculations that a steam-carriage1 so far from mounting a gradient1 could not1 without violating all natural laws1 so much as move itself on the level6 ,having satisfied himself of their power1 ,gurney took his coaches further afield4 ,in #ahbi was published the first account of a motor trip made by him and three companions through ,reading1 ,devizes1 and ,melksham4 ,the pace was1 we read1 at first only about six miles an hour1 including stoppages4 ,they drove very carefully to avoid injury to the persons or feelings of the country folk2 but at ,melksham1 where a fair was in progress1 they had to face a shower of stones1 hurled by a crowd of roughs at the instigation of some coaching postilions1 who feared losing their livelihood if the new method of locomotion became general4 ,two of the tourists were severely hurt1 and ,gurney was obliged to take shelter in a brewery1 where constables guarded his coach4 ,on the return journey the party timed their movements so as to pass through ,melksham while the inhabitants were all safely in bed4 ,the coach ran most satisfactorily1 improving every mile4 8,our pace was so rapid10 wrote one of the company1 8that the horses of the mail-cart which accompanied us were hard put to it to keep up with us4 ,at the foot of ,devizes ,hill we met a coach and another vehicle1 which stopped to see us mount this hill1 an extremely steep one4 ,we ascended it at a rapid rate4 ,the coach and passengers1 delighted at this unexpected sight1 honoured us with shouts of applause40 ,in #ahcj ,messrs4 ,ogle and ,summers completely beat the road record on a vehicle fitted with a tubular boiler4 ,this car1 put through its trials before a ,special ,commission of the ,house of ,commons1 attained the astonishing speed of #ce miles an hour on the level1 and mounted a hill near ,southampton at #bd-a_/b miles an hour4 ,it worked at a boiler pressure of #bej lbs4 to the square inch1 and though not hung on springs1 ran #hjj miles without a breakdown4 ,this performance appears all the more extraordinary when we remember the roads of that day were not generally as good as they are now1 and that in the previous year ,stephenson's 8,rocket10 running on rails1 had not reached a higher velocity4 ,the report of the ,parliamentary ,commission on horseless carriages was most favourable4 ,it urged that the steam-driven car was swifter and lighter than the mail-coaches2 better able to climb and descend hills2 safer2 more economical2 and less injurious to the roads2 and1 in conclusion1 that the heavy charges levied at the toll-gates 7often twenty times those on horse vehicles7 were nothing short of iniquitous4 ,as a result of this report1 motor services1 inaugurated by ,walter ,hancock1 ,braithwayte1 and others1 commenced between ,paddington and the ,bank1 ,london and ,greenwich1 ,london and ,windsor1 ,london and ,stratford4 ,already1 in #ahbi1 ,sir ,charles ,dance had a steam-coach running between ,cheltenham and ,gloucester4 ,in four months it ran #cejj miles and carried #cjjj passengers1 traversing the nine miles in three-quarters of an hour2 although narrow-minded landowners placed ridges of stone eighteen inches deep on the road by way of protest4 ,the most ambitious service of all was that between ,london and ,birmingham1 established in #ahcc by ,dr4 ,church4 ,the rolling-stock consisted of a single very much decorated coach4 ,the success of the road-steamer seemed now assured1 when a cloud appeared on the horizon4 ,it had already been too successful4 ,the railway companies were up in arms4 ,they saw plainly that if once the roads were covered with vehicles able to transport the public at low fares quickly from door to door on existing thoroughfares1 the construction of expensive railroads would be seriously hindered1 if not altogether stopped4 ,so1 taking advantage of two motor accidents1 the companies appealed to ,parliament--full of horse-loving squires and manufacturers1 who scented profit in the railways--and though scientific opinion ran strongly in favour of the steam-coach1 a law was passed in #ahcf which rendered the steamers harmless by robbing them of their speed4 ,the fiat went forth that in future every road locomotive should be preceded at a distance of a hundred yards by a man on foot carrying a red flag to warn passengers of its approach4 ,this law marks the end of the first period of automobilism as far as ,england is concerned4 ,at one blow it crippled a great industry1 deprived the community of a very valuable means of transport1 and crushed the energies of many clever inventors who would soon1 if we may judge by the rapid advances already made in construction1 have brought the steam-carriage to a high pitch of perfection4 ,in the very year in which they were suppressed the steam services had proved their efficiency and safety4 ,hancock's ,london service alone traversed #dbjj miles without serious accident1 and was so popular that the coaches were generally crowded4 ,it is therefore hard to believe that these vehicles did not supply a public want1 or that they were regarded by those who used them as in any way inferior to horse-drawn coaches4 ,yet ignorant prejudice drove them off the road for sixty years2 and to-day it surprises many ,englishmen to learn that what is generally considered a novel method of travelling was already fairly well developed in the time of their grandfathers4 ,second ,period 7#ahgj onwards74--,to follow the further development of the automobile we must cross the ,channel once again4 ,french invention had not been idle while ,gurney and ,hancock were building their coaches4 ,in #ahce ,m4 ,dietz established a service between ,versailles and ,paris1 and the same year ,m4 ,d',asda carried out some successful trials of his steam 8diligence0 under the eyes of ,royalty4 ,but we find that for the next thirty-five years the steam-carriage was not much improved1 owing to want of capital among its ,french admirers4 ,no ,gurney appeared1 ready to spend his thousands in experimenting2 also1 though the law left road locomotion unrestricted1 the railways offered a determined opposition to a possibly dangerous rival4 ,so that1 on the whole1 road transport by steam fared badly till after the terrible ,franco-,prussian war1 when inventors again took courage4 ,m4 ,bolle1 of ,mans1 built in #ahgc a car1 8l',obissante10 which ran from ,mans to ,paris2 and became the subject of allusions in popular songs and plays1 while its name was held up as an example to the ,paris ladies4 ,three years later he constructed a steam omnibus to carry fifty persons1 and in #ahgh exhibited a car that journeyed at the rate of eighteen miles an hour from ,paris to ,vienna1 where it aroused great admiration4 ,after the year #ahhj ,french engineers divided their attention between the heavy motor omnibus and light vehicles for pleasure parties4 ,in #ahhd ,,mm4 ,bouton and ,trpardoux1 working conjointly with the ,comte de ,dion1 produced a steam-driven tricycle1 and in #ahhg ,m4 ,serpollet followed suit with another1 fitted with the peculiar form of steam generator that bears his name4 ,then came in #ahij a very important innovation1 which has made automobilism what it now is4 ,gottlieb ,daimler1 a ,german engineer1 introduced the petrol gas-motor4 ,its comparative lightness and simplicity at once stamped it as the thing for which makers were waiting4 ,petrol-driven vehicles were soon abroad in considerable numbers and varieties1 but they did not attract public attention to any great extent until1 in #ahid1 ,m4 ,pierre ,giffard1 an editor of the ,petit ,journal1 organised a motor race from ,paris to ,rouen4 ,the proprietors of the paper offered handsome prizes to the successful competitors4 ,there were ten starters1 some on steam1 others on petrol cars4 ,the race showed that1 so far as stability went1 ,daimler's engine was the equal of the steam cylinder4 ,the next year another race of a more ambitious character was held1 the course being from ,paris to ,bordeaux and back4 ,subscriptions for prizes flowed in freely4 ,serpollet1 de ,dion1 and ,bolle prepared steam cars that should win back for steam its lost supremacy1 while the petrol faction secretly built motors of a strength to relegate steam once and for all to a back place4 ,electricity1 too1 made a bid unsuccessfully for the prize in the ,jeantaud car1 a special train being engaged in advance to distribute charged accumulators over the route4 ,the steamers broke down soon after the start1 so that the petrol cars 8walked over0 and won a most decisive victory4 ,the interest roused in the race led the ,comte de ,dion to found the ,automobile ,club of ,france1 which drew together all the enthusiastic admirers of the new locomotion4 ,automobilism now became a sport1 a craze4 ,the ,french1 with their fine straight roads1 and a not too deeply ingrained love of horseflesh1 gladly welcomed the flying car1 despite its noisy and malodorous properties4 ,orders flowed in so freely that the motor makers could not keep pace with the demand1 or promise delivery within eighteen months4 ,rich men were therefore obliged to pay double prices if they could find any one willing to sell--a state of things that remains unto this day with certain makes of ,french cars4 ,poorer folks contented themselves with ,de ,dion motor tricycles1 which showed up so well in the #ahif ,paris-,marseilles race2 or with the neat little three-wheeled cars of ,m4 ,bolle4 ,motor racing became the topic of the hour4 ,journals were started for the sole purpose of recording the doings of motorists2 and few newspapers of any popularity omitted a special column of motor news4 ,successive contests on the highroads at increasing speeds attracted increased interest4 ,the black-goggled1 fur-clad chauffeur who carried off the prizes found himself a hero4 ,in short1 the hold which automobilism has over our neighbours may be gauged from the fact that in #aija it was estimated that nearly a thousand motor cars assembled to see the sport on the ,longchamps ,course 7the scene of that ultra-8horsey0 event1 the ,grand ,prix71 and the real interest of the meet did not centre round horses of flesh and blood4 ,the ,french have not a monopoly of devotion to automobilism4 ,the speedy motor car is too much in accord with the bustling spirit of the age2 its delights too easily appreciated to be confined to one country4 ,allowing ,france the first place1 ,america1 ,germany1 and ,belgium are not far behind in their addiction to the 8sport10 and even in ,britain1 partially freed since #ahif from the red-flag tyranny1 thanks to the efforts of ,sir ,david ,salomons1 there are most visible signs that the era of the horse is beginning its end4 ,,types ,,of ,,car4 ,automobiles may be classified according to the purpose they serve1 according to their size and weight1 or according to their motive power4 ,we will first review them under the latter head4 ,a4 ,petrol4--,the petrol motor1 suitable alike for large cars of #dj to #fj horse-power and for the small bicycle weighing #gj lbs4 or so1 at present undoubtedly occupies the first place in popular estimation on account of its comparative simplicity1 which more than compensates certain defects that affect persons off the vehicle more than those on it--smell and noise4 ,the chief feature of the internal explosion motor is that at one operation it converts fuel directly into energy1 by exploding it inside a cylinder4 ,it is herein more economical than steam1 which loses power while passing from the boiler to the driving-gear4 ,petrol cycles and small cars have usually only one cylinder1 but large vehicles carry two1 three1 and sometimes four cylinders4 ,four and more avoid that bugbear of rotary motion1 8dead points10 during which the momentum of the machinery alone is doing work2 and for that reason the engines of racing cars are often quadrupled4 ,for the sake of simplicity we will describe the working of a single cylinder1 leaving the reader to imagine it acting alone or in concert with others as he pleases4 ,in the first place the fuel1 petrol1 is a very inflammable distillation of petroleum3 so ready to ignite that it must be most rigorously guarded from naked lights2 so quick to evaporate that the receptacles containing it1 if not quite airtight1 will soon render it 8stale0 and unprofitable for motor driving4 ,the engine1 to mention its most important parts1 consists of a single-action cylinder 7giving a thrust one way only72 a heavy flywheel revolving in an airtight circular case1 and connected to the piston by a hinged rod which converts the reciprocating movement of the piston into a rotary movement of the crank-shaft built in with the wheel2 inlet and outlet valves2 a carburettor for generating petrol gas1 and a device to ignite the gas-and-air mixture in the cylinder4 ,the action of the engine is as follows3 as the piston moves outwards in its first stroke it sucks through the inlet valve a quantity of mixed air and gas1 the proportions of which are regulated by special taps4 ,the stroke ended1 the piston returns1 compressing the mixture and rendering it more combustible4 ,just as the piston commences its second outward stroke an electric spark passed through the mixture mechanically ignites it1 and creates an explosion1 which drives the piston violently forwards4 ,the second return forces the burnt gas through the exhaust-valve1 which is lifted by cog-gear once in every two revolutions of the crank1 into the 8silencer40 ,the cycle of operations is then repeated4 ,we see that during three-quarters of the 8cycle0--the suction1 compression1 and expulsion--the work is performed entirely by the flywheel4 ,it follows that a single-cylinder motor1 to work at all1 must rotate the wheel at a high rate4 ,once stopped1 it can be restarted only by the action of the handle or pedals2 a task often so unpleasant and laborious that the driver of a car1 when he comes to rest for a short time only1 disconnects his motor from the driving-gear and lets it throb away idly beneath him4 ,the means of igniting the gas in the cylinders may be either a ,bunsen burner or an electric spark4 ,tube ignition is generally considered inferior to electrical because it does not permit 8timing0 of the explosion4 ,large cars are often fitted with both systems1 so as to have one in reserve should the other break down4 ,electrical ignition is most commonly produced by the aid of an intensity coil1 which consists of an inner core of coarse insulated wire1 called the primary coil2 and an outer1 or secondary coil1 of very fine wire4 ,a current passes at intervals1 timed by a cam on the exhaust-valve gear working a make-and-break contact blade1 from an accumulator through the primary coil1 exciting by induction a current of much greater intensity in the secondary4 ,the secondary is connected to a 8sparking plug10 which screws into the end of the cylinder1 and carries two platinum points about #a_/cb of an inch apart4 ,the secondary current leaps this little gap in the circuit1 and the spark1 being intensely hot1 fires the compressed gas4 ,instead of accumulators a small dynamo1 driven by the motor1 is sometimes used to produce the primary current4 ,by moving a small lever1 known as the 8advancing lever10 the driver can control the time of explosion relatively to the compression of the gas1 and raise or lower the speed of the motor4 ,the strokes of the petrol-driven cylinder are very rapid1 varying from #ajjj to #cjjj a minute4 ,the heat of very frequent explosions would soon make the cylinder too hot to work were not measures adopted to keep it cool4 ,small cylinders1 such as are carried on motor cycles1 are sufficiently cooled by a number of radiating ribs cast in a piece with the cylinder itself2 but for large machines a water jacket or tank surrounding the cylinder is a necessity4 ,water is circulated through the jacket by means of a small centrifugal pump working off the driving gear1 and through a coil of pipes fixed in the front of the car to catch the draught of progression4 ,so long as the jacket and tubes are full of water the temperature of the cylinder cannot rise above boiling point4 ,motion is transmitted from the motor to the driving-wheels by intermediate gear1 which in cycles may be only a leather band or couple of cogs1 but in cars is more or less complicated4 ,under the body of the car1 running usually across it1 is the countershaft1 fitted at each end with a small cog which drives a chain passing also over much larger cogs fixed to the driving-wheels4 ,the countershaft engages with the cylinder mechanism by a 8friction-clutch10 a couple of circular faces which can be pressed against one another by a lever4 ,to start his car the driver allows the motor to obtain a considerable momentum1 and then1 using the friction lever1 brings more and more stress on to the countershaft until the friction-clutch overcomes the inertia of the car and produces movement4 ,gearing suitable for level stretches would not be sufficiently powerful for hills3 the motor would slow and probably stop from want of momentum4 ,a car is therefore fitted with changing gears1 which give two or three speeds1 the lower for ascents1 the higher for the level3 and on declines the friction-clutch can be released1 allowing the car to 8coast40 ,b4 ,steam ,cars4--,though the petrol car has come to the front of late years it still has a powerful rival in the steam car4 ,inventors have made strenuous efforts to provide steam-engines light enough to be suitable for small pleasure cars4 ,at present the ,locomobile 7,american7 and ,serpollet 7,french7 systems are increasing their popularity4 ,the ,locomobile1 the cost of which 7about #abj7 contrasts favourably with that of even the cheaper petrol cars1 has a small multitubular boiler wound on the outside with two or three layers of piano wire1 to render it safe at high pressures4 ,as the boiler is placed under the seat it is only fit and proper that it should have a large margin of safety4 ,the fuel1 petrol1 is passed through a specially designed burner1 pierced with hundreds of fine holes arranged in circles round air inlets4 ,the feed-supply to the burner is governed by a spring valve1 which cuts off the petrol automatically as soon as the steam in the boiler reaches a certain pressure4 ,the locomobile runs very evenly and smoothly1 and with very little noise1 a welcome change after the very audible explosion motor4 ,the ,serpollet system is a peculiar method of generating steam4 ,the boiler is merely a long coil of tubing1 into which a small jet of water is squirted by a pump at every stroke of the cylinders4 ,the steam is generated and used in a moment1 and the speed of the machine is regulated by the amount of water thrown by the pumps4 ,by an ingenious device the fuel supply is controlled in combination with the water supply1 so that there may not be any undue waste in the burner4 ,c4 ,electricity4--,of electric cars there are many patterns1 but at present they are not commercially so practical as the other two types4 ,the great drawbacks to electrically-driven cars are the weight of the accumulators 7which often scale nearly as much as all the rest of the vehicle71 and the difficulty of getting them recharged when exhausted4 ,we might add to these the rapidity with which the accumulators become worn out1 and the consequent expense of renewal4 ,t4 ,a4 ,edison is reported at work on an accumulator which will surpass all hitherto constructed1 having a much longer life1 and weighing very much less1 power for power4 ,the longest continuous run ever made with electricity1 #ahg miles at ,chicago1 compares badly with the feat of a petrol car which on ,november #bc1 #aijj1 travelled a thousand miles on the ,crystal ,palace track in #dh hours #bd minutes1 without a single stop4 ,successful attempts have been made by ,,mm4 ,pieper and ,jenatsky to combine the petrol and electric systems1 by an arrangement which instead of wasting power in the cylinders when less speed is required1 throws into action electric dynamos to store up energy1 convertible1 when needed1 into motive power by reversing the dynamo into a motor4 ,but the simple electric car will not be a universal favourite until either accumulators are so light that a very large store of electricity can be carried without inconvenient addition of weight1 or until charging stations are erected all over the country at distances of fifty miles or so apart4 ,whether steam will eventually get the upper hand of the petrol engine is at present uncertain4 ,the steam car has the advantage over the gas-engine car in ease of starting1 the delicate regulation of power1 facility of reversing1 absence of vibration1 noise and smell1 and freedom from complicated gears4 ,on the other hand the petrol car has no boiler to get out of order or burst1 no troublesome gauges requiring constant attention1 and there is small difficulty about a supply of fuel4 ,petrol sufficient to give motive power for hundreds of miles can be carried if need be2 and as long as there is petrol on board the car is ready for work at a moment's notice4 ,judging by the number of the various types of vehicles actually at work we should say that while steam is best for heavy traction1 the gas-engine is most often employed on pleasure cars4 ,illustration3 ,by kind permission of ,the ,liquid ,air ,co4 ,this graceful little motor-car is driven by ,liquid ,air4 ,it makes absolutely no smell or noise4 ,d4 ,liquid ,air will also have to be reckoned with as a motive power4 ,at present it is only on its probation2 but the writer has good authority for stating that before these words appear in print there will be on the roads a car driven by liquid air1 and able to turn off eighty miles in the hour4 ,manufacture4--,as the ,english were the pioneers of the steam car1 so are the ,germans and ,french the chief manufacturers of the petrol car4 ,while the hands of ,english manufacturers were tied by shortsighted legislation1 continental nations were inventing and controlling valuable patents1 so that even now our manufacturers are greatly handicapped4 ,large numbers of petrol cars are imported annually from ,france1 ,germany1 and ,belgium4 ,steam cars come chiefly from ,america and ,france4 ,the former country sent us nearly #bjjj vehicles in #aija4 ,there are signs1 however1 that ,english engineers mean to make a determined effort to recover lost ground2 and it is satisfactory to learn that in heavy steam vehicles1 such as are turned out by ,thorneycroft and ,co41 this country holds the lead4 ,we will hope that in a few years we shall be exporters in turn4 ,having glanced at the history and nature of the various types of car1 it will be interesting to turn to a consideration of their travelling capacities4 ,as we have seen1 a steam omnibus attained1 in #ahcj1 a speed of no less than thirty-five miles an hour on what we should call bad roads4 ,it is therefore to be expected that on good modern roads the latest types of car would be able to eclipse the records of seventy years ago4 ,that such has indeed been the case is evident when we examine the performances of cars in races organised as tests of speed4 ,france1 with its straight1 beautifully-kept1 military roads1 is the country par excellence for the chauffeur4 ,one has only to glance at the map to see how the main highways conform to ,euclid's dictum that a straight line is the shortest distance between any two points1 e4g4 between ,rouen and ,dieppe1 where a park of artillery1 well posted1 could rake the road either way for miles4 ,the growth of speed in the ,french races is remarkable4 ,in #ahid the winning car ran at a mean velocity of thirteen miles an hour2 in #ahie1 of fifteen4 ,the year #ahih witnessed a great advance to twenty-three miles1 and the next year to thirty miles4 ,but all these speeds paled before that of the ,paris to ,bordeaux race of #aija1 in which the winner1 ,m4 ,fournier1 traversed the distance of #cbg-a_/b miles at a rate of #ec-c_/d miles per hour6 ,the famous ,sud express1 running between the same cities1 and considered the fastest long-distance express in the world1 was beaten by a full hour4 ,it is interesting to note that in the same races a motor bicycle1 a ,werner1 weighing #hj lbs4 or less1 successfully accomplished the course at an average rate of nearly thirty miles an hour4 ,the motor-car1 after waiting seventy years1 had had its revenge on the railways4 ,this was not the only occasion on which an express service showed up badly against its nimble rival of the roads4 ,in ,june1 #aija1 the ,french and ,german authorities forgot old animosities in a common enthusiasm for the automobile1 and organised a race between ,paris and ,berlin4 ,it was to be a big affair1 in which the cars of all nations should fight for the speed championship4 ,every possible precaution was taken to insure the safety of the competitors and the spectators4 ,flags of various colours and placards marked out the course1 which lay through ,rheims1 ,luxembourg1 ,coblentz1 ,frankfurt1 ,eisenach1 ,leipsic1 and ,potsdam to the ,german capital4 ,about fifty towns and large villages were 8neutralised0--that is to say1 the competitors had to consume a certain time in traversing them4 ,at the entrance to each neutralised zone a 8control0 was established4 ,as soon as a competitor arrived1 he must slow down1 and a card on which was written the time of his arrival was handed to a 8pilot10 who cycled in front of the car to the other 8control0 at the farther end of the zone1 from which1 when the proper time had elapsed1 the car was dismissed4 ,among other rules were3 that no car should be pushed or pulled during the race by any one else than the passengers2 that at the end of the day only a certain time should be allowed for cleaning and repairs2 and that a limited number of persons1 varying with the size of the car1 should be permitted to handle it during that period4 ,a small army of automobile club representatives1 besides thousands of police and soldiers1 were distributed along the course to restrain the crowds of spectators4 ,it was absolutely imperative that for vehicles propelled at a rate of from #ej to #fj miles an hour a clear path should be kept4 ,at dawn1 on ,july #bgth1 #aji racing machines assembled at the ,fort de ,champigny1 outside ,paris1 in readiness to start for ,berlin4 ,just before half-past three1 the first competitor received the signal2 two minutes later the second2 and then at short intervals for three hours the remaining #ajg1 among whom was one lady1 ,mme4 de ,gast4 ,at least #bj1jjj persons were present1 even at that early hour1 to give the racers a hearty farewell1 and demonstrate the interest attaching in ,france to all things connected with automobilism4 ,great excitement prevailed in ,paris during the three days of the race4 ,every few minutes telegrams arrived from posts on the route telling how the competitors fared4 ,the news showed that during the first stage at least a hard fight for the leading place was in progress4 ,the ,french cracks1 ,fournier1 ,charron1 ,de ,knyff1 ,farman1 and ,girardot pressed hard on ,hourgires1 ,no4 #b at the starting-point4 ,fournier soon secured the lead1 and those who remembered his remarkable driving in the ,paris-,bordeaux race at once selected him as the winner4 ,aix-la-,chapelle1 #bhc miles from ,paris and the end of the first stage1 was reached in #f hours #bh minutes4 ,fournier first1 ,de ,knyff second by six minutes4 ,illustration3 ,by kind permission of ,the ,liquid ,air ,co4 ,diagram of the ,liquid ,air ,motor-,car1 showing ,a1 reservoir of liquid air2 ,b1 pipes in which the liquid is transformed into atmospheric air under great pressure2 ,c1 cylinders for driving the rear wheels by means of chain-gear4 ,on the #bhth the racing became furious4 ,several accidents occurred4 ,edge1 driving the only ,english car1 wrecked his machine on a culvert1 the sharp curve of which flung the car into the air and broke its springs4 ,another ruined his chances by running over and killing a boy4 ,but ,fournier1 ,antony1 ,de ,knyff1 and ,girardot managed to avoid mishaps for that day1 and covered the ground at a tremendous pace4 ,at ,dsseldorf ,girardot won the lead from ,fournier1 to lose it again shortly4 ,antony1 driving at a reckless speed1 gained ground all day1 and arrived a close second at ,hanover1 the halting-place1 after a run averaging1 in spite of bad roads and dangerous corners1 no less than #ed miles an hour6 ,the chauffeur in such a race must indeed be a man of iron nerves4 ,through the great black goggles which shelter his face from the dust-laden hurricane set up by the speed he travels at he must keep a perpetual1 piercingly keen watch4 ,though travelling at express speed1 there are no signals to help him2 he must be his own signalman as well as driver4 ,he must mark every loose stone on the road1 every inequality1 every sudden rise or depression2 he must calculate the curves at the corners and judge whether his mechanician1 hanging out on the inward side1 will enable a car to round a turn without slackening speed4 ,his calculations and decisions must be made in the fraction of a second1 for a moment's hesitation might be disaster4 ,his driving must be furious and not reckless2 the timid chauffeur will never win1 the careless one will probably lose4 ,his head must be cool although the car leaps beneath him like a wild thing1 and the wind lashes his face4 ,at least one well-tried driver found the mere mental strain too great to bear1 and retired from the contest2 and we may be sure that few of the competitors slept much during the nights of the race4 ,at four o'clock on the #bith ,fournier started on the third stage1 which witnessed another bout of fast travelling4 ,it was now a struggle between him and ,antony for first place4 ,the pace rose at times to eighty miles an hour1 a speed at which our fastest expresses seldom travel4 ,such a speed means huge risks1 for stopping1 even with the powerful brakes fitted to the large cars1 would be a matter of a hundred yards or more4 ,not far from ,hanover ,antony met with an accident--,girardot now held second place2 and ,fournier finished an easy first4 ,all along the route crowds had cheered him1 and hurled bouquets into the car1 and wished him good speed2 but in ,berlin the assembled populace went nearly frantic at his appearance4 ,fournier was overwhelmed with flowers1 laurel wreaths1 and other offerings2 dukes1 duchesses1 and the great people of the land pressed for presentations2 he was the hero of the hour4 ,thus ended what may be termed a peaceful invasion of ,germany by the ,french4 ,among other things it had shown that over an immense stretch of country1 over roads in places bad as only ,german roads can be1 the automobile was able to maintain an average speed superior to that of the express trains running between ,paris and ,berlin2 also that1 in spite of the large number of cars employed in the race1 the accidents to the public were a negligible quantity4 ,it should be mentioned that the actual time occupied by ,fournier was #af hours #e minutes2 that out of the #aji starters #dg reached ,berlin2 and that ,osmont on a motor cycle finished only #c hours and #aj minutes behind the winner4 ,in ,england such racing would be undesirable and impossible1 owing to the crookedness of our roads4 ,it would certainly not be permissible so long as the #ab miles an hour limit is observed4 ,at the present time an agitation is on foot against this restriction1 which1 though reasonable enough among traffic and in towns1 appears unjustifiable in open country4 ,to help to convince the magisterial mind of the ease with which a car can be stopped1 and therefore of its safety even at comparatively high speeds1 trials were held on ,january #b1 #aijb1 in ,welbeck ,park4 ,the results showed that a car travelling at #ac miles an hour could be stopped dead in #d yards2 at #ah miles in #g yards2 at #bj miles in #ac yards2 or in less than half the distance required to pull up a horse-vehicle driven at similar speeds4 ,uses4--,ninety-five per cent of motors1 at least in ,england1 are attached to pleasure vehicles1 cycles1 voiturettes1 and large cars4 ,on account of the costliness of cars motorists are far less numerous than cyclists2 but those people whose means enable them to indulge in automobilism find it extremely fascinating4 ,caricaturists have presented to us in plenty the gloomier incidents of motoring--the broken chain1 the burst tyre1 the 8something gone wrong40 ,it requires personal experience to understand how lightly these mishaps weigh against the exhilaration of movement1 the rapid change of scene1 the sensation of control over power which can whirl one along tirelessly at a pace altogether beyond the capacities of horseflesh4 ,if proof were wanted of the motor car's popularity it will be seen in the unconventional dress of the chauffeur4 ,the breeze set up by his rapid rush is such as would penetrate ordinary clothing2 he dons cumbrous fur cloaks4 ,the dust is all-pervading at times2 he swathes himself in dust-proof overalls1 and mounts large goggles edged with velvet1 while a cap of semi-nautical cut tightly drawn down over neck and ears serves to protect those portions of his anatomy4 ,the general effect is peculiarly unpicturesque2 but even the most artistically-minded driver is ready to sacrifice appearances to comfort and the proper enjoyment of his car4 ,in ,england the great grievance of motorists arises from the speed limit imposed by law4 ,to restrict a powerful car to twelve miles an hour is like confining a thoroughbred to the paces of a broken-down cab horse4 ,careless driving is unpardonable1 but its occasional existence scarcely justifies the intolerant attitude of the law towards motorists in general4 ,it must1 however1 be granted in justice to the police that the chauffeur1 from constant transgression of the law1 becomes a bad judge of speed1 and often travels at a far greater velocity than he is willing to admit4 ,the convenience of the motor car for many purposes is immense1 especially for cross-country journeys1 which may be made from door to door without the monotony or indirectness of railway travel4 ,it bears the doctor swiftly on his rounds4 ,it carries the business man from his country house to his office4 ,it delivers goods for the merchant2 parcels for the post office4 ,in the warfare of the future1 too1 it will play its part1 whether to drag heavy ordnance and stores1 or to move commanding officers from point to point1 or perform errands of mercy among the wounded4 ,by the courtesy of the ,locomobile ,company we are permitted to append the testimony of ,captain ,r4 ,s4 ,walker1 ,r4,e41 to the usefulness of a car during the great ,boer ,war4 8,several months ago ,i noticed a locomobile car at ,cape ,town1 and being struck with its simplicity and neatness1 bought it and took it up country with me1 with a view to making some tests with it over bad roads1 c4 ,its first trip was over a rough course round ,pretoria1 especially chosen to find out defects before taking it into regular use4 ,naturally1 as the machine was not designed for this class of work1 there were several4 ,in about a month these had all been found out and remedied1 and the car was in constant use1 taking stores1 c41 round the towns and forts4 ,it also performed some very useful work in visiting out-stations1 where searchlights were either installed or wanted1 and in this way visited nearly all the bigger towns in the ,transvaal4 ,it was possible to go round all the likely positions for a searchlight in one day at every station1 which frequently meant considerably over fifty miles of most indifferent roads--more than a single horse could have been expected to do--and the car generally carried two persons on these occasions4 ,the car was also used as a tender to a searchlight plant1 on a gun-carriage and limber1 being utilised to fetch gasolene1 carbons1 water1 c41 c41 and also to run the dynamo for charging the accumulators used for sparking1 thus saving running the gasolene motor for this purpose4 ,to do this the trail of the carriage1 on which was the dynamo1 was lowered on to the ground1 the back of the car was pulled up1 one wheel being supported on the dynamo pulley and the other clear of the ground1 and two bolts were passed through the balance-gear to join it4 ,on one occasion the car ran a #cj c4m4 searchlight for an hour1 driving a dynamo in this way4 ,in consequence of this a trailer has been made to carry a dynamo and projector for searchlighting in the field1 but so far this has not been so used4 ,the trailer hooks into an eye1 passing just behind the balance-gear4 ,a ,maxim1 ,colt1 or small ammunition cart1 c41 could be attached to this same eye4 8,undoubtedly the best piece of work done by the car so far was its trial trip with the trailer1 when it blew up the mines at ,klein ,nek4 ,these mines were laid some eight months previously1 and had never been looked to in the interval4 ,there had been several bad storms1 the ,boers and cattle had been frequently through the ,nek1 it had been on fire1 and finally it was shelled with lyddite4 ,the mines1 eighteen in number1 were found to be intact except two1 which presumably had been fired off by the heat of the veldt fire4 ,all the insulation was burnt off the wires1 and the battery was useless4 ,it had been anticipated that a dynamo exploder would be inadequate to fire these mines1 so a #bej volt two h4p4 motor1 which happened to be in ,pretoria1 weighing about three or four hundredweight1 was placed on the trailer2 a quarter of a mile of insulated cable1 some testing gear1 the kits of three men and their rations for three days1 with a case of gasolene for the car1 were also carried on the car and trailer1 and the whole left ,pretoria one morning and trekked to ,rietfontein4 ,two of us were mounted1 the third drove the car4 ,at ,rietfontein we halted for the night1 and started next morning with an escort through ,commando ,nek1 round the north of the ,magaliesburg1 to near ,klein ,nek1 where the road had to be left1 and the car taken across country through bush veldt4 ,at the bottom the going was pretty easy2 only a few bushes had to be charged down1 and the grass1 c41 rather wound itself around the wheels and chain4 ,as the rise became steeper the stones became very large1 and the car had to be taken along very gingerly to prevent breaking the wheels4 ,a halt was made about a quarter of a mile from the top of the ,nek1 where the mines were4 ,these were reconnoitered1 and the wire1 c41 was picked up2 that portion which was useless was placed on top of the charges1 and the remainder taken to the car4 ,the dynamo was slid off the trailer1 the car backed against it2 one wheel was raised slightly and placed against the dynamo pulley1 which was held up to it by a man using his rifle as a lever2 the other wheel was on the ground with a stone under it4 ,the balance gear being free1 the dynamo was excited without the other wheel moving1 and the load being on for a very short time 7that is1 from the time of touching lead on dynamo terminal to firing of the mine7 no harm could come to the car4 ,when all the leads had been joined to the dynamo the car was started1 and after a short time1 when it was judged to have excited1 the second terminal was touched1 a bang and clouds of dust resulted1 and the ,klein ,nek ,minefield had ceased to exist4 ,the day was extremely hot1 and the work had not been light1 so the tea1 made with water drawn direct from the boiler1 which we were able to serve round to the main body of our escort was much appreciated1 and washed down the surplus rations we dispensed with to accommodate the battery and wire1 which we could not leave behind for the enemy4 8,on the return journey we found this extra load too much for the car1 and had great difficulty getting up to ,commando ,nek1 frequently having to stop to get up steam1 so these materials were left at the first blockhouse1 and the journey home continued in comfort4 8,a second night at ,rietfontein gave us a rest after our labour1 and the third afternoon saw us on our way back to ,pretoria4 ,as luck would have it1 a sandstorm overtook the car1 which had a lively time of it4 ,the storm began by blowing the sole occupant's hat off1 so1 the two mounted men being a long way behind1 he shut off steam and chased his hat4 ,in the meantime the wind increased1 and the car sailed off #8on its own1' and was only just caught in time to save a smash4 ,luckily the gale was in the right direction1 for the fire was blown out1 and it was impossible to light a match in the open4 ,the car sailed into a poort on the outskirts of ,pretoria1 got a tow from a friendly cart through it1 and then steamed home after the fire had been relit4 8,the load carried on this occasion 7without the battery1 c47 must have been at least five hundredweight besides the driver1 which1 considering the car is designed to carry two on ordinary roads1 and that these roads were by no means ordinary1 was no mean feat4 ,the car1 as ordinarily equipped for trekking1 carries the following3 ,blankets1 waterproof sheets1 c41 for two men2 four planks for crossing ditches1 bogs1 stones1 c42 all necessary tools and spare parts1 a day's supply of gasolene1 a couple of telephones1 and one mile of wire4 ,in addition1 on the trailer1 if used for searchlighting3 ,one #cj c4m4 projector1 one automatic lamp for projector1 one dynamo 7#ajj volts #bj ampres71 two short lengths of wire1 two pairs of carbons1 tools1 c4 ,this trailer would normally be carried with the baggage1 and only picked up by the car when wanted as a light2 that is1 as a rule1 after arriving in camp1 when a good many other things could be left behind40 ,perhaps the most useful work in store for the motor is to help relieve the congestion of our large towns and to restore to the country some of its lost prosperity4 ,there is no stronger inducement to make people live in the country than rapid and safe means of locomotion1 whether public or private4 ,at present the slow and congested suburban train services on some sides of ,london consume as much time as would suffice a motor car to cover twice or three times the distance4 ,we must welcome any form of travel which will tend to restore the balance between country and town by enabling the worker to live far from his work4 ,the gain to the health of the nation arising from more even distribution of population would be inestimable4 ,a world's tour is among the latest projects in automobilism4 ,on ,april #bi1 #aijb1 ,dr4 ,lehwess and nine friends started from ,hyde ,park ,corner for a nine months' tour on three vehicles1 the largest of them a luxuriously appointed #bd horse-power caravan1 built to accommodate four persons4 ,their route lies through ,france1 ,germany1 ,russia1 ,siberia1 ,china1 ,japan1 and the ,united ,states4 ,,high-,,speed ,,railways4 ,a century ago a long journey was considered an exploit1 and an exploit to be carried through as quickly as possible on account of the dangers of the road and the generally uncomfortable conditions of travel4 ,to-day1 though our express speed is many times greater than that of the lumbering coaches1 our carriages comparatively luxurious1 the risk practically nil1 the same wish lurks in the breast of ninety-nine out of a hundred railway passengers--to spend the shortest time in the train that the time-table permits of4 ,time differences that to our grandfathers would have appeared trifling are now matters of sufficient importance to make rival railway companies anxious to clip a few minutes off a #ajj-mile 8run0 simply because their passengers appreciate a few minutes' less confinement to the cars4 ,during the last fifty years the highest express speeds have not materially altered4 ,the ,great ,western ,company in its early days ran trains from ,paddington to ,slough1 #ah miles1 in #ae-a_/b minutes1 or at an average pace of #fi-a_/b miles an hour4 ,on turning to the present regular express services of the world we find ,america heading the list with a #ej-mile run between ,atlantic ,city and ,camden1 covered at the average speed of #fh miles an hour2 ,britain second with a #cc-mile run between ,forfar and ,perth at #ei miles2 and ,france a good third with an hourly average of rather more than #eh miles between ,les ,aubrais and ,s4 ,pierre des ,corps4 ,these runs are longer than that on the ,great ,western ,railway referred to above 7which now occupies twenty-four minutes71 but their average velocity is less4 ,what is the cause of this decrease of speed8 ,not want of power in modern engines2 at times our trains attain a rate of #hj miles an hour1 and in ,america a mile has been turned off in the astonishing time of thirty-two seconds4 ,we should rather seek it in the need for economy and in the physical limitations imposed by the present system of plate-laying and railroad engineering4 ,an average speed of ninety miles an hour would1 as things now stand1 be too wasteful of coal and too injurious to the rolling-stock to yield profit to the proprietors of a line2 and1 except in certain districts1 would prove perilous for the passengers4 ,before our services can be much improved the steam locomotive must be supplanted by some other application of motive power1 and the metals be laid in a manner which will make special provision for extreme speed4 ,since rapid transit is as much a matter of commercial importance as of mere personal convenience it must not be supposed that an average of #ej miles an hour will continue to meet the needs of travellers4 ,already practical experiments have been made with two systems that promise us an ordinary speed of #ajj miles an hour and an express speed considerably higher4 ,one of these1 the monorail or single-rail system1 will be employed on a railroad projected between ,manchester and ,liverpool4 ,at present passengers between these two cities--the first to be connected by a railroad of any kind--enjoy the choice of three rival services covering #cd-a_/b miles in three-quarters of an hour4 ,an eminent engineer1 ,mr4 ,f4 ,b4 ,behr1 now wishes to add a fourth of unprecedented swiftness4 ,parliamentary powers have been secured for a line starting from ,deansgate1 ,manchester1 and terminating behind the pro-,cathedral in ,liverpool1 on which single cars will run every ten minutes at a velocity of #aaj miles an hour4 ,a monorail track presents a rather curious appearance4 ,the ordinary parallel metals are replaced by a single rail carried on the summit of ,a-shaped trestles1 the legs of which are firmly bolted to sleepers4 ,a monorail car is divided lengthwise by a gap that allows it to hang half on either side of the trestles and clear them as it moves4 ,the double flanged wheels to carry and drive the car are placed at the apex of the gap4 ,as the 8centre of gravity0 is below the rail the car cannot turn over1 even when travelling round a sharp curve4 ,the first railway built on this system was constructed by ,m4 ,charles ,lartigue1 a ,french engineer1 in ,algeria1 a district where an ordinary two-rail track is often blocked by severe sand-storms4 ,he derived the idea of balancing trucks over an elevated rail from caravans of camels laden on each flank with large bags4 ,the camel1 or rather its legs1 was transformed by the engineer's eye into iron trestles1 while its burden became a car4 ,a line built as a result of this observation1 and supplied with mules as tractive power1 has for many years played an important part in the esparto-grass trade of ,algeria4 ,in #ahhf ,mr4 ,behr decided that by applying steam to ,m4 ,lartigue's system he could make it successful as a means of transporting passengers and goods4 ,he accordingly set up in ,tothill ,fields1 ,westminster1 on the site of the new ,roman ,catholic ,cathedral1 a miniature railway which during nine months of use showed that the monorail would be practical for heavy traffic1 safe1 and more cheaply maintained than the ordinary double-metal railway4 ,the train travelled easily round very sharp curves and climbed unusually steep gradients without slipping4 ,mr4 ,behr was encouraged to construct a monorail in ,kerry1 between ,listowel1 a country town famous for its butter1 and ,ballybunion1 a seaside resort of increasing popularity4 ,the line1 opened on the #bhth of ,february #ahhh1 has worked most satisfactorily ever since1 without injury to a single employ or passenger4 ,on each side of the trestles1 two feet below the apex1 run two guide-rails1 against which press small wheels attached to the carriages to prevent undue oscillation and 8tipping0 round curves4 ,at the three stations there are1 instead of points1 turn-tables or switches on to which the train runs for transference to sidings4 ,road traffic crosses the rail on drawbridges1 which are very easily worked1 and which automatically set signals against the train4 ,the bridges are in two portions and act on the principle of the ,tower ,bridge1 each half falling from a perpendicular position towards the centre1 where the ends rest on the rail1 specially strengthened at that spot to carry the extra weight4 ,the locomotive is a twin affair2 has two boilers1 two funnels1 two fireboxes2 can draw #bdj tons on the level at fifteen miles an hour1 and when running light travels a mile in two minutes4 ,the carriages1 #ah feet long and carrying twelve passengers on each side1 are divided longitudinally into two parts4 ,trucks too are used1 mainly for the transport of sand--of which each carries three tons--from ,ballybunion to ,listowel3 and in the centre of each train is a queer-looking vehicle serving as a bridge for any one who may wish to cross from one side of the rail to the other4 ,several lines on the pattern of the ,ballybunion-,listowel have been erected in different countries4 ,mr4 ,behr was not satisfied with his first success1 however1 and determined to develop the monorail in the direction of fast travelling1 which he thought would be most easily attained on a trestle-track4 ,in #ahic he startled engineers by proposing a ,lightning-,express service1 to transport passengers at a velocity of #abj miles an hour4 ,but the project seemed too ideal to tempt money from the pockets of financiers1 and ,mr4 ,behr soon saw that if a high-speed railway after his own heart were constructed it must be at his own expense4 ,he had sufficient faith in his scheme to spend #dj1jjj on an experimental track at the ,brussels ,exhibition of #ahig4 ,the exhibition was in two parts1 connected by an electric railway1 the one at the capital1 the other at ,tervueren1 seven miles away4 ,mr4 ,behr built his line at ,tervueren4 ,the greatest difficulty he encountered in its construction arose from the opposition of landowners1 mostly small peasant proprietors1 who were anxious to make advantageous terms before they would hear of the rail passing through their lands4 ,until he had concluded two hundred separate contracts1 by most of which the peasants benefited1 his platelayers could not get to work4 ,apart from this opposition the conditions were not favourable4 ,he was obliged to bridge no less than ten roads2 and the contour of the country necessitated steep gradients1 sharp curves1 long cuttings and embankments1 the last of which1 owing to a wet summer1 could not be trusted to stand quite firm4 ,the track was doubled for three miles1 passing at each end round a curve of #afjj feet radius4 ,the rail ran about four feet above the track on trestles bolted down to steel sleepers resting on ordinary ballast4 ,the carriage--,mr4 ,behr used but one on this line--weighed #fh tons1 was #ei feet long and #aa feet wide1 and could accommodate one hundred persons4 ,it was handsomely fitted up1 and had specially-shaped seats which neutralised the effect of rounding curves1 and ended fore and aft in a point1 to overcome the wind-resistance in front and the air-suction behind4 ,sixteen pairs of wheels on the under side of the carriage engaged with the two pairs of guide rails flanking the trestles1 and eight large double-flanged wheels1 #d-a_/b feet in diameter1 carried the weight of the vehicle4 ,the inner four of these wheels were driven by as many powerful electric motors contained1 along with the guiding mechanism1 in the lower part of the car4 ,the motors picked up current from the centre rail and from another steel rail laid along the sleepers on porcelain insulators4 ,the top speed attained was about ninety miles an hour4 ,on the close of the ,exhibition special experiments were made at the request of the ,belgian1 ,french1 and ,russian ,governments1 with results that proved that the ,behr system deserved a trial on a much larger scale4 ,the engineer accordingly approached the ,british ,government with a ,bill for the construction of a high-speed line between ,liverpool and ,manchester4 ,a ,committee of the ,house of ,commons rejected the ,bill on representations of the ,salford ,corporation4 ,the ,committee had to admit1 nevertheless1 that the evidence called was mainly in favour of the system2 and1 the plans of the rail having been altered to meet certain objections1 ,parliamentary consent was obtained to commence operations when the necessary capital had been subscribed4 ,in a few years the great seaport and the great cotton town will probably be within a few minutes' run of each other4 ,a question that naturally arises in the mind of the reader is this3 could the cars1 when travelling at #aaj miles an hour1 be arrested quickly enough to avoid an accident if anything got on the line8 ,the ,westinghouse air-brake has a retarding force of three miles a second4 ,it would therefore arrest a train travelling at #aaj miles per hour in #cg seconds1 or #iie yards4 ,mr4 ,behr proposes to reinforce the ,westinghouse with an electric brake1 composed of magnets #ah inches long1 exerting on the guide rails by means of current generated by the reversed motors an attractive force of #bjj lbs4 per square inch4 ,one great advantage of this brake is that its efficiency is greatest when the speed of the train is highest and when it is most needed4 ,the united brakes are expected to stop the car in half the distance of the ,westinghouse alone2 but they would not both be applied except in emergencies4 ,under ordinary conditions the slowing of a car would take place only at the termini1 where the line ascends gradients into the stations4 ,there would1 however1 be small chance of collisions1 the railway being securely fenced off throughout its entire length1 and free from level crossings1 drawbridges and points4 ,furthermore1 each train would be its own signalman4 ,suppose the total #cd-a_/b miles divided into 8block0 lengths of #g miles4 ,on leaving a terminus the train sets a danger signal behind it2 at #g miles it sets another1 and at #ad miles releases the first signal4 ,so that the driver of a car would have at least #g miles to slow down in after seeing the signals against him4 ,in case of fog he would consult a miniature signal in his cabin working electrically in unison with the large semaphores4 ,the ,manchester-,liverpool rail will be reserved for express traffic only4 ,mr4 ,behr does not believe in mixing speeds1 and considers it one of the advantages of his system that slow cars and waggons of the ordinary two-rail type cannot be run on the monorail2 because if they could managers might be tempted to place them there4 ,a train will consist of a single vehicle for forty1 fifty1 or seventy passengers1 as the occasion requires4 ,it is calculated that an average of twelve passengers at one penny per mile would pay all the expenses of running a car4 ,mr4 ,behr maintains that monorails can be constructed far more cheaply than the two-rail1 because they permit sharper curves1 and thereby save a lot of cutting and embankment2 and also because the monorail itself1 when trestles and rail are specially strengthened1 can serve as its own bridge across roads1 valleys and rivers4 ,though the single-rail has come to the front of late1 it must not be supposed that the two-rail track is for ever doomed to moderate speeds only4 ,german engineers have built an electric two-rail military line between ,berlin and ,zossen1 seventeen miles long1 over which cars have been run at a hundred miles an hour4 ,the line has very gradual curves1 and in this respect is inferior to the more sinuous monorail4 ,its chief virtue is the method of applying motive power--a method common to both systems4 ,the steam locomotive creates its own motive force1 and as long as it has fuel and water can act independently4 ,the electric locomotive1 on the other hand1 receives its power through metallic conductors from some central station4 ,should the current fail all the traffic on the line is suspended4 ,so far the advantage rests with the steamer4 ,but as regards economy the superiority of the current is obvious4 ,in the electric systems under consideration--the monorail and ,berlin-,zossen--there is less weight per passenger to be shifted1 since a comparatively light motor supersedes the heavy locomotive4 ,the cars running singly1 bridges and track are subjected to less strain1 and cost less to keep in repair4 ,but the greatest saving of all is made in fuel4 ,a steam locomotive uses coal wastefully1 sending a lot of latent power up the funnel in the shape of half-expanded steam4 ,want of space prevents the designer from fitting to a moving engine the more economical machinery to be found in the central power-station of an electric railway1 which may be so situated--by the water-side or near a pit's mouth--that fuel can be brought to it at a trifling cost4 ,not only is the expense of distributing coal over the system avoided1 but the coal itself1 by the help of triple and quadruple expansion engines should yield two or three times as much energy per ton as is developed in a locomotive furnace4 ,many schemes are afoot for the construction of high-speed railways4 ,the ,south-,eastern plans a monorail between ,cannon ,street and ,charing ,cross to avoid the delay that at present occurs in passing from one station to the other4 ,we hear also of a projected railway from ,london to ,brighton1 which will reduce the journey to half-an-hour2 and of another to connect ,dover and ,london4 ,it has even been suggested to establish monorails on existing tracks for fast passenger traffic1 the expresses passing overhead1 the slow and goods trains plodding along the double metals below4 ,but the most ambitious programme of all comes from the land of the ,czar4 ,m4 ,hippolyte ,romanoff1 a ,russian engineer1 proposes to unite ,st4 ,petersburg and ,moscow by a line that shall cover the intervening #fjj miles in three hours--an improvement of ten hours on the present time-tables4 ,he will use ,t-shaped supports to carry two rails1 one on each arm1 from which the cars are to hang4 ,the line being thus double will permit the cars--some four hundred in number--to run to and fro continuously1 urged on their way by current picked up from overhead wires4 ,each car is to have twelve wheels1 four drivers arranged vertically and eight horizontally1 to prevent derailment by gripping the rail on either side4 ,the stoppage or breakdown of any car will automatically stop those following by cutting off the current4 ,in the early days of railway history lines were projected in all directions1 regardless of the fact whether they would be of any use or not4 ,many of these lines began1 where they ended1 on paper4 ,and now that the high-speed question has cropped up1 we must not believe that every projected electric railway will be built1 though of the ultimate prevalence of far higher speeds than we now enjoy there can be no doubt4 ,the following is a time-table drawn up on the two-mile-per-minute basis4 ,a man leaving ,london at #aj ,a4,m4 would reach-- ,brighton #ej miles away1 at #aj4be ,a4,m4 ,portsmouth #fj #aj4cj ,a4,m4 ,birmingham #aac #aj4eg ,a4,m4 ,leeds #ahh #aa4cd ,a4,m4 ,liverpool #bjb #aa4da ,a4,m4 ,holyhead #bfb #ab4aa ,p4,m4 ,edinburgh #djj #a4bj ,p4,m4 ,aberdeen #edj #b4cj ,p4,m4 ,what would become of the records established in the 8,race to the ,north0 and by ,american 8fliers08 ,and what about continental travel8 ,assuming that the ,channel ,tunnel is built--perhaps a rather large assumption--,paris will be at our very doors4 ,a commercial traveller will step into the lightning express at ,london1 sleep for two hours and twenty-four minutes and wake1 refreshed1 to find the blue-smocked ,paris porters bawling in his ear4 ,or even if we prefer to keep the 8little silver streak0 free from subterranean burrows1 he will be able to catch the swift turbine steamers--of which more anon--at ,dover1 slip across to ,calais in half-an-hour1 and be at the ,french capital within four hours of quitting ,london4 ,and if ,m4 ,romanoff's standard be reached1 the latest thing in hats despatched from ,paris at noon may be worn in ,regent ,street before two o'clock4 ,such speeds would indeed produce a revolution in travelling comparable to the substitution of the steam locomotive for the stage coach4 ,as has been pithily said1 the effect of steam was to make the bulk of population travel1 whereas they had never travelled before1 but the effect of the electric railway will be to make those who travel travel much further and much oftener4 ,,sea ,,expresses4 ,in the year #ahcf the ,sirius1 a paddle-wheel vessel1 crossed the ,atlantic from ,cork ,harbour to ,new ,york in nineteen days4 ,contrast with the first steam-passage from the ,old ,world to the ,new a return journey of the ,deutschland1 a ,north ,german liner1 which in #aijj averaged over twenty-seven miles an hour between ,sandy ,hook and ,plymouth1 accomplishing the whole distance in the record time of five days seven hours thirty-eight minutes4 ,this growth of speed is even more remarkable than might appear from the mere comparison of figures4 ,a body moving through water is so retarded by the inertia and friction of the fluid that to quicken its pace a force quite out of proportion to the increase of velocity must be exerted4 ,the proportion cannot be reduced to an exact formula1 but under certain conditions the speed and the power required advance in the ratio of their cubes2 that is1 to double a given rate of progress eight times the driving-power is needed2 to treble it1 twenty-seven times4 ,the mechanism of our fast modern vessels is in every way as superior to that which moved the ,sirius1 as the beautifully-adjusted safety cycle is to the clumsy 8boneshaker0 which passed for a wonder among our grandfathers4 ,a great improvement has also taken place in the art of building ships on lines calculated to offer least resistance to the water1 and at the same time afford a good carrying capacity4 ,the big liner1 with its knife-edged bow and tapering hull1 is by its shape alone eloquent of the high speed which has earned it the title of ,ocean ,greyhound2 and as for the fastest craft of all1 torpedo-destroyers1 their designers seem to have kept in mind ,euclid's definition of a line--length without breadth4 ,but whatever its shape1 boat or ship may not shake itself free of ,nature's laws4 ,her restraining hand lies heavy upon it4 ,a single man paddles his weight-carrying dinghy along easily at four miles an hour2 eight men in the pink of condition1 after arduous training1 cannot urge their light1 slender1 racing shell more than twelve miles in the same time4 ,to understand how mail boats and 8destroyers0 attain1 despite the enormous resistance of water1 velocities that would shame many a train-service1 we have only to visit the stokeholds and engine-rooms of our sea expresses and note the many devices of marine engineers by which fuel is converted into speed4 ,we enter the stokehold through air-locks1 closing one door before we can open the other1 and find ourselves among sweating1 grimy men1 stripped to the waist4 ,as though life itself depended upon it they shovel coal into the rapacious maws of furnaces glowing with a dazzling glare under the 8forced-draught0 sent down into the hold by the fans whirling overhead4 ,the ignited furnace gases on their way to the outer air surrender a portion of their heat to the water from which they are separated by a skin of steel4 ,two kinds of marine boiler are used--the fire-tube and the water-tube4 ,in fire-tube boilers the fire passes inside the tubes and the water outside2 in water-tube boilers the reverse is the case1 the crown and sides of the furnace being composed of sheaves of small parallel pipes through which water circulates4 ,the latter type1 as generating steam very quickly1 and being able to bear very high pressures1 is most often found in war vessels of all kinds4 ,the quality sought in boiler construction is that the heating surface should be very large in proportion to the quantity of water to be heated4 ,special coal1 anthracite or ,welsh1 is used in the navy on account of its great heating power and freedom from smoke2 experiments have also been made with crude petroleum1 or liquid fuel1 which can be more quickly put on board than coal1 requires the services of fewer stokers1 and may be stored in odd corners unavailable as coal bunkers4 ,from the boiler the steam passes to the engine-room1 whither we will follow it4 ,we are now in a bewildering maze of clanking1 whirling machinery2 our noses offended by the reek of oil1 our ears deafened by the uproar of the moving metal1 our eyes wearied by the efforts to follow the motions of the cranks and rods4 ,on either side of us is ranged a series of three or perhaps even four cylinders1 of increasing size4 ,the smallest1 known as the high-pressure cylinder1 receives steam direct from the boiler4 ,it takes in through a slide-valve a supply for a stroke2 its piston is driven from end to end2 the piston-rod flies through the cylinder-end and transmits a rotary motion to a crank by means of a connecting-rod4 ,the half-expanded steam is then ejected1 not into the air as would happen on a locomotive1 but into the next cylinder1 which has a larger piston to compensate the reduction of pressure4 ,number two served1 the steam does duty a third time in number three1 and perhaps yet a fourth time before it reaches the condensers1 where its sudden conversion into water by cold produces a vacuum suction in the last cylinder of the series4 ,the secret of a marine engine's strength and economy lies then in its treatment of the steam1 which1 like clothes in a numerous family1 is not thought to have served its purpose till it has been used over and over again4 ,reciprocating 7i4e4 cylinder7 engines1 though brought to a high pitch of efficiency1 have grave disadvantages1 the greatest among which is the annoyance caused by their intense vibration to all persons in the vessel4 ,a revolving body that is not exactly balanced runs unequally1 and transmits a tremor to anything with which it may be in contact4 ,turn a cycle upside down and revolve the driving-wheel rapidly by means of the pedal4 ,the whole machine soon begins to tremble violently1 and dance up and down on the saddle springs1 because one part of the wheel is heavier than the rest1 the mere weight of the air-valve being sufficient to disturb the balance4 ,now consider what happens in the engine-room of high-powered vessels4 ,on destroyers the screws make #djj revolutions a minute4 ,that is to say1 all the momentum of the pistons1 cranks1 rods1 and valves 7weighing tons71 has to be arrested thirteen or fourteen times every second4 ,however well the moving parts may be balanced1 the vibration is felt from stem to stern of the vessel4 ,even on luxuriously-appointed liners1 with engines running at a far slower speed1 the throbbing of the screw 7i4e4 engines7 is only too noticeable and productive of discomfort4 ,we shall be told1 perhaps1 that vibration is a necessary consequence of speed4 ,this is true enough of all vehicles1 such as railway trains1 motor-cars1 cycles1 which are shaken by the irregularities of the unyielding surface over which they run1 but does not apply universally to ships and boats4 ,a sail or oar-propelled craft may be entirely free from vibration1 whatever its speed1 as the motions arising from water are usually slow and deliberate4 ,in fact1 water in its calmer moods is an ideal medium to travel on1 and the trouble begins only with the introduction of steam as motive force4 ,but even steam may be robbed of its power to annoy us4 ,the steam-turbine has arrived4 ,it works a screw propeller as smoothly as a dynamo1 and at a speed that no cylinder engine could maintain for a minute without shaking itself to pieces4 ,the steam-turbine is most closely connected with the name of the ,hon4 ,charles ,parsons1 son of ,lord ,rosse1 the famous astronomer4 ,he was the first to show1 in his speedy little ,turbinia1 the possibilities of the turbine when applied to steam navigation4 ,the results have been such as to attract the attention of the whole shipbuilding world4 ,the principle of the turbine is seen in the ordinary windmill4 ,to an axle revolving in a stationary bearing are attached vanes which oppose a current of air1 water1 or steam1 at an angle to its course1 and by it are moved sideways through a circular path4 ,mr4 ,parsons' turbine has of course been specially adapted for the action of steam4 ,it consists of a cylindrical1 air-tight chest1 inside which rotates a drum1 fitted round its circumference with rows of curved vanes4 ,the chest itself has fixed immovably to its inner side a corresponding number of vane rings1 alternating with those on the drum1 and so arranged as to deflect the steam on to the latter at the most efficient angle4 ,the diameter of the chest and drum is not constant1 but increases towards the exhaust end1 in order to give the expanding and weakening steam a larger leverage as it proceeds4 ,the steam entering the chest from the boiler at a pressure of some hundreds of pounds to the square inch strikes the first set of vanes on the drum1 passes them and meets the first set of chest-vanes1 is turned from its course on to the second set of drum-vanes1 and so on to the other end of the chest4 ,its power arises entirely from its expansive velocity1 which1 rather than turn a number of sharp corners1 will1 if possible1 compel the obstruction to move out of its way4 ,if that obstruction be from any cause difficult to stir1 the steam must pass round it until its pressure overcomes the inertia4 ,consequently the turbine differs from the cylinder engine in this respect1 that steam can pass through and be wasted without doing any work at all1 whereas1 unless the gear of a cylinder moves1 and power is exerted1 all steam ways are closed1 and there is no waste4 ,in practice1 therefore1 it is found that a turbine is most effective when running at high speed4 ,the first steam-turbines were used to drive dynamos4 ,in #ahhd ,mr4 ,parsons made a turbine in which fifteen wheels of increasing size moved at the astonishing rate of #cjj revolutions per second1 and developed #aj horse-power4 ,in #ahhh followed a #abj horse-power turbine1 and in #ahib one of #bjjj horse-power1 provided with a condenser to produce suction4 ,so successful were these steam fans for electrical work1 pumping water and ventilating mines1 that ,mr4 ,parsons determined to test them as a means of propelling ships4 ,a small vessel #ajj feet long and #i feet in beam was fitted with three turbines--high1 medium1 and low pressure1 of a total #bjjj horse-power--a proportion of motive force to tonnage hitherto not approached4 ,yet when tried over the test course the ,turbinia1 as the boat was fitly named1 ran in a most disappointing fashion4 ,the screws revolved too fast1 producing what is known as cavitation1 or the scooping out of the water by the screws1 so that they moved in a partial vacuum and utilised only a fraction of their force1 from lack of anything to 8bite0 on4 ,this defect was remedied by employing screws of coarser pitch and larger blade area1 three of which were attached to each of the three propeller shafts4 ,on a second trial the ,turbinia attained #cb-c_/d knots over the 8measured mile10 and later the astonishing speed of forty miles an hour1 or double that of the fast ,channel packets4 ,at the ,spithead ,review in #ahig one of the most interesting sights was the little nimble ,turbinia rushing up and down the rows of majestic warships at the rate of an express train4 ,illustration3 ,h4,m4,s4 ,torpedo ,destroyer 8,viper40 ,this vessel was the fastest afloat1 attaining the enormous speed of #da miles an hour4 ,the screws were worked by turbines1 giving #aa1jjj horse-power4 ,she was wrecked on ,alderney during the ,naval ,manoeuvres of #aija4 ,after this success ,mr4 ,parsons erected works at ,wallsend-on-,tyne for the special manufacture of turbines4 ,the ,admiralty soon placed with him an order for a torpedo-destroyer--the ,viper--of #cej tons2 which on its trial trip exceeded forty-one miles an hour at an estimated horse-power 7#aa1jjj7 equalling that of our largest battleships4 ,a sister vessel1 the ,cobra1 of like size1 proved as speedy4 ,misfortune1 however1 overtook both destroyers4 ,the ,viper was wrecked ,august #c1 #aija1 on the coast of ,alderney during the autumn naval manoeuvres1 and the ,cobra foundered in a severe storm on ,september #ab of the same year in the ,north ,sea4 ,this double disaster casts no reflections on the turbine engines2 being attributed to fog in the one case and to structural weakness in the other4 ,the ,admiralty has since ordered another turbine destroyer1 and before many years are past we shall probably see all the great naval powers providing themselves with like craft to act as the 8eyes of the fleet10 and travel at even higher speeds than those of the ,viper and ,cobra4 ,the turbine has been applied to mercantile as well as warlike purposes4 ,there is at the present time a turbine-propelled steamer1 the ,king ,edward1 running in the ,clyde on the ,fairlie-,campbelltown route4 ,this vessel1 #bej feet long1 #cj broad1 #ah deep1 contains three turbines4 ,in each the steam is expanded fivefold1 so that by the time it passes into the condensers it occupies #abe times its boiler volume4 7,on the ,viper the steam entered the turbine through an inlet eight inches in diameter1 and left them by an outlet four feet square47 ,in cylinder engines thirty-fold expansion is considered a high ratio2 hence the turbine extracts a great deal more power in proportion from its steam4 ,as a turbine cannot be reversed1 special turbines are attached to the two outside of the three propeller shafts to drive the vessel astern4 ,the steamer attained #bj-a_/b knots over the 8,skelmorlie mile0 in fair and calm weather1 with #cejj horse-power produced at the turbines4 ,the ,king ,edward is thus the fastest by two or three knots of all the ,clyde steamers1 as she is the most comfortable4 ,we are assured that as far as the turbines are concerned it is impossible by placing the hand upon the steam-chest to tell whether the drum inside is revolving or not6 ,every marine engine is judged by its economy in the consumption of coal4 ,except in times of national peril extra speed produced by an extravagant use of fuel would be severely avoided by all owners and captains of ships4 ,at low speeds the turbine develops less power than cylinders from the same amount of steam1 but when working at high velocity it gives at least equal results4 ,a careful record kept by the managers of the ,caledonian ,steamship ,company compares the ,king ,edward with the ,duchess of ,hamilton1 a paddle steamer of equal tonnage used on the same route and built by the same firm4 ,the record shows that though the paddle-boat ran a fraction of a mile further for every ton of coal burnt in the furnaces1 the ,king ,edward averaged two knots an hour faster1 a superiority of speed quite out of proportion to the slight excess of fuel4 ,were the ,duchess driven at #ah-a_/b knots instead of #af-a_/b her coal bill would far exceed that of the turbine4 ,as an outcome of these first trials the ,caledonian ,company are launching a second turbine vessel4 ,three high-speed turbine yachts are also on the stocks2 one of #gjj tons1 another of #aejj tons1 and a third of #agj tons4 ,the last1 the property of ,colonel ,m',calmont1 is designed for a speed of twenty-four knots4 ,mr4 ,parsons claims for his system the following advantages3 ,greatly increased speed2 increased carrying power of coal2 economy in coal consumption2 increased facilities for navigating shallow waters2 greater stability of vessels2 reduced weight of machinery 7the turbines of the ,king ,edward weigh but one-half of cylinders required to give the same power72 cheapness of attending the machinery2 absence of vibration1 lessening wear and tear of the ship's hull and assisting the accurate training of guns2 lowered centre of gravity in the vessel1 and consequent greater safety during times of war4 ,the inventor has suggested a cruiser of #bhjj tons1 engined up to #hj1jjj horse-power1 to yield a speed of forty-four knots 7about fifty miles7 an hour4 ,figures such as these suggest that we may be on the eve of a revolution of ocean travel comparable to that made by the substitution of steam for wind power4 ,whether the steam-turbine will make for increased speed all round1 or for greater economy1 remains to be seen2 but we may be assured of a higher degree of comfort4 ,we can easily believe that improvements will follow in this as in other mechanical contrivances1 and that the turbine's efficiency has not yet reached a maximum2 and even if our ocean expresses1 naval and mercantile1 do not attain the one-mile-a-minute standard1 which is still regarded as creditable to the fastest methods of land locomotion1 we look forward to a time in the near future when much higher speeds will prevail1 and the tedium of long voyages be greatly shortened4 ,already there is talk of a service which shall reduce the trans-,atlantic journey to three-and-a-half days4 ,the means are at hand to make it a fact4 ,note4--,in the recently-launched turbine destroyer ,velox a novel feature is the introduction of ordinary reciprocating engines fitted in conjunction with the steam turbines4 ,these engines are of triple-compound type1 and are coupled direct to the main turbines4 ,they take steam from the boilers direct and exhaust into the high-pressure turbine4 ,these reciprocating engines are for use at cruising speeds4 ,when higher power is needed the steam will be admitted to the turbines direct from the boilers1 and the cylinders be thrown out of gear4 ,,mechanical ,,flight4 ,few1 if any1 problems have so strongly influenced the imagination and exercised the ingenuity of mankind as that of arial navigation4 ,there is something in our nature that rebels against being condemned to the condition of 8featherless bipeds0 when birds1 bats1 and even minute insects have the whole realm of air and the wide heavens open to them4 ,who has not1 like ,solomon1 pondered upon 8the way of a bird in the air0 with feelings of envy and regret that he is chained to earth by his gross body2 contrasting our laboured movements from point to point of the earth's surface with the easy gliding of the feathered traveller8 ,the unrealised wish has found expression in legends of ,ddalus1 ,pegasus1 in the 8flying carpet0 of the fairy tale1 and in the pages of ,jules ,verne1 in which last the adventurous ,robur on his 8,clipper of the ,clouds0 anticipates the future in a most startling fashion4 ,aeromobilism--to use its most modern title--is regarded by the crowd as the mechanical counterpart of the ,philosopher's ,stone or the ,elixir of ,life2 a highly desirable but unattainable thing4 ,at times this incredulity is transformed by highly-coloured press reports into an equally unreasonable readiness to believe that the conquest of the air is completed1 followed by a feeling of irritation that facts are not as they were represented in print4 ,the proper attitude is of course half-way between these extremes4 ,reflection will show us that money1 time1 and life itself would not have been freely and ungrudgingly given or risked by many men--hard-headed1 practical men among them--in pursuit of a ,will-o'-the-,wisp1 especially in a century when scientific calculation tends always to calm down any too imaginative scheme4 ,the existing state of the arial problem may be compared to that of a railway truck which an insufficient number of men are trying to move4 ,ten men may make no impression on it1 though they are putting out all their strength4 ,yet the arrival of an eleventh may enable them to overcome the truck's inertia and move it at an increasing pace4 ,every new discovery of the scientific application of power brings us nearer to the day when the truck will move4 ,we have metals of wonderful strength in proportion to their weight2 pigmy motors containing the force of giants2 a huge fund of mechanical experience to draw upon2 in fact1 to paraphrase the ,jingo song1 8,we've got the things1 we've got the men1 we've got the money too0--but we haven't as yet got the machine that can mock the bird like the flying express mocks the strength and speed of horses4 ,the reason of this is not far to seek4 ,the difficulties attending the creation of a successful flying-machine are immense1 some unique1 not being found in aquatic and terrestrial locomotion4 ,in the first place1 the airship1 flying-machine1 aerostat1 or whatever we please to call it1 must not merely move1 but also lift itself4 ,neither a ship nor a locomotive is called upon to do this4 ,its ability to lift itself must depend upon either the employment of large balloons or upon sheer power4 ,in the first case the balloon will1 by reason of its size1 be unmanageable in a high wind2 in the second case1 a breakdown in the machinery would probably prove fatal4 ,even supposing that our aerostat can lift itself successfully1 we encounter the difficulties connected with steering in a medium traversed by ever-shifting currents of air1 which demands of the helmsman a caution and capacity seldom required on land or water4 ,add to these the difficulties of leaving the ground and alighting safely upon it2 and1 what is more serious than all1 the fact that though success can be attained only by experiment1 experiment is in this case extremely expensive and risky1 any failure often resulting in total ruin of the machine1 and sometimes in loss of life4 ,the list of those who have perished in the search for the power of flight is a very long one4 ,yet in spite of these obstacles determined attempts have been and are being made to conquer the air4 ,men in a position to judge are confident that the day of conquest is not very far distant1 and that the next generation may be as familiar with aerostats as we with motor-cars4 ,speculation as to the future is1 however1 here less profitable than a consideration of what has been already done in the direction of collecting forces for the final victory4 ,to begin at the beginning1 we see that experimenters must be divided into two great classes3 those who pin their faith to airships lighter than air1 e4g4 ,santos ,dumont1 ,zeppelin1 ,roze2 and those who have small respect for balloons1 and see the ideal air-craft in a machine lifted entirely by means of power and surfaces pressing the air after the manner of a kite4 ,sir ,hiram ,maxim and ,professor ,s4 ,p4 ,langley1 ,mr4 ,lawrence ,hargrave1 and ,mr4 ,sydney ,hollands are eminent members of the latter cult4 ,as soon as we get on the topic of steerable balloons the name of ,mr4 ,santos ,dumont looms large4 ,but before dealing with his exploits we may notice the airship of ,count ,zeppelin1 an ingenious and costly structure that was tested over ,lake ,constance in #aijj4 ,the balloon was built in a large wooden shed1 #dej by #gh by #ff feet1 that floated on the lake on ninety pontoons4 ,the shed alone cost over #aj1jjj4 ,the balloon itself was nearly #djj feet long1 with a cylindrical diameter of #ci feet1 except at its ends1 which were conical1 to offer as little resistance as possible to the air4 ,externally it afforded the appearance of a single-compartment bag1 but in reality it was divided into seventeen parts1 each gas-tight1 so that an accident to one part of the fabric should not imperil the whole4 ,a framework of aluminium rods and rings gave the bag a partial rigidity4 ,its capacity was #ab1jjj cubic yards of hydrogen gas1 which1 as our readers doubtless know1 is much lighter though more expensive than ordinary coal-gas2 each inflation costing several hundreds of pounds4 ,under the balloon hung two cars of aluminium1 the motors and the screws2 and also a great sliding weight of #fjj lbs4 for altering the 8tip0 of the airship2 and rudders to steer its course4 ,on ,june #cj a great number of scientific men and experts assembled to witness the behaviour of a balloon which had cost #bj1jjj4 ,for two days wind prevented a start1 but on ,july #b1 at #g4cj ,p4,m41 the balloon emerged from its shed1 and at eight o'clock commenced its first journey1 with and against a light easterly wind for a distance of three and a half miles4 ,a mishap to the steering-gear occurred early in the trip1 and prevented the airship appearing to advantage1 but a landing was effected easily and safely4 ,in the following ,october the ,count made a second attempt1 returning against a wind blowing at three yards a second1 or rather more than six miles an hour4 ,illustration3 ,the air-ship of ,m4 ,santos-,dumont rounding the ,eiffel ,tower during its successful run for the ,henri ,deutsch ,prize4 ,owing to lack of funds the fate of the 8,great ,eastern0 has overtaken the ,zeppelin airship--to be broken up1 and the parts sold4 ,the aged ,count had demonstrated that a petroleum motor could be used in the neighbourhood of gas without danger4 ,it was1 however1 reserved for a younger man to give a more decided proof of the steerableness of a balloon4 ,in #aijj ,m4 ,henri ,deutsch1 a member of the ,french ,aero ,club1 founded a prize of #djjj1 to win which a competitor must start from the ,aero ,club ,park1 near the ,seine in ,paris1 sail to and round the ,eiffel ,tower1 and be back at the starting-point within a time-limit of half-an-hour4 ,m4 ,santos ,dumont1 a wealthy and plucky young ,brazilian1 had1 previously to this offer1 made several successful journeys in motor balloons in the neighbourhood of the ,eiffel ,tower4 ,he therefore determined to make a bid for the prize with a specially constructed balloon 8,santos ,dumont ,v40 ,the third unsuccessful attempt ended in disaster to the airship1 which fell on to the houses1 but fortunately without injuring its occupant4 ,another balloon--8,santos ,dumont ,,vi40--was then built4 ,on ,saturday1 ,october #aith1 ,m4 ,dumont reached the ,tower in nine minutes and recrossed the starting line in #bj-a_/b more minutes1 thus complying with the conditions of the prize with half-a-minute to spare4 ,a dispute1 however1 arose as to whether the prize had been actually won1 some of the committee contending that the balloon should have come to earth within the half-hour1 instead of merely passing overhead2 but finally the well-merited prize was awarded to the determined young aeronaut4 ,the successful airship was of moderate proportions as compared with that of ,count ,zeppelin4 ,the cigar-shaped bag was #aab feet long and #bj feet in diameter1 holding #gae cubic yards of gas4 ,m4 ,dumont showed originality in furnishing it with a smaller balloon inside1 which could be pumped full of air so as to counteract any leakage in the external bag and keep it taut4 ,the motor1 on which everything depended1 was a four-cylinder petrol-driven engine1 furnished with 8water-jackets0 to prevent over-heating4 ,the motor turned a large screw--made of silk and stretched over light frames--#bjj times a minute1 giving a driving force of #age lbs4 ,behind1 a rudder directed the airship1 and in front hung down a long rope suspended by one end that could be drawn towards the centre of the frame to alter the trim of the ship4 ,the aeronaut stood in a large wicker basket flanked on either side by bags of sand ballast4 ,the fact that the motor1 once stopped1 could only be restarted by coming to earth again added an element of great uncertainty to all his trips2 and on one occasion the mis-firing of one of the cylinders almost brought about a collision with the ,eiffel ,tower4 ,from ,paris ,m4 ,dumont went to ,monaco at the invitation of the prince of that principality1 and cruised about over the bay in his balloon4 ,his fresh scheme was to cross to ,corsica1 but it was brought to an abrupt conclusion by a leakage of gas1 which precipitated balloon and balloonist into the sea4 ,dumont was rescued1 and at once set about new projects1 including a visit to the ,crystal ,palace1 where he would have made a series of ascents this summer 7#aijb7 but for damage done to the silk of the gas-bag by its immersion in salt water and the other vicissitudes it had passed through4 ,dumont's most important achievement has been1 like that of ,count ,zeppelin1 the application of the gasolene motor to aeromobilism4 ,in proportion to its size this form of motor develops a large amount of energy1 and its mechanism is comparatively simple--a matter of great moment to the aeronaut4 ,he has also shown that under favourable conditions a balloon may be steered against a head-wind1 though not with the certainty that is desirable before air travel can be pronounced an even moderately simple undertaking4 ,the fact that many inventors1 such as ,dr4 ,barton1 ,m4 ,roze1 ,henri ,deutsch1 are fitting motors to balloons in the hopes of solving the arial problem shows that the airship has still a strong hold on the minds of men4 ,but on reviewing the successes of such combinations of lifting and driving power it must be confessed1 with all due respect to ,m4 ,dumont1 that they are somewhat meagre1 and do not show any great advance4 ,the question is whether these men are not working on wrong lines1 and whether their utmost endeavours and those of their successors will ever produce anything more than a very semi-successful craft4 ,their efforts appear foredoomed to failure4 ,as ,sir ,hiram ,maxim has observed1 a balloon by its very nature is light and fragile1 it is a mere bubble4 ,if it were possible to construct a motor to develop #ajj horse-power for every pound of its weight1 it would still be impossible to navigate a balloon against a wind of more than a certain strength4 ,the mere energy of the motor would crush the gas-bag against the pressure of the wind1 deform it1 and render it unmanageable4 ,balloons therefore must be at the mercy of the wind1 and obliged to submit to it under conditions not always in accordance with the wish of the aeronaut4 ,sir ,hiram in condemning the airship was ready with a substitute4 ,on looking round on the patterns of ,nature1 he concluded that1 inasmuch as all things that fly are heavier than air1 the problem of arial navigation must be solved by a machine whose natural tendency is to fall to the ground1 and which can be sustained only by the exertion of great force4 ,its very weight would enable it to withstand1 at least to a far greater extent than the airship1 the varying currents of the air4 ,the lifting principle must be analogous to that by which a kite is suspended4 ,a kite is prevented from rising beyond a certain height by a string1 and the pressure of the wind working against it at an angle tends to lift it1 like a soft wedge continuously driven under it4 ,in practice it makes no difference whether the kite be stationary in a wind or towed rapidly through a dead calm2 the wedge-like action of the air remains the same4 ,maxim decided upon constructing what was practically a huge compound kite driven by very powerful motors4 ,but before setting to work on the machine itself he made some useful experiments to determine the necessary size of his kites or aeroplanes1 and the force requisite to move them4 ,he accordingly built a 8whirling-table10 consisting of a long arm mounted on a strong pivot at one end1 and driven by a #aj horse-power engine4 ,to the free end1 which described a circle of #bjj feet in circumference1 he attached small aeroplanes1 and by means of delicate balances discovered that at #dj miles an hour the aeroplane would lift #acc lbs4 per horse-power1 and at #fj miles per hour every square foot of surface sustained #h lbs4 weight4 ,he1 in common with other experimenters on the same lines1 became aware of the fact that if it took a certain strain to suspend a stationary weight in the air1 to advance it rapidly as well as to suspend it took a smaller strain4 ,now1 as on sea and land1 increased speed means a very rapid increase in the force required1 this is a point in favour of the flying-machine4 ,professor ,langley found that a brass plate weighing a pound1 when whirled at great speed1 was supported in the air by a pulling pressure of less than one ounce4 ,and1 of course1 as the speed increased the plate became more nearly horizontal1 offering less resistance to the air4 ,it is on this behaviour of the aeroplane that the hopes of ,maxim and others have been based4 ,the swiftly moving aeroplane1 coming constantly on to fresh air1 the inertia of which had not been disturbed1 would resemble the skater who can at high speed traverse ice that would not bear him at rest4 ,maxim next turned his attention to the construction of the aeroplanes and engines4 ,he made a special machine for testing fabrics1 to decide which would be most suitable for stretching over strong frames to form the planes4 ,the fabric must be light1 very strong1 and offer small frictional resistance to the air4 ,the testing-machine was fitted with a nozzle1 through which air was forced at a known pace on to the substance under trial1 which met the air current at a certain angle and by means of indicators showed the strength of its 8lift0 or tendency to rise1 and that of its 8drift0 or tendency to move horizontally in the direction of the air-current4 ,a piece of tin1 mounted at an angle of one in ten to the air-current1 showed a 8lift0 of ten times its 8drift40 ,this proportion was made the standard4 ,experiments conducted on velvet1 plush1 silk1 cotton and woollen goods proved that the drift of crape was several times that of its lift1 but that fine linen had a lift equal to nine times its drift2 while a sample of ,spencer's balloon fabric was as good as tin4 ,accordingly he selected this balloon fabric to stretch over light but strong frames4 ,the stretching of the material was no easy matter1 as uneven tension distorted it2 but eventually the aeroplanes were completed1 tight as drumheads4 ,the large or central plane was #ej feet wide and #dj long2 on either side were auxiliary planes1 five pairs2 giving a total area of #edjj square feet4 ,the steam-engine built to give the motive power was perhaps the most interesting feature of the whole construction4 ,maxim employed steam in preference to any other power as being one with which he was most familiar1 and yielding most force in proportion to the weight of the apparatus4 ,he designed and constructed a pair of high-pressure compound engines1 the high-pressure cylinders #e inches in diameter1 the low-pressure #h inches1 and both #a foot stroke4 ,steam was supplied to the high-pressure cylinders at #cbj lbs4 per square inch from a tubular boiler heated by a gasolene burner so powerful in its action as to raise the pressure from #ajj to #bjj lbs4 in a minute4 ,the total weight of the boiler1 burner1 and engines developing #cej horse-power was #bjjj lbs41 or about #f lbs4 per horse-power4 ,the two screw-propellers driven by the engine measured #ag feet #aa inches in diameter4 ,the completed flying-machine1 weighing #gejj lbs41 was mounted on a railway-truck of #i-;foot gauge1 in ,baldwyn's ,park1 ,kent1 not far from the gun-factories for which ,sir ,hiram is famous4 ,outside and parallel to the #i-;foot track was a second track1 #ce feet across1 with a reversed rail1 so that as soon as the machine should rise from the inner track long spars furnished with flanged wheels at their extremities should press against the under side of the outer track and prevent the machine from rising too far4 ,dynamometers1 or instruments for measuring strains1 were fitted to decide the driving and lifting power of the screws4 ,experiments proved that with the engines working at full power the screw-thrust against the air was #bbjj lbs41 and the lifting force of the aeroplanes #aj1jjj lbs41 or #aejj in excess of the machine's weight4 ,everything being ready the machine was fastened to a dynamometer and steam run up until it strained at its tether with maximum power2 when the moorings were suddenly released and it bounded forward at a terrific pace1 so suddenly that some of the crew were flung violently down on to the platform4 ,when a speed of #db miles was reached the inner wheels left their track1 and the outer wheels came into play4 ,unfortunately1 the long #ce-;foot axletrees were too weak to bear the strain1 and one of them broke4 ,the upper track gave way1 and for the first time in the history of the world a flying-machine actually left the ground fully equipped with engines1 boiler1 fuel1 and a crew4 ,the journey1 however1 was a short one1 for part of the broken track fouled the screws1 snapped a propeller blade and necessitated the shutting off of the steam1 which done1 the machine settled to earth1 the wheels sinking into the sward and showing by the absence of any marks that it had come directly downwards and not run along the surface4 ,the inventor was prevented by other business1 and by the want of a sufficiently large open space1 from continuing his experiments1 which had demonstrated that a large machine heavier than air could be made to lift itself and move at high speed4 ,misfortune alone prevented its true capacities being shown4 ,another experimenter on similar lines1 but on a less heroic scale than ,sir ,hiram ,maxim1 is ,professor ,s4 ,p4 ,langley1 the secretary of the ,smithsonian ,institution1 ,washington4 ,for sixteen years he has devoted himself to a persevering course of study of the flying-machine1 and after oft-repeated failures has scored a decided success in his ,aerodrome1 which1 though only a model1 has made considerable flights4 ,his researches have proved beyond doubt that the amount of energy required for flight is but one-fiftieth of what was formerly regarded as a minimum4 ,a ,french mathematician had proved by figures that a swallow must develop the power of a horse to maintain its rapid flight6 ,professor ,langley's aerodrome has told a very different tale1 affording another instance of the truth of the saying that an ounce of practice is worth a pound of theory4 ,a bird is nearly one thousand times heavier than the air it displaces4 ,as a motor it develops huge power for its weight1 and consumes a very large amount of fuel in doing so4 ,an observant naturalist has calculated that the homely robin devours per diem1 in proportion to its size1 what would be to a man a sausage two hundred feet long and three inches thick6 ,any one who has watched birds pulling worms out of the garden lawn and swallowing them wholesale can readily credit this4 ,professor ,langley therefore concentrated himself on the production of an extremely light and at the same time powerful machine4 ,like ,maxim1 he turned to steam for motive-power1 and by rigid economy of weight constructed an engine with boilers weighing #e lbs41 cylinders of #bf ozs41 and an energy of #a to #a-a_/b horse-power6 ,surely a masterpiece of mechanical workmanship6 ,this he enclosed in a boat-shaped cover which hung from two pairs of aeroplanes #ab-a_/b feet from tip to tip4 ,the whole apparatus weighed nearly #cj lbs41 of which one quarter represented the machinery4 ,experiments with smaller aerodromes warned the ,professor that rigidity and balance were the two most difficult things to attain2 also that the starting of the machine on its aerial course was far from an easy matter4 ,a soaring bird does not rise straight from the ground1 but opens its wings and runs along the ground until the pressure of the air raises it sufficiently to give a full stroke of its pinions4 ,also it rises against the wind to get the full benefit of its lifting force4 ,professor ,langley hired a houseboat on the ,potomac ,river1 and on the top of it built an apparatus from which the aerodrome could be launched into space at high velocity4 ,on ,may #f1 #ahif1 after a long wait for propitious weather1 the aerodrome was despatched on a trial trip4 ,it rose in the face of the wind and travelled for over half a mile at the rate of twenty-five miles an hour4 ,the water and fuel being then exhausted it settled lightly on the water and was again launched4 ,its flight on both occasions was steady1 and limited only by the rapid consumption of its power-producing elements4 ,the ,professor believes that larger machines would remain in the air for a long period and travel at speeds hitherto unknown to us4 ,in both the machines that we have considered the propulsive power was a screw4 ,no counterpart of it is seen in ,nature4 ,this is not a valid argument against its employment1 since no animal is furnished with driving-wheels1 nor does any fish carry a revolving propeller in its tail4 ,but some inventors are strongly in favour of copying ,nature as regards the employment of wings4 ,mr4 ,sydney ,h4 ,hollands1 an enthusiastic aeromobilist1 has devised an ingenious cylinder-motor so arranged as to flap a pair of long wings1 giving them a much stronger impulse on the down than on the up stroke4 ,the pectoral muscles of a bird are reproduced by two strong springs which are extended by the upward motion of the wings and store up energy for the down-stroke4 ,close attention is also being paid to the actual shape of a bird's wing1 which is not flat but hollow on its under side1 and at the front has a slightly downward dip4 8,aerocurves0 are therefore likely to supersede the 8aeroplane10 for ,nature would not have built bird's wings as they are without an object4 ,the theory of the aerocurve's action is this3 that the front of the wing1 on striking the air1 gives it a downwards motion1 and if the wing were quite flat its rear portion would strike air already in motion1 and therefore less buoyant4 ,the curvature of a floating bird's wings1 which becomes more and more pronounced towards the rear1 counteracts this yielding of the air by pressing harder upon it as it passes towards their hinder edge4 ,illustration3 ,m4 ,santos ,dumont's ,airship returning to ,longchamps after doubling the ,eiffel ,tower1 ,october #ai1 #aija4 ,the aerocurve has been used by a very interesting group of experimenters1 those who1 putting motors entirely aside1 have floated on wings1 and learnt some of the secrets of balancing in the air4 ,for a man to propel himself by flapping wings moved by legs or arms is impossible4 ,sir ,hiram ,maxim1 in addressing the ,aeronautical ,society1 once said that for a man to successfully imitate a bird his lungs must weigh #dj lbs41 to consume sufficient oxygen1 his breast muscles #ge lbs41 and his breast bone be extended in front #ba inches4 ,and unless his total weight were increased his legs must dwindle to the size of broomsticks1 his head to that of an apple6 ,so that for the present we shall be content to remain as we are6 ,dr4 ,lilienthal1 a ,german1 was the first to try scientific wing-sailing4 ,he became a regular air gymnast1 running down the sides of an artificial mound until the wings lifted him up and enabled him to float a considerable distance before reaching earth again4 ,his wings had an area of #afj square feet1 or about a foot to every pound weight4 ,he was killed by the wings collapsing in mid-air4 ,a similar fate also overtook ,mr4 ,percy ,pilcher1 who abandoned the initial run down a sloping surface in favour of being towed on a rope attached to a fast-moving vehicle4 ,at present ,mr4 ,octave ,chanute1 of ,chicago1 is the most distinguished member of the 8gliding0 school4 ,he employs1 instead of wings1 a species of kite made up of a number of small aerocurves placed one on the top of another a small distance apart4 ,these box kites are said to give a great lifting force for their weight4 ,these and many other experimenters have had the same object in view--to learn the laws of equilibrium in the air4 ,until these are fully understood the construction of large flying-machines must be regarded as somewhat premature4 ,man must walk before he can run1 and balance himself before he can fly4 ,there is no falling off in the number of arial machines and schemes brought from time to time into public notice4 ,we may assure ourselves that if patient work and experiment can do it the problem of 8how to fly0 is not very far from solution at the present moment4 ,as a sign of the times1 the ,war ,office1 not usually very ready to take up a new idea1 has interested itself in the airship1 and commissioned ,dr4 ,f4 ,a4 ,barton to construct a dirigible balloon which combines the two systems of aerostation4 ,propulsion is effected by six sets of triple propellers1 three on each side4 ,ascent is brought about partly by a balloon #ahj feet long1 containing #aef1jjj cubic feet of hydrogen1 partly by nine aeroplanes having a total superficial area of nearly #bjjj square feet4 ,the utilisation of these aeroplanes obviates the necessity to throw out ballast to rise1 or to let out gas for a descent4 ,the airship1 being just heavier than air1 is raised by the #ace horse-power motors pressing the aeroplanes against the air at the proper angle4 ,in descent they act as parachutes4 ,the most original feature of this war balloon is the automatic water-balance4 ,at each end of the 8deck0 is a tank holding forty gallons of water4 ,two pumps circulate water through these tanks1 the amount sent into a tank being regulated by a heavy pendulum which turns on the cock leading to the end which may be highest in proportion as it turns off that leading to the lower end4 ,the idea is very ingenious1 and should work successfully when the time of trial comes4 ,valuable money prizes will be competed for by aeronauts at the coming ,world's ,fair at ,st4 ,louis in #aijc4 ,sir ,hiram ,maxim has expressed an intention of spending #bj1jjj in further experiments and prizes4 ,in this country1 too1 certain journals have offered large rewards to any aeronaut who shall make prescribed journeys in a given time4 ,it has also been suggested that aeronautical research should be endowed by the state1 since ,england has nothing to fear more than the flying machine and the submarine boat1 each of which tends to rob her of the advantages of being an island by exposing her to unexpected and unseen attacks4 ,tennyson1 in a fine passage in 8,locksley ,hall10 turns a poetical eye towards the future4 ,this is what he sees-- 8,for ,i dipt into the future1 far as human eye could see1 ,saw the vision of the world and all the wonder that would be1 ,saw the heavens fill with commerce1 argosies of magic sail1 ,pilots of the purple twilight dropping down with costly bales1 ,heard the heavens fill with shouting1 then there rained a ghostly dew1 ,from the nations' airy navies1 grappling in the central blue40 ,expressed in more prosaic language1 the flying-machine will primarily be used for military purposes4 ,a country cannot spread a metal umbrella over itself to protect its towns from explosives dropped from the clouds4 ,mail services will be revolutionised4 ,the pleasure aerodrome will take the place of the yacht and motor-car1 affording grand opportunities for the mountaineer and explorer 7if the latter could find anything new to explore74 ,then there will also be a direct route to the ,north ,pole over the top of those terrible icefields that have cost civilisation so many gallant lives4 ,and possibly the ease of transit will bring the nations closer together1 and produce good-fellowship and concord among them4 ,it is pleasanter to regard the flying-machine of the future as a bringer of peace than as a novel means of spreading death and destruction4 ,,type-,,setting ,,by ,,machinery4 ,to the ,assyrian brickmakers who1 thousands of years ago1 used blocks wherewith to impress on their unbaked bricks hieroglyphics and symbolical characters1 must be attributed the first hesitating step towards that most marvellous and revolutionary of human discoveries--the art of printing4 ,not1 however1 till the early part of the fifteenth century did ,gutenberg and ,coster conceive the brilliant but simple idea of printing from separate types1 which could be set in different orders and combinations to represent different ideas4 ,for ,englishmen1 #adgd deserves to rank with #ahae1 as in that year a very ,waterloo was won on ,english soil against the forces of ignorance and oppression1 though the effects of the victory were not at once evident4 ,considering the stir made at the time by the appearance of ,caxton's first book at ,westminster1 it seems strange that an invention of such importance as the printing-press should have been frowned upon by those in power1 and so discouraged that for nearly two centuries printing remained an ill-used and unprogressive art1 a giant half strangled in his cradle4 ,yet as soon as prejudice gave it an open field1 improved methods followed close on one another's heels4 ,to-day we have in the place of ,caxton's rude hand-made press great cylinder machines capable of absorbing paper by the mile1 and grinding out #bj1jjj impressions an hour as easily as a child can unwind a reel of cotton4 ,side by side with the problem how to produce the greatest possible number of copies in a given time from one machine1 has arisen another3--how to set up type with a proportionate rapidity4 ,a press without type is as useless as a chaff-cutter without hay or straw4 ,the type once assembled1 as many casts or stereotypes can be made from it as there are machines to be worked4 ,but to arrange a large body of type in a short time brings the printer face to face with the need of employing the expensive services of a small army of compositors--unless he can attain his end by some equally efficient and less costly means4 ,for the last century a struggle has been in progress between the machine compositor and the human compositor1 mechanical ingenuity against eye and brains4 ,in the last five years the battle has turned most decidedly in favour of the machine4 ,to-day there are in existence two wonderful contrivances which enable a man to set up type six times as fast as he could by hand from a box of type1 with an ease that reminds one of the mythical machine for the conversion of live pigs into strings of sausages by an uninterrupted series of movements4 ,these machines are called respectively the ,linotype and ,monotype4 ,roughly described1 they are to the compositor what a typewriter is to a clerk--forming words in obedience to the depression of keys on a keyboard4 ,but whereas the typewriter merely imprints a single character on paper1 the linotype and monotype cast1 deliver1 and set up type from which an indefinite number of impressions can be taken4 ,they meet the compositor more than half-way1 and simplify his labour while hugely increasing his productiveness4 ,as far back as #ahdb periodicals were mechanically composed by a machine which is now practically forgotten4 ,since that time hundreds of other inventions have been patented1 and some scores of different machines tried1 though with small success in most cases2 as it was found that quality of composition was sacrificed to quantity1 and that what at first appeared a short cut to the printing-press was after all the longest way round1 when corrections had all been attended to4 ,a really economical type-setter must be accurate as well as prolific4 ,slipshod work will not pay in the long run4 ,such a machine was perfected a few years ago by ,ottmar ,mergenthaler of ,baltimore1 who devised the plan of casting a whole line of type4 ,the ,linotype ,composing ,machine1 to give it its full title1 produces type all ready for the presses in 8slugs0 or lines--hence the name1 ,lin' o' type4 ,it deserves at least a short description4 ,the ,linotype occupies about six square feet of floor space1 weighs one ton1 and is entirely operated by one man4 ,its most prominent features are a sloping magazine at the top to hold the brass matrices1 or dies from which the type is cast1 a keyboard controlling the machinery to drop and collect the dies1 and a long lever which restores the dies to the magazine when done with4 ,illustration3 ,by kind permission of ,the ,linotype ,co4 ,the ,linotype ,machine4 ,by pressing keys on the key-board the operator causes lines of type to be set up1 cast1 and arranged on the 8galley0 ready for the printers4 ,the operator sits facing the keyboard1 in which are ninety keys1 variously coloured to distinguish the different kinds of letters4 ,his hands twinkle over the keys1 and the brass dies fly into place4 ,when a key is depressed a die shoots from the magazine on to a travelling belt and is whirled off to the assembling-box4 ,each die is a flat1 oblong brass plate1 of a thickness varying with the letter1 having a large ,v-shaped notch in the top1 and the letter cut half-way down on one of the longer sides4 ,a corresponding letter is stamped on the side nearest to the operator so that he may see what he is doing and make needful corrections4 ,as soon as a word is complete1 he touches the 8spacing0 lever at the side of the keyboard4 ,the action causes a 8space0 to be placed against the last die to separate it from the following word4 ,the operations are repeated until the tinkle of a bell warns him that1 though there may be room for one or two more letters1 the line will not admit another whole syllable4 ,the line must therefore be 8justified10 that is1 the spaces between the words increased till the vacant room is filled in4 ,in hand composition this takes a considerable time1 and is irksome2 but at the linotype the operator merely twists a handle and the wedge-shaped 8spaces10 placed thin end upwards1 are driven up simultaneously1 giving the lateral expansion required to make the line of the right measure4 ,a word about the 8spaces10 or space-bands4 ,were each a single wedge the pressure would be on the bottom only of the dies1 and their tops1 being able to move slightly1 would admit lead between them4 ,to obviate this a small second wedge1 thin end downwards1 is arranged to slide on the larger wedge1 so that in all positions parallelism is secured4 ,this smaller wedge is of the same shape as the dies and remains stationary in line with them1 the larger one only moving4 ,the line of dies being now complete1 it is automatically borne off and pressed into contact with the casting wheel4 ,this wheel1 revolving on its centre1 has a slit in it corresponding in length and width to the size of line required4 ,at first the slit is horizontal1 and the dies fit against it so that the row of sunk letters on the faces are in the exact position to receive the molten lead1 which is squirted through the slit from behind by an automatic pump1 supplied from a metal-pot4 ,the pot is kept at a proper heat of #eej ,fahrenheit by the flames of a ,bunsen burner4 ,the lead solidifies in an instant1 and the 8slug0 of type is ready for removal1 after its back has been carefully trimmed by a knife4 ,the wheel revolves for a quarter-turn1 bringing the slit into a vertical position2 a punch drives out the 8slug10 which is slid into the galley to join its predecessors4 ,the wheel then resumes its former horizontal position in readiness for another cast4 ,the assembled dies have for the time done their work and must be returned to the magazine4 ,the mechanism used to effect this is peculiarly ingenious4 ,an arm carrying a ribbed bar descends4 ,the dies are pushed up1 leaving the 8spaces0 behind to be restored to their proper compartment1 till on a level with the ribbed bar1 on to which they are slid by a lateral movement1 the notches of the ,v-shaped opening in the top side of each die engaging with the ribs on the bar4 ,the bar then ascends till it is in line with a longer bar of like section passing over the open top of the entire magazine4 ,a set of horizontal screw-bars1 rotating at high speed1 transfer the dies from the short to the long bar1 along which they move till1 as a die comes above its proper division of the magazine1 the arrangement of the teeth allows it to drop4 ,while all this has been going on1 the operator has composed another line of moulds1 which will in turn be transferred to the casting wheel1 and then back to the magazine4 ,so that the three operations of composing1 casting1 and sorting moulds are in progress simultaneously in different parts of the machine2 with the result that as many as #bj1jjj letters can be formed by an expert in the space of an hour1 against the #aejj letters of a skilled hand compositor4 ,how about corrections8 ,even a comma too few or too many needs the whole line cast over again4 ,it is a convincing proof of the difference in speed between the two methods that a column of type can be corrected much faster by the machine1 handicapped as it is by its solid 8slugs10 than by hand4 ,no wonder then that more than #ajjj linotypes are to be found in the printing offices of ,great ,britain4 ,the ,monotype1 like the ,linotype1 aims at speed in composition1 but in its mechanism it differs essentially from the linotype4 ,in the first place1 the apparatus is constructed in two quite separate parts4 ,there is a keyboard1 which may be on the third floor of the printing offices1 and the casting machine1 which ceaselessly casts and sets type in the basement4 ,yet they are but one whole4 ,the connecting link is the long strip of paper punched by the keyboard mechanism1 and then transferred to the casting machine to bring about the formation of type4 ,the keyboard is the servant of man2 the casting machine is the slave of the keyboard4 ,secondly1 the ,monotype casts type1 not in blocks or a whole line1 but in separate letters4 ,it is thus a complete type-foundry4 ,order it to cast ,g's and it will turn them out by the thousand till another letter is required4 ,thirdly1 by means of the punched paper roll1 the same type can be set up time after time without a second recourse to the keyboard1 just as a tune is ground repeatedly out of a barrel organ4 ,the keyboard has a formidable appearance4 ,it contains #bbe keys1 providing as many characters2 also thirty keys to regulate the spacing of the words4 ,at the back of the machine a roll of paper runs over rollers and above a row of thirty little punches worked by the keys4 ,a key being depressed1 an opened valve admits air into two cylinders1 each driving a punch4 ,the punches fly up and cut two neat little holes in the paper4 ,the roll then moves forward for the next letter4 ,at the end of the word a special lever is used to register a space1 and so on to the end of the line4 ,the operator then consults an automatic indicator which tells him exactly how much space is left1 and how much too long or too short the line would be if the spaces were of the normal size4 ,supposing1 for instance1 that there are ten spaces1 and that there is one-tenth of an inch to spare4 ,it is obvious that by extending each space one-hundredth of an inch the vacant room will be exactly filled4 ,similarly1 if the ten normal spaces would make the line one-tenth of an inch too long1 by decreasing the spaces each one-hundredth inch the line will also be 8justified40 ,illustration3 ,by kind permission of ,the ,monotype ,co4 ,the ,monotype ,casting ,machine4 ,a punched paper roll fed through the top of the machine automatically casts and sets up type in separate letters4 ,but the operator need not trouble his head about calculations of this kind4 ,his indicator1 a vertical cylinder covered with tiny squares1 in each of which are printed two figures1 tell him exactly what he has to do4 ,on pressing a certain key the cylinder revolves and comes to rest with the tip of a pointer over a square4 ,the operator at once presses down the keys bearing the numbers printed on that square1 confident that the line will be of the proper length4 ,as soon as the roll is finished1 it is detached from the keyboard and introduced to the casting machine4 ,hitherto passive1 it now becomes active4 ,having been placed in position on the rollers it is slowly unwound by the machinery4 ,the paper passes over a hollow bar in which there are as many holes as there were punches in the keyboard1 and in precisely the same position4 ,when a hole in the paper comes over a hole in the hollow bar air rushes in1 and passing through a tube actuates the type-setting machinery in a certain manner1 so as to bring the desired die into contact with molten lead4 ,the dies are1 in the monotype1 all carried in a magazine about three inches square1 which moves backwards or forwards1 to right or left1 in obedience to orders from the perforated roll4 ,the dies are arranged in exactly the same way as the keys on the keyboard4 ,so that1 supposing ,a to have been stamped on the roll1 one of the perforations causes the magazine to slide one way1 while the other shoves it another1 until the combined motions bring the matrix engraved with the ,a underneath the small hole through which molten lead is forced4 ,the letter is ejected and moves sideways through a narrow channel1 pushing preceding letters before it1 and the magazine is free for other movements4 ,at the end of each word a 8space0 or blank lead is cast1 its size exactly determined by the 8justifying0 hole belonging to that line4 ,word follows word till the line is complete2 then a knife-like lever rises1 and the type is propelled into the 8galley40 ,though a slave the casting machine will not tolerate injustice4 ,should the compositor have made a mistake1 so that the line is too long or too short1 automatic machinery at once comes into play1 and slips the driving belt from the fixed to the loose pulley1 thus stopping the machine till some one can attend to it4 ,but if the punching has been correctly done1 the machine will work away unattended till1 a whole column of type having been set up1 it comes to a standstill4 ,the advantages of the ,monotype are easily seen4 ,in order to save money a man need not possess the complete apparatus4 ,if he has the keyboard only he becomes to a certain extent his own compositor1 able to set up the type1 as it were by proxy1 at any convenient time4 ,he can give his undivided attention to the keyboard1 stop work whenever he likes without keeping a casting-machine idle1 and as soon as his roll is complete forward it to a central establishment where type is set4 ,there a single man can superintend the completion of half-a-dozen men's labours at the keyboard4 ,that means a great reduction of expense4 ,in due time he receives back his copy in the shape of set-up type1 all ready to be corrected and transferred to the printing machines4 ,the type done with1 he can melt it down without fear of future regret1 for he knows that the paper roll locked up in his cupboard will do its work a second time as well as it did the first4 ,should he need the same matter re-setting1 he has only to send the roll through the post to the central establishment4 ,thanks to ,mr4 ,lanston's invention we may hope for the day when every parish will be able to do its own printing1 or at least set up its own magazine4 ,the only thing needful will be a monotype keyboard supplied by an enlightened ,parish ,council--as soon as the expense appears justifiable--and kept in the ,post ,office or ,village ,institute4 ,the payment of a small fee will entitle the ,squire to punch out his speech on behalf of the ,conservative ,candidate1 the ,schoolmaster to compose special information for his pupils1 the ,rector to reduce to print pamphlets and appeals to charity4 ,and if those of humbler degree think they can strike eloquence from the keys1 they too will of course be allowed to turn out their ideas literally by the yard4 ,,photography ,,in ,,colours4 ,while photography was still in its infancy many people believed that1 a means having been found of impressing the representation of an object on a sensitised surface1 a short time only would have to elapse before the discovery of some method of registering the colours as well as the forms of nature4 ,photography has during the last forty years passed through some startling developments1 especially as regards speed4 ,experts1 such as ,m4 ,marey1 have proved the superiority of the camera over the human eye in its power to grasp the various phases of animal motion4 ,even rifle bullets have been arrested in their lightning flight by the sensitised plate4 ,but while the camera is a valuable aid to the eye in the matter of form1 the eye still has the advantage so far as colour is concerned4 ,it is still impossible for a photographer by a simple process similar to that of making an ordinary black-and-white negative1 to affect a plate in such a manner that from it prints may be made by a single operation showing objects in their natural colours4 ,nor1 for the matter of that1 does colour photography direct from nature seem any nearer attainment now than it was in the time of ,daguerre4 ,there are1 however1 extant several methods of making colour photographs in an indirect or roundabout way4 ,these various 8dodges0 are1 apart from their beautiful results1 so extremely ingenious and interesting that we propose to here examine three of the best known4 ,the reader must be careful to banish from his mind those coloured photographs so often to be seen in railway carriages and shop windows1 which are purely the result of hand-work and mechanical printing1 and therefore not colour photographs at all4 ,before embarking on an explanation of these three methods it will be necessary to examine briefly the nature of those phenomena on which all are based--light and colour4 ,the two are really identical1 light is colour and colour is light4 ,scientists now agree that the sensation of light arises from the wave-like movements of that mysterious fluid1 the omnipresent ether4 ,in a beam of white light several rates of wave vibrations exist side by side4 ,pass the beam through a prism and the various rapidities are sorted out into violet1 indigo1 blue1 green1 yellow1 orange and red1 which are called the pure colours1 since if any of them be passed again through a prism the result is still that colour4 ,crimson1 brown1 c41 the composite colours1 would1 if subjected to the prism1 at once split up into their component pure colours4 ,there are several points to be noticed about the relationship of the seven pure colours4 ,in the first place1 though they are all allies in the task of making white light1 there is hostility among them1 each being jealous of the others1 and only waiting a chance to show it4 ,thus1 suppose that we have on a strip of paper squares of the seven colours1 and look at the strip through a piece of red glass we see only one square--the red--in its natural colour1 since that square is in harmony only with red rays4 7,compare the sympathy of a piano with a note struck on another instrument2 if ,c is struck1 say on a violin1 the piano strings producing the corresponding note will sound1 but the other strings will be silent47 ,the orange square suggests orange1 but the green and blue and violet appear black4 ,red glass has arrested their ether vibrations and said 8no way here40 ,green and violet would serve just the same trick on red or on each other4 ,it is from this readiness to absorb or stop dissimilar rays that we have the different colours in a landscape flooded by a common white sunlight4 ,the trees and grass absorb all but the green rays1 which they reflect4 ,the dandelions and buttercups capture and hold fast all but the yellow rays4 ,the poppies in the corn send us back red only1 and the cornflowers only blue2 but the daisy is more generous and gives up all the seven4 ,colour therefore is not a thing that can be touched1 any more than sound1 but merely the capacity to affect the retina of the eye with a certain number of ether vibrations per second1 and it makes no difference whether light is reflected from a substance or refracted through a substance2 a red brick and a piece of red glass have similar effects on the eye4 ,this then is the first thing to be clearly grasped1 that whenever a colour has a chance to make prisoners of other colours it will do so4 ,the second point is rather more intricate1 viz4 that this imprisonment is going on even when friendly concord appears to be the order of the day4 ,let us endeavour to present this clearly to the reader4 ,of the pure colours1 violet1 green and red--the extremes and the centre--are sufficient to produce white1 because each contains an element of its neighbours4 ,violet has a certain amount of indigo1 green some yellow1 red some orange2 in fact every colour of the spectrum contains a greater or less degree of several of the others1 but not enough to destroy its own identity4 ,now1 suppose that we have three lanterns projecting their rays on to the same portion of a white sheet1 and that in front of the first is placed a violet glass1 in front of the second a green glass1 in front of the third a red glass4 ,what is the result8 ,a white light4 ,why8 ,because they meet on equal terms1 and as no one of them is in a point of advantage no prisoners can be made and they must work in harmony4 ,next1 turn down the violet lantern1 and green and red produce a yellow1 half-way between them2 turn down red and turn up violet1 indigo-blue results4 ,all the way through a compromise is effected4 ,but supposing that the red and green glasses are put in front of the same lantern and the white light sent through them--where has the yellow gone to8 only a brownish-black light reaches the screen4 ,the same thing happens with red and violet or green and violet4 ,prisoners have been taken1 because one colour has had to demand passage from the other4 ,red says to green1 8,you want your rays to pass through me1 but they shall not40 ,green retorts1 8,very well2 but ,i myself have already cut off all but green rays1 and if they don't pass you1 nothing shall40 ,and the consequence of the quarrel is practical darkness4 ,the same phenomenon may be illustrated with blue and yellow4 ,lights of these two colours projected simultaneously on to a sheet yield white2 but white light sent through blue and yellow glass in succession produces a green light4 ,also1 blue paint mixed with yellow gives green4 ,in neither case is there darkness or entire cutting-off of colour1 as in the case of ,red ,violet or ,green ,red4 ,the reason is easy to see4 ,blue light is a compromise of violet and green2 yellow of green and red4 ,hence the two coloured lights falling on the screen make a combination which can be expressed as an addition sum4 ,blue green violet4 ,yellow green red4 -------------------- green violet red white4 ,but when light is passed through two coloured glasses in succession1 or reflected from two layers of coloured paints1 there are prisoners to be made4 ,blue passes green and violet only4 ,yellow passes green and red only4 ,so violet is captured by yellow1 and red by blue1 green being free to pass on its way4 ,there is1 then1 a great difference between the mixing of colours1 which evokes any tendency to antagonism1 and the adding of colours under such conditions that they meet on equal terms4 ,the first process happens1 as we have seen1 when a ray of light is passed through colours in succession2 the second1 when lights stream simultaneously on to an object4 ,a white screen1 being capable of reflecting any colour that falls on to it1 will with equal readiness show green1 red1 violet1 or a combination2 but a substance that is in white light red1 or green1 or violet will capture any other colour4 ,so that if for the white screen we substituted a red one1 violet or green falling simultaneously1 would yield blackness1 because red takes both prisoners2 if it were violet1 green would be captured1 and so on4 ,from this follows another phenomenon3 that whereas projection of two or more lights may yield white1 white cannot result from any mixture of pigments4 ,a person with a whole boxful of paints could not get white were he to mix them in an infinitude of different ways2 but with the aid of his lanterns and as many differently coloured glasses the feat is easy enough4 ,any two colours which meet on equal terms to make white are called complementary colours4 ,thus yellow 7 red green lights7 is complementary of violet4 ,thus pink 7 red violet lights7 is complementary of green4 ,thus blue 7 violet green lights7 is complementary of red4 ,this does not of course apply to mixture of paints1 for complementary colours must act together1 not in antagonism4 ,if the reader has mastered these preliminary considerations he will have no difficulty in following out the following processes4 7a7 ,the ,joly ,process1 invented by ,professor ,joly of ,dublin4 ,a glass plate is ruled across with fine parallel lines--#cej to the inch1 we believe4 ,these lines are filled in alternately with violet1 green1 and red matter1 every third being violet1 green or red as the case may be4 ,the colour-screen is placed in the camera in front of the sensitised plate4 ,upon an exposure being made1 all light reflected from a red object 7to select a colour7 is allowed to pass through the red lines1 but blocked by all the green and violet lines4 ,so that on development that part of the negative corresponding to the position of the red object will be covered with dark lines separated by transparent belts of twice the breadth4 ,from the negative a positive is printed1 which of course shows transparent lines separated by opaque belts of twice their breadth4 ,now1 suppose that we take the colour-screen and place it again in front of the plate in the position it occupied when the negative was taken1 the red lines being opposite the transparent parts of the positive will be visible1 but the green and violet being blocked by the black deposit behind them will not be noticeable4 ,so that the object is represented by a number of red lines1 which at a small distance appear to blend into a continuous whole4 ,the violet and green affect the plate in a corresponding manner2 and composite colours will affect two sets of lines in varying degrees1 the lights from the two sets blending in the eye4 ,thus yellow will obtain passage from both green and red1 and when the screen is held up against the positive1 the light streaming through the green and red lines will blend into yellow in the same manner as they would make yellow if projected by lanterns on to a screen4 ,the same applies to all the colours4 ,the advantage of the ,joly process is that in it only one negative has to be made4 7b7 ,the ,ives ,process4--,mr4 ,frederic ,eugene ,ives1 of ,philadelphia1 arrives at the same result as ,professor ,joly1 but by an entirely different means4 ,he takes three negatives of the same object1 one through a violet-blue1 another through a green1 and a third through a red screen placed in front of the lens4 ,the red negative is affected by red rays only2 the green by green rays only1 and the violet-blue by violet-blue rays only1 in the proper gradations4 ,that is to say1 each negative will have opaque patches wherever the rays of a certain kind strike it2 and the positive printed off will be by consequence transparent at the same places4 ,by holding the positive made from the red-screen negative against a piece of red glass1 we should see light only in those parts of the positive which were transparent4 ,similarly with the green and violet positives if viewed through glasses of proper colour4 ,the most ingenious part of ,mr4 ,ives' method is the apparatus for presenting all three positives 7lighted through their coloured glasses7 to the eye simultaneously4 ,when properly adjusted1 so that their various parts exactly coincide1 the eye blends the three together1 seeing green1 red1 or violet separately1 or blended in correct proportions4 ,the ,kromoscope1 as the viewing apparatus is termed1 contains three mirrors1 projecting the reflections from the positives in a single line4 ,as the three slides are taken stereoscopically the result gives the impression of solidity as well as of colour1 and is most realistic4 7c7 ,the ,sanger ,shepherd ,process4--,this is employed mostly for lantern transparencies4 ,as in the ,ives process1 three negatives and three transparent positives are made4 ,but instead of coloured glasses being used to give effect to the positives the positives themselves are dyed1 and placed one on the top of another in close contact1 so that the light from the lantern passes through them in succession4 ,we have therefore now quitted the realms of harmony for that of discord1 in which prisoners are made2 and ,mr4 ,shepherd has had to so arrange matters that in every case the capture of prisoners does not interfere with the final result1 but conduces to it4 ,in the first place1 three negatives are secured through violet1 green1 and red screens4 ,positives are printed by the carbon process on thin celluloid films4 ,the carbon film contains gelatine and bichromate of potassium4 ,the light acts on the bichromate in such a way as to render the gelatine insoluble4 ,the result is that1 though in the positives there is at first no colour1 patches of gelatine are left which will absorb dyes of various colours4 ,the dyeing process requires a large amount of care and patience4 ,now1 it would be a mistake to suppose that each positive is dyed in the colour of the screen through which its negative was taken4 ,a moment's consideration will show us why4 ,let us assume that we are photographing a red object1 a flower-pot for instance4 ,the red negative represents the pot by a dark deposit4 ,the positive printed off will consequently show clear glass at that spot1 the unaffected gelatine being soluble4 ,so that to dye the plate would be to make all red except the very part which we require red2 and on holding it up to the light the flower-pot would appear as a white transparent patch4 ,how then is the problem to be solved8 ,mr4 ,shepherd's process is based upon an ordered system of prisoner-taking4 ,thus1 as red in this particular case is wanted it will be attained by the other two positives 7which are placed in contact with the red positive1 so that all three coincide exactly71 robbing white light of all but its red rays4 ,now if the other positives were dyed green and violet1 what would happen8 ,they would not produce red1 but by robbing white light between them of red1 green1 and violet1 would produce blackness1 and we should be as far as ever from our object4 ,the positives are therefore dyed1 not in the same colours as the screens used when the negatives were made1 but in their complementary colours1 i4e4 as explained above1 those colours which added to the colour of the screen would make white4 ,the red screen negative is therefore dyed 7violet green7 blue4 ,the green negative 7red violet7 pink4 ,the violet negative 7red green7 yellow4 ,to return to our flower-pot4 ,the red-screen positive 7dyed blue7 is1 as we saw1 quite transparent where the pot should be4 ,but behind the transparent gap are the pink and yellow positives4 ,white light 7 violet green red7 passes through pink 7 violet red71 and has to surrender all its green rays4 ,the violet and red pass on and encounter yellow 7 green red71 and violet falls a victim to green1 leaving red unmolested4 ,if the flower-pot had been white all three positives would have contained clear patches unaffected by the three dyes1 and the white light would have been unobstructed4 ,the gradations and mixtures of colours are obtained by two of the screens being influenced by the colour of the object4 ,thus1 if it were crimson1 both violet and red-screen negatives would be affected by the rays reflected by it1 and the green screen negative not at all4 ,hence the pink positive would be pink1 the yellow clear1 and the blue clear4 ,white light passing through is robbed by pink of green1 leaving red violet crimson4 ,,colour ,,printing4 ,printing in ink colours is done in a manner very similar to the ,sanger ,shepherd lantern slide process4 ,three blocks are made1 by the help of photography1 through violet1 green and red screens1 and etched away with acid1 like ordinary half-tone black-and-white blocks4 ,the three blocks have applied to them ink of a complementary colour to the screen they represent1 just as in the ,sanger ,shepherd process the positives were dyed4 ,the three inks are laid over one another on the paper by the blocks1 the relieved parts of which 7corresponding to the undissolved gelatine of the ,shepherd positives7 only take the ink4 ,white light being reflected through layers of coloured inks is treated in just the same way as it would be were it transmitted through coloured glasses1 yielding all the colours in approximately correct gradations4 ,,lighting4 ,the production of fire by artificial means has been reasonably regarded as the greatest invention in the history of the human race4 ,prior to the day when a man was first able to call heat from the substances about him the condition of our ancestors must have been wretched indeed4 ,raw food was their portion2 metals mingled with other matter mocked their efforts to separate them2 the cold of winter drove them to the recesses of gloomy caverns1 where night reigned perpetual4 ,the production of fire also1 of course1 entailed the creation of light1 which in its developments has been of an importance second only to the improved methods of heating4 ,so accustomed are we to our candles1 our lamps1 our gas-jets1 our electric lights1 that it is hard for us to imagine what an immense effect their sudden and complete removal would have on our existence4 ,at times1 when floods1 explosions1 or other accidents cause a temporary stoppage of the gas or current supply1 a town may for a time be plunged into darkness2 but this only for a short period1 the distress of which can be alleviated by recourse to paraffin lamps1 or the more homely candle4 ,the earliest method of illumination was the rough-and-ready one of kindling a pile of brushwood or logs4 ,the light produced was very uncertain and feeble1 but possibly sufficient for the needs of the cave-dweller4 ,with the advance of civilisation arose an increasing necessity for a more steady illuminant1 discovered in vegetable oils1 burned in lamps of various designs4 ,lamps have been found in old ,egyptian and ,etruscan tombs constructed thousands of years ago4 ,these lamps do not differ essentially from those in use to-day1 being reservoirs fitted with a channel to carry a wick4 ,but probably from the difficulty of procuring oil1 lamps fell into comparative disuse1 or rather were almost unknown1 in many countries of ,europe as late as the fifteenth century2 when the cottage and baronial hall were alike lit by the blazing torch fixed into an iron sconce or bracket on the wall4 ,the rushlight1 consisting of a peeled rush1 coated by repeated dipping into a vessel of melted fat1 made a feeble effort to dispel the gloom of long winter evenings4 ,this was succeeded by the tallow and more scientifically made wax candle1 which last still maintains a certain popularity4 ,how our grandmothers managed to 8keep their eyes0 as they worked at stitching by the light of a couple of candles1 whose advent was the event of the evening1 is now a mystery4 ,to-day we feel aggrieved if our lamps are not of many candle-power1 and protest that our sight will be ruined by what one hundred and fifty years ago would have seemed a marvel of illumination4 ,in the case of lighting necessity has been the mother of invention4 ,the tendency of modern life is to turn night into day4 ,we go to bed late and we get up late2 this is perhaps foolish1 but still we do it4 ,and1 what is more1 we make increasing use of places1 such as basements1 underground tunnels1 and 8tubes10 to which the light of heaven cannot penetrate during any of the daily twenty-four hours4 ,the nineteenth century saw a wonderful advance in the science of illumination4 ,as early as #ahjd the famous scientist1 ,sir ,humphrey ,davy1 discovered the electric arc1 presently to be put to such universal use4 ,about the same time gas was first manufactured and led about in pipes4 ,but before electricity for lighting purposes had been rendered sufficiently cheap the discovery of the huge oil deposits in ,pennsylvania flooded the world with an inexpensive illuminant4 ,as early as the thirteenth century ,marco ,polo1 the explorer1 wrote of a natural petroleum spring at ,baku1 on the ,caspian ,sea3 8,there is a fountain of great abundance1 inasmuch as a thousand shiploads might be taken from it at one time4 ,this oil is not good to use with food1 but it is good to burn2 and is also used to anoint camels that have the mange4 ,people come from vast distances to fetch it1 for in all other countries there is no oil40 ,his last words have been confuted by the ,american oil-fields1 yielding many thousands of barrels a day--often in such quantities that the oil runs to waste for lack of a buyer4 ,the rivals for pre-eminence in lighting to-day are electricity1 coal gas1 petroleum1 and acetylene gas4 ,the two former have the advantage of being easily turned on at will1 like water2 the third is more generally available4 ,the invention of the dynamo by ,gramme in #ahgj marks the beginning of an epoch in the history of illumination4 ,with its aid current of such intensity as to constantly bridge an air-gap between carbon points could be generated for a fraction of the cost entailed by other previous methods4 ,paul ,jablochkoff devised in #ahgf his 8electric candle0--a couple of parallel carbon rods separated by an insulating medium that wasted away under the influence of heat at the same rate as the rods4 ,the 8candles0 were used with rapidly-alternating currents1 as the positive 8pole0 wasted twice as quickly as the negative4 ,during the ,paris ,exhibition of #ahgh visitors to ,paris were delighted by the new method of illumination installed in some of the principal streets and theatres4 ,the arc-lamp of to-day1 such as we see in our streets1 factories1 and railway stations1 is a modification of ,m4 ,jablochkoff's principle4 ,carbon rods are used1 but they are pointed towards each other1 the distance between their extremities being kept constant by ingenious mechanical contrivances4 ,arc-lamps of all types labour under the disadvantage of being1 by necessity1 very powerful2 and were they only available the employment of electric lighting would be greatly restricted4 ,as it is1 we have1 thanks to the genius of ,mr4 ,edison1 a means of utilising current in but small quantities to yield a gentler light4 ,the glow-lamp1 as it is called1 is so familiar to us that we ought to know something of its antecedents4 ,in the arc-lamp the electric circuit is broken at the point where light is required4 ,in glow or incandescent lamps the current is only hindered by the interposition of a bad conductor of electricity1 which must also be incombustible4 ,just as a current of water flows in less volume as the bore of a pipe is reduced1 and requires that greater pressure shall be exerted to force a constant amount through the pipe1 so is an electric current choked by its conductor being reduced in size or altered in nature4 ,edison in #ahgh employed as the current-choker a very fine platinum wire1 which1 having a melting temperature of #cdej degrees ,fahrenheit1 allowed a very white heat to be generated in it4 ,the wire was enclosed in a glass bulb almost entirely exhausted of air by a mercury-pump before being sealed4 ,but it was found that even platinum could not always withstand the heating effect of a strong current2 and accordingly ,edison looked about for some less combustible material4 ,mr4 ,j4 ,w4 ,swan of ,newcastle-on-,tyne had already experimented with carbon filaments made from cotton threads steeped in sulphuric acid4 ,edison and ,swan joined hands to produce the present well-known lamp1 8,the ,ediswan10 the filament of which is a bamboo fibre1 carbonised during the exhaustion of air in the bulb to one-millionth of an atmosphere pressure by passing the electric current through it4 ,these bamboo filaments are very elastic and capable of standing almost any heat4 ,glow-lamps are made in all sizes--from tiny globes small enough to top a tie-pin to powerful lamps of #ajjj candle-power4 ,their independence of atmospheric air renders them most convenient in places where other forms of illumination would be dangerous or impossible2 e4g4 in coal mines1 and under water during diving operations4 ,by their aid great improvements have been effected in the lighting of theatres1 which require a quick switching on and off of light4 ,they have also been used in connection with minute cameras to explore the recesses of the human body4 ,in libraries they illuminate without injuring the books4 ,in living rooms they do not foul the air or blacken the ceiling like oil or gas burners4 ,the advantages of the 8,edison lamp0 are1 in short1 multitudinous4 ,cheapness of current to work them is1 of course1 a very important condition of their economy4 ,in some small country villages the cottages are lit by electricity even in ,england1 but these are generally within easy reach of water power4 ,mountainous districts1 such as ,norway and ,switzerland1 with their rushing streams and high water-falls1 are peculiarly suited for electric lighting3 the cost of which is mainly represented by the expense of the generating apparatus and the motive power4 ,one of the greatest engineering undertakings in the world is connected with the manufacture of electric current4 ,niagara1 the 8,thunder of the ,waters0 as the ,indians called it1 has been harnessed to produce electrical energy1 convertible at will into motion1 heat1 or light4 ,the falls pass all the water overflowing from nearly #ajj1jjj square miles of lakes1 which in turn drain a far larger area of territory4 ,upwards of #aj1jjj cubic yards of water leap over the falls every second1 and are hurled downwards for more than #bjj feet1 with an energy of eight or nine million horse-power6 ,in #ahhf a company determined to turn some of this huge force to account4 ,they bought up land on the ,american bank1 and cut a tunnel #fgjj yards long1 beginning a mile and a half above the falls1 and terminating below them4 ,water drawn from the river thunders into the tunnel through a number of wheel pits1 at the bottom of each of which is a water-turbine developing #ejjj horse-power4 ,the united force of the turbines is said to approximate #ajj1jjj horse-power2 and as if this were but a small thing1 the same ,company has obtained concessions to erect plant on the ,canadian bank to double or treble the total power4 ,so cheaply is current thus produced that the ,company is in a position to supply it at rates which appear small compared with those that prevail in this country4 ,a farthing will there purchase what would here cost from ninepence to a shilling4 ,under such conditions the electric lamp need fear no competitor4 ,but in less favoured districts gas and petroleum are again holding up their heads4 ,both coal and oil-gas develop a great amount of heat in proportion to the light they yield4 ,the hydrogen they contain in large quantities burns1 when pure1 with an almost invisible flame1 but more hotly than any other known gas4 ,the particles of carbon also present in the flame are heated to whiteness by the hydrogen1 but they are not sufficient in number to convert more than a fraction of the heat into light4 ,a ,german1 ,auer von ,welsbach1 conceived the idea of suspending round the flame a circular 8mantle0 of woven cotton steeped in a solution of certain rare earths 7e4g4 lanthanum1 yttrium1 zirconium71 to arrest the heat and compel it to produce bright incandescence in the arresting substance4 ,with the same gas consumption a ,welsbach burner yields seven or more times the light of an ordinary batswing burner4 ,the light itself is also of a more pleasant description1 being well supplied with the blue rays of the spectrum4 ,the mantle is used with other systems than the ordinary gas-jet4 ,recently two methods of illumination have been introduced in which the source of illumination is supplied under pressure4 ,the high-pressure incandescent gas installations of ,mr4 ,william ,sugg supply gas to burners at five or six times the ordinary pressure of the mains4 ,the effect is to pulverise the gas as it issues from the nozzle of the burners1 and1 by rendering it more inflammable1 to increase its heating power until the surrounding mantle glows with a very brilliant and white light of great penetration4 ,gas is forced through the pipes connected with the lamps by hydraulic rams working gas-pumps1 which alternately suck in and expel the gas under a pressure of twelve inches 7i4e4 a pressure sufficient to maintain a column of water twelve inches high74 ,the gas under this pressure passes into a cylinder of a capacity considerably greater than the capacity of the pumps4 ,this cylinder neutralises the shock of the rams1 when the stroke changes from up-to downstroke1 and vice vers4 ,on the top of the cylinder is fixed a governor consisting of a strong leathern gas-holder1 which has a stroke of about three inches1 and actuates a lever which opens and closes the valve through which the supply of water to the rams flows1 and reduces the flow of the water when it exceeds ten or twelve inches pressure1 according to circumstances4 ,the gas-holder of the governor is lifted by the pressure of the gas in the cylinder1 which passes through a small opening from the cylinder to the governor so as not to cause any sudden rise or fall of the gas-holder4 ,by this means a nearly constant pressure is maintained2 and from the outlet of the cylinder the gas passes to another governor sufficient to supply the number of lights the apparatus is designed for1 and to maintain the pressure without variation whether all or a few lamps are in action4 ,for very large installations steam is used4 ,each burner develops #cjj candle-power4 ,a double-cylinder steam-engine working a double pump supplies #cjj of these burners1 giving a total lighting-power of #ij1jjj candles4 ,as compared with the cost of low-pressure incandescent lighting the high-pressure system is very economical1 being but half as expensive for the same amount of light4 ,it is largely used in factories and railway stations4 ,it may be seen on the ,tower ,bridge1 ,blackfriars ,bridge1 ,euston ,station1 and in the terminus of the ,great ,central ,railway1 ,st4 ,john's ,wood4 ,perhaps the most formidable rival to the electric arc-lamp for the lighting of large spaces and buildings is the ,kitson ,oil ,lamp1 now so largely used in ,america and this country4 ,the lamp is usually placed on the top of an iron post similar to an ordinary gas-light standard4 ,at the bottom of the post is a chamber containing a steel reservoir capable of holding from five to forty gallons of petroleum4 ,above the oil is an air-space into which air has been forced at a pressure of fifty lbs4 to the square inch1 to act as an elastic cushion to press the oil into the burners4 ,the oil passes upwards through an extremely fine tube scarcely thicker than electric incandescent wires to a pair of cross tubes above the burners4 ,the top one of these acts as a filter to arrest any foreign matter that finds its way into the oil2 the lower one1 in diameter about the size of a lead-pencil and eight inches long1 is immediately above the mantles1 the heat from which vaporises the small quantity of oil in the tube4 ,the oil-gas then passes through a tiny hole no larger than a needle-point into an open mixing-tube where sufficient air is drawn in for supporting combustion4 ,the mixture then travels down to the mantle1 inside which it burns4 ,an ingenious device has lately been added to the system for facilitating the lighting of the lamp4 ,at the base of the lamp-post a small hermetically-closed can containing petroleum ether is placed1 and connected by very fine copper-tubing with a burner under the vaporising tube4 ,when the lamp is to be lit a small rubber bulb is squeezed1 forcing a quantity of the ether vapour into the burner1 where it is ignited by a platinum wire rendered incandescent by a current passing from a small accumulator also placed in the lamp-post4 ,the burner rapidly heats the vaporising tube1 and in a few moments oil-gas is passing into the mantles1 where it is ignited by the burner4 ,so economical is the system that a light of #ajjj candle-power is produced by the combustion of about half-a-pint of petroleum per hour6 ,comparisons are proverbially odious1 but in many cases very instructive4 ,professor ,v4 ,b4 ,lewes thus tabulates the results of experiments with various illuminants3-- ,cost of #ajjj candles per hour4 s4 d4 ,electricity ,per unit1 #c-a_/b;d4 ,incandescent1 #a #b ,arc1 #j #c-c_/d ,coal-gas ,flat flame1 #a #f ,incandescent1 #j #b-a_/d high pressure1 #j #a-c_/d ,oil ,lamp 7oil at #h;d4 per gall471 #j #g-a_/d ,incandescent lamp1 #j #b-a_/d ,kitson lamp1 #j #a ,petroleum1 therefore1 at present comes in a very good first in ,england4 ,the system that we have noticed at some length has been adapted for lighthouse use1 as it gives a light peculiarly fog-piercing4 ,it is said to approximate most closely to ordinary sunlight1 and on that account has been found very useful for the taking of photographs at night-time4 ,the portability of the apparatus makes it popular with contractors2 and the fact that its installation requires no tearing up of the streets is a great recommendation with the long-suffering public of some of our large towns4 ,another very powerful light is produced by burning the gas given off by carbide of calcium when immersed in water4 ,acetylene gas1 as it is called1 is now widely used in cycle and motor lamps1 which emit a shaft of light sometimes painfully dazzling to those who have to face it4 ,in ,germany the gas is largely employed in village streets2 and in this country it is gaining ground as an illuminant of country houses1 being easy to manufacture--in small gasometers of a few cubic yards capacity--and economical to burn4 ,well supplied as we are with lights1 we find1 nevertheless1 that savants are constantly in pursuit of an ideal illuminant4 ,from the sun are borne to us through the ether light waves1 heat waves1 magnetic waves1 and other waves of which we have as yet but a dim perception4 ,the waves are commingled1 and we are unable to separate them absolutely4 ,and as soon as we try to copy the sun's effects as a source of heat or light we find the same difficulty4 ,the fire that cooks our food gives off a quantity of useless light-waves2 the oil-lamp that brightens one's rooms gives off a quantity of useless1 often obnoxious1 heat4 ,the ideal illuminant and the ideal heating agent must be one in which the required waves are in a great majority4 ,unfortunately1 even with our most perfected methods1 the production of light is accompanied by the exertion of a disproportionate amount of wasted energy4 ,in the ordinary incandescent lamp1 to take an instance1 only #e or #f per cent4 of the energy put into it as electricity results in light4 ,the rest is dispelled in overcoming the resistance of the filament and agitating the few air-molecules in the bulb4 ,to this we must add the fact that the current itself represents but a fraction of the power exerted to produce it4 ,the following words of ,professor ,lodge are to the point on this subject3-- 8,look at the furnaces and boilers of a steam-engine driving a group of dynamos1 and estimate the energy expended2 and then look at the incandescent filaments of the lamps excited by them1 and estimate how much of their radiated energy is of real service to the eye4 ,it will be as the energy of a pitch-pipe to an entire orchestra4 8,it is not too much to say that a boy turning a handle could1 if his energy were properly directed1 produce quite as much real light as is produced by all this mass of mechanism and consumption of material40#f #f ,professor ,oliver ,lodge1 in a lecture to the ,ashmolean ,society1 #crd ,june #ahhi4 ,the most perfect light in nature is probably that of the glow-worm and firefly--a phosphorescent or 8cold0 light1 illuminating without combustion owing to the absence of all waves but those of the requisite frequency4 ,the task before mankind is to imitate the glow-worm in the production of isolated light-waves4 ,the nearest approach to its achievement has occurred in the laboratories of ,mr4 ,nikola ,tesla1 the famous electrician4 ,by means of a special oscillator1 invented by himself1 he has succeeded in throwing the ether particles into such an intense state of vibration that they become luminous4 ,in other words1 he has created vibrations of the enormous rapidity of light1 and this without the creation of heat waves to any appreciable extent4 ,an incandescent lamp1 mounted on a powerful coil1 is lit without contact by ether waves transmitted from a cable running round the laboratory1 or bulbs and tubes containing highly rarefied gases are placed between two large plate-terminals arranged on the end walls4 ,as soon as the bulbs are held in the path of the currents passing through the ether from plate to plate they become incandescent1 shining with a light which1 though weak1 is sufficiently strong to take photographs by with a long exposure4 ,tesla has also invented what he calls a 8sanitary0 light1 as he claims for it the germ-killing properties of sunshine4 ,the lamps are glass tubes several feet long1 bent into spirals or other convolutions1 and filled before sealing with a certain gas4 ,the ends of the glass tube are coated with metal and provided with hooks to connect the lamp with an electric current4 ,the gas becomes luminous under the influence of current1 but not strictly incandescent1 as there is very little heat engendered4 ,this means economy in use4 ,the lamps are said to be cheaply manufactured1 but as yet they are not 8on the market40 ,we shall hear more of them in the near future1 which will probably witness no more interesting development than that of lighting4 ,before closing this chapter a few words may be said about new heating methods4 ,gas stoves are becoming increasingly popular by reason of the ease with which they can be put in action and made to maintain an even temperature4 ,but the most up-to-date heating apparatus is undoubtedly electrical4 ,utensils of all sorts are fitted with very thin heating strips 7formed by the deposition of precious metals1 such as gold1 platinum1 c41 on exceedingly thin mica sheets71 through which are passed powerful currents from the mains4 ,the resistance of the strip converts the electromotive energy of the current into heat1 which is either radiated into the air or into water for cookery1 c4 ,in all parts of the house the electric current may be made to do work besides that of lighting4 ,it warms the passages by means of special radiators--replacing the clumsy coal and 8stuffy0 gas stove2 in the kitchen it boils1 stews1 and fries1 heats the flat-irons and ovens2 in the breakfast room boils the kettle1 keeps the dishes1 teapots1 and coffee-pots warm2 in the bathroom heats the water2 in the smoking-room replaces matches2 in the bedroom electrifies footwarmers1 and--last wonder of all--even makes possible an artificially warm bed-quilt to heat the chilled limbs of invalids6 ,the great advantage of electric heating is the freedom from all smell and smoke that accompanies it4 ,but until current can be provided at cheaper rates than prevail at present1 its employment will be chiefly restricted to the houses of the wealthy or to large establishments1 such as hotels1 where it can be used on a sufficient scale to be comparatively economical4 ,,the ,,end ,printed by ,,ballantyne1 ,,hanson ,,co4 ,edinburgh ,london 99 99 99 99 99 ,the ,romance of ,modern ,invention ,,by ,,the ,,same ,,author ,uniform with this ,volume ,,the ,,romance ,,of ,,modern ,,engineering ,containing ,interesting ,descriptions in ,non-,technical ,language of the ,nile ,dam1 the ,panama ,canal1 the ,tower ,bridge1 the ,brooklyn ,bridge1 the ,trans-,siberian ,railway1 the ,niagara ,falls ,power ,co41 ,bermuda ,floating ,dock1 etc4 etc4 8,a series of descriptions which rival one another in lucidity of explanation and in interest1 both of subject and treatment40--,manchester ,courier4 8,men of any age will be interested in this volume2 boys will be fascinated by it40--,spectator4 8,if there lives a boy who is fond of engineering and speaks the ,english tongue1 this is the book for him40--,the ,bookman4 ,with #bd ,illustrations4 ,gilt edges4 ,price #es4 ,,the ,,romance ,,of ,,modern ,,locomotion ,containing ,interesting ,descriptions in ,non-,technical ,language of the ,rise and ,development of the ,railroad ,systems in all ,parts of the ,world4 8,the book is crisply written1 is brimful of incident not less than instruction1 and should be as welcome to an intelligent lad as a ,ballantyne story or a ,mayne ,reid romance40--,glasgow ,herald4 ,with #be ,illustrations4 ,crown #hvo1 cloth ,gilt1 ,gilt edges4 ,price #es4 99 99 99 99 99 ,,uniform ,,with ,,this ,,volume ,,the ,,library ,,of ,,romance ,extra ,crown #hvo4 ,with many illustrations1 #es4 each 8,messrs4 ,seeley's well-known series of gift books1 finely illustrated and in most attractive bindings40 ,the ,northern ,whig4 8,these popular natural history books are written by competent authorities1 and besides being entertaining are instructive and educative40--,the ,liverpool ,courier4 ,by ,prof4 ,g4 ,f4 ,,scott ,,elliot1 ,m4,a41 ,b4,sc4 ,,the ,,romance ,,of ,,plant ,,life ,by ,h4 ,,coupin1 ,d4,sc41 ,,john ,,lea1 ,b4,a4 ,,the ,,romance ,,of ,,animal ,,arts ,,and ,,crafts ,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 ,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 ,,electricity ,by ,,edmund ,,selous ,,the ,,romance ,,of ,,the ,,animal ,,world ,,the ,,romance ,,of ,,insect ,,life ,by ,,agnes ,,giberne ,,the ,,romance ,,of ,,the ,,mighty ,,deep ,,seeley ,co41 ,,limited