,illustration ,,scientific ,,american ,,supplement ,,no4 #ddc4 ,,new ,,york1 ,,june #bh1 #ahhd4 ,scientific ,american ,supplement4 ,vol4 ,,xvii41 ,no4 #ddc4 ,scientific ,american established #ahde ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 99 99 99 99 99 ,,table ,,of ,,contents4 ,i4 ,,chemistry ,,and ,,metallurgy4--,beeswax and its ,adulterations4 --,chemical ingredients4--,detection of adulterations4 #gjfd ,phenol in the ,stem1 ,leaves1 and ,cones of ,pinus ,sylvestris4 --,a discovery bearing on the flora of the ,carboniferous epoch and the formation of petroleum4 #gjfe ,the ,school of ,physics and ,chemistry of ,paris4--,with engraving of laboratory4 #gjfe ,some ,relations of ,heat to ,voltaic and ,thermo ,electric ,action of ,metals in ,electrolysis4--,by ,g4 ,,gore4 #gjgj ,,ii4 ,,engineering1 ,,mechanics1 ,,etc4--,air ,refrigerating ,machine4--#e figures4 #gjga ,a ,gas ,radiator and ,heater4 #gjga ,concrete ,water ,pipes4 #gjga ,the ,sellers ,standard ,system of ,screw ,threads4 ,nuts1 and ,bolt ,heads4--,a table4 #gjgb ,an ,english ,railway ,ferry ,boat4--#c figures4 #gjgb ,the ,problem of ,flight and the ,flying ,machine4 #gjgb ,,iii4 ,,technical4--,concrete ,buildings for ,farms4--,how to construct them4 #gjfc ,what ,causes ,paint to ,blister and ,peel8--,how to prevent it4 #gjfc ,olive ,oil4--,difficulties encountered in raising an olive crop4--,process of making ,oil4 #gjfd ,,iv4 ,,electricity4 ,,etc4--,telephony and ,telegraphy on the ,same ,wires ,simultaneously4--#d figures4 #gjfg ,the ,electric ,marigraph4--,an apparatus for measuring the height of the tide4--,with engravings and diagrams showing the ,siemens and ,halske marigraph and the operation of the same4 #gjfh ,delune ,co4's ,system of ,laying ,underground ,cables4--#b figures4 #gjfi ,electricity ,applied to ,horseshoeing4--,quieting an unruly animal4--#c engravings4 #gjfi ,esteve's ,automatic ,pile4--#a figure4 #gjgj ,woodward's ,diffusion ,motor4 #gjgj ,v4 ,,astronomy4--,lunar ,heat4--,its reflected and obscure heat4--,trifling influence of the moon upon wind and weather4--,by ,prof4 ,c4,a4 ,,young4 #gjgc ,,vi4 ,,natural ,,history4--,the ,long-haired ,pointer ,mylord4 --,with engraving4 #gjgc ,,vii4 ,,horticulture1 ,,etc4--,apple ,tree ,borers4--,protection against the same4 #gjgd ,keffel's ,germinating ,apparatus4--,with engraving4 #gjgd ,millet4--,its ,cultivation4 #gjgd ,,viii4 ,,miscellaneous4--,puerta del ,sol1 ,madrid1 ,spain4--,with engraving4 #gjfc ,dust-free ,spaces4--,a lecture delivered by ,dr4 ,,oliver ,j4 ,,lodge before the ,royal ,dublin ,society4 #gjfg 99 99 99 99 99 ,,puerta ,,del ,,sol1 ,,madrid4 ,puerta del ,sol1 or ,gate of the ,sun1 ,madrid1 is the most famous and favorite public square in the ,spanish city of ,madrid4 ,it was the eastern portal of the old city4 ,from this square radiate several of the finest streets1 such as ,alcala1 one of the handsomest thoroughfares in the world1 ,mayor1 ,martera1 ,carretas1 ,geronimo4 ,in our engraving the post office is seen on the right4 ,large and splendid buildings adorn the other sides1 which embrace hotels1 cafes1 reading rooms1 elegant stores1 etc4 ,from this square the street railway lines traverse the city in all directions4 ,the population of the city is about #djj1jjj4 ,it contains many magnificent buildings4 ,our engraving is from ,illustrirte ,zeitung4 ,illustration3 ,,the ,,puerta ,,del ,,sol1 ,,madrid1 ,,spain 7,from a ,photograph47 99 99 99 99 99 ,,concrete ,,buildings ,,for ,,farms4 ,buildings made of concrete have never received the attention in this country that they deserve4 ,they have the merit of being durable and fire-proof1 and of not being liable to be blown down by violent winds4 ,it is very easy to erect them in places where sand and gravel are near at hand and lime is comparatively cheap4 ,experiments made in ,england show that coal screenings may be employed to good advantage in the place of sand and gravel4 ,mr4 ,samuel ,preston1 of ,mount ,carroll1 ,ill41 has a dwelling and several other buildings made of concrete and erected by himself4 ,they were put up in #ahea1 and are in excellent condition4 ,in ,the ,farmers' ,review he gives the following directions for building concrete walls3 ,first1 secure a good stone foundation1 the bottom below frost1 the top about one foot above ground4 ,near the top of the foundation bed in #bd scantling edgewise transversely with the walls1 at such distances apart as the length of the planks that form the boxes to hold the concrete may require1 the ends of the scantling to run six inches beyond the outside and inside of the wall4 ,now take #bf studding1 one foot longer than the height of the concrete walls are to be1 bolt in an upright position in pairs to each end of the #bd scantling1 and1 if a foot wall is to be built1 sixteen inches apart1 as the box plank will take up four inches4 ,to hold the studding together at the top1 take pieces of #bf lumber1 make two mortises in each piece large enough to slip easily up and down on the studding1 forming a tie4 ,make one mortise long enough to insert a key1 so that the studding can be opened at the top when the box plank are to be raised4 ,when the box plank are in position1 nail cleats with a hole in each of them on each side of the studding1 and corresponding holes in the studding1 into which insert a pin to hold the plank to the studding4 ,bore holes along up in the studding1 to hold the boxes when raised4 ,to make the walls hollow1 and ,i would do it in a building for any purpose1 use inch boards the same width of the box plank1 one side planed2 put the two rough sides together with shingles between1 nailing them together with six-penny nails2 place them in the middle of the wall1 the thin end of the shingle down4 ,that gives them a bevel and can be easily raised with the boxes4 ,to tie the wall together1 at every third course place strips of boards a little shorter than the thickness of the wall2 cut notches in each so that the concrete will fill in1 holding all fast4 ,the side walls being up1 place two inch planks on top of the wall upon which to rest the upper joists1 put on joist and rafters1 remove the box plank1 take inch boards for boxes1 cut to fit between joists and rafters1 and fill with concrete to upper side of rafters1 which makes walls that will keep out cold and damp1 all kinds of vermin1 and a roof which nothing but a cyclone can remove4 ,in making door and window frames1 make the jambs two inches narrower than the thickness of the walls1 nailing on temporary two inch strips4 ,make the mortar bed large enough to hold the material for one course2 put in unslaked quicklime in proportion to #a to #bj or #cj of other material2 throw into it plenty of water1 and don't have that antediluvian idea that you can drown it2 put in clean sand and gravel1 broken stone1 making it thin enough1 so that when it is put into boxes the thinner portion will run in1 filling all interstices1 forming a solid mass4 ,a brick trowel is necessary to work it down alongside the boxing plank4 ,one of the best and easiest things to carry the concrete to the boxes is a railroad wheelbarrow1 scooping it in with a scoop shovel4 ,two courses a week is about as fast as it will be safe to lay up the walls4 99 99 99 99 99 ,the ,medical ,summary recommends the external use of buttermilk to ladies who are exposed to tan or freckles4 99 99 99 99 99 ,,what ,,causes ,,paint ,,to ,,blister ,,and ,,peel8 ,,how ,,to ,,prevent ,,it4 ,this subject has been treated by many1 but out of the numerous ideas that have been brought to bear upon it1 the writers have failed to elucidate the question fully1 probably owing to the fact that in most parts they were themselves dubious as to the real cause4 ,last year ,w4,s4 gave a lengthy description in the ,building ,news1 in which he classified blistering and peeling of paint into one of blistering only4 ,he stated in the beginning of his treatise the following3 ,the subject of blistering of paint has from time to time engrossed the attention of practical men2 but so far as we can follow it in the literature pertaining to the building trade1 its cause has never been clearly laid down1 and hence it is a detail enshrouded in mystery4 ,w4,s4 dwells mostly1 in his following explanations on blistering paints1 on steam raised in damp wood4 ,also an ,english painter1 according to the ,painters' ,journal1 lately reiterates the same theory1 and gives sundry reasons how water will get into wood through paint1 but is oblivious that the channels which lead water into wood are open to let it out again4 ,he lays great stress on boiled oil holding water in suspense to cause blistering1 which is merely a conjecture4 ,water boils at #bab ,f4 and linseed oil at #fjj ,f41 consequently no water can possibly remain after boiling1 and a drop of water put into boiling oil would cause an explosion too dangerous to be encountered4 ,it will be shown herewith that boiled oil1 though in general use1 is unfit for durable painting1 that it is the cause of most of the troubles painters have to contend with1 and that raw linseed oil seasoned by age is the only source to bind pigments for durable painting2 but how to procure it is another trouble to overcome1 as all our ,american raw linseed oil has been heated by the manufacturers1 to qualify it for quick drying and an early market1 thereby impairing its quality4 ,after linseed oil has been boiled1 it becomes a poor varnish2 it remains soft and pliable when used in paint1 giving way to air pressure from the wood in hot weather1 forming blisters4 ,turpentine causes no blistering2 it evaporates upon being exposed1 and leaves the paint in a porous condition for the gas in the wood to escape2 but all painters agree that blistering is caused by gas1 and on investigation we find two main sources from which gas is generated to blister paint--one from the wood1 the other from the ingredients of the paint4 ,the first named source of gas is started in hot weather by expansion of air confined in painted wood1 which presses against the paint and raises blisters when the paint is too soft to resist4 ,tough1 well-cemented paint resists the pressure and keeps the air back4 ,these blisters mostly subside as soon as the air cools and returns to the pores1 but subsequently peel off4 ,w4,s4 and others assert that damp in painted wood turns into steam when exposed to sun heat1 forming blisters1 which cannot be possible when we know that water does not take a gaseous form 7steam7 at less than #bab ,f4 ,they have very likely been deluded by the known way of distilling water with the aid of sunshine without concentrating the rays of the sun1 based upon the solubility of water in air1 viz43 ,air holds more water in solution 7or suspension7 in a warmer than in a cooler degree of temperature2 by means of a simple apparatus sun-heated air is guided over sun-heated water1 when the air saturated with water is conducted into a cooler1 to give up its water again4 ,but water has an influence toward hastening to blister paint2 it holds the unhardened woodsap in solution1 forming a slight solvent of the oil1 thereby loosening the paint from the wood1 favoring blistering and peeling4 ,there is a certain kind of blister which appears in certain spots or places only1 and nowhere else1 puzzling many painters4 ,the explanation of this is the same as before--soft paint at these spots1 caused by accident or sluggish workmen having saturated the wood with coal oil1 wax1 tar1 grease1 or any other paint-softening material before the wood was painted1 which reacts on the paint to give way to air pressure1 forming blisters4 ,the second cause of paint blistering from the ingredients of the paint happens between any layer of paint or varnish on wood1 iron1 stone1 or any other substance4 ,its origin is the gaseous formation of volatile oils during the heated season1 of which the lighter coal oils play the most conspicuous part2 they being less valuable than all other volatile oils1 are used in low priced japan driers and varnishes4 ,these volatile oils take a gaseous form at different temperatures1 lie partly dormant until the thermometer hovers at #ij ,f4 in the shade1 when they develop into gas1 forming blisters in airtight paint1 or escape unnoticed in porous paint4 ,this is the reason why coal-tar paint is so liable to blister in hot weather2 an elastic1 soft coal-tar covering holds part of its volatile oil confined until heated to generate into gas2 a few drops only of such oil is sufficient to spoil the best painted work1 and worse1 when it has been applied in priming1 it settles into the pores of the wood1 needing often from two to three repetitions of scraping and repainting before the evil is overcome4 ,now1 inasmuch as soft drying paint is unfit to answer the purpose1 it is equally as bad when paint too hard or brittle has been used1 that does not expand and contract in harmony with the painted article1 causing the paint to crack and peel off1 which is always the case when either oil or varnish has been too sparingly and turpentine too freely used4 ,intense cold favors the action1 when all paints become very brittle1 a fact much to be seen on low-priced vehicles in winter time4 ,damp in wood will also hasten it1 as stated in blistering1 the woodsap undermining the paint4 ,to avoid peeling and blistering1 the paint should be mixed with raw linseed oil in such proportions that it neither becomes too brittle nor too soft when dry4 ,priming paint with nearly all oil and hardly any pigment is the foundation of many evils in painting2 it leaves too much free oil in the paint1 forming a soft undercoat4 ,for durable painting1 paint should be mixed with as much of a base pigment as it can possibly be spread with a brush1 giving a thin coat and forming a chemical combination called soap4 ,to avoid an excess of oil1 the following coats need turpentine to insure the same proportion of oil and pigment4 ,as proof of this1 prime a piece of wood and a piece of iron with the same paint2 when the wood takes up part of the oil from the paint and leaves the rest in proportion to harden well1 where at the same time the paint on iron remains soft4 ,to be more lucid1 it need be explained1 linseed oil boiled has lost its oleic acid and glycerine ether1 which form with the bases of pigments the insoluble soap1 as well as its albumen1 which in boiling is thrown out4 ,it coagulates at #afj ,f4 heat2 each is needed to better withstand the action of wind and weather1 preventing the dust from attaching itself to a painted surface1 a channel for ammonia in damp weather to dissolve and wash off the paint4 ,in later years linseed oil has been extracted from linseed meal by the aid of naphtha and percolation1 the product of a very clear1 quick drying oil1 but lacking in its binding quality1 no doubt caused by the naphtha dissolving the fatty matter only1 leaving the glycerine and albumen in the meal4 ,all pigments of paint group according to their affinity to raw linseed oil into three classes4 ,first1 those that form chemical combinations1 called soap4 ,this kind is the most durable1 is used for priming purposes1 and consists of lead1 zinc1 and iron bases1 of which red lead takes up the most oil2 next1 white lead1 the pure carbonate ,dutch process made1 following with zinc white and iron carbonates1 as iron ore paint1 ,turkey umber1 yellow ocher2 also faintly the chromates of lead--chrome-green and chrome-yellow1 finishing with the poorest of all1 modern white lead1 made by the wet or vinegar process4 ,the second class being neutrals have no chemical affinity to linseed oil2 they need a large quantity of drier to harden the paint1 and include all blacks1 vermilion1 ,prussian1 ,paris1 and ,chinese blue1 also terra di ,sienna1 ,vandyke brown1 ,paris green1 verdigris1 ultramarine1 genuine carmine1 and madderlake4 ,the last seven are1 on account of their transparency1 better adapted for varnish mixtures--glazing4 ,the third class of pigments act destructively to linseed oil2 they having an acid base 7mostly tin salt1 hydrochloride of tin1 and redwood dye71 form with the gelatinous matter of the oil a jelly that will neither work well under the brush nor harden sufficiently1 and can be used in varnish for glazing only2 they are not permanent in color1 and among the most troublesome are the lower grades of so-called carmines1 madderlakes1 rose pinks1 etc41 which contain more or less acidous dyes1 forming a soft paint with linseed oil that once dry on a job can be twisted or peeled off like the skin of a ripe peach4 ,all these combinations of paint have to be closely observed by the painter to insure his success4 ,twenty-five years ago a house needed to be painted outside but once in from five to seven years2 it looked well all the time1 as no dust settled in the paint to make it unsightly4 ,painters then used the ,dutch-process-made white-lead1 a base and raw linseed oil1 a fat acid1 which formed the insoluble soap4 ,they also put turpentine in the following coats1 to keep up the proportions of oil and pigment4 ,all held out well against wind and weather4 ,now they use the wet-process-made white lead1 neutralized by vinegar1 with oil neutralized by boiling1 from the first to the last coat1 and--fail in making their work permanent4 ,w4,s41 in the ,building ,news1 relates an unaccountable mysterious blistering in a leaky house1 where the rainwater came from above on a painted wood wall1 blistering the paint in streaks and filled at the lower ends with water1 which no doubt was caused by the water soaking the wood at the upper ends where there was no paint1 and following it down through the fibers1 pushed and peeled off the soft1 inadhesive paint4 ,green1 sappy1 and resinous wood is unfit for durable painting1 and to avoid blistering and peeling wood should be well seasoned and primed with all raw linseed oil1 some drier1 to insure a moderately slow drying1 and as much of a base pigment as the painter can possibly spread 7much drier takes up too much oil acid1 needed for the pigment base to combine with71 which insures a tough paint that never fails to stand against blistering or peeling1 as well as wind1 weather1 and ammonia4 ,the coach1 car1 and house painter can materially improve his painting where his needs lie by first oiling the wood with raw oil1 then smoothing the surface down with lump pumicestone1 washing it with a mixture of japan drier or1 better yet1 gold sizing and turpentine1 wiping dry1 and following it up with a coat of white lead1 oil1 and turpentine4 ,the explanation is3 the raw oil penetrates the wood and raises the wood fibers on the surface to be rubbed down with pumicestone1 insuring the best surface for the following painting3 to harden the oil in the wood it receives a coat of japan drier1 which follows into the pores and there forms a tough1 resinous matter1 resisting any air pressure that might arise from within1 and at the same time reacts on the first coat of lead as a drier4 ,this mode insures the smoothest and toughest foundation for the following painting1 and may be exposed to the hottest ,july sun without fear of either blistering or peeling4 ,,louis ,,matern4 ,bloomington1 ,ill4 99 99 99 99 99 ,,olive ,,oil4 ,the following particulars with regard to the production of olive oil in ,tuscany have been furnished to ,mr4 ,consul ,inglis by one of the principal exporters in ,leghorn3 ,the olive oil produced in ,tuscany from the first pressing of the fruit is intended for consumption as an article of food4 ,hence1 great attention is paid both to the culture of the olive tree and the process of making oil4 ,the olive crop is subject to many vicissitudes1 and is an uncertain one4 ,it may be taken as a rule that a good crop does not occur more frequently than once in three years4 ,a prolonged drought in summer may cause the greater part of the small fruit to fall off the trees4 ,a warm and wet autumn will subject the fruit to the ravages of a maggot or worm1 which eats its way into it4 ,fruit thus injured falls to the ground prematurely1 and the oil made from it is of very bad quality1 being nauseous in taste and somewhat thick and viscous4 ,frost following immediately on a fall of snow or sleet1 when the trees are still wet1 will irretrievably damage the fruit1 causing it to shrivel up and greatly diminishing the yield of oil1 while the oil itself has a dark color1 and loses its delicate flavor4 ,the olive tree in ,tuscany generally blossoms in ,april4 ,by ,november the fruit has attained its full size1 though not full maturity1 and the olive harvest generally commences then4 ,the fruit1 generally speaking1 is gathered as it falls to the ground1 either from ripeness or in windy weather4 ,in some districts1 however1 and when the crop is short1 the practice is to strip the fruit from the trees early in the season4 ,when there is a full crop the harvest lasts many months1 and may not be finished till the end of ,may1 as the fruit does not all ripen simultaneously4 ,oil made early in the season has a deeper color1 and is distinguished by a fruity flavor1 with a certain degree of pungency2 while as the season advances it becomes lighter in color1 thinner in body1 and milder and sweeter in taste4 ,oil made toward the close of the harvest in ,april or ,may from extremely ripe fruit is of a very pale straw color1 mild and sweet to the taste1 though sometimes1 if the fruit has remained too long on the trees1 it may be slightly rancid4 ,oil very light in color is much prized in certain countries1 notably ,france1 and hence1 if it also possesses good quality1 commands a higher price in the ,tuscan markets4 ,the fruit of the olive tree varies just as much in quality as does the grape1 according to the species of the tree itself1 the nature of the soil1 exposure1 and climate of the locality where it grows4 ,some varieties of the olive tree largely grown1 because thought to be better suited to the special conditions of some districts1 yield a fruit which imparts a bitter taste to the oil made from it2 such oil1 even when otherwise perfect1 ranks as a second rate quality4 ,the highest quality of oil can only be obtained when the fruit is perfectly and uniformly sound1 well ripened1 gathered as soon as it has dropped from the trees1 and crushed immediately with great attention4 ,should the fruit remain any time on the ground1 particularly during wet weather1 it deteriorates fast and gets an earthy taste2 while if allowed to remain an undue length of time in the garners it heats1 begins to decompose1 and will yield only bad oil4 ,the process of making oil is as follows3 ,the fruit is crushed in a stone mill1 generally moved by water power2 the pulp is then put into bags made of fiber1 and a certain number of these bags1 piled one upon another1 are placed in a press1 most frequently worked by hand2 when pressure is applied1 the oil flows down into a channel by which it is conveyed to a receptacle or tank4 ,when oil ceases to flow1 tepid water is poured upon the bags to carry off oil retained by the bags4 ,the pulp is then removed from the bags1 ground again in the mill1 then replaced in the bags1 and pressed a second time4 ,the water used in the process of making oil must be quite pure2 the mill1 press1 bags1 and vessels sweet and clean1 as the least taint would ruin the quality of the oil produced4 ,the oil which has collected in the tank or receptacle just mentioned is removed day by day1 and the water also drained off1 as oil would suffer in quality if left in contact with water2 the water also1 which necessarily contains some oil mingled with it1 is sent to a deposit outside1 and at some distance from the crushing house1 which is called the ,inferno1 where it is allowed to accumulate1 and the oil which comes to the surface is skimmed off from time to time4 ,it is fit only for manufacturing purposes4 ,after the second pressing the olive-pulp is not yet done with2 it is beaten up with water by mechanical agitators moved by water-power1 and then the whole discharged into open-air tanks adjoining the crushing house4 ,there the crushed olive kernels sink to the bottom1 are gathered up and sold for fuel1 fetching about #ab francs per #a1jjj kilos1 while the debris of the pulp is skimmed off the surface of the tank and again pressed in bags1 yielding a considerable quantity of inferior oil1 called olio lavato1 or washed oil1 which1 if freshly made1 is even used for food by the poorer classes4 ,the pulp then remaining has still further use4 ,it is sold for treatment in factories by the sulphide of carbon process1 and by this method yields from seven to nine per cent4 of oil1 of course suitable only for manufacturing purposes4 ,only the first two pressings yield oil which ranks as first quality1 subject of course to the condition of the fruit being unexceptionable4 ,new oil is allowed to rest a while in order to get rid of sediment2 it is then clarified by passing through clean cotton wool1 when it is fit for use4 ,the highest quality of olive oil for eating purposes should not only be free from the least taint in taste or smell1 but possessed of a delicate1 appetizing flavor4 ,when so many favorable conditions are needed as to growth1 maturity1 and soundness of the fruit1 coupled with great attention during the process of oil-making1 it is not to be wondered at that by no means all or even the greater part of the oil produced in the most favored districts of ,tuscany is of the highest quality4 ,on the contrary1 the bulk is inferior and defective4 ,these defective oils are largely dealt in both for home consumption and export1 when price and not quality is the object4 ,in foreign countries there is always a market for inferior1 defective olive oil for cooking purposes1 etc41 provided the price be low4 ,price and not quality is the object1 so much so that when olive oil is dear1 cotton-seed1 ground-nut1 and other oils are substituted1 which bear the same relation to good olive oil that butterine and similar preparations do to real butter4 ,the very choicest qualities of pure olive oil are largely shipped from ,leghorn to ,england1 along with the very lowest qualities1 often also adulterated4 ,the oil put into ,florence flasks is of the latter kind4 ,many years back this was not the case1 but now it is a recognized fact that nothing but the lowest quality of oil is put into these flasks2 oil utterly unfit for food1 and so bad that it is a mystery to what use it is applied in ,england4 ,importers in ,england of oil in these flasks care nothing1 however1 about quality2 cheapness is the only desideratum4 ,the best quality of ,tuscan olive oil is imported in ,london in casks1 bottled there1 and bears the name of the importers alone on the label4 ,there is no difficulty in procuring in ,england the best ,tuscan oil1 which nothing produced elsewhere can surpass2 but consumers who wish to get1 and are willing to pay for1 the best article must look to the name and reputation of the importers and the general excellence of all the articles they sell1 which is the best guarantee they can have of quality4 99 99 99 99 99 ,,beeswax ,,and ,,its ,,adulterations4 ,beeswax is a peculiar waxy substance secreted only by bees1 and consisting of #hj4b per cent4 carbon1 #ac4d per cent4 hydrogen1 and #f4d per cent4 oxygen4 ,it is a mixture of myricine1 cerotic acid1 and cerolein1 the first of which is insoluble in boiling alcohol1 the second is soluble in hot alcohol and crystallizes out on cooling1 while the third remains dissolved in cold alcohol4 ,although we are unable to produce real beeswax artificially1 there are many imitations which are made use of to adulterate the genuine article1 and their detection is a matter of considerable difficulty4 ,huebl says 7,dingl4 ,jour41 p4 #cch7 that the most reliable method of estimating the adulteration of beeswax is that proposed by ,becker1 and known as the saponification method4 ,the quantity of potassic hydrate required to saponify one gramme or #ae grains of pure beeswax varies from #ig to #ajg milligrammes4 ,other kinds of wax and its substitutes require in some cases more and in others less of the alkali4 ,this method would1 however1 lead to very erroneous conclusions if applied to a mixture of which some of the constituents have higher saponification numbers than beeswax and others higher1 as one error would balance the other4 ,to avoid this1 the quantity of alkali required to saponify the myricine is first ascertained1 and then that required to saturate the free cerotic acid4 ,in this way two numbers are obtained2 and in an investigation of twenty samples of ,austrian yellow beeswax1 the author found these numbers stood to each other almost in the constant ratio of #a to #c4gj4 ,although this ratio cannot be considered as definitely established by so few experiments1 it may serve as a guide in judging of the purity of beeswax4 ,the experiment is carried out as follows3 #c or #d grammes of the wax that has been melted in water are put in #bj c4c4 of neutral #ie per cent1 alcohol1 and warmed until the wax melts1 when phenolphthaleine is added1 and enough of an alcoholic solution of potash run in from a burette until on shaking it retains a faint but permanent red color4 ,the burette used by the author is divided in #j4je c4c4 ,after adding #bj c4c4 more of a half normal potash solution1 it is heated on a water bath for hour4 ,then the uncombined excess of alkali is titrated with half normal hydrochloric acid4 ,the alcohol must be tested as to its reaction before using it1 and carefully neutralized with the acid of phenolphthalein4 ,to saturate the free acid in #a gramme of wax requires #ai to #ba milligrammes of potassic hydrate1 while #gc to #gf milligrammes more are necessary to saponify the myricine ether4 ,the lower numbers in the one usually occur with low numbers for the other1 so that the proportions remain #a to #c4f or #a to #c4h4 ,for comparison he gives the following numbers obtained with one gramme of the more common adulterants3 ---------------------------------------- ------------- ,to ,to ,total neutralize convert saponifi- the acid4the ether4 cation4 ,ratio4 ---------------------------------------- ------------- ,japanese wax #bj #bjj #bbj #aj ,carnauba wax #d #ge #gi #ai ,tallow #d #agf #ahj #dd ,stearic acid #aie #j #aie #j_/aie ,rosin #aaj #a4f #aab #j4jae ,paraffine #j #j #j #j ,ceresine #j #j #j #j ,yellow beeswax #bj #ge #ie #c4ge ---------------------------------------- ------------- ,the author deduces the following conclusions as the results of these investigations3 #a4 ,if the numbers obtained lie between these limits1 #ai to #ba1 #gc to #gf1 #ib to #ig1 and #c4f to #c4h respectively1 it may be assumed that the beeswax is pure1 provided it also corresponds to beeswax in its physical properties4 #b4 ,if the saponification figures fall below #ib and yet the ratio is correct1 it is adulterated with some neutral substance like paraffine4 #c4 ,if the ratio is above #c4h1 it is very probable that ,japanese or carnauba wax or grease has been added4 #d4 ,if the ratio falls below #c4f1 stearic acid or resin has been used as the adulterant4 99 99 99 99 99 ,,phenol ,,in ,,the ,,stem1 ,,leaves1 ,,and ,,cones ,,of ,,pinus ,,sylvestris4 ,a ,,discovery ,,bearing ,,on ,,the ,,flora ,,of ,,the ,,carboniferous ,,epoch ,,and ,,the ,,formation ,,of ,,petroleum4 ,by ,a4,b4 ,,griffiths1 ,ph4,d41 ,f4,c4,s4 ,membre de la ,societe ,chimique de ,paris1 ,medallist in ,chemistry and ,botany1 etc4 ,having found1 in small quantities1 alcohols of the ,cn,h#bn-#g series1 last summer1 in the stem1 acicular leaves1 and cones of ,pinus sylvestris1 ,i wish in this paper to say a few words on the subject4 ,first of all1 ,i took a number of cones1 cut them up into small pieces1 and placed them in a large glass beaker1 then nearly filled it with distilled water1 and heated to about #hj ,c41 keeping the decoction at this temperature for about half an hour1 ,i occasionally stirred with a glass rod1 and then allowed it to cool1 and filtered4 ,this filtrate was then evaporated nearly to dryness1 when a small quantity of six-sided prisms crystallized out1 which subsequently were found to be the hydrate of phenol 7,c#f;,h#e;,,ho7#b;,h#b,o4 ,its melting point was found to be #ag4b ,c4 ,further1 the crystals already referred to were dissolved in ether1 and then allowed to evaporate1 when long colorless needles were obtained1 which1 on being placed in a dry test tube and the tube placed in a water bath kept at #db ,c41 were found to melt2 and on making a careful combustion analysis of these crystals1 the following composition was obtained3 ,carbon #gf4f ,hydrogen #f4d ,oxygen #ag4j ----- #ajj4j ,this gives ,c#f;,h#f,o1 which is the formula for phenol4 ,on dissolving some of these crystals in water 7excess7 and adding ferric chloride1 a beautiful violet color was imparted to the solution4 ,to another aqueous solution of the crystals was added bromine water1 and a white precipitate was obtained1 consisting of tribromophenol4 ,an aqueous solution of the crystals immediately coagulated albumen4 ,all these reactions show that the phenol occurs in the free state in the cones of this plant4 ,in the same manner ,i treated the acicular leaves1 and portions of the stem separately1 both being previously cut up into small pieces1 and from both ,i obtained phenol4 ,i have ascertained the relative amount of phenol in each part of the plant operated upon2 by heating the stem with water at #hj ,c41 and filtering1 and repeating this operation until the aqueous filtrate gave no violet color with ferric chloride and no white precipitate with bromine water4 ,i found various quantities according to the age of the stem4 ,the older portions yielding as much as #j4ajba per cent1 while the young portions only gave #j4jfed per cent4 ,the leaves yielding according to their age1 #j4jicf and #j4jcae per cent42 and the cones also gave varying amounts1 according to their maturity1 the amounts varying between #j4jggd and #j4jbic4 ,two methods were used in the quantitative estimation of the amount of phenol4 ,the first was the new volumetric method of ,m4 ,chandelon 7,bulletin de la ,societe ,chemique de ,paris1 ,july #bj1 #ahhb2 and ,deutsch-,americanishe ,apotheker ,zeitung1 vol4 iii41 ,no4 #ab1 ,september #a1 #ahhb71 which ,i have found to be very satisfactory4 ,the process depends on the precipitation of phenol by a dilute aqueous solution of bromine as tribromophenol4 ,the second method was to extract1 as already staled1 a known weight of each part of the plant with water1 until the last extract gives no violet color with ferric chloride1 and no white precipitate with the bromine test 7which is capable of detecting in a solution the #a_/fjjjj part of phenol74 ,the aqueous extract is at this point evaporated1 then ether is added1 and finally the ethereal solution is allowed to evaporate4 ,the residue 7phenol7 is weighed directly1 and from this the percentage can be ascertained4 ,by this method of extraction1 the oil of turpentine1 resins1 etc41 contained in ,pinus sylvestris do not pass into solution1 because they are insoluble in water1 even when boiling2 what passes into solution besides phenol is a little tannin1 which is practically insoluble in ether4 ,from this investigation it will be seen that phenol exists in various proportions in the free state in the leaves1 stem1 and cones of ,pinus sylvestris1 and as this compound is a product in the distillation of coal1 and as geologists have to a certain extent direct evidence that the flora of the ,carboniferous epoch was essentially crytogamous1 the only phnogamous plants which constituted any feature in the coal forests being the conifer1 and as coal is the fossil remains of that gigantic flora which contained phenol1 ,i think my discovery of phenol in the conifer of the present day further supports1 from a chemical point of view1 the views of geologists that the conifer existed so far back in the world's history as the ,carboniferous age4 ,i think this discovery also supports the theory that the origin of petroleum in nature is produced by moderate heat on coal or similar matter of a vegetable origin4 ,for we know from the researches of ,freund and ,pebal 7,ann4 ,chem4 ,pharm41 cxv4 #ai71 that petroleum contains phenol and its homologues1 and as ,i have found this organic compound in the conifer of to-day1 it is probable that petroleum in certain areas has been produced from the conifers and the flora generally of some primval forests4 ,it is stated by numerous chemists that petroleum almost always contains solid paraffin and similar hydrocarbons4 ,professors ,schorlemmer and ,thorpe have found heptane in ,pinus1 which heptane yielded primary heptyl-alcohol1 and methyl-pentyl-carbinol1 exactly as the heptane obtained from petroleum does 7,annalen de ,chemie1 ccxvii41 #aci1 and clxxxviii41 #bdi2 and ,berichte der ,deutschen ,chemischen ,gesellschaft1 viii41 #afdi72 and1 further1 petroleum contains a large number of hydrocarbons which are found in coal4 ,again1 ,mendelejeff1 ,beilstein1 and others 7,bulletin de la ,societe ,chemique de ,paris1 ,no4 #a1 ,july #e1 #ahhc71 have found hydrocarbons of the-- ,cn,h#bn#b1 ,cn,h#bn-#f1 also hydrocarbons of the ,cn,h#bn series in the petroleum of ,baku1 ,american petroleum containing similar hydrocarbons4 ,i think all these facts give very great weight to the theory that petroleum is of organic origin4 ,on the other hand1 ,berthelot1 from his synthetic production of hydrocarbons1 believes that the interior of the globe contains alkaline metals in the free state1 which yield acetylides in the presence of carbonic anhydride1 which are decomposed into acetylene by aqueous vapor4 ,but it has been already proved that acetylene may be polymerized1 so as to produce aromatic carbides1 or the derivatives of marsh gas1 by the absorption of hydrogen4 ,berthelot's view1 therefore1 is too imaginative2 for the presence of free alkaline metals in the earth's interior is an unproved and very improbable hypothesis4 ,byasson states that petroleum is formed by the action of water1 carbonic anhydride1 and sulphureted hydrogen upon incandescent iron4 ,mendelejeff thinks it is formed by the action of aqueous vapor upon carbides of iron2 and in his article1 ,petroleum1 the ,light of the ,poor 7in this month's--,february--number of ,good ,words71 ,sir ,lyon ,playfair1 ,k4,c4,b41 ,f4,r4,s41 etc41 holds opinions similar to those of ,mendelejeff4 ,taking in consideration the facts that solid paraffin is found in petroleum and is also found in coal1 and from my own work that phenol exists in ,pinus sylvestris1 and has been found by others in coal which is produced from the decomposition of a flora containing numerous gigantic conifer allied to ,pinus1 and that petroleum contains phenol1 and each 7i4e41 petroleum and coal7 contains a number of hydrocarbons common to both1 ,i am inclined to think that the balance of evidence is in favor of the hypothesis that petroleum has been produced in nature from a vegetable source in the interior of the globe4 ,of course1 there can be no practical or direct evidence as to the origin of petroleum2 therefore theories are the only lights with which we can penetrate the obscurity of the unknown1 and they are to be valued just as far as they illuminate our path4 ,in conclusion1 ,i think that there is a connecting link between the old pine and fir forest of bygone ages and the origin of petroleum in nature4--,chemical ,news4 99 99 99 99 99 ,,the ,,school ,,of ,,physics ,,and ,,chemistry ,,of ,,paris4 ,recently we paid a visit to the ,new ,municipal ,school of ,physics and ,chemistry that the city of ,paris founded in #ahhb1 and that is now in operation in the large building of the old ,rollin ,college4 ,this establishment is one of those that supply a long-felt want of our time1 and we are happy to make it known to our readers4 ,the object for which it was designed was1 in the intention of its founders1 to give young people who have just graduated from the higher primary schools special instruction which shall be at once scientific and practical1 and which shall fit them to become engineers or superintendents in laboratories connected with chemical and physical industries4 ,to reach such a result it has been necessary to give the teaching an essentially practical character1 by permitting the pupils to proceed of themselves in manipulations in well fitted laboratories4 ,it is upon this important point that we shall now more particularly dwell2 but1 before making known the general mode of teaching1 we wish to quote a few passages from the school's official programme3 ,many questions and problems1 in physics as well as in chemistry1 find their solution only with the aid of mathematics and mechanics4 ,it therefore became necessary1 through lectures bearing upon the useful branches of mathematics1 to supplement the too limited ideas that pupils brought with them on entering the school4 ,mathematics and mechanics are therefore taught here at the same time with physics and chemistry1 but they are merely regarded in the light of auxiliaries to the latter4 ,the studies extend over three years4 ,each of the three divisions 7#ast1 #b;d1 and #c;d years7 includes thirty pupils4 ,during the three first semesters1 pupils of the same grade attend lectures and go through manipulations in chemistry1 physics1 mathematics1 and draughting in common4 ,at the end of the third semester they are divided into #aj physical and #bj chemical students4 ,from this moment1 although certain courses still remain wholly or partially common to the two categories of pupils 7physical and chemical71 the same is no longer the case with regard to the practical exercises1 for the physical students thereafter manipulate only in the physical laboratories1 and the chemical only in the chemical laboratories2 moreover1 the manipulations acquire a greater importance through the time that is devoted to them4 ,at each promotion the three first semesters are taken up with general and scientific studies4 ,technical applications are the subject of the lectures and exercises of the three last semesters4 ,at the end of the third year certificates are given to those pupils who have undergone examination in a satisfactory manner1 and diplomas to such as have particularly distinguished themselves4 ,when pupils have been received at the school1 after passing the necessary examination1 their time of working is divided up between lectures and questionings and different laboratory manipulations4 ,the course of lectures on general and applied physics comprises hydrostatics and heat 7,prof4 ,dommer71 electricity and magnetism 7,prof4 ,hospitalier71 and optics and acoustics 7,prof4 ,baille74 ,lectures on general chemistry are delivered by ,profs4 ,schultzenberger and ,henninger1 on analytical chemistry by ,prof4 ,silva1 on chemistry applied to the industries by ,prof4 ,henninger 7for inorganic7 and ,prof4 ,schultzenberger 7for organic74 ,the lectures on pure and applied mathematics and mechanics are delivered by ,profs4 ,levy and ,roze4 ,illustration3 ,,general ,,view ,,of ,a ,,laboratory ,,at ,,the ,,paris ,,school ,,of ,,physics ,,and ,,chemistry4 ,the pupils occupy themselves regularly every day1 during half the time spent at the school1 with practical work in analytical and applied chemistry and physics and general chemistry4 ,this practical work is a complement to the various lectures1 and has reference to what has been taught therein4 ,once or twice per week the pupils spend three hours in a shop devoted to wood and metal working1 and learn how to turn1 forge1 file1 adjust1 etc4 ,the school's cabinets are now provided with the best instruments for study1 and are daily becoming richer therein4 ,the chemical laboratories are none the less remarkably organized4 ,in the accompanying cut we give a view of one of these--the one that is under the direction of ,mr4 ,schultzenberger1 professor of chemistry and director of the new school4 ,each pupil has his own place in front of a large table provided with a stand whereon he may arrange all the products that he has to employ4 ,beneath the work-table he has at his disposal a closet in which to place his apparatus after he is through using them4 ,each pupil has in front of him a water-faucet1 which is fixed to a vertical column and placed over a sink4 ,alongside of this faucet there is a double gas burner1 which may be connected with furnaces and heating apparatus by means of rubber tubing4 ,a special hall1 with draught and ventilation1 is set apart for precipitations by sulphureted hydrogen and the preparation of chlorine and other ill-smelling and deleterious gases4 ,the great amount of light and space provided secure the best of conditions of hygiene to this fine and vast laboratory1 where young people have all the necessary requisites for becoming true chemists4--,la ,nature4 99 99 99 99 99 ,,dust-,,free ,,spaces4#a ,footnote #a3 ,lecture to the ,royal ,dublin ,society by ,dr4 ,oliver ,j4 ,lodge1 ,april #b1 #ahhd4 ,within the last few years a singular interest has arisen in the subject of dust1 smoke1 and fog1 and several scientific researches into the nature and properties of these phenomena have been recently conducted4 ,it so happened that at the time ,i received a request from the secretary of this society to lecture here this afternoon ,i was in the middle of a research connected with dust1 which ,i had been carrying on for some months in conjunction with ,mr4 ,j4,w4 ,clark1 ,demonstrator of ,physics in ,university ,college1 ,liverpool1 and which had led us to some interesting results4 ,it struck me that possibly some sort of account of this investigation might not be unacceptable to a learned body such as this1 and accordingly ,i telegraphed off to ,mr4 ,moss the title of this afternoon's lecture4 ,but now that the time has come for me to approach the subject before you1 ,i find myself conscious of some misgivings1 and the misgivings are founded upon this ground3 that the subject is not one that lends itself easily to experimental demonstration before an audience4 ,many of the experiments can only be made on a small scale1 and require to be watched closely4 ,however1 by help of diagrams and by not confining myself too closely to our special investigation1 but dealing somewhat with the wider subject of dust in general1 ,i may hope to render myself and my subject intelligible if not very entertaining4 ,first of all1 ,i draw no distinction between dust and smoke4 ,it would be possible to draw such a distinction1 but it would hardly be in accordance with usage4 ,dust might be defined as smoke which had settled1 and the term smoke applied to solid particles still suspended in the air4 ,but at present the term smoke is applied to solid particles produced by combustion only1 and dust to particles owing their floating existence to some other cause4 ,this is evidently an unessential distinction1 and for the present ,i shall use either term without distinction1 meaning by dust or smoke1 solid particles floating in the air4 ,then fog2 this differs from smoke only in the fact that the particles are liquid instead of solid4 ,and the three terms dust1 smoke1 and fog1 come to much the same thing1 only that the latter term is applied when the suspended particles are liquid4 ,i do not think1 however1 that we usually apply the term fog when the liquid particles are pure water2 we call it then mostly either mist or cloud4 ,the name fog1 at any rate in towns1 carries with it the idea of a hideous1 greasy compound1 consisting of smoke and mist and sulphur and filth1 as unlike the mists on a ,highland mountain as a country meadow is unlike a city slum4 ,nevertheless1 the finest cloud or mist that ever existed consists simply of little globules of water suspended in air1 and thus for our present purpose differs in no important respect from fog1 dust1 and smoke4 ,a cloud or mist is1 in fact1 fine water-dust4 ,rain is coarse water-dust formed by the aggregation of smaller globules1 and varying in fineness from the ,scotch mist to the tropical deluge4 ,it has often been asked how it is that clouds and mists are able to float about when water is so much heavier 7#hjj times heavier7 than air4 ,the answer to this is easy4 ,it depends on the resistance or viscosity of fluids1 and on the smallness of the particles concerned4 ,bodies falling far through fluids acquire a terminal velocity1 at which they are in stable equilibrium--their weight being exactly equal to the resistance--and this terminal velocity is greater for large particles than for small2 consequently we have all sorts of rain velocity1 depending on the size of the drops2 and large particles of dust settle more quickly than small4 ,cloud-spherules are falling therefore1 but falling very slowly4 ,to recognize the presence of dust in air there are two principal tests2 the first is1 the obvious one of looking at it with plenty of light1 the way one is accustomed to look for anything else2 the other is a method of ,mr4 ,john ,aitken's1 viz41 to observe the condensation of water vapor4 ,take these in order4 ,when a sunbeam enters a darkened room through a chink1 it is commonly said to be rendered visible by the motes or dust particles dancing in it2 but of course really it is not the motes which make the sunbeam visible1 but the sunbeam the motes4 ,a dust particle is illuminated like any other solid screen1 and is able to send a sufficient fraction of light to our eyes to render itself visible4 ,if there are no such particles in the beam--nothing but clear1 invisible air--then of course nothing is seen1 and the beam plunges on its way quite invisible to us unless we place our eyes in its course4 ,in other words1 to be visible1 light must enter the eye4 7,a concentrated beam was passed through an empty tube1 and then ordinary air let in47 ,the other test1 that of ,mr4 ,aitken1 depends on the condensation of steam4 ,when a jet of steam finds itself in dusty air1 it condenses around each dust particle as a nucleus1 and forms the white visible cloud popularly called steam4 ,in the absence of nuclei ,mr4 ,aitken has shown that the steam cannot condense until it is highly supersaturated1 and that when it does it condenses straight into rain--that is1 into large drops which fall4 ,the condensation of steam is a more delicate test for dust than is a beam of light4 ,a curious illustration of the action of nuclei in condensing moisture has just occurred to me1 in the experiment--well known to children--of writing on a reasonably clean window-pane with1 say1 a blunt wooden point1 and then breathing on the glass2 the condensation of the breath renders the writing legible4 ,no doubt the nuclei are partially wiped away by the writing1 and the moisture will condense into larger drops with less light-scattering power along the written lines than over the general surface of the pane where the nuclei are plentiful1 and the drops therefore numerous and minute4 ,mr4 ,aitken points out that if the air were ever quite dustless1 vapor could not condense1 but the air would gradually get into a horribly supersaturated condition1 soaking all our walls and clothes1 dripping from every leaf1 and penetrating everywhere1 instead of falling in an honest shower1 against which umbrellas and slate roofs are some protection4 ,but let us understand what sort of dust it is which is necessary for this condensing process4 ,it is not the dust and smoke of towns1 it is not the dust of a country road2 all such particles as these are gross and large compared with those which are able to act as condensers of moisture4 ,the fine dust of ,mr4 ,aitken exists everywhere1 even in the upper regions of the atmosphere2 many of its particles are of ultra-microscopic fineness1 one of them must exist in every raindrop1 nay1 even in every spherule of a mist or cloud1 but it is only occasionally that one can find them with the microscope4 ,it is to such particles as these that we owe the blue of the sky1 and yet they are sufficiently gross and tangible to be capable of being filtered out of the air by a packed mass of cotton-wool4 ,such dust as this1 then1 we need never be afraid of being without4 ,without it there could be no rain1 and existence would be insupportable1 perhaps impossible2 but it is not manufactured in towns2 the sea makes it2 trees and wind make it2 but the kind of dust made in towns rises only a few hundred yards or so into the atmosphere1 floating as a canopy or pall over those unfortunate regions1 and sinks and settles most of it as soon as the air is quiet1 but scarcely any of it ever rises into the upper regions of the atmosphere at all4 ,dust1 then1 being so universally prevalent1 what do ,i mean by dust-free spaces8 ,how are such things possible8 ,and where are they to be found8 ,in #ahgj ,dr4 ,tyndall was examining dusty air by means of a beam of light in which a spirit-lamp happened to be burning1 when he noticed that from the flame there poured up torrents of apparently thick black smoke4 ,he could not think the flame was really smoky1 but to make sure he tried1 first a ,bunsen gas flame and then a hydrogen flame4 ,they all showed the same effect1 and smoke was out of the question4 ,he then used a red-hot poker1 a platinum wire ignited by an electric current1 and ultimately a flask of hot water1 and he found that from all warm bodies examined in dusty air by a beam of light the upstreaming convection currents were dark4 ,now1 of course smoke would behave very differently4 ,dusty air itself is only a kind of smoke1 and it looks bright1 and the thicker the smoke the brighter it looks2 the blackness is simply the utter absence of smoke2 there is nothing at all for the light to illuminate1 accordingly we have the blankness of sheer invisibility4 ,here is a flame burning under the beam1 and1 to show what real smoke looks like1 ,i will burn also this spirit lamp filled with turpentine instead of alcohol4 ,why the convention currents were free from dust was unknown2 ,tyndall thought the dust was burnt and consumed2 ,dr4 ,frankland thought it was simply evaporated4 ,in #ahha ,lord ,rayleigh took the matter up1 not feeling satisfied with these explanations1 and repeated the experiment very carefully4 ,he noted several new points1 and hit on the capital idea of seeing what a cold body did4 ,from the cold body the descending current was just as dark and dust-free as from a warm body4 ,combustion and evaporation explanations suffered their death-blow4 ,but he was unable to suggest any other explanation in their room1 and so the phenomenon remained curious and unexplained4 ,in this state ,mr4 ,clark and ,i took the matter up last summer1 and critically examined all sorts of hypotheses that suggested themselves1 ,mr4 ,clark following up the phenomena experimentally with great ingenuity and perseverance4 ,one hypothesis after another suggested itself1 seemed hopeful for a time1 but ultimately had to be discarded4 ,some died quickly1 others lingered long4 ,in the examination of one electrical hypothesis which suggested itself we came across various curious phenomena which we hope still to follow up4#b ,it was some months before what we now believe to be the true explanation began to dawn upon us4 ,meanwhile we had acquired various new facts1 and first and foremost we found that the dark plane rising from a warm body was only the upstreaming portion of a dust-free coat perpetually being renewed on the surface of the body4 ,let me describe the appearance and mode of seeing it by help of a diagram4 7,for full description see ,philosophical ,magazine for ,march1 #ahhd47 ,footnote #b3 ,for instance1 the electric properties of crystals can be readily examined in illuminated dusty air2 the dust grows on them in little bushes and marks out their poles and neutral regions1 without any need for an electrometer4 ,magnesia smoke answers capitally4 ,surrounding all bodies warmer than the air is a thin region free from dust1 which shows itself as a dark space when examined by looking along a cylinder illuminated transversely1 and with a dark background4 ,at high temperatures the coat is thick2 at very low temperatures it is absent1 and dust then rapidly collects on the rod4 ,on a warm surface only the heavy particles are able to settle--there is evidently some action tending to drive small bodies away4 ,an excess of temperature of a degree or two is sufficient to establish this dust-free coat1 and it is easy to see the dust-free plane rising from it4 ,the appearances may also be examined by looking along a cylinder toward the source of light1 when the dust-free spaces will appear brighter than the rest4 ,a rod of electric light carbon warmed and fixed horizontally across a bell-jar full of dense smoke is very suitable for this experiment1 and by means of a lens the dust-free regions may be thus projected on to a screen4 ,diminished pressure makes the coat thicker4 ,increased pressure makes it thinner4 ,in hydrogen it is thicker1 and in carbonic acid thinner1 than in air4 ,we have also succeeded in observing it in liquids--for instance1 in water holding fine rouge in suspension1 the solid body being a metal steam tube4 ,quantitative determinations are now in progress4 ,illustration3 ,fig4 #a and ,fig4 #b ,fig4 #a shows the appearance when looking along a copper or carbon rod laterally illuminated2 the paths of the dust particles are roughly indicated4 ,fig4 #b shows the coat on a semi-cylinder of sheet copper with the concave side turned toward the light4 ,it is difficult to give the full explanation of the dust free spaces in a few words1 but we may say roughly that there is a molecular bombardment from all warm surfaces by means of which small suspended bodies get driven outward and kept away from the surface4 ,it is a sort of differential bombardment of the gas molecules on the two faces of a dust particle somewhat analogous to the action on ,mr4 ,crookes' radiometer vanes4 ,near cold surfaces the bombardment is very feeble1 and if they are cold enough it appears to act toward the body1 driving the dust inward--at any rate1 there is no outward bombardment sufficient to keep the dust away1 and bodies colder than the atmosphere surrounding them soon get dusty4 ,thus if ,i hold this piece of glass in a magnesium flame1 or in a turpentine or camphor flame1 it quickly gets covered with smoke--white in the one case1 black in the other4 ,i take two conical flasks with their surfaces blackened with camphor black1 and filling one with ice1 the other with boiling water1 ,i cork them and put a bell jar over them1 under which ,i burn some magnesium wire2 in a quarter of an hour or so we find that the cold one is white and hoary1 the hot one has only a few larger specks of dust on it1 these being of such size that the bombardment was unable to sustain their weight1 and they have settled by gravitation4 ,we thus see that when the air in a room is warmer than the solids in it--as will be the case when stoves1 gas-burners1 etc41 are used--things will get very dusty2 whereas when walls and objects are warmer than the air--as will be the case in sunshine1 or when open fireplaces are used1 things will tend to keep themselves more free from dust4 ,mr4 ,aitken points out that soot in a chimney is an illustration of this kind of deposition of dust2 and as another illustration it strikes me as just possible that the dirtiness of snow during a thaw may be partly due to the bombardment on to the cold surface of dust out of the warmer air above4 ,mr4 ,aitken has indeed suggested a sort of practical dust or smoke filter on this principle1 passing air between two surfaces--one hot and one cold--so as to vigorously bombard the particles on to the cold surface and leave the air free4 ,but we have found another and apparently much more effectual mode of clearing air than this4 ,we do it by discharging electricity into it4 ,it is easily possible to electrify air by means of a point or flame1 and an electrified body has this curious property1 that the dust near it at once aggregates together into larger particles4 ,it is not difficult to understand why this happens2 each of the particles becomes polarized by induction1 and they then cling together end to end1 just like iron filings near a magnet4 ,a feeble charge is often sufficient to start this coagulating action4 ,and when the particles have grown into big ones1 they easily and quickly fall4 ,a stronger charge forcibly drives them on to all electrified surfaces1 where they cling4 ,a fine water fog in a bell jar1 electrified1 turns first into a coarse fog or ,scotch mist1 and then into rain4 ,smoke also has its particles coagulated1 and a space can thus be cleared of it4 ,i will illustrate this action by making some artificial fogs in a bell-jar furnished with a metal point4 ,first burn some magnesium wire1 electrify it by a few turns of this small ,voss machine1 and the smoke has become snow2 the particles are elongated1 and by pointing to the charged rod indicate the lines of electrostatic force very beautifully2 electrify further1 and the air is perfectly clear4 ,next burn turpentine1 and electrify gently2 the dense black smoke coagulates into black masses over an inch long2 electrify further1 and the glass is covered with soot1 but the air is clear4 ,turpentine smoke acts very well1 and can be tried on a larger scale2 a room filled with turpentine smoke1 so dense that a gas-light is invisible inside it1 begins to clear in a minute or two after the machine begins to turn1 and in a quarter of an hour one can go in and find the walls thickly covered with stringy blacks1 notably on the gas-pipes and everything most easily charged by induction4 ,next fill a bell-jar full of steam1 and electrify1 paying attention to insulation of the supply point in this case4 ,in a few seconds the air looks clear1 and turning on a beam of light we see the globules of water dancing about1 no longer fine and impalpable1 but separately visible and rapidly falling4 ,finally1 make a ,london fog by burning turpentine and sulphur1 adding a little sulphuric acid1 either directly as vapor or indirectly by a trace of nitric oxide1 and then blowing in steam4 ,electrify1 and it soon becomes clear1 although it lakes a little longer than before2 and on removing the bell-jar we find that even the smell of ,,so#b has disappeared1 and only a little vapor of turpentine remains4 ,similarly we can make a ,widnes fog by sulphureted hydrogen1 chlorine1 sulphuric acid1 and a little steam4 ,probably the steam assists the clearing when gases have to be dealt with4 ,it may be possible to clear the air of tunnels by simply discharging electricity into the air--the electricity being supplied by ,holtz machines1 driven say by small turbines--a very handy form of power1 difficult to get out of order4 ,or possibly some hydro-electric arrangement might be devised for the locomotive steam to do the work4 ,i even hope to make some impression on a ,london fog1 discharging from lightning conductors or captive balloons carrying flames1 but it is premature to say anything about this matter yet4 ,i have1 however1 cleared a room of smoke very quickly with a small hand machine4 ,it will naturally strike you how closely allied these phenomena must be to the fact of popular science that thunder clears the air4 ,ozone is undoubtedly generated by the flashes1 and may have a beneficial effect1 but the dust-coagulating and dust-expelling power of the electricity has a much more rapid effect1 though it may not act till the cloud is discharged4 ,consider a cloud electrified slightly2 the mists and clouds in its vicinity begin to coagulate1 and go on till large drops are formed1 which may be held up by electrical action1 the drops dancing from one cloud to another and thus forming the very dense thunder cloud4 ,the coagulation of charged drops increases the potential1 as ,prof4 ,tait points out1 until at length--flash--the cloud is discharged1 and the large drops fall in a violent shower4 ,moreover1 the rapid excursion to and fro of the drops may easily have caused them to evaporate so fast as to freeze1 and hence we may get hail4 ,while the cloud was electrified1 it acted inductively on the earth underneath1 drawing up an opposite charge from all points1 and thus electrifying the atmosphere4 ,when the discharge occurs this atmospheric electrification engages with the earth1 clearing the air between1 and driving the dust and germs on to all exposed surfaces4 ,in some such way also it may be that thunder turns milk sour1 and exerts other putrefactive influences on the bodies which receive the germs and dust from the air4 ,but we are now no longer on safe and thoroughly explored territory4 ,i have allowed myself to found upon a basis of experimental fact1 a superstructure of practical application to the explanation of the phenomena of nature and to the uses of man4 ,the basis seems to me strong enough to bear most of the superstructure1 but before being sure it will be necessary actually to put the methods into operation and to experiment on a very large scale4 ,i hope to do this when ,i can get to a suitable place of operation4 ,liverpool fogs are poor affairs1 and not worth clearing off4 ,manchester fogs are much better and more frequent1 but there is nothing to beat the real article as found in ,london1 and in ,london if possible ,i intend to rig up some large machines and to see what happens4 ,the underground railway also offers its suffocating murkiness as a most tempting field for experiment1 and ,i wish ,i were able already to tell you the actual result instead of being only in a position to indicate possibilities4 ,whether anything comes of it practically or not1 it is an instructive example of how the smallest and most unpromising beginnings may1 if only followed up long enough1 lead to suggestions for large practical application4 ,when we began the investigation into the dust-free spaces found above warm bodies1 we were not only without expectation1 but without hope or idea of any sort1 that anything was likely to come of it2 the phenomenon itself possessed its own interest and charm4 ,and so it must ever be4 ,the devotee of pure science never has practical developments as his primary aim2 often he not only does not know1 but does not in the least care whether his researches will ever lead to any beneficial result4 ,in some minds this passive ignoring of the practical goes so far as to become active repulsion2 so that some singularly biased minds will not engage in anything which seems likely to lead to practical use4 ,i regard this as an error1 and as the sign of a warped judgment1 for after all man is to us the most important part of nature2 but the system works well nevertheless1 and the division of labor accomplishes its object4 ,one man investigates nature impelled simply by his own genius1 and because he feels he cannot help it2 it never occurs to him to give a reason for or to justify his pursuits4 ,another subsequently utilizes his results1 and applies them to the benefit of the race4 ,meanwhile1 however1 it may happen that the yet unapplied and unfruitful results evoke a sneer1 and the question3 ,cui bono8 the only answer to which question seems to be3 ,no one is wise enough to tell beforehand what gigantic developments may not spring from the most insignificant fact4 99 99 99 99 99 ,,telephony ,,and ,,telegraphy ,,on ,,the ,,same ,,wires ,,simultaneously4 ,for the last eighteen months a system has been in active operation in ,belgium whereby the ordinary telegraph wires are used to convey telephonic communications at the same time that they are being employed in their ordinary work of transmitting telegraphic messages4 ,this system1 the invention of ,m4 ,van ,rysselberghe1 whose previous devices for diminishing the evil effects of induction in the telephone service will be remembered1 has lately been described in the ,journal ,telegraphique of ,berne1 by ,m4,j4 ,banneux of the ,belgian ,telegraph ,department4 ,our information is derived from this article and from others by ,m4 ,hospitalier4 ,the method previously adopted by ,van ,rysselberghe1 to prevent induction from taking place between the telegraph wires and those running parallel to them used for telephone work1 was briefly as follows3 ,the system of sending the dots and dashes of the code--usually done by depressing and raising a key which suddenly turns on the current and then suddenly turns it off--was modified so that the current should rise gradually and fall gradually in its strength by the introduction of suitable resistances4 ,these were introduced into the circuit at the moment of closing or opening by a simple automatic arrangement worked exactly as before by a key4 ,the result1 of the gradual opening and gradual closing of the circuit was that the current attained its full strength gradually instead of suddenly1 and died away also gradually4 ,and as induction from one wire to another depends not on the strength of the current1 but on the rate at which the strength changes1 this very simple modification had the effect of suppressing induction4 ,later ,van ,rysselberghe changed these arrangements for the still simpler device of introducing permanently into the circuit either condensers or else electro-magnets having a high coefficient of self-induction4 ,these1 as is well known to all telegraphic engineers1 retard the rise or fall of an electric current2 they fulfill the conditions required for the working of ,van ,rysselberghe's method better than any other device4 ,having got thus far in his devices for destroying induction from one line to another1 ,van ,rysselberghe saw that1 as an immediate consequence1 it might be concluded that1 if the telegraph currents were thus modified and graduated so that they produced no induction in a neighboring telephone line1 they would produce no sound in the telephone if that instrument were itself joined up in the telegraph line4 ,and such was found to be case4 ,why this is so will be more readily comprehended if it be remembered that a telephone is sensitive to the changes in the strength of the current if those changes occur with a frequency of some hundreds or in some cases thousands of times per second4 ,on the other hand1 currents vibrating with such rapidity as this are utterly incompetent to affect the moving parts of telegraphic instruments1 which cannot at the most be worked so as to give more than #bjj to #hjj separate signals per minute4 ,illustration3 ,fig4 #a ,illustration3 ,fig4 #b ,the simplest arrangement for carrying out this method is shown in ,fig4 #a1 which illustrates the arrangements at one end of a line4 ,m is the ,morse key for sending messages1 and is shown as in its position of rest for receiving4 ,the currents arriving from the line pass first through a graduating electromagnet1 ,e#b1 of about #ejj ohms resistance1 then through the key1 thence through the electromagnet1 ,r1 of the receiving ,morse instrument1 and so to the earth4 ,a condenser1 ,c1 of #b microfarads capacity is also introduced between the key and earth4 ,there is a second graduating electromagnet1 ,e#a1 of #ejj ohms resistance introduced between the sending battery1 ,b1 and the key4 ,when the key1 ,m1 is depressed in order to send a signal1 the current from the battery must charge the condenser1 ,c1 and must magnetize the cores of the two electromagnets1 ,e#a and ,e#b1 and is thereby retarded in rising to its full strength4 ,consequently no sound is heard in a telephone1 ,t1 inserted in the line-circuit4 ,neither the currents which start from one end nor those which start from the other will affect the telephones inserted in the line4 ,and1 if these currents do not affect telephones in the actual line1 it is clear that they will not affect telephones in neighboring lines4 ,also the telephones so inserted in the main line might be used for speaking to one another1 though the arrangement of the telephones in the same actual line would be inconvenient4 ,accordingly ,m4 ,van ,rysselberghe has devised a further modification in which a separate branch taken from the telegraph line is made available for the telephone service4 ,to understand this matter1 one other fact must be explained4 ,telephonic conversation can be carried on1 even though the actual metallic communication be severed by the insertion of a condenser4 ,indeed1 in quite the early days of the ,bell telephone1 an operator in the ,states used a condenser in the telegraph line to enable him to talk through the wire4 ,if a telephonic set at ,t#a 7,fig4 #b7 communicate through the line to a distant station1 ,t#b1 through a condenser1 ,c1 of a capacity of half a microfarad1 conversation is still perfectly audible1 provided the telephonic system is one that acts by induction currents4 ,and since in this case the interposition of the condenser prevents any continuous flow of current through the line1 no perceptible weakening will be felt if a shunt ,s1 of as high a resistance as #ejj ohms and of great electromagnetic rigidity1 that is to say1 having a high coefficient of self-induction1 be placed across the circuit from line to earth4 ,in this1 as well as in the other figures1 the telephones indicated are of the ,bell pattern1 and if set up as shown in ,fig4 #b1 without any battery1 would be used both as transmitter and receiver on ,bell's original plan4 ,but as a matter of fact any ordinary telephone might be used4 ,in practice the ,bell telephone is not advantageous as a transmitter1 and has been abandoned except for receiving2 the ,blake1 ,ader1 or some other modification of the microphone being used in conjunction with a separate battery4 ,to avoid complication in the drawings1 however1 the simplest case is taken4 ,and it must be understood that instead of the single instrument shown at ,t#a or ,t#b1 a complete set of telephonic instruments1 including transmitter1 battery1 induction-coil1 and receiver or receivers1 may be substituted4 ,and if a shunt1 ,s1 of #ejj ohms placed across the circuit makes no difference to the talking in the telephones because of the interposition of the separating condenser1 ,c1 it will readily be understood that a telegraphic system properly graduated1 and having also a resistance of #ejj ohms1 will not affect the telephones if interposed in the place of ,s4 ,this arrangement is shown in ,fig4 #c1 where the graduated telegraph-set from ,fig4 #a is intercalated into the telephonic system of ,fig4 #b1 so that both work simultaneously1 but independently1 through a single line4 ,the combined system at each end of the line will then consist of the telephone-set1 ,t#a1 the telegraph instruments 7comprising battery1 ,b#a1 key1 ,m#a and ,morse receiver1 ,r#a71 the graduating electromagnets1 ,e#a1 and ,e#b1 the graduating condenser1 ,c#a1 and the separating condenser1 ,c#b4 ,it was found by actual experiments that the same arrangement was good for lines varying from #bh to #bjj miles in length4 ,a single wire between ,brussels1 ,ghent1 and ,ostend is now regularly employed for transmission by telegraph of the ordinary messages and of the telemeteorographic signals between the two observatories at those places1 and by telephone of verbal simultaneous correspondence1 for one of the ,ghent newspapers4 ,a still more interesting arrangement is possible1 and is indicated in ,fig4 #d4 ,here a separating condenser is introduced at the intermediate station at ,ghent between earth and the line1 which is thereby cut into two independent sections for telephonic purposes1 while remaining for telegraphic purposes a single undivided line between ,brussels and ,ostend4 ,brussels can telegraph to ,ostend1 or ,ostend to ,brussels1 and at the same time the wire can be used to telephone between ,ghent and ,ostend1 or between ,ghent and ,brussels1 or both sections may be simultaneously used4 ,illustration3 ,fig4 #c ,illustration3 ,fig4 #d ,it would appear1 then1 that ,m4 ,van ,rysselberghe has made an advance of very extraordinary merit in devising these combinations4 ,we have seen in recent years how duplex telegraphy superseded single working1 only to be in turn superseded by the quadruplex system4 ,multiplex telegraphy of various kinds has been actively pursued1 but chiefly on the other side of the ,atlantic rather than in this country1 where our fast-speed automatic system has proved quite adequate hitherto4 ,whether we shall see the adoption in the ,united ,kingdom of ,van ,rysselberghe's system is1 however1 by no means certain4 ,the essence of it consists in retarding the telegraphic signals to a degree quite incompatible with the fast-speed automatic transmission of telegraphic messages in which our ,post ,office system excels4 ,we are not likely to spoil our telegraphic system for the sake of simultaneous telephony1 unless there is something to be gained of much greater advantage than as yet appears4--,nature4 99 99 99 99 99 ,,the ,,electric ,,marigraph4 ,for registering the height of the tide at every instant1 hydrographic services generally adopt quite a simple marigraph4 ,the apparatus consists in principle of a counterpoised float whose rising and falling motion1 reduced to a tenth1 by means of a system of toothed wheels1 is transmitted to a pencil which moves in front of a vertical cylinder4 ,this cylinder itself moves around its axis by means of a clockwork mechanism1 and accomplishes one entire revolution every twenty-four hours4 ,by this means is obtained a curve of the tide in which the times are taken for abscisses and the heights of the sea for ordinates4 ,however little such marigraphs have had to be used1 great defects have been recognized in them4 ,when we come to change the sheet on the cylinder 7and such change should be made at least once every fifteen days71 there is an interruption in the curve4 ,it is necessary1 besides1 to perform office work of the most detailed kind in order to refer to the same origin all these curves1 which are intercrossed and often superposed in certain parts upon the original sheet4 ,in order to render such a disentanglement possible1 it is indispensable to mark by hand1 at least once every twenty-four hours1 upon each curve1 the date of the day corresponding to it4 ,it is equally useful to verify the exactness of the indications given by the apparatus by making readings several times a day on a scale of tides placed alongside of the float4 ,nine times out of ten the rise of the waves renders such readings very difficult and the control absolutely illusory4 ,all these conditions united1 as well as others that we neglect in this brief discussion1 necessitate a surveillance at every instant4 ,the result is that these marigraphs must be installed in a special structure1 very near the bank1 so as to be reachable at all times1 and that the indications that they give are always vitiated by error1 since the operation is performed upon a level at which are exerted disturbing influences that are not found at a kilometer at sea4 ,it were to be desired that the float could be isolated by placing it a certain distance from the shore1 and transmit its indications1 by meant of a play of currents1 to a registering apparatus situated upon terra firma4 ,in the course of one of his lectures published in the ,december number 7#ahhc7 of the ,elektrotechnische ,zeitschrift1 ,mr4 ,von ,hefner-,alteneck tells us that such a desideratum has been supplied by the firm of ,siemens ,halske4 ,this marigraph1 constructed on an order of the ,german ,admiralty1 gives the level of the sea every ten minutes with an approximation of #j4ab per cent41 and that too for a difference of #h meters between the highest and lowest sea4 ,the apparatus consists1 as we said above1 of a float and registering device1 connected with each other by means of a cable4 ,this latter is formed of three ordinary conductors covered with gutta percha and surrounded with a leaden sheath1 which latter is itself protected against accident by means of a strong covering of iron wire and hemp4 ,the return is effected through the earth4 ,we shall enter into details concerning each of these two apparatus in-succession1 by beginning with the float1 of which ,fig4 #a gives a general view1 and ,fig4 #b a diagrammatic sketch4 ,the float moves in a cast iron cylinder1 having at its lower part a large number of apertures of small diameter1 so that the motion of the waves does not perceptibly influence the level of the water in the interior of the cylinder4 ,it is attached to a copper ribbon1 ,b1 whose other extremity is fixed to the drum1 ,t4 ,the ribbon winds around the latter in the rising motion of the float1 owing to a spiral spring arranged so as to act upon the drum4 ,the tension of this spring goes on increasing in measure as the float descends4 ,illustration3 ,,fig4 #a4--;,,float ,,of ,,siemens ,,and ,,halske',s ,,marigraph4 ,illustration3 ,,fig4 #b4 ,this difference in tension is utilized for balancing at every instant the weight of the ribbon unwound1 and thus causing the float to immerse itself in the water to a constant degree4 ,the ribbon1 ,b1 is provided throughout its length with equidistant apertures that exactly correspond to tappets that project from the circumference of the wheel1 ,r4 ,when the float moves its position1 the wheel1 ,r1 begins to turn and carries along in doing so the pinion1 w1 which revolves over the toothed wheels1 s#a1 s#b1 and s#c4 ,the thickness of w is equal to that of the three wheels1 s#a1 s#b1 and s#c1 and a special spring secures at every instant an intimate contact between the pinion and the said wheels4 ,these latter are insulated from each other and from the axle upon which they are keyed1 and communicate1 each of them1 with conductors1 ,i41 ,,ii41 and ,,iii4 ,they are so formed and mounted that1 in each of them1 the tooth in one corresponds to the interspace in the two others4 ,as a result of this1 in the motion of the pinion1 w1 the latter is never in contact with but one of the three wheels1 s#a1 s#b1 and s#c4 ,if we add that the lines1 ,i41 ,,ii41 and ,,iii4 are united at the shore station with one of the poles of a pile whose other pole is connected with the earth1 and that w communicates with the earth through the intermedium of ,r1 and the body of the apparatus1 it is easy to see that in a vertical motion of the float in one direction we shall have currents succeeding each other in the order ,i41 ,,ii41 ,,iii41 ,i41 ,,ii41 etc41 while the order will become ,,iii41 ,,ii41 ,i41 ,,iii41 ,,ii41 etc41 if the direction of the float's motion happen to change4 ,illustration3 ,,fig4 #c4 ,illustration3 ,,fig4 #d4 ,in order to understand how a variation in currents of this kind can be applied in general for producing a rotary motion in the two directions1 it will only be necessary to refer to ,figs4 #c and #d4 ,the conductors1 ,l#a1 ,l#b1 and ,l#c communicate with the bobbins of three electromagnets1 ,e#a1 ,e#b1 and ,e#c1 whose poles are bent at right angles to the circumference of the wheel1 ,r4 ,there is never but one pole opposite a tooth4 ,the distance between two consecutive poles must be equal to a multiple of the pitch increased 7,fig4 #c7 or diminished 7,fig4 #d7 by one-third thereof4 ,it will be seen upon a simple inspection of the figures that ,r will revolve in the direction of the hands of a watch when the currents follow the order ,l#a1 ,l#b1 ,l#c1 etc41 in the case shown in ,fig4 #c1 while in the case shown in ,fig4 #d the rotary motion will be in the contrary direction for this same order of currents4 ,but1 in both cases1 and this is the important point1 the direction of rotation changes when the order in the succession of currents2 is inverted4 ,fig4 #f gives a perspective view of the registering apparatus1 and ,fig4 #e represents it in diagram4 ,it will be at once seen that1 the toothed wheel1 r1 is reduced to its simplest expression1 since it consists of two teeth only4 ,the electro-magnets are arranged at an angle of #abj1 and for a change of current the wheel1 r1 describes an angle of #fj1 that is to say1 a sixth of a circumference4 ,the motion of r is transmitted1 by means of the pinion1 d1 and the wheel1 e1 to the wheel1 ,t4 ,for a one-meter variation in level the wheel1 ,t1 makes one complete revolution4 ,it is divided into #ajj equal parts1 and each arc therefore corresponds to a difference of one centimeter in the level1 and carries1 engraved in projection1 the corresponding number4 ,as a consequence1 there is upon the entire circumference a series of numbers from to #ii4 ,the axle upon which the wheel1 ,t1 is keyed is prolonged1 on the side opposite e1 by a threaded part1 a1 which actuates a stylet1 g4 ,this latter is held above by a rod1 ,i1 which is connected with a fork movable around a vertical axis1 shown in ,fig4 #f4 ,the rectilinear motion of g is #e mm4 for a variation of one meter in level4 ,its total travel is consequently #dj mm4 ,the sheet of paper upon which the indications are taken1 and which is shown of actual size in ,fig4 #g1 winds around the drum1 ,p1 and receives its motion from the cylinder1 ,w4 ,this sheet is covered throughout its length with fine prepared paper that permits of taking the imprints by impression4 ,illustration3 ,,fig4 #e ,illustration3 ,,fig4 #f--,,receiver ,,of ,,siemens ,,and ,,halske',s ,,marigraph4 ,illustration3 ,,fig4 #g ,this stated1 the play of the apparatus may be easily understood4 ,every ten minutes a regulating clock closes the circuit of the local pile1 ,b#b1 and establishes a contact at ,c4 ,the electro-magnet1 ,e#d1 attracts its armature1 and thus acts upon the lever1 h1 which presses the sheet of paper against the stylet in front that serves to mark the level of the lowest waters1 and against the stylet1 g1 and the wheels1 ,t and ,z4 ,in falling back1 the lever1 h1 causes the advance1 by one notch1 of the ratchet wheel that is mounted at the extremity of the cylinder ,w1 and thus displaces the sheet of paper a distance of #e mm4 ,the wheel1 ,z1 carries engraved in projection upon its circumference the hours in ,roman figures1 and moves forward one division every #fj minutes4 ,the motion of this wheel is likewise controlled by the cylinder1 ,w4 ,it will be seen upon referring to ,fig4 #g1 that there is obtained a very sharp curve marked by points4 ,we have a general view on considering the curve itself1 and the height in meters is read directly4 ,the fractions of a meter1 as well as the times1 are in the margin4 ,thus1 at the point1 a1 the apparatus gives at #c o'clock and #bj minutes a height of tide of #d4bh m4 above the level of the lowest water4 ,this apparatus might possibly operate well1 and yet not be in accord with the real indications of the float1 so it has been judged necessary to add to it the following control4 ,every time the float reaches #c meters above the level of the lowest tide1 the circuit of one of the lines that is open at this moment 7that of line ,i1 for example7 closes at ,c 7,fig4 #b71 into this new circuit there is interposed a considerable resistance1 ,w1 so that the energy of the current is weakened to such a point that it in nowise influences the normal travel of the wheel1 r4 ,at the shore station1 there is placed in deviation a galvanoscope1 ,k1 whose needle is deflected4 ,it suffices1 then1 to take datum points upon the registering apparatus1 upon the wheel1 ,t1 and the screw1 a1 in such a way as to ascertain the moment at which the stylet1 g1 is going to mark #c meters4 ,at this moment the circuit of the galvanoscope1 ,k1 is closed1 and we ascertain whether there is a deviation of the needle4 ,as the sea generally rises to the height of #c meters twice a day1 it is possible to control the apparatus twice a day1 and this is fully sufficient4 ,it always belongs to practice to judge of an invention4 ,mr4 ,von ,hefner-,alteneck tells us that two of these apparatus have been set up--one of them a year ago in the port of ,kiel1 and the other more recently at the ,isle of ,wangeroog in the ,north ,sea--and that both have behaved excellently since the very first day of their installation4 ,we shall add nothing to this1 since it is evidently the best eulogium that can be accorded them4--,la ,lumiere ,electrique4 99 99 99 99 99 ,,delune ,,co4',s ,,system ,,of ,,laying ,,underground ,,cables4 ,in recent times considerable attention has been paid to the subject of laying telegraph cables underground1 and various methods have been devised4 ,in some cases the cables have been covered with an armor of iron1 and in others they have been inclosed in cast-iron pipes4 ,for telephonic service they are generally inclosed in leaden tubes4 ,what this external envelope shall be that is to protect the wires from injury is a question of the highest importance1 since not only the subject of protection is concerned1 but also that of cost4 ,it is therefore interesting to note the efforts that are being made in this line of electric industry4 ,illustration3 ,,fig4 #a4 ,section of the ,pipe ,open4 ,illustration3 ,,fig4 #b4 ,section of the ,pipe ,closed4 ,messrs4 ,delune ,co4 have recently taken out a patent for an arrangement consisting of pipes made of beton4 ,the annexed cuts1 borrowed from ,l',electricite1 represent this new system4 ,the pipes1 which are provided with a longitudinal opening1 are placed end to end and coupled with a cement sleeve4 ,the cables are put in place by simply unwinding them as the work proceeds1 and thus all that traction is done away with that they are submitted to when cast iron pipes are used4 ,when once the cables are in place the longitudinal opening is stopped up with cement mortar1 and in this way a very tight conduit is obtained whose hardness increases with time4 ,the value of the system therefore depends1 as in all cement work1 on the care with which the manufacturing is done4 ,experiments have been made with the system at ,toulouse1 by the ,minister of ,post ,offices and ,telegraphs1 and at ,lyons1 by the ,general ,society of ,telephones4 ,here1 as with all similar questions1 no opinion can be pronounced until after a prolonged experience4 ,but we cannot help setting forth the advantages that the system offers4 ,these are1 in the first place1 a saving of about #ej per cent4 over iron pipe1 and in the second1 a better insulation1 and consequently a better protection of the currents against all kinds of disturbance1 since a non-conducting mass of cement is here substituted for metal4 99 99 99 99 99 ,,electricity ,,applied ,,to ,,horse-,,shoeing4 ,there is nothing new but what has been forgotten1 said ,marie ,antoinette to her milliner1 ,mdlle4 ,bertin1 and what is true of fashion is also somewhat so of science4 ,shoeing restive horses by the aid of electricity is not new1 experiments thereon having been performed as long ago as #ahgi by ,mr4 ,defoy1 who operated with a small magneto machine4 ,but the two photographs reproduced in ,figs4 #a and #b have appeared to us curious enough to be submitted to our readers1 as illustrating ,mr4 ,defoy's method of operating with an unruly animal4 ,illustration3 ,,fig4 #a4--,,the ,,horse ,,receiving ,,the ,,current4 ,the battery used was a small ,grenet bichromate of potash pile1 which was easy to graduate on account of the depth to which the zinc could be immersed4 ,this pile was connected with the inductor of a small ,ruhmkorff coil1 whose armature was connected with a snaffle-bit placed in the horse's mouth4 ,illustration3 ,,fig4 #b4--,,the ,,horse ,,conquered4 ,this bit was arranged as follows 7,fig4 #c73 ,the two conductors1 which were uncovered for a length of about three centimeters at their extremity1 were placed opposite each other on the two joints of the snaffle1 and about five or six centimeters apart4 ,the mouth-pieces of the bit had previously been inclosed in a piece of rubber tubing1 in order to insulate the extremities of the conductors and permit the recomposition of the current to take place through the animal's tongue or palate4 ,each of the bare ends of the conductors was provided1 under a circular brass ligature1 with a small damp sponge1 which1 surrounding the mouth-piece1 secured a perfect contact of each end of the circuit with the horse's mouth4 ,illustration3 ,,fig4 #c4--;,,arrangement ,,of ,,the ,,bit ,the horse having been led in1 defended himself vigorously as long as an endeavor was made to remove his shoes by the ordinary method1 but the current had acted scarcely fifteen seconds when it became possible to lift his feet and strike his shoes with the hammer4 ,the experimenter having taken care during this experiment to place the bobbin quite near the horse's ear1 so that he could hear the humming of the interrupter1 undertook a second experiment in the following way3 ,having detached the conductors from the armature1 he placed himself in front of the horse 7as shown in ,fig4 #b71 and began to imitate the humming sound of the interrupter with his mouth4 ,the animal at once assumed the stupefied position that the action of the current gave him in the first experiment1 and allowed his feet to be lifted and shod without his even being held by the snaffle4 ,the horse was for ever after subdued1 and yet his viciousness and his repugnance to shoeing were such that he could only be shod previously by confining his legs with a kicking-strap4 ,it should be noted that the action of the induction coil1 mounted as this was1 was very feeble and not very painful2 and yet it was very disagreeable in the mouth1 and gave in this case a shock with a sensation of light before the eyes1 as we have found by experimenting upon ourselves4 ,from our own most recent experiments1 we have ascertained the following facts1 which may guide every horse-owner in the application of electricity to an animal that is opposed to being shod3 7#a7 ,to a horse that defends himself because he is irritable by temperament1 and nervous and impressionable 7as happens with animals of pure or nearly pure blood71 the shock must be administered feebly and gradually before an endeavor is made to take hold of his leg4 ,the horse will then make a jump1 and try to roll over4 ,the jump must be followed1 while an assistant holds the bridle1 and the action of the current must be at once arrested4 ,after this the horse will not endeavor to defend himself1 and his leg may be easily handled4 7#b7 ,certain large1 heavy1 naturally ugly horses kick through sheer viciousness4 ,in this case1 while the current is being given it should be gradually increased in intensity1 and the horse's foot must be seized during its action4 ,in most cases the passage of a current through such horses 7whose mucous membrane is less sensitive7 produces only a slightly stupefied and contracted position of the head1 accompanied with a slight tremor4 ,the current must be shut off as soon as the horse's foot is well in one's hand1 and be at once renewed if he endeavors to defend himself again1 as is rarely the case4 ,it is a mare of this nature that is represented in the annexed figures4 ,we know that this same system has been applied for bringing to an abrupt standstill runaway horses1 harnessed to vehicles2 but knowing the effect of a sudden stoppage under such circumstances1 we believe that the remedy would prove worse than the disease1 since the coachman and vehicle1 in obedience to the laws of inertia1 would continue their motion and pass over the animals1 much to their detriment4--,science et ,nature4 99 99 99 99 99 ,,esteve',s ,,automatic ,,pile4 ,mr4 ,esteve has recently devised a generator of electricity which he claims to be energetic1 constant1 and always ready to operate4 ,the apparatus is designed for the production of light and for actuating electric motors1 large induction bobbins1 etc4 ,we give a description of it herewith from data communicated by its inventor4 ,the accompanying cut represents a battery of #f elements1 with a reservoir1 ,r1 for the liquid1 provided at its lower part with a cock for allowing the liquid to enter the pile4 ,the vessels of the different elements are of rectangular form4 ,at the upper part1 and in the wider surfaces of each1 there are two tubes4 ,the first tube of the first vessel receives the extremity of a safety-tube1 ,a1 whose other extremity enters the upper part of the reservoir1 ,r4 ,this tube is designed for regulating the flow of the liquid into the pile4 ,when the cock1 r1 is too widely open1 the liquid might have a tendency to flow over the edges of the vessel2 but this would close the orifice of the tube1 ,a1 and1 as the air would then no longer enter the reservoir1 ,r1 the flow would be stopped automatically4 ,the second tube of the first vessel is connected with a lead tube1 #a1 one of the extremities of which enters the second vessel4 ,the other tubes are arranged in the same way in the other vessels4 ,the renewal of the liquids is effected by displacement1 in flowing upward from one element over into another2 and the liquids make their exit from the pile at ,d1 after having served six times4 ,the electrodes of the two first elements are represented as renewed in the cut1 in order to show the arrangement of the tubes4 ,illustration3 ,,esteve',s ,,automatic ,,pile4 ,dimensions4--,the zinc1 #b1 has a superficies of #aebj centimeters1 and is cut out of the ordinary commercial sheet metal4 ,it may be turned upside down when one end has become worn away1 thus permitting of its being entirely utilized4 ,the negative electrode is formed of four carbons1 which have1 each of them1 a superficies of #hba centimeters4 ,these four carbons are less fragile and are more easily handled than two having the same surface4 ,their arrangement is shown at the left of the figure4 ,they are fixed to a strip of copper1 a1 to which is soldered another strip1 ,l1 bent at right angles4 ,there are thus two pairs of carbon per element1 and these are simply suspended from a piece of wood1 as shown in the figure4 ,upon this wooden holder will be seen the two strips1 ,,ll1 that are designed to be put in contact with the zinc of the succeeding element by means of pinchers that connect the electrodes with one another4 ,this arrangement permits the pile to be taken apart very quickly4 ,charging1 ,work1 and ,duration of the ,pile4--,the inventor has made a large number of experiments with solutions of bichromate of potash of various degrees of saturation1 and has found the following to give the best results3 ,bichromate of potash4 #a kilogramme4 ,sulphuric acid #b liters4 ,water #h ,when a larger quantity of the salt is used1 crystallization occurs in the pile4 ,constants and work ,constants and work of an element of a round ,bunsen having a zinc of element1 #bjcj cm4 #afbj cm4 ,volts4 #a4i #a4h ,resistance4 #j4je #j4bd ,work disposable in the external circuit4 #a4hci k4 #j4cdd k4 ,the work disposable in the external circuit is deduced from the formula3 ,t ,e_/7#d,r #i4ha7 ,it will be seen that an element thus charged gives as much energy as #e4c large ,bunsen elements4 ,the battery is charged with #aj liters of solution1 and is capable of furnishing for #e hours a current of #g amperes with a difference of potential of #i volts at the pile terminals4 ,the work1 according to the formula 7,,ei7_/g1 equals #f4dbb kilogram-meters2 with a feebler resistance in the external circuit it is capable of producing a current of #ai amperes for an hour and an half4 ,in this case the resistance of the external circuit equals the interior resistance of the pile4 ,upon immersing the electrodes in new liquid1 and with no resistance in the external circuit1 the current may reach #ajj amperes4 ,on renewing the liquids during the operation of the pile1 a current of #g amperes is kept up if about a liter of saturation per hour be allowed to pass into the battery4 ,for five hours1 then1 only #e liters are used instead of the #aj that are necessary when the liquid is not renewed while the pile is in action4--,la ,nature4 99 99 99 99 99 ,,woodward',s ,,diffusion ,,motor4 ,the energy produced by the phenomena of diffusion is exhibited in lecture courses by placing a bell glass filled with hydrogen over a porous vessel at whose base is fixed a glass tube that dips into water4 ,the hydrogen1 in diffusing1 enters the porous vessel1 increases the internal pressure1 and a number of bubbles escapes from the tube4 ,on withdrawing the bell glass of hydrogen1 the latter becomes diffused externally1 a lower pressure occurs in the porous vessel1 and the level of the water rises4 ,the arrangement devised by ,mr4 ,c4,j4 ,woodward1 and recently presented to the ,physical ,society of ,london1 is an adaptation of this experiment to the production of an oscillating motion by alternations in the internal and external diffusion of the hydrogen4 ,the apparatus1 represented herewith1 consists of a scale beam about three feet in length that supports at one end a scale pan and weights1 and1 at the other1 a corked porous vessel that carries a glass tube1 c1 which dips into a vessel containing either water or methylic alcohol4 ,three or four gas jets1 one of which is shown at ,e1 are arranged around the porous vessel1 as close as possible1 but in such a way as not to touch it during the oscillation of the beam4 ,these gas jets communicate with a gasometer tilled with hydrogen1 the bell of which is so charged as to furnish a jet of sufficient strength4 ,experience will indicate the best place to give the gas jets1 but1 in general1 it is well to locate them at near the center of the porous vessel when the beam is horizontal4 ,illustration ,it is now easy to see how the device operates4 ,when the hydrogen comes in presence of the porous vessel it becomes diffused therein1 and the pressure exerted in the interior then produces an ascent4 ,when the bottom of the porous vessel gets above the jets1 the internal diffusion ceases and the hydrogen becomes diffused externally1 the internal pressure diminishes1 and the vessel descends4 ,the vessel then comes opposite the jets of hydrogen and the same motion occurs again1 and soon indefinitely4 ,the work produced by this motor1 which has purely a scientific interest1 is very feeble1 and much below that assigned to it by theory4 ,in order to obtain a maximum1 it would be necessary to completely surround the porous vessel each time with hydrogen1 and afterward remove the jets to facilitate the access of air4 ,all the mechanical arrangements employed for obtaining such a result have failed1 because the friction introduced by the maneuvering parts also introduces a resistance greater than the motor can overcome4 ,there is therefore a waste of energy due to the continuous flow of hydrogen2 but the apparatus1 for all that1 constitutes none the less an original and interesting device4--,la ,nature4 99 99 99 99 99 ,,some ,,relations ,,of ,,heat ,,to ,,voltaic ,,and ,,thermo-,,electric ,,action ,,of ,,metals ,,in ,,electrolytes4#a ,footnote #a3 ,read before the ,royal ,society1 ,nov41 #ahhc4 ,by ,g4 ,,gore1 ,f4,r4,s41 ,,ll4,d4 ,the experiments described in this paper throw considerable light upon the real cause of the voltaic current4 ,the results of them are contained in twenty tables2 and by comparing them with each other1 and also by means of additional experiments1 the following general conclusions and chief facts were obtained4 ,when metals in liquids are heated1 they are more frequently rendered positive than negative in the proportion of about #b4h to #a4j2 and while the proportion in weak solutions was about #b4bi to #a4j1 in strong ones it was about #c4bg to #a4j1 and this accords with their thermo-electric behavior as metals alone4 ,the thermo-electric order of metals in liquids was1 with nearly every solution1 whether strong or weak1 widely different from the thermo-electric order of the same metals alone4 ,a conclusion previously arrived at was also confirmed1 viz41 that the liquids in which the hot metal was thermo-electro-positive in the largest proportion of cases were those containing highly electro-positive bases1 such as the alkali metals4 ,the thermo-electric effect of gradually heating a metal in a liquid was sometimes different from that of suddenly heating it1 and was occasionally attended by a reversal of the current4 ,degree of strength of liquid greatly affected the thermo-electric order of metals4 ,increase of strength usually and considerably increased the potential of metals thermo-electro-negative in liquids1 and somewhat increased that of those positive in liquids4 ,the electric potential of metals1 thermo-electro-positive in weak liquids1 was usually about #c4hg times1 and in strong ones #a4hg times1 as great as of those which were negative4 ,the potential of the strongest thermo-electric couple1 viz41 that of aluminum in weak solution of sodic phosphate1 was #j4ff volt for #ajj ,f4 difference of temperature1 or about #ajj times that of a bismuth and antimony couple4 ,heating one of the metals1 either the positive or negative1 of a voltaic couple1 usually increased their electric difference1 making most metals more positive1 and some more negative2 while heating the second one also usually neutralized to a large extent the effect of heating the first one4 ,the electrical effect of heating a voltaic couple is nearly wholly composed of the united effects of heating each of the two metals separately1 but is not however exactly the same1 because while in the former case the metals are dissimilar1 and are heated to the same temperature1 in the latter they are similar1 but heated to different temperatures4 ,also1 when heating a voltaic pair1 the heat is applied to two metals1 both of which are previously electro-polar by contact with each other as well as by contact with the liquid2 but when heating one junction of a metal and liquid couple1 the metal has not been previously rendered electro-polar by contact with a different one1 and is therefore in a somewhat different state4 ,when a voltaic combination1 in which the positive metal is thermo-negative1 and the negative one is thermo-positive1 is heated1 the electric potential of the couple diminishes1 notwithstanding that the internal resistance is decreased4 ,magnesium in particular1 also zinc and cadmium1 were greatly depressed in electromotive force in electrolytes by elevation of temperature4 ,reversals of position of two metals of a voltaic couple in the tension series by rise of temperature were chiefly due to one of the two metals increasing in electromotive force faster than the other1 and in many cases to one metal increasing and the other decreasing in electromotive force1 but only in a few cases was it a result of simultaneous but unequal diminution of potential of the two metals4 ,with eighteen different voltaic couples1 by rise of temperature from #fj to #afj ,f41 the electromotive force in twelve cases was increased1 and in six decreased1 and the average proportions of increase for the eighteen instances was #j4aj volt for the #ajj ,f4 of elevation4 ,a great difference in chemical composition of the liquid was attended by a considerable change in the order of the volta-tension series1 and the differences of such order in two similar liquids1 such as solutions of hydric chloride and potassic chloride1 were much greater than those produced in either of those liquids by a difference of #ajj ,f4 of temperature4 ,difference of strength of solution1 like difference of composition or of temperature1 altered the order of such series with nearly every liquid2 and the amount of such alteration by an increase of four or five times in the strength of the liquid was rather less than that caused by a difference of #ajj ,f4 of temperature4 ,while also a variation of strength of liquid caused only a moderate amount of change of order in the volta-tension series1 it produced more than three times that amount of change in the thermo-electric tension series4 ,the usual effect of increasing the strength of the liquid upon the volta-electromotive force was to considerably increase it1 but its effect upon the thermo-electro-motive force was to largely decrease it4 ,the degree of potential of a metal and liquid thermo-couple was not always exactly the same at the same temperature during a rise as during a fall of temperature2 this is analogous to the variations of melting and solidifying points of bodies under such conditions1 and also to that of supersaturation of a liquid by a salt1 and is probably due to some hinderance to change of molecular movement4 ,the rate of ordinary chemical corrosion of each metal varied in every different liquid2 in each solution also it differed with every different metal4 ,the most chemically positive metals were usually the most quickly corroded1 and the corrosion of each metal was usually the fastest with the most acid solutions4 ,the rate of corrosion at any given temperature was dependent both upon the nature of the metal and upon that of the liquid1 and was limited by the most feebly active of the two1 usually the electrolyte4 ,the order of rate of corrosion of metals also differed in every different liquid4 ,the more dissimilar the chemical characters of two liquids1 the more diverse usually was the order of rapidity of corrosion of a series of metals in them4 ,the order of rate of simple corrosion in any of the liquids examined differed from that of chemico-electric and still more from that of thermo-electric tension4 ,corrosion is not the cause of thermo-electric action of metals in liquids4 ,out of fifty-eight cases of rise of temperature the rate of ordinary corrosion was increased in every instance except one1 and that was only a feeble exception--the increase of corrosion from #fj to #afj ,f4 with different metals was extremely variable1 and was from #a4e to #cba4f times4 ,whether a metal increased or decreased in thermo-electromotive force by being heated1 it increased in rapidity of corrosion4 ,the proportions in which the most corroded metal was also the most thermo-electro-positive one was #fe4eg per cent4 in liquids at #fj ,f41 and #fi4ab in the same liquids at #afj ,f42 and the proportion in which it was the most chemico-electro-positive at #fj ,f4 was #hd4dd per cent1 and at #afj ,f4 #hj4gg per cent4 ,the proportion of cases therefore in which the most chemico-electro-negative metal was the most corroded one increased from #ae4ef to #ai4bc per cent1 by a rise of temperature of #ajj ,f4 ,comparison of these proportions shows that corrosion usually influenced in a greater degree chemico-electric rather than thermo-electric actions of metals in liquids4 ,not only was the relative number of cases in which the volta-negative metal was the most corroded increased by rise of temperature1 but also the average relative loss by corrosion of the negative to that of the positive one was increased from #c4aa to #f4cb4 ,the explanation most consistent with all the various results and conclusions is a kinetic one3 ,that metals and electrolytes are throughout their masses in a state of molecular vibration4 ,that the molecules of those substances1 being frictionless bodies in a frictionless medium1 and their motion not being dissipated by conduction or radiation1 continue incessantly in motion until some cause arises to prevent them4 ,that each metal 7or electrolyte71 when unequally heated1 has to a certain extent an unlike class of motions in its differently heated parts1 and behaves in those parts somewhat like two metals 7or electrolytes71 and those unlike motions are enabled1 through the intermediate conducting portion of the substance1 to render those parts electro-polar4 ,that every different metal and electrolyte has a different class of motions1 and in consequence of this1 they also1 by contact alone with each other at the same temperature1 become electro-polar4 ,the molecular motion of each different substance also increases at a different rate by rise of temperature4 ,this theory is equally in agreement with the chemico-electric results4 ,in accordance with it1 when in the case of a metal and an electrolyte1 the two classes of motions are sufficiently unlike1 chemical corrosion of the metal by the liquid takes place1 and the voltaic current originated by inherent molecular motion1 under the condition of contact1 is maintained by the portions of motion lost by the metal and liquid during the act of uniting together4 ,corrosion therefore is an effect of molecular motion1 and is one of the modes by which that motion is converted into and produces electric current4 ,in accordance with this theory1 if we take a thermo-electric pair consisting of a non-corrodible metal and an electrolyte 7the two being already electro-polar by mutual contact71 and heat one of their points of contact1 the molecular motions of the heated end of each substance at the junction are altered2 and as thermo-electric energy in such combinations usually increases by rise of temperature1 the metal and liquid1 each singly1 usually becomes more electro polar4 ,in such a case the unequally heated metal behaves to some extent like two metals1 and the unequally heated liquid like two liquids1 and so the thermo-electric pair is like a feeble chemico-electric one of two metals in two liquids1 but without corrosion of either metal4 ,if the metal and liquid are each1 when alone1 thermo-electro-positive1 and if1 when in contact1 the metal increases in positive condition faster than the liquid by being heated1 the latter appears thermo-electro-negative1 but if less rapidly than the liquid1 the metal appears thermo-electro-negative4 ,as also the proportion of cases is small in which metals that are positive in the ordinary thermo-electric series of metals only become negative in the metal and liquid ones 7viz41 only #gc out of #bhf in weak solutions1 and #dh out of the same number in strong ones71 we may conclude that the metals1 more frequently than the liquids1 have the greatest thermo-electric influence1 and also that the relative largeness of the number of instances of thermo-electro-positive metals in the series of metals and liquids1 as in the series of metals only1 is partly a consequence of the circumstance that rise of temperature usually makes substances--metals in particular--electro-positive4 ,these statements are also consistent with the view that the elementary substances lose a portion of their molecular activity when they unite to form acids or salts1 and that electrolytes therefore have usually a less degree of molecular motion than the metals of which they are partly composed4 ,the current from a thermo-couple of metal and liquid1 therefore1 may be viewed as the united result of difference of molecular motion1 first1 of the two junctions1 and second1 of the two heated 7or cooled7 substances2 and in all cases1 both of thermo- and chemico-electric action1 the immediate true cause of the current is the original molecular vibrations of the substances1 while contact is only a static permitting condition4 ,also that while in the case of thermo-electric action the sustaining cause is molecular motion1 supplied by an external source of heat1 in the case of chemico-electric action it is the motion lost by the metal and liquid when chemically uniting together4 ,the direction of the current in thermo-electric cases appears to depend upon which of the two substances composing a junction increases in molecular activity the fastest by rise of temperature1 or decreases the most rapidly by cooling4 99 99 99 99 99 ,,air ,,refrigerating ,,machine4 ,illustration3 ,,improved ,,air ,,refrigerating ,,machine4 ,messrs4 ,j4 ,e4 ,hall1 ,dartford1 exhibit at the ,international ,health ,exhibition1 ,london1 in connection with a cold storage room1 two sizes of ,ellis' patent air refrigerator1 the larger one capable of delivering #e1jjj cubic feet of cold air per hour1 when running at a speed of #aej revolutions per minute2 and the smaller one #b1jjj cubic feet of cold air per hour1 at #bbe revolutions per minute4 ,the special features in these machines are the arrangement of parts1 by which great compactness is secured1 and the adoption of flat slides for the compressor1 instead of the ordinary beat valves1 which permits of a high rate of revolution without the objectionable noise which is caused by clacks beating on their seats4 ,the engraving shows the general arrangement of the apparatus4 ,figs4 #a to #d show details of the compression and expansion valves1 which are ordinary flat slides1 partly balanced1 and held up to their faces by strong springs from behind4 ,the steam1 compression1 and expansion cylinders are severally bolted to the end of a strong frame1 which though attached to the cooler box does not form part of it1 the object being to meet the strains between the cylinders and shaft in as direct a manner as possible without allowing them to act on the cooler casting4 ,each cylinder is double acting1 the pistons being coupled to the shaft by three connecting rods1 the two outer ones working upon crank pins fixed to overhung disks1 and the center one on a crank formed in the shaft4 ,the slide valves for all the cylinders are driven from two weigh shafts1 the main valve shaft being actuated by a follow crank1 and the expansion and cut off valves from the crosshead pin of the compressor4 ,the machines may be used either in the vertical position as exhibited1 or may be fixed horizontally2 and it is stated that the construction is such as to admit of speeds of #bjj and #cjj revolutions per minute respectively for the larger and smaller machines1 under which conditions the delivery of cold air may be taken at about #g1jjj and #b1fjj cubic feet per hour4 ,messrs4 ,hall also make this class of refrigerator without the steam cylinder1 and arranged to be driven by a belt from a gas engine or any existing motive power4 99 99 99 99 99 ,a ,,gas ,,radiator ,,and ,,heater4 ,illustration3 ,fig4 #a ,fig4 #b ,a ,,gas ,,radiator ,,and ,,heater4 ,there is now being introduced into ,germany a gas radiator and heater1 the invention of ,herr ,wobbe4 ,it consists1 as will be seen in engraving above1 of a series of vertical ,u-shaped pipes1 of wrought iron1 #ej millimeters 7#b inches7 in diameter4 ,the two legs of the ,u are of unequal length2 the longer being about #e feet1 and the shorter #c feet 7exclusive of the bend at the top74 ,beneath the open end of the shorter leg of each pipe is placed a burner1 attached to a horizontal gas-pipe1 which turns upon an axis4 ,the object of having this pipe rotate is to bring the burners into an inclined position--shown by the dotted lines in ,fig4 #b--;for lighting them4 ,on turning them back to the vertical position1 the heated products of combustion pass up the shorter tube and down the longer1 where they enter a common receptacle1 from which they pass into the chimney or out of doors4 ,surrounding the pipes are plates of sheet iron1 inclined at the angle shown in ,fig4 #b4 ,the object of the plates is to prevent the heated air of the room from passing up to the ceiling1 and send it out into the room4 ,to prevent any of the pipes acting as chimneys1 and bringing the products of combustion back into the room1 as well as to avoid any back-pressure1 a damper is attached to the outlet receptacle4 ,the heated gas becomes cooled so much 7to about #ajj ,fahr47 that water is condensed and precipitated1 and collects in the vessel below the outlet4 ,each burner has a separate cock1 by which it may be kept closed1 half-open1 or open4 ,to obviate danger of explosion1 there is a strip of sheet iron in front of the burners1 which prevents their being lighted when in a vertical position2 so that1 in case any unburned gas gets into the pipes1 it cannot be ignited1 for the burners can only be lighted when inclined to the front4 ,in starting the stove the burners are lighted1 in the inclined position2 the chain from the damper pulled up2 the burners set vertical2 and1 as soon as they are all drawing well into the tubes1 the damper is closed4 ,if less heat is desired1 the cocks are turned half off4 ,it is not permissible to entirely extinguish some of the burners1 unless the unused pipes are closed to prevent the products of combustion coming back into the room4 ,the consumption of gas per burner1 full open1 with a pressure of #h_/aj1 is said to be only #d-c_/h cubic feet per hour4 99 99 99 99 99 ,,concrete ,,water ,,pipes4 ,concrete water pipes of small diameter1 according to a foreign contemporary1 are used in parts of ,france1 notably for water mains for the towns of ,coulommiers and ,aix-en-,provence4 ,the pipes were formed of concrete in the trench itself4 ,the mould into which the concrete was stamped was sheet iron about two yards in length4 ,the several pipes were not specially joined to each other1 the joints being set with mortar4 ,the concrete consisted of three parts of slow setting cement and three parts of river sand1 mixed with five parts of limestone debris4 ,the inner diameter of the pipes was nine inches2 their thickness1 three inches4 ,the average fall is given at one in five hundred2 the lowest speed of the current at one foot nine inches per second4 ,to facilitate the cleaning of the pipes1 man-holes are constructed every one hundred yards or so1 the sides of which are also made of concrete4 ,the trenches are about five feet deep4 ,the work was done by four men1 who laid down nearly two hundred feet of pipe in a working day2 the cost was about ninety-three cents per running yard4 ,it is claimed as an advantage for the new method that the pipes adhere closely to the inequalities of the trench1 and thus lie firmly on the ground4 ,when submitted to great pressure1 however1 they have not proved effective1 and the method1 consequently1 is only suitable for pipes in which there is no pressure1 or only a very trifling one4 99 99 99 99 99 ,,the ,,sellers ,,standard ,,system ,,of ,,screw ,,threads1 ,,nuts1 ,,and ,,bolt ,,heads4 ,,screw ,,threads4 ,diam4 ,threads ,diameter ,area of ,width of per at root of ,bolt at of ,screw4 inch4 ,thread4 root of ,flat4 ,thread4 #a_/d #bj 4#ahe #ac_/fd 4#jbf 4#jjfb #e_/af #ah 4#bdj #ae_/fd 4#jde 4#jjgd #c_/h #af 4#bid #ai_/fd 4#jfg 4#jjgh #g_/af #ad 4#cdd #aa_/cb 4#jib 4#jjhi #a_/b #ac 4#djj #ac_/cb 4#abe 4#jjif #i_/af #ab 4#ded #bi_/fd 4#afa 4#jajd #e_/h #aa 4#ejg #cc_/fd 4#bja 4#jaac #c_/d #aj 4#fbj #e_/h 4#cja 4#jabe #g_/h #i 4#gca #dg_/fd 4#dai 4#jach #a #h 4#hcg #bg_/cb 4#eej 4#jaef #a-a_/h #g 4#idj #ae_/af 4#fic 4#jagh #a-a_/d #g #a4jfe #a- #a_/af 4#hij 4#jagh #a-c_/h #f #a4afj #a- #e_/cb #a4jef 4#jbjh #a-a_/b #f #a4bhd #a- #i_/cb #a4bid 4#jbjh #a-e_/h #e-a_/b #a4chi #a-be_/fd #a4eae 4#jbbg #a-c_/d #e #a4dia #a-ca_/fd #a4gdf 4#jbej #a-g_/h #e #a4faf #a-ci_/fd #b4jea 4#jbej #b #d-a_/b #a4gdb #a-bc_/cb #b4cja 4#jbgg #b-a_/d #d-a_/b #a4ifb #a-ca_/cb #c4jbc 4#jbgg #b-a_/b #d #b4agf #b-aa_/fd #c4gah 4#jcab #b-c_/d #d #b4dbf #b-bg_/fd #d4fbb 4#jcab #c #c-a_/b #b4fbi #b- #e_/h #e4dbh 4#jceg #c-a_/d #c-a_/b #b4hgi #b- #g_/h #f4eji 4#jceg #c-a_/b #c-a_/d #c4ajj #c- #c_/cb #g4edg 4#jchd #c-c_/d #c #c4cag #c- #e_/af #h4fad 4#jdac #d #c #c4efg #c- #i_/af #i4iic 4#jdac #d-a_/d #b-g_/h #c4gih #c-ea_/fd #aa4cbi 4#jdce #d-a_/b #b-c_/d #d4jbh #d- #a_/cb #ab4gdb 4#jded #d-c_/d #b-e_/h #d4bef #d- #a_/d #ad4bbf 4#jdgf #e #b-a_/b #d4dhj #d-ca_/fd #ae4gfc 4#jejj #e-a_/d #b-a_/b #d4gcj #d-dg_/fd #ag4egj 4#jejj #e-a_/b #b-c_/h #d4iec #d-fa_/fd #ai4bfg 4#jebf #e-c_/d #b-c_/h #e4bjc #e-ac_/fd #ba4bfa 4#jebf #f #b-a_/d #e4dbc #e-bg_/fd #bc4jig 4#jeee ,,nuts4 ,short ,short ,long ,long ,thick- ,thick- ,diam4 ,diam4 ,diam4 ,diam4 ness ness ,rough4 ,finish4 ,rough4 ,rough4 ,rough4 ,finish4 7,hex47 7,hex47 7,hex47 7,square7 #a_/b #g_/af #cg_/fd #g_/aj #a_/d #c_/af #ai_/cb #ag_/cb #aa_/af #aj_/ab #e_/af #a_/d #aa_/af #e_/h #ea_/fd #fc_/fd #c_/h #e_/af #be_/cb #bc_/cc #i_/aj #a- #g_/fd #g_/af #c_/h #g_/h #ac_/af #a #a-ae_/fd #a_/b #g_/af #ca_/cb #bi_/cb #a- #a_/h #a-bc_/fd #i_/af #a_/b #a-a_/af #a #a- #g_/cb #a- #a_/b #e_/h #i_/af #a-a_/d #a-c_/af #a- #g_/af #a-di_/fd #c_/d #aa_/af #a-g_/af #a-c_/h #a-ba_/cb #b- #a_/cb #g_/h #ac_/af #a- #e_/h #a-i_/af #a- #g_/h #b-ai_/fd #a #ae_/af #a-ac_/af #a- #c_/d #b- #e_/cb #b- #i_/af #a-a_/h #a- #a_/af #b #a-ae_/af #b- #e_/af #b-ec_/fd #a-a_/d #a- #c_/af #b- #c_/af #b- #a_/h #b-ag_/cb #c- #c_/cb #a-c_/h #a- #e_/af #b- #c_/h #b- #e_/af #b- #c_/d #c-bc_/fd #a-a_/b #a- #g_/af #b- #i_/af #b- #a_/b #b-ca_/cb #c- #e_/h #a-e_/h #a- #i_/af #b- #c_/d #b-aa_/af #c- #c_/af #c-eg_/fd #a-c_/d #a-aa_/af #b-ae_/af #b- #g_/h #c-ac_/cb #d- #e_/cb #a-g_/h #a-ac_/af #c-a_/h #c- #a_/af #c- #e_/h #d-bg_/fd #b #a-ae_/af #c-a_/b #c- #g_/af #d- #a_/af #d-fa_/fd #b-a_/d #b- #c_/af #c-g_/h #c-ac_/af #d- #a_/b #e-ca_/fd #b-a_/b #b- #g_/af #d-a_/d #d- #c_/af #d-bi_/cb #f #b-c_/d #b-aa_/af #d-e_/h #d- #i_/af #e- #c_/h #f-ag_/cb #c #b-ae_/af #e #d-ae_/af #e-ac_/af #g- #a_/af #c-a_/d #c- #c_/af #e-c_/h #e- #e_/af #f- #g_/cb #g-ci_/fd #c-a_/b #c- #g_/af #e-c_/d #e-aa_/af #f-ba_/cb #h- #a_/h #c-c_/d #c-aa_/af #f-a_/h #f- #a_/af #g- #c_/cb #h-da_/fd #d #c-ae_/af #f-a_/b #f- #g_/af #g- #i_/af #i- #c_/af #d-a_/d #d- #c_/af #f-g_/h #f-ac_/af #g-ca_/cb #i- #c_/d #d-a_/b #d- #g_/af #g-a_/d #g- #c_/af #h-ac_/cb #aj- #a_/d #d-c_/d #d-aa_/af #g-e_/h #g- #i_/af #h-bg_/cb #aj-di_/fd #e #d-ae_/af #h #g-ae_/af #i- #i_/cb #aa-bc_/fd #e-a_/d #e- #c_/af #h-c_/h #h- #e_/af #i-bc_/cb #aa- #g_/h #e-a_/b #e- #g_/af #h-c_/d #h-aa_/af #aj- #e_/cb #ab- #c_/h #e-c_/d #e-aa_/af #i-a_/h #i- #a_/af #aj-ai_/cb #ab-ae_/af #f #e-ae_/af ,,bolt ,,heads4 ,short ,short ,long ,long ,thick- ,thick- ,diam4 ,diam4 ,diam4 ,diam4 ness ness ,rough4 ,finish4 ,rough4 ,rough4 ,rough4 ,finish4 7,hex47 7,hex47 7,hex47 7,square7 #a_/b #g_/af #cg_/fd #g_/aj #a_/d #c_/af #ai_/cb #ag_/cb #aa_/af #aj_/ab #ai_/fd #a_/d #aa_/af #e_/h #ea_/fd #fc_/fd #aa_/cb #e_/af #be_/cb #bc_/cb #i_/af #a-g_/fd #be_/fd #c_/h #g_/h #ac_/af #a #a-ae_/fd #g_/af #g_/af #ca_/cb #bi_/cb #a- #a_/h #a-bc_/fd #ca_/fd #a_/b #a- #a_/af #a #a- #g_/cb #a- #a_/b #ag_/cb #i_/af #a- #a_/d #a- #c_/af #a- #g_/af #a-di_/fd #e_/h #aa_/af #a- #g_/af #a- #c_/h #a-ba_/cb #b- #a_/cb #bc_/cb #ac_/af #a- #e_/h #a- #i_/af #a- #g_/h #b-ai_/fd #ac_/af #ae_/af #a-ac_/af #a- #c_/d #b- #e_/cb #b- #g_/af #bi_/cb #a- #a_/af #b #a-ae_/af #b- #e_/af #b-ec_/fd #a #a- #c_/af #b- #c_/af #b- #a_/h #b-ag_/cb #c- #c_/cb #a- #c_/cb #a- #e_/af #b- #c_/h #b- #e_/af #b- #c_/d #c-bc_/fd #a- #c_/af #a- #g_/af #b- #i_/af #b- #a_/b #b-ca_/cb #c- #e_/h #a- #i_/cb #a- #i_/af #b- #c_/d #b-aa_/af #c- #c_/af #c-eg_/fd #a- #c_/h #a-aa_/af #b-ae_/af #b- #g_/h #c-ac_/cb #d- #e_/cb #a-ae_/cb #a-ac_/af #c- #a_/h #c- #a_/af #c- #e_/h #d-bg_/fd #a- #i_/af #a-ae_/af #c- #a_/b #c- #g_/af #d- #a_/af #d-fa_/fd #a- #c_/d #b- #c_/af #c- #g_/h #c-ac_/af #d- #a_/b #e-ca_/fd #a-ae_/af #b- #g_/af #d- #a_/d #d- #c_/af #d-bi_/cb #f #b- #a_/h #b-aa_/af #d- #e_/h #d- #i_/af #e- #c_/h #f-ag_/cb #b- #e_/af #b-ae_/af #e #d-ae_/af #e-ac_/af #g- #a_/af #b- #a_/b #c- #c_/af #e- #c_/h #e- #e_/af #f- #g_/cb #g-ci_/fd #b-aa_/af #c- #g_/af #e- #c_/d #e-aa_/af #f-ba_/cb #h- #a_/h #b- #g_/h #c-aa_/af #f- #a_/h #f- #a_/af #g- #c_/cb #h-da_/fd #c- #a_/af #c-ae_/af #f- #a_/b #f- #g_/af #g- #i_/af #i- #c_/af #c- #a_/d #d- #c_/af #f- #g_/h #f-ac_/af #g-ca_/cb #i- #c_/d #c- #g_/af #d- #g_/af #g- #a_/d #g- #c_/af #h-ac_/cb #aj- #a_/d #c- #e_/h #d-aa_/af #g- #e_/h #g- #i_/af #h-bg_/cb #aj-di_/fd #c-ac_/af #d-ae_/af #h #g-ae_/af #i- #i_/cb #aa-bc_/fd #d #e- #c_/af #h- #c_/h #h- #e_/af #i-bc_/cb #aa- #g_/h #d- #c_/af #e- #g_/af #h- #c_/d #h-aa_/af #aj- #e_/cb #ab- #c_/h #d- #c_/h #e-aa_/af #i- #a_/h #i- #a_/af #aj-ai_/cb #ab-ae_/af #d- #i_/af #e-ae_/af ,the dimensions given for diameter at root of threads are also those for diameter of hole in nuts and diameter of lap drills4 ,all bolts and studs #c_/d in4 diameter and above1 screwed into boilers1 have #ab threads per inch1 sharp thread1 a taper of #a_/af in4 per #a inch2 tap drill should be #i_/fd in4 less than normal diameter of bolts4 ,the table is based upon the following general formul for certain dimensions3 ,short diam4 rough nut or head #aa_/b diam4 of bolt #a_/h4 finished nut or head #aa_/b diam4 of bolt #a_/af4 ,thickness rough nut diameter of bolt4 ,thickness finished nut diameter of bolt - #a_/af4 ,thickness rough head #a_/b short diameter4 ,thickness finished head diameter of bolt - #a_/af4 99 99 99 99 99 ,,an ,,english ,,railway ,,ferry ,,boat4 ,illustration3 ,,an ,,english ,,railway ,,ferry ,,boat4 ,the illustrations above represent a double screw steam ferry boat for transporting railway carriages1 vehicles1 and passengers1 etc41 designed and constructed by ,messrs4 ,edwards and ,symes1 of ,cubitt ,town1 ,london4 ,the hull is constructed of iron1 and is of the following dimensions3 ,length #fj ft42 beam #af ft42 over sponsons #be ft4 ,the vessel was fitted with a propeller1 rudder1 and steering gear at each end1 to enable it to run in either direction without having to turn around4 ,the boat was designed for the purpose of working the train service across the bay of ,san ,juan1 in the island of ,puerto ,rico1 and for this purpose a single line of steel rails1 of meter gauge1 is laid along the center of the deck1 and also along the hinged platforms at each end4 ,in the engraving these platforms are shown1 one hoisted up1 and the other lowered to the level of the deck4 ,when the boat is at one of the landing stages1 the platform is lowered to the level of the rails on the pier1 and the carriages and trucks are run on to the deck by means of the small hauling engine1 which works an endless chain running the whole length of the deck4 ,the trucks1 etc41 being on board1 the platform is raised by means of two compact hand winches worked by worm and worm-wheels in the positions shown2 thus these two platforms form the end bulwarks to the boat when crossing the bay4 ,on arriving at the opposite shore the operation is repeated1 the other platform is lowered1 and the hauling engine runs the trucks1 etc41 on to the shore4 ,with a load of #be tons the draught is #d ft4 ,the seats shown on the deck are for the convenience of foot passengers1 and the whole of the deck is protected from the sun of that tropical climate by a canvas awning4 ,the steering of the vessel is effected from the bridge at the center1 which extends from side to side of the vessel1 and there are two steering wheels with independent steering gear for each end1 with locking gear for the forward rudder when in motion4 ,the man at the wheel communicates with the engineer by means of a speaking tube at the wheel4 ,there is a small deck house for the use of deck stores1 on one side of which is the entrance to the engine room4 ,the cross battens1 shown between the rails1 are for the purpose of horse traffic1 when horses are used for hauling the trucks1 or for ordinary carts or wagons4 ,the plan below deck shows the arrangement of the bulkheads1 with a small windlass at each end for lifting the anchors1 and a small hatch at each side for entrance to these compartments4 ,the central compartment contains the machinery1 which consists of a pair of compound surface condensing engines1 with cylinders #aa in4 and #bj in4 in diameter2 the shafting running the whole length of the vessel1 with a propeller at each end4 ,steam is generated in a steel boiler of locomotive form1 so arranged that the funnel passes through the deck at the side of the vessel2 and it is designed for a working pressure of #ajj lb4 per square inch4 ,this boiler also supplies steam for the small hauling engine fixed on the bulkhead4 ,light to this compartment is obtained by means of large side scuttles along each side of the boat and glass deck lights1 and the iron grating at the entrance near the deck house4 ,this boat was constructed in six pieces for shipment1 and the whole put together in the builders' yard4 ,the machinery was fixed1 and the engine driven by steam from its own boiler1 then the whole was marked and taken asunder1 and shipped to the ,west ,indies1 where it was put together and found to answer the purpose intended4--,engineering4 99 99 99 99 99 ,for ,,the ,,scientific ,,american4 ,,the ,,problem ,,of ,,flight1 ,,and ,,the ,,flying ,,machine4 ,as a result of reading the various communications to the ,,scientific ,,american and ,,supplement1 and ,van ,nostrand's ,engineering ,magazine1 including descriptions of proposed and tested machines1 and the reports of the ,british ,aeronautical ,society1 the writer of the following concludes3 ,that1 as precedents for the construction of a successful flying machine1 the investigation of some species of birds as a base of the principles of all is correct only in connection with the species and habits of the bird2 that the general mechanical principles of flight applicable to the operation of the same unit of wing in all species are alone applicable to the flying machine4 ,that these principles of operation do not demand the principles of construction of the bird4 ,that as the wing is in its stroke an arc of a screw propeller's operation1 and in its angle a screw propeller blade1 its animal operation compels its reciprocation instead of rotation4 ,that the swifter the wing beat1 the more efficient its effect per unit of surface1 the greater the load carried1 and the swifter the flight4 ,that the screw action being1 in full flight1 that of a screw propeller whose axis of rotation forms a slight angle with the vertical1 the distance of flight per virtual revolution of screw wing far exceeds the pitch distance of said screw4 ,that consequently a bird's flight answers to an iceboat close hauled2 the wing force answering to the wind1 the wing angle to the sail1 the bird's weight to the leeway fulcrum of the ice1 and the passage across direction of the wing flop to the fresh moving inertia of the wind1 both yielding a maximum of force to bird or iceboat4 ,that the speed of reciprocation of a fly's wing being equivalent to a screw rotation of #i1jjj per minute1 proves that a screw may be run at this speed without losing efficiency by centrifugal vacuum4 ,that as the object of wing or screw is to mount upon the inertia of the particles of a mobile fluid1 and as the rotation of steamship propellers in water--a fluid of many times the inertia of air--is already in excess of the highest speed heretofore tried in the propellers of moderately successful flying machines1 it is plain that the speed employed in water must be many times exceeded in air4 ,that with a sufficient speed of rotation1 the supporting power of the inertia of air must equal that of water4 ,that as mere speed of rotation of propeller shaft1 minus blades1 must absorb but a small proportion of power of engine1 the addition of blades will not cause more resistance than that actually encountered from inertia of air4 ,that this must be the measure of load lifted4 ,that without slip of screw1 the actual power expended1 will be little in excess of that required to support the machine in water1 with a slower rotation of screw4 ,that in case the same power is expended in water or air1 the only difference will lie in the sizes and speed of engines or screws4 ,that the greater the speed1 the less weight of engine1 boiler1 and screw must be1 and the stronger their construction4 ,that1 in consequence1 solid metal worked down1 instead of bolts and truss work1 must be used4 ,that as the bird wing is a screw in action1 and acts directly between the inertias of the load and the air1 the position and operation of the screw1 to the load1 must imitate it4 ,that1 in consequence1 machines having wing planes1 driven against one inertia of air by screws acting in the line1 of flight against another inertia of air1 lose fifty per cent4 of useful effect1 besides exposing to a head wind the cross section of the stationary screw wing planes and the rotating screw discs2 and supporting the dead weight of the wing planes1 and having all the screw slip in the line of flight1 and carrying slow and heavy engines4 ,that as a result of these conclusions1 the supporting and propelling power should be expressed in the rotation of screws combining both functions1 the position of whose planes of rotation to a fixed horizontal line of direction determines the progress and speed of machine upon other lines4 ,that the whole weight carried by the screws should be at all times exactly below the center of gravity of the plane of support1 whether it be horizontal or inclined4 ,that while the permanently positioned weight1 such as the engines1 frame1 holding screws1 etc41 may be rigidly connected to or around the screw plane of support1 the variable positioned weight1 such as the passenger and the car1 should be connected by a flexible joint to the said plane of support4 ,consequently1 the car may oscillate without altering its weight position under center of supporting plane1 thus avoiding an involuntary alteration of speed or direction of flight4 ,that to steer a machine so constructed1 it is merely necessary to move the point of attachment of car to machine proper1 out of the center of plane of support in the desired direction1 and thus cause the plane of support or rotation of propellers to incline in that direction4 ,that the reservoir of power1 the boiler1 etc41 should be placed in the car1 and steam carried to engines through joint connecting car with machine4 ,that at present material exists1 and power also1 of sufficient lightness and strength to admit of a machine construction capable of a limited successful flight in any fair wind and direction4 ,that such machine once built1 the finding of a power for long flights will be easy1 if not already close at hand in electricity4 ,that the easiest design for such actual machine should be adopted1 leaving the adaptation of the principles involved to the making of more perfect machines1 to a time after the success of the first4 ,that such design may be a propeller1 and its engine at each end of a steel frame tube1 supporting tube horizontally1 a car to be supported by a universal joint from center of said tube1 and the joint apparatus movable along the tube or a short distance transverse to it1 to alter position of center of gravity4 ,that the machine so built might traverse the water as well as air4 99 99 99 99 99 ,,the ,,longhaired ,,pointer ,,mylord4 ,pointers are trained to search for game1 and to indicate that they have found the same by standing motionless in front of it1 and1 when it has been shot1 to carry the game to the huntsman4 ,several kinds of pointers are known1 such as smooth1 longhaired1 and bushyhaired pointers4 ,the smoothhaired pointers are better for hunting on high land1 whereas the longhaired or bushyhaired dogs are better for low1 marshy countries1 crossed by numerous streams1 etc4 ,mylord1 the dog represented in the annexed cut taken from the ,illustrirte ,zeitung1 is an excellent specimen of the longhaired pointer1 and is owned by ,mr4 ,g4 ,borcher1 of ,braunschweig1 ,germany4 ,illustration3 ,,the ,,longhaired ,,pointer1 ,,mylord4 ,the longhaired pointer is generally above the medium size1 powerful1 somewhat longer than the normal dog1 the body is narrower and not quite as round as that of the smoothhaired dog1 and the muscles of the shoulders and hind legs are not as well developed and not as prominent4 ,the head and neck are erect1 the head being specially long1 and the tail is almost horizontal to the middle1 and then curves upward slightly4 ,the long hair hangs in wavy lines on both sides of his body4 ,the expression of his face is intelligent1 bright1 and good-natured1 and his step is light and almost noiseless4 ,the pointer is specially valuable1 as it can be employed for many different purposes2 he is an excellent dog for the woods1 for the woodsman and hunter who uses only one dog for different kinds of game4 ,the intelligence of the ,german pointer is very great1 but he does not develop as rapidly as the ,english dog1 which has been raised for generations for one purpose only4 ,the ,german pointer hunts very slowly1 but surely4 ,it is not difficult to train this dog1 but he cannot be trained until he has reached a certain age4 99 99 99 99 99 ,,lunar ,,heat4 ,by ,professor ,c4,a4 ,,young4 ,one of the most interesting inquiries relating to the moon is that which deals with the heat she sends us1 and the probable temperature of her surface4 ,the problem seems to have been first attacked by ,tschirnhausen and ,la ,hire1 about #agjj2 and they both found1 that even when the moon's rays were concentrated by the most powerful burning-lenses and mirrors they could obtain1 its heat was too small to produce the slightest perceptible effect on the most delicate thermometers then known4 ,for more than a hundred years1 this was all that could be made out1 though the experiment was often repeated4 ,it was not until #ahca that ,melloni1 with his newly-invented thermopile1 #a succeeded in making the lunar heat sensible2 and in #ahce1 taking his apparatus to the top of ,vesuvius1 he obtained not only perceptible1 but measurable1 results1 getting a deviation of four or five divisions of his galvanometer4 ,footnote #a3 ,probably most of our readers know that the thermopile consists of a number of little bars of two different metals1 connected in pairs1 and having the ends joined in a conducting circuit with a galvanometer4 ,if1 now1 one set of the junctures is heated more than the other set1 a current of electricity will be generated1 which will affect the galvanometer4 ,the bars are usually made of bismuth and antimony though iron and ,german silver answer pretty well4 ,they are commonly about half or three-quarters of an inch long1 and about half as large as an ordinary match4 ,the pile is made of from fifty to a hundred such bars packed closely1 but insulated by thin strips of mica1 except just at the soldered junctions4 ,with an instrument of this kind and a very delicate galvanometer1 ,professor ,henry found that the heat from a person's face could be perceived at a distance of several hundred feet4 ,there is however1 some doubt whether he was not mistaken in respect to this extreme sensitiveness4 ,others repeated the experiment several times between this time and #ahef1 with more or less success2 but1 so far as ,i know1 the first quantitative result was that obtained in #ahef by ,piazzi ,smyth during his ,teneriffe expedition4 ,on the top of the mountain1 at an elevation of ten thousand feet1 he found that the moon's rays affected his thermopile to the same extent as a standard candle ten feet away4 ,marie ,davy has since shown that this corresponds to a heating effect of about #a_/acjj of a ,centigrade degree4 ,the subject was resumed in #ahfh by ,lord ,rosse in ,ireland2 and a long series of observations1 running through several years1 was made by the aid of his three-foot reflector 7not the great six-foot instrument1 which is too unwieldy for such work74 ,the results of his work have1 until very recently1 been accepted as authoritative4 ,it should be mentioned that1 at about the same time1 observations were also made at ,paris by ,marie ,davy and ,martin2 but they are generally looked upon merely as corroborative of ,rosse's work1 which was more elaborate and extensive4 ,rosse considered that his results show that the heat from the moon is mainly obscure1 radiated heat2 the reflected heat1 according to him1 being much less in amount4 ,a moment's thought will show that the moon's heat must consist of two portions4 ,first1 there will be reflected solar heat4 ,the amount and character of this will depend in no way upon the temperature of the moon's surface1 but solely upon its reflecting power4 ,and it is to be noted that moon-light is only a part of this reflected radiant energy1 differing from the invisible portion of the same merely in having such a wave-length and vibration period as to bring it within the range of perception of the human eye4 ,the second portion of the heat sent us by the moon is that which she emits on her own account as a warm body--warmed1 of course1 mainly1 if not entirely1 by the action of the sun4 ,the amount of this heat will depend upon the temperature of the moon's surface and its radiating power2 and the temperature will depend upon a number of things 7chiefly heat-absorbing power of the surface1 and the nature and density of the lunar atmosphere1 as well as the supply of heat received from the sun71 being determined by a balance between give and take4 ,so long as more heat is received in a second than is thrown off in the same time1 the temperature will rise1 and vice versa4 ,it is to be noted1 further1 that this second component of the moon's thermal radiance must be mainly what is called obscure or dark heat1 like that from a stove or teakettle1 and characterized by the same want of penetrative power4 ,no one knows why at present2 but it is a fact that the heat-radiations from bodies at a low temperature--radiations of which the vibrations are relatively slow1 and the wave-length great--have no such power of penetrating transparent media as the higher-pitched vibrations which come from incandescent bodies4 ,a great part1 therefore1 of this contingent of the lunar heat is probably stopped in the upper air1 and never reaches the surface of the earth at all4 ,now1 the thermopile cannot1 of course1 discriminate directly between the two portions of the lunar heat2 but to some extent it does enable us to do so indirectly1 since they vary in quite a different way with the moon's age4 ,the simple reflected heat must follow the same law as moonlight1 and come to its maximum at full moon4 ,the radiated heat1 on the other hand1 will reach its maximum when the average temperature of that part of the moon's surface turned toward the earth is highest2 and this must be some time after full moon1 for the same sort of reasons that make the hottest part of a summer's day come two or three hours after noon4 ,the conclusion early reached by ,lord ,rosse was that nearly all the lunar heat belonged to the second category--dark heat radiated from the moon's warmed surface1 the reflected portion being comparatively small--and he estimated that the temperature of the hottest parts of the moon's surface must run as high as #ejj ,f42 well up toward the boiling-point of mercury4 ,since the lunar day is a whole month long1 and there are never any clouds in the lunar sky1 it is easy to imagine that along toward two or three o'clock in the lunar afternoon 7if ,i may use the expression71 the weather gets pretty hot2 for when the sun stands in the lunar sky as it does at ,boston at two ,p4,m41 it has been shining continuously for more than two hundred hours4 ,on the other hand1 the coldest parts of the moon's surface1 when the sun has only just risen after a night of three hundred and forty hours1 must have a temperature more than a hundred degrees below zero4 ,lord ,rosse's later observations modified his conclusions1 to some extent1 showing that he had at first underestimated the percentage of simple reflected heat1 but without causing him to make any radical change in his ideas as to the maximum heat of the moon's surface4 ,for some time1 however1 there has been a growing skepticism among astronomers1 relating not so much to the correctness of his measures as to the computations by which he inferred the high percentage of obscure radiated beat compared with the reflected heat1 and so deduced the high temperature of lunar noon4 ,professor ,langley1 who is now engaged in investigating the subject1 finds himself compelled to believe that the lunar surface never gets even comfortably warm--because it has no blanket4 ,it receives heat1 it is true1 from the sun1 and probably some twenty-five or thirty per cent4 more than the earth1 since there are no clouds and no air to absorb a large proportion of the incident rays2 but1 at the same time1 there is nothing to retain the heat1 and prevent the radiation into space as soon as the surface begins to warm4 ,we have not yet the data to determine exactly how much the temperature of the lunar rocks would have to be raised above the absolute zero 7-#bgc ,c4 or -#dei ,f47 in order that they might throw off into space as much heat in a second as they would get from the sun in a second4 ,but ,professor ,langley's observations1 made on ,mount ,whitney at an elevation of fifteen thousand feet1 when the barometer stood at seventeen inches 7indicating that about fifty-seven per cent4 of the air was still above him71 showed that rocks exposed to the perpendicular rays of the sun were not heated to any such extent as those at the base of the mountain similarly exposed2 and the difference was so great as to make it almost certain that a mass of rock not covered by a reasonably dense atmosphere could never attain a temperature of even #bjj or #cjj ,f4 under solar radiation1 however long continued4 ,it must1 in fact1 be considered at present extremely doubtful whether any portion of the moon's surface ever reaches a temperature as high as -#ajj4 ,the subject1 undoubtedly1 needs further investigation1 and it is now receiving it4 ,professor ,langley is at work upon it with new and specially constructed apparatus1 including a bolometer so sensitive that1 whereas previous experimenters have thought themselves fortunate if they could get deflections of ten or twelve galvanometric divisions to work with1 he easily obtains three or four hundred4 ,we have no time or space here to describe ,professor ,langley's bolometer2 it must suffice to say that it seems to stand to the thermopile much as that does to the thermometer4 ,there is good reason to believe that its inventor will be able to advance our knowledge of the subject by a long and important step2 and it is no breach of confidence to add that so far1 although the research is not near completion yet1 everything seems to confirm the belief that the radiated heat of the moon1 instead of forming the principal part of the heat we get from her1 is relatively almost insignificant1 and that the lunar surface now never experiences a thaw under any circumstances4 ,since the superstition as to the moon's influence upon the wind and weather is so widespread and deep seated1 a word on that subject may be in order4 ,in the first place1 since the total heat received from the moon1 even according to the highest determination 7that of ,smyth71 is not so much as #j4jjjja of that received from the sun1 and since the only hold the moon has on the earth's weather is through the heat she sends us 7,i ignore here the utterly insignificant atmospheric tide71 it follows necessarily that her influence must be very trifling4 ,in the next place1 all carefully collated observations show that it is so1 and not only trifling1 but generally absolutely insensible4 ,for example1 different investigators have examined the question of nocturnal cloudiness at the time of full moon1 there being a prevalent belief that the full moon eats up light clouds4 ,on comparing thirty or forty years' observations at each of several stations 7,greenwich4 ,paris1 etc471 it is found that there is no ground for the belief4 ,and so in almost every case of imagined lunar meteorological influence4 ,as to the coincidence of weather changes with changes of the moon1 it is enough to say that the idea is absolutely inconsistent with that progressive movement of the weather across the country from west to east1 with which the ,signal ,service has now made us all so familiar4 ,princeton1 ,april #ab1 #ahhd4 99 99 99 99 99 ,,apple ,,tree ,,borers4 ,the apple tree borers have destroyed thousands of trees in ,new ,england1 and are likely to destroy thousands more4 ,there are three kinds of borers which assail the apple tree4 ,the round headed or two striped apple tree borer1 ,saperda candida1 is a native of this country1 infesting the native crabs1 thorn bushes1 and ,june berry4 ,it was first described by ,thomas ,say1 in #ahbd1 but was probably widely distributed before that4 ,in his ,insects ,injurious to ,fruit1 ,prof4 ,saunders thus describes the borer3 ,in its perfect state it is a very handsome beetle1 about three-quarters of an inch long1 cylindrical in form1 of a pale brown color1 with two broad1 creamy white stripes running the whole length of its body2 the face and under surface are hoary white1 the antenn and legs gray4 ,the females are larger than the males1 and have shorter antenn4 ,the beetle makes its appearance during the months of ,june and ,july1 usually remaining in concealment during the day1 and becoming active at dusk4 ,the eggs are deposited late in ,june and during ,july1 one in a place1 on the bark of the tree1 near its base4 ,within two weeks the young worms are hatched1 and at once commence with their sharp mandibles to gnaw their way through the outer bark to the interior4 ,it is generally conceded that the larv are three years in reaching maturity4 ,the young ones lie for the first year in the sapwood and the inner bark1 excavating flat1 shallow cavities1 about the size of a silver dollar1 which are filled with their sawdust-like castings4 ,the holes by which they enter being small are soon filled up1 though not until a few grains of castings have fallen from them4 ,their presence may1 however1 often be detected in young trees from the bark becoming dark colored1 and sometimes dry and dead enough to crack4 ,on the approach of winter1 it descends to the lower part of its burrow1 where it remains inactive until spring4 ,the second season it continues its work in the sapwood1 and in case two or three are at work in the same tree may completely girdle it1 thus destroying it4 ,the third year it penetrates to the heart of the tree1 makes an excavation1 and awaits its transformation4 ,the fourth spring it comes forth a perfect beetle1 and lays its eggs for another generation4 ,,the ,,flat-,,headed ,,borer4 ,the flat-headed apple tree borer1 ,chrysobothris femorata1 is also a native of this country4 ,it is a very active insect1 delights to bask in the hot sunshine2 runs up and down the tree with great rapidity1 but flies away when molested4 ,it is about half an inch in length4 ,it is of a flattish1 oblong form1 and of a shining1 greenish black color1 each of its wing cases having three raised lines1 the outer two interrupted by two impressed transverse spots of brassy color dividing each wing cover into three nearly equal portions4 ,the under side of the body and legs shine like burnished copper2 the feet are shining green4 ,this beetle appears in ,june and ,july1 and does not confine its work to the base of the tree1 but attacks the trunk in any part1 and sometimes the larger branches4 ,the eggs are deposited in cracks or crevices of the bark1 and soon hatch4 ,the young larva eats its way through the bark and sapwood1 where it bores broad and flat channels1 sometimes girdling and killing the tree4 ,as it approaches maturity1 it bores deeper into the tree1 working upward1 then eats out to the bark1 but not quite through the bark1 where it changes into a beetle1 and then cuts through the bark and emerges to propagate its kind4 ,this insect is sought out when just beneath the bark1 and devoured by woodpeckers and insect enemies4 ,another borer1 the long-horned borer1 ,leptostylus aculifer1 is widely distributed1 but is not a common insect1 and does not cause much annoyance to the fruit grower4 ,it appears in ,august1 and deposits its eggs upon the trunks of apple trees4 ,the larv soon hatch1 eat through the bark1 and burrow in the outer surface of the wood just under the bark4 ,,protection ,,against ,,borers4 ,the practical point is1 ,what remedies can be used to prevent the ravages of the borers8 ,the usual means of fighting the borers is1 to seek after them in the burrows1 and try to kill them by digging them out1 or by reaching them with a wire4 ,this seems to be the most effectual method of dealing with them after they have once entered the tree1 but the orchardist should endeavor to prevent the insects from entering the tree4 ,for this purpose1 various washes have been recommended for applying to the tree1 either for destroying the young larv before they enter the bark1 or for preventing the beetles depositing their eggs4 ,it has been found that trees which have been coated with alkaline washes are avoided by beetles when laying their eggs4 ,prof4 ,saunders recommends that soft soap be reduced to the consistency of a thick paint1 by the addition of a strong solution of washing soda in water1 and be applied to the bark of the tree1 especially about the base or collar1 and also extended upward to the crotches where the main branches have their origin4 ,it should be applied in the evening of a warm day1 so that it may dry and form a coating not easily dissolved by the rain4 ,this affords a protection against all three kinds of borers4 ,it should be applied early in ,june1 before the beetles begin to lay their eggs1 and again in ,july1 so as to keep the tree well protected4 ,hon4 ,t4,s4 ,gold1 of ,connecticut1 at a meeting of the ,massachusetts ,state ,board of ,agriculture1 in regard to preventing the ravages of the borer1 said3 ,a wash made of soap1 tobacco water1 and fresh cow manure mingled to the consistency of cream1 and put on early with an old broom1 and allowed to trickle down about the roots of the tree1 has proved with me a very excellent preventive of the ravages of the borer1 and a healthful wash for the trunk of the tree1 much to be preferred to the application of lime or whitewash1 which ,i have often seen applied1 but which ,i am inclined to think is not as desirable an application as the potash1 or the soda1 as this mixture of soft soap and manure4 ,j4,b4 ,moore1 of ,concord1 ,mass41 at the same meeting said1 in regard to the destruction of the borer3 ,i have found1 ,i think1 that whale oil soap can be used successfully for the destruction of that insect4 ,it is a very simple thing2 it will not hurt the tree if you put it on its full strength4 ,you can take whale oil soap and dilute until it is about as thick as paint1 and put a coating of it on the tree where the holes are1 and ,i will bet you will never see a borer on that tree until the new crop comes4 ,i feel certain of it1 because ,i have done it4 ,for borers1 tarred paper #a or #b feet wide has been recommended to be wrapped about the base of the trunk of the tree1 the lower edge being #a or #b inches below the surface of the soil4 ,this prevents the two-striped borer from laying its eggs in the tree1 but would not be entirely effectual against the flat-headed borer1 which attacks any part of the trunk and the branches4 ,by the general use of these means for the prevention of the ravages of the borers1 the damages done by these insects could be brought within very narrow limits1 and hundreds of valuable apple trees saved4 ,h4 ,,reynolds1 ,m4,d4 ,livermore ,falls1 ,me4 99 99 99 99 99 ,,keffel',s ,,germinating ,,apparatus4 ,the apparatus represented in the annexed cut is designed to show the quality of various commercial seeds1 and make known any fraudulent adulterations that they may have undergone4 ,it is based upon a direct observation1 of the germination of the seeds to be studied4 ,illustration3 ,,keffel',s ,,germinating ,,apparatus4 ,the apparatus consists of a cylindrical vessel containing water to the height of #j4jg m4 ,above the water is a germinating disk containing #ajj apertures for the insertion of the seeds to be studied1 the germinating end of the latter being directed toward the water4 ,after the seeds are in place the disk is filled with damp sand up to the top of its rim1 and the apparatus is closed with a cover which carries in its center a thermometer whose bulb nearly reaches the surface of the water4 ,the apparatus is then set in a place where the temperature is about #ah1 and where there are no currents of air4 ,an accurate result is reached at the end of about twenty or twenty-four hours4 ,as the germinating disk contains #ajj apertures for as many seeds1 it is only necessary to count the number of seeds that have germinated in order to get the percentage of fresh and stale ones4 ,the aqueous vapor that continuously moistens all the seeds1 under absolutely identical conditions for each1 brings about their germination under good conditions for accuracy and comparison4 ,if it be desired to observe the starting of the leaves1 it is only necessary to remove the cover after the seeds have germinated4 ,this ingenious device is certainly capable of rendering services to brewers1 distillers1 seedsmen1 millers1 farmers1 and gardeners1 and it may prove useful to those who have horses to feed1 and to amateur gardeners1 since it permits of ascertaining the value and quality of seeds of every nature4--,la ,nature4 99 99 99 99 99 ,,millet4 ,the season is now at hand when farmers who have light lands1 and who may possibly find themselves short of fodder for next winter feeding1 should prepare for a crop of millet4 ,this is a plant that rivals corn for enduring a drought1 and for rapid growth4 ,there are three popular varieties now before the public1 besides others not yet sufficiently tested for full indorsement--the coarse1 light colored millet1 with a rough head1 ,hungarian millet1 with a smooth1 dark brown head1 yielding seeds nearly black1 and a newer1 light colored1 round seeded1 and later variety1 known as the golden millet4 ,hungarian millet has been the popular variety with us for many years1 although the light seeded1 common millet is but slightly different in appearance or value for cultivation4 ,they grow in a short time1 eight weeks being amply sufficient for producing a forage crop1 though a couple of weeks more would be required for maturing the seed4 ,millet should not be sown in early spring1 when the weather and ground are both cold4 ,it requires the hot weather of ,june and ,july to do well2 then it will keep ahead of most weeds1 while if sown in ,april the weeds on foul land would smother it4 ,millet needs about two months to grow in1 but if sowed late in ,july it will seem to hurry up1 and make a very respectable showing in less time4 ,we have sown it in ,august1 and obtained a paying crop1 but do not recommend it for such late seeding1 as there are other plants that will give better satisfaction4 ,golden millet has been cultivated but a few years in this country1 and as yet is but little known1 but from a few trials we have been quite favorably impressed with it4 ,it is coarser than the other varieties1 but cattle appear to be very fond of it nevertheless4 ,it resembles corn in its growth nearly as much as grass1 and1 compared with the former1 it is fine and soft1 and it cures readily1 like grass1 and may be packed away in hay mows with perfect safety4 ,it is about two weeks later than the other millets1 and consequently cannot be grown in quite so short a time1 although it may produce as much weight to the acre1 in a given period1 as either of the other more common varieties4 ,a bushel of seed per acre is not too much for either variety of millet4--,n4,e4 ,farmer4 99 99 99 99 99 ,a ,,catalogue containing brief notices of many important scientific papers heretofore published in the ,,supplement1 may be had gratis at this office4 99 99 99 99 99 ,,the ,,scientific ,,american ,,supplement4 ,,published ,,weekly4 ,,terms ,,of ,,subscription1 #e ,a ,,year4 ,sent by mail1 postage prepaid1 to subscribers in any part of the ,united ,states or ,canada4 ,six dollars a year1 sent1 prepaid1 to any foreign country4 99 99 99 99 99 ,all the back numbers of ,,the ,,supplement1 from the commencement1 ,january #a1 #ahgf1 can be had4 ,price1 #aj cents each4 99 99 99 99 99 ,all the back volumes of ,,the ,,supplement can likewise be supplied4 ,two volumes are issued yearly4 ,price of each volume1 #b4ej1 stitched in paper1 or #c4ej bound in stiff covers4 99 99 99 99 99 ,,combined ,,rates--,one copy of ,,scientific ,,american and one copy of ,,scientific ,,american ,,supplement1 one year1 postpaid1 #g4jj4 ,a liberal discount to booksellers1 news agents1 and canvassers4 ,,munn ,,co41 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