,transcriber's note3 ,italics denoted by underscores4 ,bold text denoted by plus signs4 ,illustration3 ,scientific ,american ,supplement ,no4 #dfg ,scientific ,american ,supplement1 ,vol4 ,,xviii ,no4 #dfg4 ,scientific ,american1 established #ahde4 ,,new ,,york1 ,,december #ac1 #ahhd4 ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 ,,the ,,new ,,building ,,of ,,the ,,technical ,,high ,,school ,,of ,,berlin4 ,the ,berlin ,academy of ,industry and the ,academy of ,building were united in #ahgf to form the ,technical ,high ,school4 ,it was found that the buildings were not sufficiently large for the great number of scholars1 and arrangements were made for erecting new buildings affording better accommodations4 ,the first design was made by ,lucal1 who1 after his death1 was succeeded by ,hitzig1 who died in #ahba1 and who was succeeded1 in turn1 by ,mr4 ,raschdorff4 ,the main building is shown in the annexed cut1 taken from the ,illustrirte ,zeitung4 ,it is four stories high and #ged ft4 long1 and the middle and side wings are about #fef ft4 deep1 the portions between the wings being about #afd ft4 deep4 ,in the interior five square courts are arranged1 of which two are at the right and two at the left1 and are separated by intermediate building4 ,the middle court in the central portion of the building is covered by a glass roof and forms a vestibule surrounded by arcades1 the halls of which lead to different rooms4 ,in the middle portion are the rooms for the officers1 and the reading rooms4 ,the courts are erected in brick with sgraffito ornamentation2 and the front1 sides1 and rear are erected in sandstone on a granite base4 ,the first story1 or ground floor1 is of a yellowish color1 and the upper story is of a clear whitish-gray4 ,the building is richly ornamented by statues1 busts1 reliefs1 and groups representing the different architects1 artists1 scientists1 etc4 ,illustration3 ,,the ,,new ,,technical ,,high ,,school ,,at ,,berlin4 ,,the ,,new ,,university ,,buildings ,,at ,,strassburg4 ,the buildings of the ,university of ,strassburg are arranged in two groups2 one in the northern and the other in the southern part of the city4 ,all the buildings of the medical department were erected in the neighborhood of the hospital1 which is located between the south wall of the city and the ,river ,ill4 ,in front of the old ,fischerthor1 or ,fishergate1 the college house1 or college building proper1 in which are located the offices1 lecture rooms1 etc41 was erected4 ,a front perspective view of this building is shown in the lower part of the annexed cut1 taken from the ,illustrirte ,zeitung4 ,behind this main building1 and between the ,universitts and ,goethe ,strasse1 the buildings of the ,chemical ,institute1 the ,physical ,institute1 with its tower2 the ,botanical ,institute1 with the gardens and hothouses1 and the ,astronomical ,institute1 with its observatory and movable dome1 are located4 ,these buildings were designed by the architects ,hermann1 ,eggert1 ,brion1 and ,salomon1 all of ,strassburg4 ,illustration3 ,,general ,,view ,,of ,,the ,,strassburg ,,university ,,buildings4 ,illustration3 ,,the ,,college ,,house ,,of ,,the ,,strassburg ,,university4 ,the main building was designed by ,prof4 ,warth1 of ,karlsruhe1 and the style of the same is a noble ,italian renaisance of the early period4 ,upon a base of red sandstone the basement is erected in freestone rustic masonry1 upon which the first story is erected in smooth stone with conspicuous joints4 ,the top story is constructed with arched windows separated by ,ionic columns or pilasters4 ,the central portion1 which projects from the front of the building1 has a grand staircase and two corner pavilions4 ,the upper part of the central portion is constructed with fluted ,corinthian columns1 between which niches are provided1 in which busts of the ideal representatives of the faculties are placed1 viz41 ,homer1 ,paulus1 ,solon1 ,hippocrates1 ,aristotle1 and ,archimedes4 ,above the cornice1 in the tympanum1 is placed a group1 of which ,athene1 with the torch of science1 is the main figure4 ,in the niches in the pavilions at the corners of the middle portion are the statues of ,germania and ,argentina1 the representative of the free city of ,strassburg4 ,the pavilions at the ends of the building are ornamented by thirty-six statues of ,german scientists4 ,the middle portion of the building directly beyond the grand staircase is occupied by a large open court1 having a rich glass roof4 ,the left part of the lower story is divided into lecture rooms1 and the right side into rooms for the officers1 etc4 ,the collections are in the upper story1 and the chapel1 or main hall1 is in the middle of the building4 ,,the ,,wave ,,theory ,,of ,,light4#a ,by ,sir ,,william ,,thomson1 ,f4,r4,s41 ,,ll4,d41 etc4 #a ,a ,lecture delivered at the ,academy of ,music1 ,philadelphia1 under the auspices of the ,franklin ,institute1 ,september #bi1 #ahhd4 ,the subject upon which ,i am to speak to you this evening is happily for me not new in ,philadelphia4 ,the beautiful lectures on light which were given several years ago by ,president ,morton1 of the ,stevens ,institute1 and the succession of lectures on the same subject so admirably illustrated by ,prof4 ,tyndall1 which many now present have heard1 have fully prepared you for anything ,i can tell you this evening in respect to the wave theory of light4 ,it is indeed my humble part to bring before you some mathematical and dynamical details of this great theory4 ,i cannot have the pleasure of illustrating them to you by anything comparable with the splendid and instructive experiments which many of you have already seen4 ,it is satisfactory to me to know that so many of you now present are so thoroughly prepared to understand anything ,i can say1 that those who have seen the experiments will not feel their absence at this time4 ,at the same time ,i wish to make them intelligible to those who have not had the advantages to be gained by a systematic course of lectures4 ,i must say in the first place1 without further preface1 as time is short and the subject is long1 simply that sound and light are both due to vibrations propagated in the manner of waves2 and ,i shall endeavor in the first place to define the manner of propagation and mode of motion that constitute those two subjects of our senses1 the sense of sound and the sense of light4 ,each is due to vibrations4 ,the vibrations of light differ widely from the vibrations of sound4 ,something that ,i can tell you more easily than anything in the way of dynamics or mathematics respecting the two classes of vibrations is1 that there is a great difference in the frequency of the vibrations of light when compared with the frequency of the vibrations of sound4 ,the term frequency1 applied to vibrations1 is a convenient term1 applied by ,lord ,rayleigh in his book on sound to a definite number of full vibrations of a vibrating body per unit of time4 ,consider1 then1 in respect to sound1 the frequency of the vibrations of notes1 which you all know in music represented by letters1 and by the syllables for singing the do1 re1 mi1 etc4 ,the notes of the modern scale correspond to different frequencies of vibrations4 ,a certain note and the octave above it correspond to a certain number of vibrations per second and double that number4 ,i may explain in the first place conveniently the note called ,c2 ,i mean the middle ,c4 ,i believe it is the ,c of the tenor voice1 that most nearly approaches the tones used in speaking4 ,that note corresponds to two hundred and fifty-six full vibrations per second1 two hundred and fifty-six times to and fro per second of time4 ,think of one vibration per second of time4 ,the seconds pendulum of the clock performs one vibration in two seconds1 or a half vibration in one direction per second4 ,take a #aj-;inch pendulum of a drawing-room clock1 which vibrates twice as fast as the pendulum of an ordinary eight-day clock1 and it gives a vibration of one per second1 a full period of one per second to and fro4 ,now think of three vibrations per second4 ,i can move my hand three times per second easily1 and by a violent effort ,i can move it to and fro five times per second4 ,with four times as great force1 if ,i could apply it1 ,i could move it twice five times per second4 ,let us think1 then1 of an exceedingly muscular arm that would cause it to vibrate ten times per second1 that is1 ten times to the left and ten times to the right4 ,think of twice ten times1 that is1 twenty times per second1 which would require four times as much force2 three times ten1 or thirty times a second1 which require nine times as much force4 ,if a person were nine times as strong as the most muscular arm can be1 he could vibrate his hand to and fro thirty times per second1 and without any other musical instrument could make a musical note by the movement of his hand which would correspond to one of the pedal notes of an organ4 ,if you want to know the length of a pedal pipe1 you can calculate it in this way4 ,there are some numbers you must remember1 and one of them is this4 ,you1 in this country1 are subjected to the ,british insularity in weights and measures2 you use the foot and inch and yard4 ,i am obliged to use that system1 but ,i apologize to you for doing so1 because it is so inconvenient1 and ,i hope all ,americans will do everything in their power to introduce the ,french metrical system4 ,i hope the evil action performed by an ,english minister whose name ,i need not mention1 because ,i do not wish to throw obloquy on any one1 may be remedied4 ,he abrogated a useful rule1 which for a short time was followed and which ,i hope will soon be again enjoined1 that the ,french metrical system be taught in all our national schools4 ,i do not know how it is in ,america4 ,the school system seems to be very admirable1 and ,i hope the teaching of the metrical system will not be let slip in the ,american schools any more than the use of the globes4 ,i say this seriously4 ,i do not think any one knows how seriously ,i speak of it4 ,i look upon our ,english system as a wickedly brain-destroying piece of bondage under which we suffer4 ,the reason why we continue to use it is the imaginary difficulty of making a change1 and nothing else2 but ,i do not think that in ,america any such difficulty should stand in the way of adopting so splendidly useful a reform4 ,i know the velocity of sound in feet per second4 ,if ,i remember rightly1 it is #a1jhi feet per second in dry air at the freezing point1 and #a1aae feet per second in air of what we call moderate temperature1 #ei or #fj degrees 7,i do not know whether that temperature is ever attained in ,philadelphia or not2 ,i have had no experience of it1 but people tell me it is sometimes #ei or #fj degrees in ,philadelphia1 and ,i believe them72 in round numbers let us call it #a1jjj feet per second4 ,sometimes we call it a thousand musical feet per second1 it saves trouble in calculating the length of organ pipes2 the time of vibration in an organ pipe is the time it takes a vibration to run from one end to the other and back4 ,in an organ pipe #ejj feet long the period would be one per second2 in an organ pipe #aj feet long the period would be #ej per second2 in an organ pipe #bj feet long the period would be #be per second at the same rate4 ,thus #be per second and #ej per second of frequencies correspond to the periods of organ pipes of #bj feet and #aj feet4 ,the period of vibration of an organ pipe1 open at both ends1 is approximately the time it takes sound to travel from one end to the other and back4 ,you remember that the velocity in dry air in a pipe #aj feet long is a little more than #ej periods per second2 going up to #bef periods per second1 the vibrations correspond to those of a pipe #b feet long4 ,let us take #eab periods per second2 that corresponds to a pipe about a foot long4 ,in a flute1 open at both ends1 the holes are so arranged that the length of the sound wave is about #a foot1 for one of the chief open notes4 ,higher musical notes correspond to greater and greater frequency of vibration1 viz41 #a1jjj1 #b1jjj1 #d1jjj vibrations per second2 #d1jjj vibrations per second correspond to a piccolo flute of exceedingly small length2 it would be but one and a half inches long4 ,think of a note from a little dog call1 or other whistle one and a half inches long1 open at both ends1 or from a little key having a tube three-quarters of an inch long1 closed at one end2 you will then have #d1jjj vibrations per second4 ,a wave length of sound is the distance traversed in the period of vibration4 ,i will illustrate what the vibrations of sound are by this condensation traveling along our picture on the screen4 ,alternate condensations and rarefactions of the air are made continuously by a sounding body4 ,when ,i pass my hand vigorously in one direction1 the air before it becomes dense1 and the air on the other side becomes rarefied4 ,when ,i move it in the other direction1 these things become reversed2 there is a spreading out of condensation from the place where my hand moves in one direction and then in the reverse4 ,each condensation is succeeded by a rarefaction4 ,rarefaction succeeds condensation at an interval of one-half what we call wave lengths4 ,condensation succeeds condensation at the full interval of what we call wave lengths4 ,we have here these luminous particles on this scale1#b representing portions of the air close together1 dense2 a little higher up1 portions of air less dense4 ,i now slowly turn the handle of the apparatus in the lantern1 and you see the luminous sectors showing condensation traveling slowly upward on the screen2 now you have another condensation2 making one wave length4 #b ,alluding to a moving diagram of wave motion of sound produced by a working slide for lantern projection4 ,this picture or chart represents a wave length of four feet4 ,it represents a wave of sound four feet long4 ,the fourth part of a thousand is #bej4 ,what we see now of the actual scale represents the lower note ,c of the tenor voice4 ,the air from the mouth of a singer is alternately condensed and rarefied just as you see here4 ,but that process shoots forward at the rate of one thousand feet per second2 the exact period of the motion is #bef vibrations per second for the actual case before you4 ,follow one particle of the air forming part of a sound wave1 as represented by these moving spots of light on the screen2 now it goes down1 then another portion goes down rapidly2 now it stops going down2 now it begins to go up2 now it goes down and up again4 ,as the maximum of condensation is approached1 it is going up with diminishing maximum velocity4 ,the maximum of rarefaction has now reached it1 and the particle stops going up and begins to move down4 ,when it is of mean density the particles are moving with maximum velocity1 one way or the other4 ,you can easily follow these motions1 and you will see that each particle moves to and fro1 and the thing that we call condensation travels along4 ,i shall show the distinction between these vibrations and the vibrations of light4 ,here is the fixed appearance of the particles when displaced but not in motion4 ,you can imagine particles of something1 the thing whose motion constitutes light4 ,this thing we call the luminiferous ether4 ,that is the only substance we are confident of in dynamics4 ,one thing we are sure of1 and that is the reality and substantiality of the luminiferous ether4 ,this instrument is merely a method of giving motion to a diagram designed for the purpose of illustrating wave motion of light4 ,i will show you the same thing in a fixed diagram1 but this arrangement shows the mode of motion4 ,now follow the motion of each particle4 ,this represents a particle of the luminiferous ether1 moving at the greatest speed when it is at the middle position4 ,you see two modes of vibration1#c sound and light now moving together--the traveling of the wave of condensation and rarefaction1 and the traveling of the wave of transverse displacement4 ,note the direction of propagation4 ,here it is from your left to your right1 as you look at it4 ,look at the motion when made faster4 ,we have now the direction reversed4 ,the propagation of the wave is from right to left1 again the propagation of the wave is from left to right2 each particle moves perpendicularly to the line of propagation4 #c ,showing two moving diagrams1 simultaneously1 on the screen1 depicting a wave motion of light1 the other a sound vibration4 ,i have given you an illustration of the vibration of sound waves1 but ,i must tell you that the movement illustrating the condensation and rarefaction represented in that moving diagram are necessarily very much exaggerated to let the motion be perceptible1 whereas the greatest condensation in actual sound motion is not more than one or two per cent1 or a small fraction of a per cent4 ,except that the amount of condensation was exaggerated in the diagram for sound1 you have a correct representation of what actually takes in the low note ,c4 ,on the other hand1 in the moving diagram representing light waves what had we8 ,we had a great exaggeration of the inclination of the line of particles4 ,you must first imagine a line of particles in a straight line1 and then you must imagine them disturbed into a wave curve1 the shape of the curve corresponding to the disturbance4 ,having seen what the propagation of the wave is1 look at this diagram and then look at that one4 ,this1 in light1 corresponds to the different sounds ,i spoke of at first4 ,the wave length of light is the distance from crest to crest of the wave1 or from hollow to hollow4 ,i speak of crests and hollows1 because we have a diagram of ups and downs as the diagram is placed4 ,illustration3 ,waves of ,red ,light4 ,illustration3 ,waves of ,violet ,light4 ,here1 then1 you have a wave length4#d ,in this lower diagram you have the wave length of violet light4 ,it is but one-half the length of the upper wave of red light2 the period of vibration is but half as long4 ,now1 on an enormous scale1 exaggerated not only as to slope1 but immensely magnified as to wave length1 we have an illustration of the waves of light4 ,the drawing marked red corresponds to red light1 and this lower diagram corresponds to violet light4 ,the upper curve really corresponds to something a little below the red ray of light in the spectrum1 and the lower curve to something beyond the violet light4 ,the variation in length between the most extreme rays is in the proportion of four and a half of red to eight of the violet1 instead of four and eight2 the red waves are nearly as one to two of the violet4 #d ,exhibiting a large drawing1 or chart1 representing a red and a violet wave of light4 ,to make a comparison between the number of vibrations for each wave of sound and the number of vibrations constituting light waves1 ,i may say that #cj vibrations per second is about the smallest number which will produce a musical sound2 #ej per second give one of the grave pedal notes of an organ1 #ajj or #bjj per second give the low notes of the bass voice1 higher notes with #bej per second1 #cjj per second1 #a1jjj1 #d1jjj1 up to #h1jjj per second1 give about the shrillest notes audible to the human ear4 ,instead of the numbers1 which we have1 say1 in the most commonly used part of the musical scale1 i4 e41 from #bjj or #cjj to #fjj or #gjj per second1 we have millions and millions of vibrations per second in light waves2 that is to say1 #djj million million per second1 instead of #djj per second4 ,that number of vibrations is performed when we have red light produced4 ,an exhibition of red light traveling through space from the remotest star is due to the propagation by waves or vibrations1 in which each individual particle of the transmitting medium vibrates to and fro #djj million million times in a second4 ,some people say they cannot understand a million million4 ,those people cannot understand that twice two makes four4 ,that is the way ,i put it to people who talk to me about the incomprehensibility of such large numbers4 ,i say finitude is incomprehensible1 the infinite in the universe is comprehensible4 ,now apply a little logic to this4 ,is the negation of infinitude incomprehensible8 ,what would you think of a universe in which you could travel one1 ten1 or a thousand miles1 or even to ,california1 and then find it come to an end8 ,can you suppose an end of matter1 or an end of space8 ,the idea is incomprehensible4 ,even if you were to go millions and millions of miles1 the idea of coming to an end is incomprehensible4 ,you can understand one thousand per second as easily as you can understand one per second4 ,you can go from one to ten1 and ten times ten and then to a thousand without taxing your understanding1 and then you can go on to a thousand million and a million million4 ,you can all understand it4 ,now #djj million million vibrations per second is the kind of thing that exists as a factor in the illumination by red light4 ,violet light1 after what we have seen and have illustrated by that curve1 ,i need not tell you corresponds to vibrations of #hjj million million per second4 ,there are recognizable qualities of light caused by vibrations of much greater frequency and much less frequency than this4 ,you may imagine vibrations having about twice the frequency of violet light and one fifteenth the frequency of red light1 and still you do not pass the limit of the range of continuous phenomena only a part of which constitutes visible light4 ,everybody knows the photographer's light1 and has heard of invisible light producing visible effects upon the chemically prepared plate in the camera4 ,speaking in round numbers1 ,i may say that1 in going up to about twice the frequency ,i have mentioned for violet light1 you have gone to the extreme end of the range of known light of the highest rates of vibration2 ,i mean to say that you have reached the greatest frequency that has yet been observed4 ,when you go below visible red light1 what have you8 ,we have something we do not see with the eye1 something that the ordinary photographer does not bring out on his photographically sensitive plates4 ,it is light1 but we do not see it4 ,it is something so closely continuous with light visible1 that we may define it by the name of invisible light4 ,it is commonly called radiant heat2 invisible radiant heat4 ,perhaps1 in this thorny path of logic1 with hard words flying in our faces1 the least troublesome way of speaking of it is to call it radiant heat4 ,the heat effect you experience when you go near a bright1 hot coal fire1 or a hot steam boiler2 or when you go near1 but not over1 a set of hot water pipes used for heating a house2 the thing we perceive in our face and hands when we go near a boiling pot and hold the hand on a level with it1 is radiant heat2 the heat of the hands and face caused by a hot fire1 or a hot kettle when held under the kettle1 is also radiant heat4 ,you might readily make the experiment with an earthen teapot2 it radiates heat better than polished silver4 ,hold your hands below1 and you perceive a sense of heat2 above the teapot you get more heat2 either way you perceive heat4 ,if held over the teapot1 you readily understand that there is a little current of air rising4 ,if you put your hand under the teapot1 you get cold air2 the upper side of your hand is heated by radiation1 while the lower side is fanned and is actually cooled by virtue of the heated kettle above it4 ,that perception by the sense of heat is the perception of something actually continuous with light4 ,we have knowledge of rays of radiant heat perceptible down to 7in round numbers7 about four times the wave length1 or one-fourth the period of visible or red light4 ,let us take red light at #djj million million vibrations per second2 then the lowest radiant heat1 as yet investigated1 is about #ajj million million per second in the way of frequency of vibration4 ,i had hoped to be able to give you a lower figure4 ,prof4 ,langley has made splendid experiments on the top of ,mount ,whitney1 at the height of #a1ejj feet above the sea level1 with his bolometer1 and has made actual measurements of the wave lengths of radiant heat down to exceedingly low figures4 ,i will read you one of the figures2 ,i have not got it by heart yet1 because ,i am expecting more from him4#e ,i learned a year and a half ago that the lowest radiant heat observed by the diffraction method of ,prof4 ,langley corresponded to #bh one-hundred-thousandths of a centimeter for wave length1 #bh as compared with red light1 which is #g4c1 or nearly fourfold4 ,thus wave lengths of four times the amplitude or one-fourth the frequency per second of red light have been experimented on by ,prof4 ,langley1 and recognized as radiant heat4 #e ,since my lecture ,i have heard from ,prof4 ,langley that he has measured the refrangibility by a rock salt prism1 and inferred the wave length of heat rays from a ,leslie cube 7a metal vessel of hot water radiating from a blackened side74 ,the greatest wave length he has thus found is one one-thousandth of a centimeter1 which is seventeen times that of sodium light4 ,the corresponding period is about thirty million million to the second4--,w4,t4 ,photographic or actinic light1 as far as our knowledge extends at present1 takes us to a little less than one-half the wave length of violet light4 ,you will thus see that while our acquaintance with wave motion below the red extends down to one-quarter of the slowest rate which affects the eye1 our knowledge of vibrations at the other end of the scale only comprehends those having twice the frequency of violet light4 ,in round numbers1 we have four octaves of light1 corresponding to four octaves of sound in music4 ,in music the octave has a range to a note of double frequency4 ,in light we have one octave of visible light1 one octave above the visible range1 and two octaves below the visible range4 ,we have one hundred per second1 two hundred per second1 four hundred per second 7million million understood7 for invisible radiant heat1 eight hundred per second for visible light1 and one thousand six hundred per second for invisible light4 ,one thing in common to the whole is the heat effect4 ,it is extremely small in moonlight1 so small that nobody until recently knew there was any heat in the moon's rays4 ,herschel thought it was perceptible in our atmosphere by noticing that it dissolved away very light clouds1 an effect which seemed to show in full moonlight more than when we have less than full moon4 ,herschel1 however1 pointed this out as doubtful1 but now1 instead of its being a doubtful question1 we have ,prof4 ,langley giving as a fact that the light from the moon drives the indicator of his sensitive instrument clear across the scale1 and with a comparatively prodigious heating effect6 ,i must tell you that if any of you want to experiment with the heat of the moonlight1 you must compare the heat with whatever comes within the influence of the moon's rays only4 ,this is a very necessary precaution2 if1 for instance1 you should take your bolometer or other heat detecter from a comparatively warm room into the night air1 you would obtain an indication of a fall in temperature owing to this change4 ,you must be sure that your apparatus is in thermal equilibrium with the surrounding air1 then take your burning glass1 and first point it to the moon and then to space in the sky beside the moon2 you thus get a differential measurement in which you compare the radiation of the moon with the radiation of the sky4 ,you will then see that the moon has a distinctly heating effect4 ,to continue our study of visible light1 that is1 undulations extending from red to violet in the spectrum 7which ,i am going to show you presently71 ,i would first point out on this chart that in the section from letter ,a to letter ,d1 we have visual effect and heating effect only2 but no ordinary chemical or photographic effect4 ,illustration3 ,the ,solar ,spectrum4 ,photographers can leave their usual sensitive1 chemically prepared plates exposed to yellow light and red light without experiencing any sensible effect2 but when you get toward the blue end of the spectrum1 the photographic effect begins to tell1 more and more as you get toward the violet end4 ,when you get beyond the violet1 there is the invisible light known chiefly by its chemical action4 ,from yellow to violet we have visual effect1 heating effect1 and chemical effect1 all three2 above the violet1 only chemical and heating effect1 and so little of the heating effect that it is scarcely perceptible4 ,the prismatic spectrum is ,newton's discovery of the composition of white light4 ,white light consists of every variety of color from red to violet4 ,here1 now1 we have ,newton's prismatic spectrum produced by a prism4 ,i will illustrate a little in regard to the nature of color by putting something before the light which is like colored glass2 it is colored gelatin4 ,i will put in a plate of red gelatin which is carefully prepared of chemical materials1 and see what that will do4 ,of all the light passing to it from violet to red1 it only lets through the red and orange1 giving a mixed reddish color4 ,here is another plate of green gelatin4 ,the green absorbs all the red1 giving only green4 ,here is another plate absorbing something from each portion of the spectrum1 taking away a great deal of the violet and giving a yellow or orange appearance to the light4 ,here is another absorbing out the green1 leaving red1 orange1 and a very little faint green1 and absorbing out all the violet4 ,when the spectrum is very carefully produced1 far more perfectly than ,newton knew how to show it1 we have a homogeneous spectrum4 ,it must be noticed that ,newton did not understand what we call a homogeneous spectrum2 he did not produce it1 and does not point out in his writings the conditions for producing it4 ,with an exceedingly fine line of light we can bring it out as in sunlight1 like this upper picture1 red1 orange1 yellow1 green1 blue1 indigo1 and violet according to ,newton's nomenclature4 ,newton never used a narrow beam of light1 and so could not have had a homogeneous spectrum4 ,this is a diagram painted on glass and showing the colors as we know them4 ,it would take two or three hours if ,i were to explain the subject of spectrum analysis to-night4 ,we must tear ourselves away from it4 ,i will just read out to you the wave lengths corresponding to the different positions in the sun's spectrum of certain dark lines commonly called ,fraunhofer's lines4 ,i will take as a unit the one-hundred-thousandth of a centimeter4 ,a centimeter is #j4d of an inch2 it is a rather small half an inch4 ,i take the thousandth of a centimeter and the hundred of that as a unit4 ,at the red end of the spectrum the light in the neighborhood of that black line ,a has for its wave length #g4f2 ,b has #f4hg2 ,d has #e4hi2 the frequency for ,a is #c4i times #ajj million million2 the frequency of ,d light is #e4a times #ajj million million per second4 ,now1 what force is concerned in those vibrations as compared with sound at the rate of #djj vibrations per second8 ,suppose for a moment the same matter was to move to and fro through the same range but #djj million million times per second4 ,the force required is as the square of the number expressing the frequency4 ,double frequency would require quadruple force for the vibration of the same body4 ,suppose ,i vibrate my hand again1 as ,i did before4 ,if ,i move it once per second1 a moderate force is required2 for it to vibrate ten times per second1 #ajj times as much force is required2 for #djj vibrations per second1 #afj1jjj times as much force4 ,if ,i move my hand once per second through a space of a quarter of an inch2 a very small force is required2 it would require very considerable force to move it ten times a second1 even through so small a range2 but think of the force required to move a tuning fork #djj times a second2 compare that with the force required for a motion of #djj million million times a second4 ,if the mass moved is the same1 and the range of motion is the same1 then the force would be one million million million million times as great as the force required to move the prongs of the tuning fork4 ,it is as easy to understand that number as any number like #b1 #c1 or #d4 ,consider gravely what that number means1 and what we are to infer from it4 ,what force is there in space between my eye and that light8 ,what forces are there in space between our eyes and the sun and our eyes and the remotest visible star6 ,there is matter and there is motion1 but what magnitude of force may there be8 ,i move through this luminiferous ether as if it were nothing4 ,but were there vibrations with such frequency in a medium of steel or brass1 they would be measured by millions and millions and millions of tons action on a square inch of matter4 ,there are no such forces in our air4 ,comets make a disturbance in the air1 and perhaps the luminiferous ether is split up by the motion of a comet through it4 ,so when we explain the nature of electricity1 we explain it by a motion of the luminiferous ether4 ,we cannot say that it is electricity4 ,what can this luminiferous ether be8 ,it is something that the planets move through with the greatest ease4 ,it permeates our air2 it is nearly in the same condition1 so far as our means of judging are concerned1 in our air and in the interplanetary space4 ,the air disturbs it but little2 you may reduce the air by air pumps to the hundred thousandth of its density1 and you make little effect in the transmission of light through it4 ,the luminiferous ether is an elastic solid4 ,the nearest analogy ,i can give you is this jelly which you see4#f ,the nearest analogy to the waves of light is the motion1 which you can imagine1 of this elastic jelly1 with a ball of wood floating in the middle of it4 ,look there1 when with my hand ,i vibrate the little red ball up and down1 or when ,i turn it quickly round the vertical diameter1 alternately in opposite directions2 that is the nearest representation ,i can give you of the vibrations of luminiferous ether4 #f ,exhibiting a large bowl of clear jelly with a small red wooden ball embedded in the surface near the center4 ,another illustration is ,scottish shoemaker's wax or ,burgundy pitch1 but ,i know ,scottish shoemaker's wax better4 ,it is heavier than water1 and absolutely answers my purpose4 ,i take a large slab of the wax1 place it in a glass jar filled with water1 place a number of corks on the lower side and bullets on the upper side4 ,it is brittle like the ,trinidad or ,burgundy pitch which ,i have in my hand4 ,you can see how hard it is1 but if left to itself it flows like a fluid4 ,the shoemaker's wax breaks with a brittle fracture1 but it is viscous1 and gradually yields4 ,what we know of the luminiferous ether is that it has the rigidity of a solid1 and gradually yields4 ,whether or not it is brittle and cracks we cannot yet tell1 but ,i believe the discoveries in electricity1 and the motions of comets and the marvelous spurts of light from them1 tend to show cracks in the luminiferous ether--show a correspondence between the electric flash and the aurora borealis and cracks in the luminiferous ether4 ,do not take this as an assertion1 it is hardly more than a vague scientific dream2 but you may regard the existence of the luminiferous ether as a reality of science1 that is1 we have an all-pervading medium1 an elastic solid1 with a great degree of rigidity2 its rigidity is so prodigious in proportion to its density that the vibrations of light in it have the frequencies ,i have mentioned1 with the wave lengths ,i have mentioned4 ,the fundamental question as to whether or not luminiferous ether has gravity has not been answered4 ,we have no knowledge that the luminiferous ether is attracted by gravity2 it is sometimes called imponderable because some people vainly imagine that it has no weight4 ,i call it matter with the same kind of rigidity that this elastic jelly has4 ,here are two tourmalines2 if you look through them toward the light1 you see the white light all around1 i4 e41 they are transparent4 ,if ,i turn round one of these tourmalines the light is extinguished1 it is absolutely black1 as though the tourmalines were opaque4 ,this is an illustration of what is called polarization of light4 ,i cannot speak to you about qualities of light without speaking of the polarization of light4 ,i want to show you a most beautiful effect of polarizing light1 before illustrating a little further by means of this large mechanical illustration which you have in the bowl of jelly4 ,now ,i put in the lantern another instrument called a ,nicol prism4 ,what you saw first were two plates of the crystal tourmaline which came from ,brazil1 ,i believe1 having the property of letting light pass when both plates are placed in one particular direction as regards their axes of crystallization1 and extinguishing it when it passes through the first plate held in another direction4 ,we have now an instrument which also gives rays of polarized light4 ,a ,nico prism is a piece of ,iceland spar1 cut in two and turned1 one part relatively to the other1 in a very ingenious way1 and put together again1 and cemented into one by ,canada balsam4 ,the ,nicol prism takes advantage of the property which the spar has of double refraction1 and produces the phenomenon which ,i now show you4 ,i turn one prism round in a certain direction and you get light1 a maximum of light4 ,i turn it through a right angle and you get blackness4 ,i turn it one-quarter round again and get maximum light2 one-quarter more1 maximum blackness2 one-quarter more1 and bright light4 ,we rarely have such a grand specimen of a ,nicol prism as this4 ,there is another way of producing polarized light4 ,i stand before that light1 and look at its reflection in a plate of glass on the table through one of the ,nicol prisms1 which ,i turn round1 so4 ,now ,i must incline that piece of glass at a particular angle1 rather more than forty-five degrees2 ,i find a particular angle in which1 if ,i look at it and then turn the prism round in the hand1 the effect is absolutely to extinguish the light in one position and to give it maximum brightness in another position4 ,i use the term absolute somewhat rashly4 ,it is only a reduction to a very small quantity of light1 not an absolute annulment as we have in the case of the two ,nicol prisms used conjointly4 ,those of you who have never heard of this before would not know what ,i am talking about4 ,as to the mechanics of the thing1 it could only be explained to you by a course of lectures on physical optics4 ,the thing is this3 vibrations of light must be in a definite direction relatively to the line in which the light travels4 ,look at this diagram3 the light goes from left to right2 we have vibrations perpendicular to the line of transmission4 ,there is a line up and down1 which is the line of vibration4 ,imagine here a source of light1 violet light1 and here in front of it is the line of propagation4 ,sound vibrations are to and fro2 this is transverse to the line of propagation4 ,here is another1 perpendicular to the diagram1 still following the law of transverse vibration2 here is another circular vibration4 ,imagine a long rope3 you whirl one end of it1 and you send a screw-like motion running along2 you can get the circular motion in one direction or in the opposite4 ,plane polarized light is light with the vibrations all in a single plane1 perpendicular to the plane through the ray1 which is technically called the plane of polarization4 ,circular polarized light consists of undulations of luminiferous ether having a circular motion4 ,elliptically polarized light is something between the two1 not in a straight line1 and not in a circular line2 the course of vibration is an ellipse4 ,polarized light is light that performs its motions continually in one mode or direction4 ,if in a straight line1 it is plane polarized2 if in a circular direction1 it is circularly polarized light2 when elliptical1 it is elliptically polarized light4 ,with ,iceland spar1 one unpolarized ray of light divides on entering it into two rays of polarized light1 by reason of its power of double refraction1 and the vibrations are perpendicular to one another in the two emerging rays4 ,light is always polarized when it is reflected from a plate of unsilvered glass1 or water1 at a certain definite angle of fifty-six degrees for glass1 fifty-two degrees for water1 the angle being reckoned in each case from a perpendicular to the surface4 ,the angle for water is the angle whose tangent is #a4d4 ,i wish you to look at the polarization with your own eyes4 ,light from glass at fifty six degrees and from water at fifty-two degrees goes away vibrating perpendicularly to the plane of incidence and plane of reflection4 ,we can distinguish it without the aid of an instrument4 ,there is a phenomenon well known in physical optics as ,haidinger's brushes4 ,the discoverer is well known in ,philadelphia as a mineralogist1 and the phenomenon ,i speak of goes by his name4 ,look at the sky in a direction of ninety degrees from the sun1 and you will see a yellow and blue cross1 with the yellow toward the sun1 and from the sun1 spreading out like two foxes' tails with blue between1 and then two red brushes in the space at right angles to the blue4 ,if you do not see it1 it is because your eyes are not sensitive enough1 but a little training will give them the needed sensitiveness4 ,if you cannot see it in this way1 try another method4 ,look into a pail of water with a black bottom2 or take a clear glass dish of water1 rest it on a black cloth and look down at the surface of the water on a day with a white cloudy sky 7if there is such a thing ever to be seen in ,philadelphia74 ,you will see the white sky reflected in the basin of water at an angle of about fifty degrees4 ,look at it with the head tipped to one side1 and then again with the head tipped to the other side1 keeping your eyes on the water1 and you will see ,haidinger's brushes4 ,do not do it fast1 or you will make yourself giddy4 ,the explanation of this is the refreshing of the sensibility of the retina4 ,the ,haidinger's brush is always there1 but you do not see it because your eye is not sensitive enough4 ,after once seeing it1 you always see it2 it does not thrust itself inconveniently before you when you do not want to see it4 ,you can readily see it in a piece of glass with dark cloth below it1 or in a basin of water4 ,i am going to conclude by telling you how we know the wave lengths of light and how we know the frequency of the vibrations4 ,we shall actually make a measurement of the wave length of the yellow light4 ,i am going to show you the diffraction spectrum4 ,you see on the screen1#g on each side of a central white bar of light1 a set of bars of light variegated colors1 the first one1 on each side1 showing blue or indigo color1 about four inches from the central white bar and red about four inches farther1 with vivid green between the blue and the red4 ,that effect is produced by a grating with #djj lines to the centimeter1 engraved on glass1 which ,i now hold in my hand4 ,the next grating has #c1jjj lines on a ,paris inch4 ,you see the central space1 and on each side a large number of spectrums1 blue at one end and red at the other4 ,the fact that1 in the first spectrum1 red is about twice as far from the center as the blue1 proves that a wave length of red light is double that of blue light4 #g ,showing the chromatic bands thrown upon the screen from a diffraction grating4 ,i will now show you the operation of measuring the length of a wave of sodium light1 that is1 a light like that marked ,d on the spectrum1 a light produced by a spirit lamp with salt in it4 ,the sodium vapor is heated up to several thousand degrees1 when it becomes self-luminous1 and gives such a light as we get by throwing salt upon a spirit lamp in the game of snap dragon4 ,i hold in my hand a beautiful grating of glass silvered by ,liebig's process of metallic silver1 a grating with #f1dhj lines to the inch1 belonging to my friend ,prof4 ,barker1 which he has kindly brought here for us this evening4 ,you will see the brilliancy of color as ,i turn the light reflected from the grating toward you and pass the beam around the room4 ,you have now seen directly with your own eyes these brilliant colors reflected from the grating1 and you have also seen them thrown upon the screen from a grating placed in the lantern4 ,with a grating of #ag1jjj lines1 a much greater number of lines per inch than the other1 you will see how much further from the central bright space the first spectrum is2 how much more this grating changes the direction or diffraction of the beam of light4 ,here is the center of the grating1 and there is the first spectrum4 ,you will note that the violet light is least diffracted and the red light is most diffracted4 ,this diffraction of light first proved to us definitely the reality of the undulatory theory of light4 ,you ask1 ,why does not light go round the corner as sound does8 ,light goes round a corner in these diffraction spectrums2 it is shown going round a corner1 it passes through these bars and is turned round an angle of thirty degrees4 ,light going round a corner by instruments adapted to show the result1 and to measure the angles at which it is turned1 is called the diffraction of light4 ,i can show you an instrument which will measure the wave lengths of light4 ,without proving the formula1 let me tell it to you4 ,a spirit lamp with salt sprinkled on the wick gives very nearly homogeneous light1 that is to say1 light all of one wave length1 or all of the same period4 ,i have a little grating that ,i take in my hand4 ,i look through this grating1 and see that candle before me4 ,close behind it you see a blackened slip of wood with two white marks on it ten inches asunder4 ,the line on which they are marked is placed perpendicular to the line at which ,i shall go from it4 ,when ,i look at this salted spirit lamp1 ,i see a series of spectrums of yellow light4 ,as ,i am somewhat short-sighted1 ,i am making my eye see with this eye-glass and the natural lenses of the eye what a long-sighted person would make out without an eye-glass4 ,on that screen you saw a succession of spectrums4 ,i now look direct at the candle1 and what do ,i see8 ,i see a succession of five or six brilliantly colored spectrums on each side of the candle4 ,but when ,i look at the salted spirit lamp1 now ,i see ten spectrums on one side and ten on the other1 each of which is a monochromatic band of light4 ,i will measure the wave lengths of light thus3 ,i walk away to a considerable distance1 and look at the candle and marks4 ,i see a set of spectrums4 ,the first white line is exactly behind the candle4 ,i want the first spectrum to the right of that white line to fall exactly on the other white line1 which is ten inches from the first4 ,as ,i walk away from it1 ,i see it is now very near it2 it is now on it4 ,now the distance from my eye is to be measured1 and the problem is again to reduce feet to inches4 ,the distance from the spectrum of the flame to my eye is thirty-four feet nine inches4 ,mr4 ,president1 how many inches is that8 ,four hundred and seventeen inches1 in round numbers #dbj inches4 ,then we have the proportion1 as #dbj is to #aj so is the length from bar to bar of the grating to the wave length of sodium light--that is to say1 as forty-two is to one4 ,the distance from bar to bar is the four-hundredth of a centimeter2 therefore the #db;d part of the four-hundredth of a centimeter is the required wave length1 or the #af1hjjth of a centimeter is the wave length according to our simple1 and easy1 and hasty experiment4 ,the true wave length of sodium light1 according to the most accurate measurement1 is about a #ag1jjjth of a centimeter1 which differs by scarcely more than one per cent4 from our result6 ,the only apparatus you see is this little grating2 it is a piece of glass with four-tenths of an inch ruled with #djj fine lines4 ,any of you who will take the trouble to buy one may measure the wave lengths of a candle flame himself4 ,i hope some of you will be induced to make the experiment for yourselves4 ,if ,i put salt on the flame of a spirit lamp1 what do ,i see through this grating8 ,i see merely a sharply defined yellow light1 constituting the spectrum of vaporized sodium1 while from the candle flame ,i see an exquisitely colored spectrum1 far more beautiful than ,i showed you on the screen4 ,i see1 in fact1 a series of spectrums on the two sides with the blue toward the candle flame and the red further out4 ,i cannot get one definite thing to measure from in the spectrum from the candle flame as ,i can with the flame of a spirit lamp with the salt thrown on it1 which gives1 as ,i have said1 a simple yellow light4 ,the highest blue light ,i see in the candle flame is now exactly on the line4 ,now measure to my eye2 it is forty-four feet four inches1 or #ecb inches4 ,the length of this wave then is the #ecb;d part of the four-hundredth of a centimeter1 which would be the #ba1bhjth of a centimeter1 say the #ba1jjjth of a centimeter4 ,then measure for the red1 and you would find something like the #aa1jjjth for the lowest of the red light4 ,lastly1 how do we know the frequency of vibration8 ,why1 by the velocity of light4 ,how do we know that8 ,we know it in a number of different ways1 which ,i cannot explain now because time forbids4 ,take the velocity of light4 ,it is #ahg1jjj ,british statute miles per second4 ,but it is much better to take a kilometer for the unit4 ,that is about six-tenths of a mile4 ,the velocity is very accurately #cjj1jjj kilometers per second2 that is1 #cj1jjj1jjj1jjj centimeters per second4 ,take the wave length as the #ag1jjjth of a centimeter1 and you find the frequency of the sodium light to be #eaj million million per second4 ,there1 then1 you find a calculation of the frequency from a simple observation which you can all make for yourselves4 ,illustration3 ,vibrating ,spherule ,imbedded in an ,elastic ,solid4 ,lastly1 ,i must tell you about the color of the blue sky which was illustrated by the spherule embedded in an elastic solid4 ,i want to explain to you in two minutes the mode of vibrations4 ,take the simplest plane-polarized light4 ,here is a spherule which is producing it in an elastic solid4 ,imagine the solid to extend miles horizontally and miles down1 and imagine this spherule to vibrate up and down4 ,it is quite clear that it will make transverse vibrations similarly in all horizontal directions4 ,the plane of polarization is defined as a plane perpendicular to the line of vibration4 ,thus1 light produced by a molecule vibrating up and down1 as this red globe in the jelly before you1 is polarized in a horizontal plane because the vibrations are vertical4 ,here is another mode of vibrations4 ,let me twist this spherule in the jelly as ,i am doing it1 and that will produce vibrations1 also spreading out equally in all horizontal directions4 ,when ,i twist this globe round1 it draws the jelly round with it2 twist it rapidly back1 and the jelly flies back4 ,by the inertia of the jelly the vibrations spread in all directions1 and the lines of vibration are horizontal all through the jelly4 ,everywhere1 miles away1 that solid is placed in vibration4 ,you do not see it1 but you must understand that they are there4 ,if it flies back it makes vibration1 and we have waves of horizontal vibrations traveling out in all directions from the exciting molecule4 ,i am now causing the red globe to vibrate to and fro horizontally4 ,that will cause vibrations to be produced which will be parallel to the line of motion at all places of the plane perpendicular to the range of the exciting molecule4 ,what makes the blue sky8 ,these are exactly the motions that make the blue light of the sky which is due to spherules in the luminiferous ether1 but little modified by the air4 ,think of the sun near the horizon1 think of the light of the sun streaming through and giving you the azure blue and violet overhead4 ,think first of any one particle of the sun1 and think of it moving in such a way as to give horizontal and vertical vibrations and what not of circular and elliptic vibrations4 ,you see the blue sky in high pressure steam blown into the air2 you see it in the experiment of ,tyndall's blue sky1 in which a delicate condensation of vapor gives rise to exactly the azure blue of the sky4 ,now the motion of the luminiferous ether relatively to the spherule gives rise to the same effect as would an opposite motion impressed upon the spherule quite independently by an independent force4 ,so you may think of the blue color coming from the sky as being produced by to and fro vibrations of matter in the air1 which vibrates much as this little globe vibrates embedded in the jelly4 ,the result in a general way is this3 ,the light coming from the blue sky is polarized in a plane through the sun1 but the blue light of the sky is complicated by a great number of circumstances1 and one of them is this3 that the air is illuminated not only by the sun1 but by the earth4 ,if we could get the earth covered by a black cloth1 then we could study the polarized light of the sky with simplicity1 which we cannot do now4 ,there are1 in nature1 reflections from seas1 and rocks1 and hills1 and waters in an indefinitely complicated manner4 ,let observers observe the blue sky not only in winter1 when the earth is covered with snow1 but in summer1 when it is covered with dark green foliage4 ,this will help to unravel the complicated phenomena in question4 ,but the azure blue of the sky is light produced by the reaction on the vibrating ether of little spherules of water1 of perhaps a fifty-thousandth or a hundred-thousandth of a centimeter diameter1 or perhaps little motes1 or lumps1 or crystals of common salt1 or particles of dust1 or germs of vegetable or animal species wafted about in the air4 ,now what is the luminiferous ether8 ,it is matter prodigiously less dense than air1 millions and millions and millions of times less dense than air4 ,we can form some sort of idea of its limitations4 ,we believe it is a real thing1 with great rigidity in comparison with its density1 and it may be made to vibrate #djj million million times per second1 and yet with such rigidity as not to produce the slightest resistance to any body going through it4 ,going back to the illustration of the shoemaker's wax2 if a cork will in the course of a year push its way up through a plate of that wax when placed under water1 and if a lead bullet will penetrate downward to the bottom1 what is the law of the resistance8 ,it clearly depends on time4 ,the cork slowly in the course of a year works its way up through two inches of that substance2 give it one or two thousand years to do it1 and the resistance will be enormously less2 thus the motion of a cork or bullet1 at the rate of one inch in #b1jjj years1 may be compared with that of the earth1 moving at the rate of six times ninety-three million miles a year1 or nineteen miles per second1 through the luminiferous ether1 but when we have a thing elastic like jelly and yielding like pitch1 surely we have a large and solid ground for our faith in the speculative hypothesis of an elastic luminiferous ether1 which constitutes the wave theory of light4 ,,the ,,limitations ,,of ,,submarine ,,telegraphy4#h #h ,reproduced in abridged form from the ,electrical ,review and the cuts from ,la ,lumiere ,electrique4--,science4 ,the weight of the conductors1 says ,henry ,vivarez in ,la ,lumiere ,electrique1 plays an important part in submarine telegraphy1 not merely as a heavy item in the outlay1 but as one of the principal factors in laying down the lines1 and in taking them up in case of damage4 ,when the conductor is being raised1 the grappling-irons which lift it have to resist not merely the vertical component of the weight of the cable1 but also the considerable effects resulting from friction against the water4 ,it thus frequently happens1 when working at great depths1 that the conductor may be exposed to a strain greater than it is able to bear1 and we are forced to have recourse to stratagems to bring it to the surface4 ,these artifices consist in the use of two or more ships in raising1 which is done as shown in ,figs4 #b and #c1 or1 in the most simple cases1 with the aid of an auxiliary buoy1 as in ,fig4 #d4 ,in any event1 we see that the difficulties1 and of course the cost of raising1 must be considerable4 ,illustration3 ,fig4 #a4 ,hence to decrease the weight of the cables would be an important step in advance4 ,if the weight is in general very great1 it is because the copper core does not take any part in the strain which the entire cable has to resist4 ,we know1 indeed1 that copper cannot bear a breaking-strain greater1 at most1 than #bh kilos per square millimeter4 ,besides1 it would be elongated by such a strain by a very considerable fraction of its initial length2 and1 if the core were made to take part in any manner whatever in the strain which the entire cable has to support1 it would be drawn out beyond its limit of elasticity1 and would remain permanently elongated1 while the substances in which it is inclosed would return to their natural length4 ,it would result that1 being no longer able to find room in a sheath which had become too short1 the copper wire would take a sinuous form in its gutta-percha envelope1 and would occasion at certain points ruptures1 the effect of which would be to decentralize the wire1 to perforate the layer of insulating matter1 and finally to open out a fault in the cable4 ,but there exists an alloy 7silicium bronze7 which can be drawn out into wires having a conductivity equal to that of copper1 and a mechanical resistance equal to that of the best iron4 ,the use of this alloy would render it possible to set free the coating of the cables from a part of the strain which it now has to resist1 and to diminish1 consequently1 their dimensions and weight4 ,wires are now made of this alloy1 having a conductivity of from ninety-seven to ninety-nine per cent4 of the standard1 which at #j;,c41 and with the diameter of a millimeter1 have a resistance of #bj4eg ohms per kilometer4 ,these wires do not break with a less strain than from #de to #dh kilos4 per square millimeter1 and1 which is a very precious property1 their increase in length at the moment of rupture does not exceed one or one and a half per cent4 ,let us consider the deep-sea section of cable of the ,french company from ,paris to ,new ,york--the so-called ,pouyer-,quertier cable1 constructed and laid in #ahgi by ,siemens ,brothers of ,london4 ,the respective weight of each of its component elements is1 per nautical mile1 copper core1 #bbj kilos2 gutta-percha1 #ahj kilos2 hemp1 or an equivalent1 #hj kilos2 #ah wires of galvanized iron of #b millimeters in diameter1 #hfj kilos2 external hemp and composition1 #djj kilos2 total1 #a1gdj kilos4 ,total diameter1 #cj millimeters4 ,total mechanical strength1 #c1jjj kilos1 the wires of the covering being supposed to be of iron4 ,weight under water1 #dej kilos4 ,it can support its own weight without breaking for a length of from six to seven miles4 ,illustration3 ,fig4 #b4 ,the ,atlantic presents from north to south1 and at about an equal distance from each continent1 a sort of longitudinal ridge1 in which the depths vary from #cjj to #djj meters4 ,this ridge spreads out1 in #ej north latitude1 into the region which has received the principal wires connecting ,england and ,france with the ,united ,states4 ,on both coasts there are depressions in which the bottom is at the depth of from #d1jjj to #f1jjj meters4 ,the one on the east extends from the south point of ,ireland to the latitude of the ,cape of ,good ,hope1 and its left-hand boundary follows the general outlines of the west coasts of ,europe and ,africa4 ,the two others1 the northwestern and the southwestern1 form two basins1 bordering respectively on the ,united ,states and the ,antilles and ,south ,america4 ,in these depressions soundings have shown certain zones in which the depths exceed #f1jjj meters1 the principal of which are found to the west of the ,canaries1 to the south of ,newfoundland1 between ,porto ,rico and the ,bermudas1 and to the right of the ,isle of ,marten-,vaz4 ,illustration3 ,fig4 #c4 ,the great depths of the ,pacific are differently distributed4 ,between ,japan and ,california1 between #dj and #ej north latitude1 there is the ,tuscarora depression1 which has depths of from #f1jjj to #h1jjj meters4 ,parallel to ,japan and the ,kuriles there is a depression in which has been found the greatest known depth--#h1eac meters4 ,we see1 therefore1 that any new great submarine line1 having to extend into another zone than that which has received the present ,atlantic cables1 must traverse depressions in which the bottom reaches a maximum depth of #d1jjj meters4 ,the possibility of raising a damaged cable would be very problematical under such conditions1 and it would become certainly impossible in case of a cable from ,san ,francisco to ,japan4 ,under these conditions1 we are forced to conclude that the use of the present cables limits strikingly the progress of submarine telegraphy1 which must remain confined to certain zones of the ,atlantic1 to inland seas1 and to lines along the coasts4 ,but if we consider the daily progress of applied science1 and the constantly increasing demand for rapid communication between nations1 it is certain that we must shortly undertake the study of new cables intended to traverse the greatest depths of the ocean for long distances4 ,necessity1 therefore1 compels us to investigate the new solutions of the problem1 which may furnish us with light cables1 easy to lay1 and possible to repair4 ,illustration3 ,fig4 #d4 ,a cable made by ,mr4 ,j4 ,richards is composed as follows3 core of silicium bronze equal in weight to that of the ,pouyer-,quertier cable1 or1 per nautical mile1 #bbj kilos2 gutta-percha1 #ahj kilos2 layer of hemp1 #hj kilos4 ,the sheathing is formed of #bh wires of galvanized iron of #a4be millimeters in diameter1 each covered with hemp1 and all twisted into a rope around the dielectric2 the wires1 #ejj kilos3 the hemp covering them1 #bej kilos4 ,the weight of the cable is1 therefore1 #a1bcj kilos in the air1 and #cbj kilos in the water4 ,its diameter is #be centimeters1 and its resistance to fracture #b1hjj kilos1 of which the core supports one-half4 ,under these conditions1 the cable can support from eight to nine nautical miles of its length1 and can be raised from the greatest depths4 ,the results of this comparative examination are self-evident4 ,for an equal conductivity and an approximately equal mechanical strength1 the new cable is in weight and bulk equal to about two-thirds of the ,pouyer-,quertier cable4 ,it would cost about #afe less per mile1 and would require1 for laying1 a ship and engines of less power1 and therefore cheaper4 ,the reduced armature will suffice to resist friction and the attacks of animal life in the deep sea2 but for the shore ends we must keep to the types generally employed4 ,such as it is1 and although it may undergo modifications in detail from a more complete study and from experience1 it merits the attention of competent engineers4 ,,williams' ,,system ,,of ,,coast ,,defense ,,by ,,electrical ,,torpedoes4 ,our adjoining engravings illustrate the system of ,j4 ,s4 ,williams1 for working electrical torpedoes1 launches1 and torpedo boats1 and the appliances be proposes for their equipment and his method of utilizing a system of electrical appliances for the defense of sea-ports1 harbors1 coast1 and coaling stations4 ,we use ,mr4 ,williams' own words in describing this invention4 ,fig4 #a illustrates men-of-war or vessels attempting to force their way into a harbor defended by such means4 ,the movable and controllable torpedoes are indicated by letters of reference1 ,a1 connected through the medium of paying-out electrical cables1 ,g1 with the base of operations upon the shore at ,c1 and the launches and floating torpedo batteries or vessels1 ,d4 ,several lines of torpedo defense or attack are shown1 and illustrate the hostile vessels coming within the destructive radius of the movable and controllable torpedoes1 which radius is limited only by the length of the paying-out cable1 which length can be #a miles 7more or less74 ,these means secure an effective weapon at all times under command from the base of operations over a radius of #a miles1 as against a radius of #ej ft41 which is the estimated effective range of destruction for fixed mines containing an equal explosive charge4 ,the movable torpedoes operated from the shore can be supplied with electric power from the main circuits extending along the coast from the developing source1 at any distance from the electric power station or base from which the movable torpedoes are operated or supplied4 ,any natural force1 fuel1 or other means can be employed for the development of the electric force1 which can be transmitted through the main circuits with high tension or pressure to the power stations along the coast1 or to the floating magazines1 where electric accumulators are placed to hold a reserve of energy4 ,the accumulators at such stations can be compounded so as to be at all times ready for supplying power1 and being charged1 except when the limit of storage is reached4 ,electric cut-offs are provided in the loop or derived circuits from the main to cut the magazines out of the circuit when such predetermined limit of energy is in reserve1 and means are employed to prevent the backward flow of the current toward the source from the power stations supplied from the main or other circuit4 ,means are also employed to automatically regulate and prevent any excess of current passing through the circuit in which the accumulators are included4 ,the discharging circuits from the reserve magazines can be connected at the will of an operator with an electric circuit1 including electric magazines1 forming part of the equipment of the launches1 vessels1 or torpedoes1 so as to supply electric power thereto4 ,this can be accomplished at the wharves or through the medium of a cable buoyed along the coast1 so as to obviate the necessity of the launches or vessels returning or running into harbor4 ,signaling devices can extend from such buoy to the operator along the shore1 who will close the circuit from the reserve or main supply circuit4 ,fig4 #b illustrates a sectional elevation of an electrical torpedo provided with mechanism at the stern for operating the rudder electrically1 and the force is regulated by an automatic or manually operative variable resistance interposed in the electrical circuit at the switch board of the cable4 ,a circuit reverser and variable resistance are arranged upon the switch board1 so that the operator at the base can change the direction of the current1 and regulate the force applied through the medium of the electrical cable in such a manner as to adjust the rudder to port or starboard1 and1 if so arranged1 to maintain it at any angle by varying the resistance in the circuit4 ,the rudder mechanism can be operated by the electric energy stored on board the torpedo through the medium of an electric circuit thereto from the electric accumulator provided with a circuit closer and variable resistance worked by the force passed through the paying-out cable4 ,the force passing there through is regulated by a pressure regulator and controlled by a circuit reverser and variable resistance upon the keyboard4 ,means are also employed for indicating to the operator the position of the rudder at any moment1 and such position will correspond to some defined resistance introduced at any given moment in the circuit4 ,the mechanism combined with the rudder can consist of an arrangement of compound solenoids1 the armatures of which are connected to a lever on the rudder head1 or a small electric motor can be employed for operating worm gearing in1 or combined with1 the rudder head4 ,the rudder is brought back to the midship or normal position by springs or counterbalance weights4 ,illustration3 ,,fig4 #a --,,fig4 #c-- --,,fig4 #d-- --,,fig4 #e-- --,,fig4 #f-- --,,fig4 #b-- ,,williams' ,,system ,,of ,,coast ,,defense ,,by ,,electrical ,,torpedoes4 ,the motor of the torpedo1 as illustrated1 is composed of a number of disk-shaped armatures fastened on the shaft1 combined with the screw propeller2 the field magnets1 being also of disk form1 are arranged so that the armatures revolve within close proximity1 but not touching the pole surfaces4 ,this enables an exceedingly high efficiency and great power to be realized from a motor of light weight4 ,this construction of motor is specially suitable for use in the equipment of torpedoes and launches1 and permits an increase of the power of the motor in either of two directions1 i4 e41 either by increasing the number of disks of a given diameter upon the shaft1 or by increasing the diameter of the disks1 both of these methods giving increased power in direct ratio to the increase of size4 ,the accumulator or secondary battery1 c1 is especially designed to store the energy in a small space1 and with light weight1 and so as to command an amount of energy representing the power necessary for a speed of #be miles an hour or more4 ,in the electrical circuit1 between the motor and accumulator1 variable resistances and other governing devices are interposed1 by which the current passing to the motor is regulated automatically in accordance with the speed of the motor1 or with the electric pressure in the circuit from the accumulator4 ,a circuit closer or variable resistance operating in the circuit is connected by the cable with a variable resistance at the switch board1 and operated by the current controlled thereby4 ,the force to the motor can be regulated1 controlled1 or stopped at the will of the manipulator at the switch board placed at the point from which the torpedo is dispatched4 ,signaling devices or guide rods1 ,o1 for indicating the position and direction of movement of the torpedo to the operator can be arranged to be raised and lowered1 through the medium of electrical appliances1 ,p1 at will1 by a current sent through the paying-out cable from the keyboard at the base of operations4 ,fixed means or sight rods can be used1 and hooded incandescent lamps1 ,o#b1 can be carried by the signal or sight rods1 by which means at night or in the day the operator will be enabled to direct the torpedo to the object of attack in spite of adverse or cross currents1 or a change in the position of the vessel under attack4 ,the body of the torpedo containing the machinery and explosive can be arranged to be any desired depth below the surface of the water1 and be supported by a buoy as a shield1 or be covered by a protection against shot1 the displacement of the torpedo being regulated in accordance with the means employed for maintaining it the desired distance below the surface4 ,the torpedo can be ballasted and provided with fins to offer the necessary resistance to the action of the propelling machinery4 ,the electrical paying-out cable1 ,g1 is shown in a coil in proximity to the chamber at the bow1 which is designed to carry the explosive charge in a fixed or detachable magazine1 arranged when detachable to drop a determined distance1 and to be fired electrically by the operator or automatically4 ,fig4 #f illustrates an apparatus in which a dynamo is operated by a rotary engine having a throttling device controlled electrically by the current passing through the discharging circuit of the generator2 the circuit of the generator is connected with the paying-out cable of the torpedo1 through the medium of the key board1 in which a variable resistance and regulating devices are employed for controlling the operation of the torpedo4 ,electric magazines are shown arranged to operate in the discharging circuit of the generator1 and to be connected with the appliances forming part of the equipment of the torpedo through the medium of the paying-out cable1 in conjunction with which is arranged the circuit-closing devices of the switch board under the control of the operator at the stations4 ,automatic electric pressure regulators are used in the circuit from the source1 so as to reduce or regulate the pressure to some predetermined limit4 ,the circuit controllers and manually operative variable resistances upon the switch or keyboard can have indicators connected with them4 ,under such conditions1 with the circuits and appliances upon the torpedo constructed to a known standard1 the control of such torpedo in all its movements and operations is easy and certain4 ,such appliances are especially designed for use upon men-of-war or steam or electric launches when the torpedo vessels are not equipped with electrical magazines4 ,fig4 #e illustrates a floating fort or battery equipped with machinery1 electrical apparatus1 and torpedoes1 as illustrated in ,figs4 #b and #f4 ,the floating fort or battery equipped with electrical or other machinery for propelling can be anchored in suitable positions1 or moved from place to place to be in torpedo range of a fleet1 or in a suitable position for supplying torpedo launches with torpedoes1 and electric or other means of power4 ,fig4 #c illustrates a steam launch1 and ,fig4 #d an electric launch fitted with electrical appliances and compartments containing a means for carrying and discharging electrical torpedoes4 ,by the employment of such means1 and a well-organized system of coast defense1 it will be practically impossible for hostile vessels to land troops1 or to inflict a serious damage upon shipping or seaport towns4 ,any extent of coast or estuary can be thoroughly protected by launches1 light vessels1 and appliances operated from fixed electrical stations1 supplied with power and means of operation from any point1 however distant4 ,for carrying such a system into practical operation1 the cost will1 it is claimed1 be but a tithe of what would be required for placing an inefficient system of fixed mines and forts1 or for building men-of-war for coast defense1 as men-of-war are practically defenseless against a greater number of high-speed launches equipped with movable and controllable torpedoes1 the reasons for which are obvious1 as a sufficient number of such launches would cover a greater distinctive range than the vessel which depended upon the range of its guns1 or those combined with uncontrollable torpedoes4 ,,new ,,electric ,,gas ,,lighter4 ,let not the epithet ,perpetual1 which the inventor applies to the little apparatus that we are about to describe1 frighten the reader1 for its only purpose is to indicate that the instrument in question is capable of operating indefinitely1 without care and without there ever being any need of taking it apart4 ,illustration3 ,fig4 #a--,,perpetual ,,gas ,,lighter4 ,in this gas lighter the inflammation is produced by a small spark1 but this latter1 instead of being obtained by means of a pile1 which1 after a certain length of time1 has to be mounted anew or entirely renewed1 is secured by borrowing the energy produced by the operator pressing upon a button4 ,it is1 then1 in reality1 a mechanical lighter in which electricity intervenes as an intermedium charged with the transformation of work into sufficient of a spark to produce inflammation4 ,thanks to this principle1 and to the arrangement of the apparatus1 there is secured cleanness1 safety1 and economy4 ,the lighting is reduced1 then1 to opening the cock and placing the extremity of the rod over the burner1 or over the edge of the glass in burners provided with a chimney4 ,upon pressing the button and then freeing it1 a spark leaps between the two points and lights the gas4 7,fig4 #a47 ,illustration3 ,fig4 #b4--;,a1 cylinder with lighting rod1 ,g4 ,b1 movable cylinder fixed upon the axis1 ,e4 ,d1 handle containing a rack actuated by a button1 ,f4 ,the electric generator is a static induction machine of very small size1 and the arrangement of which will be understood by reference to ,fig4 #a1 which gives a general view of the apparatus with a portion removed in order to show the relative position of the different parts1 and to ,fig4 #b1 which shows the latter detached4 ,a is an ebonite cylinder containing the entire machine1 and closed above by a cap of the same substance upon which is screwed the lighting rod4 ,the cap is traversed by conducting wires which end in two contact springs that establish an electric communication with the lighting tube4 ,two inducting armatures of tin are cemented to the interior of the cylinder1 ,a1 and occupy1 each of them1 about a third of its circumference4 ,the bottom of the cylinder1 ,a1 supports six contact springs1 parallel with each other and constituting three distinct pairs which are properly connected1 two by two1 with the different parts of the rest of the apparatus4 ,the movable or induced cylinder1 ,b1 of ebonite is provided with six equidistant and insulated thin sheets of tin of a width nearly equal to the interval which separates them4 ,this cylinder is given a rapid rotary motion by means of a system of rack and gearing every time the button1 ,f1 is pressed4 ,during the revolution of the cylinder the six insulated plates come successively into communication with the six springs1 and these put them successively in communication1 two by two1 first with the fixed inducting armatures1 second1 with the conductors connected with the two points between which the spark is to pass1 and1 third1 with each other4 ,the apparatus operates1 then1 like ,sir ,william ,thomson's replenisher4 ,it is only necessary for the armatures upon the cylinder1 ,a1 to be at the start at a difference of potential as small as desirable to suppose it1 in order to have the play of the machine multiply the charge and soon give it sufficient tension to cross the interval that separates the two points fixed at the extremity of the lighting rod1 ,g4 ,from a technical point of view1 the ingenious and new idea resides in the application of a multiplier of charges with which the priming and operation are always secured1 provided the insulating parts are so dry that the losses due to dampness are inferior to the machine's power of production4 ,this result1 moreover1 is easily attained by the use of a hermetically closed system1 and of drying substances placed in that part of the cylinder which forms the handle of the apparatus4 ,from a mechanical point of view1 the lighter contains a series of practical and simple arrangements which make it an apparatus at once convenient1 strong1 and sufficiently perpetual1 as regards duration1 to partially justify the name that has been bestowed upon it by its inventor1 ,mr4 ,j4 ,ullmann4--,la ,nature4 ,,insulators ,,for ,,telegraph ,,and ,,telephone ,,lines4 ,in the accompanying cut we bring together a few figures of porcelain insulators for uncovered wires placed inside or outside of houses4 ,illustration3 ,,porcelain ,,insulators ,,for ,,telegraph ,,and ,,telephone ,,lines4 ,figs4 #a and #b represent simple and double channeled pulleys to be fixed against a wall1 or upon a pole or a door post1 by means of nails simply4 ,fig4 #c shows a pulley of larger dimensions for iron wires4 ,figs4 #d1 #e1 and #f show perforated insulators1 that are quite convenient for holding and supporting a wire1 but which are not convenient to put in position when the wire is of some length4 ,fig4 #g shows a device for protecting a wire that passes through a wall4 ,fig4 #h shows a support designed especially for small poles4 ,it may be used either by passing the wires through the aperture or winding it around the neck of the bell4 ,fig4 #h shows a cleft insulator designed especially for fixing a wire in places where it must form an angle4--,la ,nature4 ,,electric ,,light ,,in ,,theaters4 ,m4 ,brandt places alternately1 in a continuous line1 forty lamps of ordinary glass1 forty of green glass1 and forty of red glass1 making a hundred and twenty lamps in all1 at the foot of the stage4 ,each series of forty lamps forms a separate circuit4 ,the three series can be lighted independently1 or they may be combined1 in order to obtain different effects of color4 ,for example1 a delicate rose hue may be produced by simultaneously lighting the red and the white lamps2 a moonlight effect1 by a combination of the white and the green lamps4 ,in order to pass gradually from the latter to full daylight1 it is only necessary to increase the resistance in the green circuit while strengthening the current in the white lamps4 ,moreover1 the two sides of the stage may be lighted independently1 because the #abj lamps are again subdivided into two circuits of sixty each4 ,we may thus have a moonlight on one side of the stage1 while the other side1 at the moment when an actor enters with a torch in his hand1 seems to be illuminated by the reflection from the torch4 ,when the footlights are of gas1 a current of hot air ascends above the whole line of lights1 forming a sort of gaseous wall between the stage and the audience1 which often makes it difficult to hear the actors4 ,this inconvenience is suppressed by electric lighting1 and the opera singers are agreeably surprised at the great improvement4--,lumiere ,electr4 ,,the ,,new ,,dam ,,at ,,suresnes4 ,it was not till #ahfg1 on the occasion of the ,universal ,exhibition1 that a dam was constructed at ,suresnes that permitted of omnibus-boat service4 ,the effect that this dam had was to raise the water #g feet up stream1 and to consequently suppress the natural incline of the river between ,paris and ,suresnes4 ,its action made itself felt as far as to the ,austerlitz ,bridge in front of the ,garden of ,plants4 ,between ,suresnes and ,lavallois the ,seine is divided into two arms that are separated by the isles of ,puteaux and ,grande-,jabbe4 ,the left arm was dammed at ,suresnes1 and here was established the sluice that allowed boats to cross the falls4 ,the right arm was dammed at ,levallois4 ,a law of ,april #f1 #ahgh1 decided the increase of the depth of the ,seine between ,paris and ,rouen in order to allow boats of a draught of ten feet to reach ,paris1 and to bring thither1 without transfer1 ,english coal and ,bordeaux wines4 ,the ,consul-,general of the ,seine having offered to contribute toward the expense1 on condition that such boats might have it in their power to ascend as far as to ,bercy1 a law of ,july #ba1 #ahhj1 decided that the ,suresnes dam should be raised about three feet in order to increase the anchorage4 ,to effect this1 the dams of #ahfg were entirely rebuilt1 the new ones being located at ,suresnes1 across the two arms of the river4 ,at the same time1 the existing sluice was doubled by another one that was larger and deeper4 ,this great work was executed under the able direction of ,mr4 ,boule1 engineer in chief of roads and bridges1 who has in charge the navigation of the ,seine1 outside of ,paris1 between ,montereau and ,poissy4 ,the new sluice was constructed in #ahhj and #ahha1 the dam to the left and the intermediate weir in #ahhb and #ahhc1 and the pass to the right in #ahhd4 ,the width of the ,seine at this point is about #hbj feet1 the length of the passes varies between #bji and #bcf feet1 and the two sluices occupy a width of #ih feet4 ,in the construction of the three passes there were established1 up and down stream1 dikes about #cbe feet apart1 thus giving considerable space for the installation of work yards1 and much facilitating operations4 ,the new dam is closed by movable mechanisms of the kind invented by ,engineer ,poiret in #ahcd4 ,the iron trestles that support the wickets are the largest that have ever been constructed1 their height being nearly #bj feet and their weight #c1iej pounds4 ,during freshets they are laid upon the bed of the sluice1 and when the water subsides they are raised vertically4 ,upon these supports are placed swinging wickets1 like those of mills1 according to a system devised by ,mr4 ,boulet in #ahgd1 and which has been tried since then with success at the ,port-a-l',anglais dam near ,paris4 ,this system has likewise been successfully applied upon the ,moskowa1 below ,moscow1 and upon the ,saone1 at the ,mulatiere dam1 near ,lyons4#i #i ,see ,,supplement ,no4 #bfd for an illustrated description4 ,the construction of the new sluice presented great difficulties1 by reason of the fact that it was necessary to avoid obstructing navigation in the existing sluice1 where the boats stood thirteen or fifteen feet above the laborers who were working at the side1 behind simple dikes4 ,yet it became necessary to forbid the passage of the sluices for nearly a month each year4 ,at ,suresnes this was taken advantage of each time to keep the works in full blast during the whole night1 the lighting being done by electricity4 ,during these interruptions the boats accumulated at the sides of the dam1 and gave the public an idea of what ,paris would be as a sea port4 ,all the work is now finished4 ,its estimated cost is six millions1 two of which were devoted to the construction of about half a mile of dock wall and of a long and wide sewer4 ,the sluices were opened for navigation on the #aeth of ,september last4 ,the new dams will be in operation in #ahhe1 and next summer they will increase the height of water in ,paris by one meter4--,l',illustration4 ,illustration3 ,,improvement ,,of ,,the ,,river ,,seine4--,,the ,,new ,,dam ,,at ,,suresnes4 ,,brearey',s ,,aeronautical ,,machine4 ,mr4 ,fred4 ,w4 ,brearey has been the honorary secretary of the ,aeronautical ,society of ,great ,britain ever since its establishment in #ahff4 ,in the course of his experiments1 extending over some years1 he found that if a serpentine action were imparted to a fabric it would propel an attached object many times its weight in the air4 ,he records in his published magazine articles that he took the idea from watching the movements of a skate in an aquarium1 which in swimming undulated its whole body4 ,illustration3 ,,brearey',s ,,flying ,,machine4 ,in applying the principle to locomotion in air1 it is of course impossible to undulate what may called the backbone of the whole structure in the manner of the skate4 ,but a fabric may be so attached to a receptacle1 and so worked from thence by a suitable motive power1 that its undulations will propel and support a considerable weight1 depending upon the energy with which such fabric is thrown into waves4 ,he believes that the awning of a vessel can be made in this way to contribute to a ship's progress at the same time that it would cool the passengers4 ,mr4 ,brearey argues that the instinct of the bird enables it to adapt itself instantaneously to varying circumstances2 that in any arrangement for effecting flight by machinery--the adjustment of parts to meet sudden requirements being a matter requiring momentary thought--it is desirable1 if practicable1 to employ large surfaces for parachutic action1 at the same time making this means of safety not an incumbrance1 but an aid4 ,the possession of instinct allows of the employment of the smallest surface in proportion to weight2 the possession of forethought renders it necessary that intermittent action shall be safeguarded by large surfaces4 ,this requirement is fully met1 the inventor says1 by the arrangement advocated by him1 and none but edge resistance is offered to the air1 except the sharp lines of the necessary vehicle4 ,the manufacture of such an apparatus upon a scale of utility would be as follows3 ,a flat-bottomed receptacle1 somewhat of boat shape1 would be fixed upon wheels4 ,at the fore part of the boat a motor would from each side elevate and depress two wing-arms1 each #ae ft4 long4 7,see ,figure47 ,along the wing-arms is attached a fabric which would form the front part of a kite1 which1 being fastened in the center to the edge of the boat1 would continue for #ae ft4 to the rear1 being extended about #f ft4 farther than the stern of the boat by a continuing spar4 ,to a cross piece here would be fastened the tail end of the kite1 which1 however1 instead of a point1 would be about #e ft4 in width4 ,from this again would extend a tail of about #ab ft41 to which either a lateral1 twisting1 or a vertical movement could be imparted by cords in the hands of the operator in the boat for steering purposes4 ,from the fore part of the boat would extend a bowsprit1 from which cords would be attached to the two wing-arms to prevent the weight of the fabric from dragging them backward4 ,an important arrangement has been adopted by the inventor1 which he calls the pectoral cord1 which by its automatic action assumes the functions of the pectoral muscle of the bird4 ,this is an ,india-rubber cord4 ,it is attached by its two extremities to the under portion of each wing-arm1 and in models passes underneath a central shaft--in this case the boat4 ,its degree of elasticity is regulated by the weight4 ,when any model with wings is committed to the action of the air1 the pressure of the air causes the wings to fly upward1 and power is required according to the weight sustained to depress the wings against the weight4 ,the strength of the cord1 however1 is such that it maintains the outstretched wings at that angle which is suitable for gliding upon the air without1 in the case of the bird1 any enforced muscular exertion4 ,the contraction of this cord assists the power exerted in the downward stroke4 ,the wing arms would not be rigid throughout their length4 ,they would consist of a number of rattans or canes firmly bound together by close wrapping1 and tapered by cutting off one at intervals1 this being practically unbreakable by any accident likely to occur4 ,the portion next to the body for #e ft4 or #f ft4 might be stiffened by a steel tube1 forming the center round which the rattans are wrapped4 ,by this method of forming the wing-arms their length may be increased at pleasure4 ,a small model upon this principle1 but without any motive power1 was liberated as an experiment by ,captain ,templer1 from a balloon which had risen #bjj ft4 or #cjj ft4 from ,woolwich ,arsenal1 and it traveled back again to the arsenal half a mile against the wind uninjured4 ,the importance of such an apparatus might become manifest in any flight of a balloon from a besieged place over the heads of an investing army4 ,the results of a rapid survey of the enemy's positions could be written and dispatched from a height against the same current which wafted the balloon1 so as to fall within the lines of the besieged4 ,given a light motive power1 which it is hoped may soon be forthcoming1 ,mr4 ,brearey anticipates the action of the machine as follows3 ,a surface will be provided according to the weight to be carried1 the supporting surface of a parachute being known4 ,upon being run down an incline the envelope will be inflated by the pressure of the air1 and the wing arms raised to that point where their further elevation is restrained by the pectoral cord4 ,the machine will then naturally float away from the incline1 and the occupant must set his motor in action4 ,the downward blow of the wing-arms will cause the fabric immediately attached thereto to imprison a mass of compressed air1 and the following wave will force it along the under side of the fabric4 ,this will cause propulsion4 ,the return or up stroke cuts off and diverts from the upper part that air which1 but for the rise of the wing-arms1 would flow over the back1 and shunts it underneath1 while that which is embraced in the concave fabric following the up-stroke is thrown off in a wave to the rear above the machine1 and so on alternately4 ,during this energetic action the whole fabric is kept in a state of corrugation1 and to such extent is rigid4 ,it possesses all the properties of a plane1 and superiority over a plane1 inasmuch as it propels itself1 and upon cessation of action assumes the functions of a parachute1 the descent of which a man may regulate by a step backward or forward4 ,the latest invention which has been completed upon a full scale is the idea of ,mr4 ,h4 ,c4 ,linfield1 of ,margate4 ,it is really a plane-propelling machine1 but the planes are compressed1 it may be said1 into small compass1 being only two inches apart1 and being of such number and extent as to present #dch square feet of strained and varnished linen in two frames1 each five feet square4 ,the dimensions of the machine are #bj ft4 #i in4 in length1 #ae ft4 in width1 and #h ft4 #c ins4 in height4 ,it runs upon four wheels2 the two front wheels are #f ft4 in diameter1 the two hind wheels #c ft4 ,the frames before mentioned are fixed one on each outer side of the front wheel at an upward angle4 ,the wheels have been tested to sustain a weight of #e cwt4 ,the weight of the machine is #bdj lb41 and of its inventor #ahj lb4 ,he sits between the wheels and works two treadles1 which actuate a nine-bladed screw #g ft4 in diameter1 fixed in front of the machine1 to which he can impart #aab revolutions per minute4 ,this suffices to enable him to travel along a level road4 ,,raising ,,of ,,the ,,fallen ,,girder ,,of ,,the ,,douarnenez ,,viaduct4 ,during the erection of the viaduct at ,douarnenez--,department of ,finistre--over the river ,pouldavid1 one end of one of the heavy latticework girders dropped into the river1 as shown in the upper one of the annexed cuts taken from ,l',illustration4 ,the difficult problem to be solved was to remove the obstruction in as short a time as possible1 and at the least expense2 and the engineers came to the conclusion that it would be best to raise the fallen end1 as the girder was intact1 with the exception of those parts that struck the bottom of the river1 and which could easily be replaced by others4 ,illustration3 ,,the ,,viaduct ,,of ,,douarnenez4--,,the ,,position ,,of ,,the ,,fallen ,,girder4 ,illustration3 ,,the ,,viaduct ,,of ,,douarnenez4--,,the ,,girder ,,raised4 ,the viaduct has three spans of #aij ft4 each1 and is #hh ft4 above the surface of the water4 ,while rolling the girders upon the piers1 the pivot of one of the rollers broke1 and a projecting length of #ahc ft4 of the girder dropped a vertical distance of #gb ft4 ,that part of the girder that had to be raised was #ahc ft4 long1 and weighed #ade tons1 and the free end had to be moved a distance of #gb ft4 in an arc the radius of which was #ahc ft4 ,suitable scaffoldings were erected on the piers and below the fallen end of the girder2 four strong and heavy double chains were connected with the lower end of the girder and passed over a scaffolding erected for this purpose1 and the opposite ends of the chains were connected with a heavy box weighted with rails1 and containing #b1gjj cubic ft4 of water4 ,the upper end of the fallen girder was disconnected from the other parts of the structure1 and a heavy steel pivot bar inserted1 upon which the girder could turn4 ,the box was so weighted that the fallen girder was somewhat heavier than the box1 and then windlass chains were connected with the lower end of the girder1 and wound upon windlass drums operated on top of the scaffolding4 ,the weighted box thus merely acted as a counterbalancing weight1 the raising being accomplished by means of the windlass4 ,on the #ast of ,august the lower end of the girder was raised #ag inches1 and remained in this position for twenty-four hours1 during which time examinations were made which proved that the calculations were correct1 and that all the parts worked perfectly4 ,the operation was completed the next day with perfect success1 and was witnessed by a great multitude1 attracted by the novel sight4 ,,improved ,,wire ,,testing ,,machine4 ,the illustration represents a multiple wire tester1 constructed for the ,trenton ,iron and ,steel ,company by ,riehle ,bros41 of ,philadelphia4 ,it consists of a weighing mechanism 7seen on the left1 with a capacity of #d1jjj pounds71 two single or alternating pumps1 a hydraulic jack1 a patented three-way valve1 and a rising and falling accumulator4 ,the weighing end of the machine1 placed horizontally and secured by bolts to a foundation1 is accurate1 and will weigh the strain on one to six wires at a time4 ,it is provided with self-adjusting grips to take in wires from ,no4 #aj to ,no4 #af1 and hold them firmly4 ,it can be adapted to take in a larger or smaller range of numbers when desired4 ,there is a set of gripping appliances at both ends1 and in the present instance they are #ij feet apart--one set at the scale end1 and the other secured to head of piston4 ,the jack is #e feet in length1 and lined with brass2 its outside diameter is #c inches2 its inside diameter1 #b inches4 ,like the scale end1 it is firmly bolted down to its foundations4 ,the plunger has a stroke of #d feet4 ,it is supported and guided by three guides1 the top one being a straight tube running on turned rollers4 ,a three-way valve controls the movements of the jack and accumulator1 and supplies water to the jack by a lever4 ,when the lever is raised1 the water is forced into the larger area of the jack1 causing the plunger to move backward and bring a strain on to the wires or other specimens2 when the lever is lowered1 the water in the larger area of the jack only returns to the reservoir of the pump 7to be used again74 ,now1 without changing the position of the lever1 the plunger will return automatically1 without weight or counterbalance1 with a steady1 smooth1 and uniform motion4 ,the pump has a slow motion1 #fj revolutions per minute4 ,it has two single action pistons1 and the valves are so simple and readily accessible that an ordinary mechanic can examine and repair1 when necessary1 in a short time4 ,the accumulator is so arranged as to overflow when it comes to its maximum height4 ,the machine can be adapted to stretching and straightening wires in lengths to a given amount4 ,the weight on the scale and that on the accumulator is made to correspond1 so that wires of a certain number or size can be quickly tested in quantities under exactly the same conditions1 with only the movement of the lever4 ,illustration3 ,,improved ,,wire ,,testing ,,machine4 ,,improved ,,doubling ,,and ,,laying ,,machine4 ,the tenacity with which whip cord1 cotton cord1 and other similar lines preserve their twist when properly made1 is a little remarkable when considered in relation to the materials from which they are manufactured1 and which as a rule show a tendency when ordinarily twisted to return to a straight line4 ,this was one of the reflections which occurred to us when watching a ,james doubling and laying machine at work at the late ,textile ,exhibition1 on the stand of ,walter ,t4 ,glover ,co41 of ,manchester4 ,we give a perspective view of this machine4 ,illustration3 ,,improved ,,doubling ,,and ,,laying ,,machine4 ,there are several ways of carrying out the process of doubling1 which in its simplest sense consists in laying a given number of folds of yarn together and putting a twist into them4 ,but beyond this we come to spindle banding1 which is cord1 or rope in miniature1 and it is made of three or more ends of the doubled yarn just mentioned1 such doubled yarn becoming1 in fact1 the strand of a small rope4 ,to lay these strands properly into a cord they should not only be twisted together1 but each should be twisted separately in the opposite direction to the twist of the cord4 ,a banding machine1 therefore1 has to impart a double twist1 and to perform the work perfectly each twist should be capable of easy regulation2 and the drag upon the bobbins should admit of being adjusted to requirements4 ,these conditions are met in the ,james machine1 as evidenced by the samples of work produced by it4 ,as shown in our engraving1 the apparatus consists of three heads1 of four spindles each1 being capable therefore of doubling a four-strand cord4 ,the heads work independently of each other1 and by throwing one or two of the spindles out of action a three-strand or a two-strand cord will be produced4 ,the cord is twisted regularly1 and may be made continuously to any length4 ,the uniformity of the twist depends upon the fact that the cord is taken up at a regular rate1 by a simple and neat motion1 consisting merely of a pair of pulleys1 one grooved and the other with a roughened surface4 ,after leaving these1 the cord is coiled upon the reels seen on the top of the framework4 ,the twist given to the cord depends upon the rate at which it is taken up1 the speed of the center spindle remaining constant4 ,the twist in the strands is governed by the speed at which the bobbin spindles revolve4 ,this may be adjusted as required1 by a series of change wheels4 ,an effective stop motion is also applied to automatically stop the head in which a breakage takes place1 whether of the cord itself or of a single strand4 ,either head is started by depressing the handle or knob in front of it4 ,a feature for which particular merit is claimed is that a heavy drag is put upon all the strands separately for the purpose of taking out all the stretch before twisting1 which is an important desideratum for the production of good banding4 ,this is accomplished by hanging weights on the spindles1 which cause the strands to be twisted under tension4 ,the tension is altered as required by the size and nature of the yarn1 by removing or adding to the weights4 ,the heads being independent of each other enables the machine to be employed on three cords of different material and thickness4 ,the production is about #a1cjj yards per head for ten hours1 and it is stated that a girl can mind as many as #hj or #ij heads4--,iron4 ,,boiler ,,tubes4 ,the following table gives the draught area and heating surface of the various sized boiler tubes and flues3 ---------------------------------------- --------------------------- ,no4 of ,heating surface tubes in #a ,external ,draught area ,draught ,area in feet sq4 foot of ,diameter4 in sq4 inches4 in sq4 feet4 per ft4 of tube draught in length4 area4 ---------------------------------------- --------------------------- #e_/h 444444 444444 4#afcf 44444 444444 444444 4#aifc 44444 #a 4#ege 4#jjdj 4#bfah #bej4j #a 4#ifh 4#jjfg 4#cbgb #adi4c #a #a4chi 4#jjifd 4#cibg #ajc4g #a #a4iaa 4#jacc 4#deha #ge4b #b #b4egc 4#jagi 4#ebcf #ee4i #b #c4ccc 4#jbca 4#ehia #dc4c #b #d4jhc 4#jbhd 4#fede #ce4b #b #e4jbg 4#jcdi 4#gbjj #bh4g #c #f4jgj 4#jdbb 4#ghed #bc4g #c #g4aaf 4#jdid 4#hejh #bj4b #c #h4cdg 4#jehj 4#iafc #ag4b #c #i4fgf 4#jfgb 4#ihah #ad4i #d #aj4ic 4#jgei #a4jdgb #ac4b #d #ad4je 4#jiif #a4agha #aj4b #e #ag4ce 4#abje #a4cjij #h4c #f #be4be 4#agec #a4egjh #e4g #g #cd4id 4#bdbf #a4hcbf #d4a #h #df4bj 4#cbjh #b4jidd #c4a #i #eh4fc 4#djgb #b4cefb #b4e #aj #gb4bc 4#ejaf #b4fahj #b4j ---------------------------------------- --------------------------- ,,improved ,,ladle ,,carriage4 ,we give below two views of a ladle carriage which has been constructed from the designs of ,mr4 ,thomas ,wood1 the chief engineer to the ,ebbw ,vale ,steel1 ,iron1 and ,coal ,company4 ,these works cover a large extent of ground1 the ,victoria furnaces and the ,ebbw ,vale furnaces1 both of which supply one steel plant1 being over a mile apart4 ,although this gives a long distance over which the molten metal from the furnaces has to be carried1 it is by no means unprecedented2 the ,barrow furnaces for instance being situated still further from the steel works they supply4 ,until a short time ago1 however1 the ,ebbw ,vale ,company had their ,sirhowy furnaces in blast4 ,these are1 or rather were1 for now they are dismantled1 situated six miles by rail from the converters they supplied at ,ebbw ,vale1 consequently the ladle containing the #aj tons of molten metal had to be brought this distance each time the converters were charged4 ,in order to meet the exigencies of such a service1 the ladle carriage we now illustrate was designed by ,mr4 ,wood4 ,by means of the gearing of wormwheel1 rack1 and pinion1 which are clearly shown in ,fig4 #b1 the ladle can be retained in the center of the carriage and kept upright for running2 a clip which is easily knocked out of gear being fitted to retain it in the necessary position4 ,when the ladle is in the required spot to enable the charge to be tipped into the runner which takes it to the converter1 the loose wrought-iron handle1 ,a1 is slipped on to the square end of the wormshaft1 and by turning this the ladle is tipped1 and at the same time travels on the rack from its position in the center of the carriage1 one man being sufficient to perform the operation4 ,the dotted lines at ,b represent a wrought-iron shield for protecting the tipping gear from splashes of metal1 etc4 ,illustration3 ,,improved ,,ladle ,,carriage4 ,with the old cast-iron frame carriage the weight of the ladle and charge is practically carried by the two bearings on one side1 as the ladle has to be overhung from the center of the carriage1 in order that the metal may tip clear of the rails and into the well2 supposing of course there are not conveniences for tipping direct into the converter4 ,it will be seen that in ,mr4 ,wood's arrangement1 when the ladle is in a vertical position it stands fairly in the middle of the carriage1 but the action of tipping carries it to the side1 so that the charge will clear the rails4 ,this carriage has now been in work for about three years1 and since its introduction there has not been the slightest hitch1 even when running ten tons of metal at a considerable speed over the six miles of line from the ,sirhowy furnaces4 ,this has been a pleasing contrast compared to the trouble that used to be experienced at ,ebbw ,vale with the original cast-iron frames4 ,these1 under the heavy duty put upon them1 were continually breaking on the side which had to carry the weight1 and this would entail the metal having to be tipped on the ground so that it might be broken for recharging4 ,although the exceptional nature of the work at ,ebbw ,vale called forth this arrangement1 it will of course be understood that the advantages it possesses are also manifest upon shorter journeys4--,engineering4 ,,the ,,repair ,,of ,,boiler ,,tubes4#aj #aj ,annales ,industrielles4 ,the tubes of tubular boilers must1 for different reasons1 be taken out when the generator has worked for a certain length of time4 ,such a necessity presents itself when the extremities of the tubes are worn out and can no longer be fastened with sufficient tightness into the plate1 or when the portion of the tube in contact with water is so incrusted that there results a notable diminution in the production of steam1 or when the tubes exhibit local injuries1 or1 finally1 when the interior of the boiler must be examined4 ,illustration3 ,,repair ,,of ,,boiler ,,tubes4 ,this latter contingency arises for every boiler after a period of from #f to #h years1 and it requires the removal of all the tubes4 ,it furnishes an occasion to remedy the other defects1 that would have of themselves required the renewal of only a certain number of the tubes4 ,in the interval between these thorough inspections defects may present themselves which require the removal of a certain number of tubes4 ,the frequency of such repairs depends upon the nature of the feed water1 upon the quality of the fuel1 upon the pressure at which the generator operates1 upon the state of repair in which the boiler is kept1 and naturally also upon the quality of the metal of which the tubes themselves are composed4 ,selenitic water deposits in the long run a very hard and adhesive incrustation1 which acts as an obstacle to the transmission of heat4 ,the more calcareous waters fill the intervals between the tubes with deposits which can be but partially removed by the washing of the boiler1 and which often form a calcareous mass such as to prevent all circulation of water around the tubes4 ,in both cases the tubes are heated beyond measure1 elongate1 detach themselves from the tube-plates1 and burn in places1 or lose enough of their resistance to allow them to become flattened by the pressure of the steam4 ,the loosening of the tubes likewise acts injuriously upon the plates1 which the pressure causes to bend outwardly4 ,the result is that the tubes may become completely detached4 ,sulphurous fuel corrodes the extremities of the tubes near the fire-box and also notably attacks the hind extremities1 in the interior1 against the tube-plate4 ,it likewise renders brittle those tubes whose metal is bad1 so that they split either of themselves or at the least effort made to tighten them up in the tube-plate4 ,in tubes made of poor metal these brittle places are not only found near the plates1 but also in other parts4 ,the tubes likewise have to undergo too lively a combustion when the boilers are driven4 ,leakages from the tubes often proceed from the fact that an expansion of the boiler lengthwise is prevented1 or from a cooling of the tubes by a current of air which passes1 without becoming heated1 through a badly covered grate4 ,leakages may also occur if a boiler that has just been emptied is filled too soon4 ,it will be seen that the causes of the deterioration of tubes are numerous2 and the repairs that they give rise to in railway shops are therefore very important1 and are generally known as a whole4 ,yet they differ in some points of detail according to the shop in which they are made1 so that it may not be without utility to pass them in review1 in order to compare the results of the practice of several persons pursuing the same object4 ,the author of this article has had1 during a long experience1 occasion to make such comparisons3 several of the methods that he describes were derived by him in shops that he directed1 and have been applied upon a large scale2 and numerous visits to other shops have permitted him to see different processes and to judge of results4 ,the different repairs to be made in boiler tubes may be classified as follows3 #a4 ,repairs to leaky tubes4 #b4 ,removal of worn-out tubes4 #c4 ,repair of tubes in service1 and putting them in place again4 #a4 ,,repair ,,of ,,leaky ,,tubes4 ,leakages at the point of insertion of the tubes are still generally and exclusively repaired by means of roller apparatus for opening the tubes1 and with which an endeavor is made to tighten the latter in the hole in the tube-plate4 ,the cones which were formerly employed injured the ends of the tubes by splitting them2 if the workman was not very skillful1 the holes in the plate became oval2 and fractures likewise quite often occurred between the holes in the plate itself4 ,the best apparatus to open the tubes are those in which the wedge that separates the rollers is actuated by a screw2 those in which the wedge is driven in by a hammer are scarcely better than the old cones4 ,when apparatus for opening tubes are used1 care must be taken to begin with the external tubes1 and to open these gradually4 ,the same operation is afterward performed upon the neighboring ones1 in approaching the center1 and then the first ones are taken up4 ,the tubes should never be opened at one operation1 but each one should be subjected to several passes4 ,at the second pass1 the rollers should be placed a little more deeply1 and should then be half within the tube-plate4 ,the tube thus opens behind the plate and forms a bearing against it1 and this not only renders it tighter1 but also increases its adhesion to the plate4 ,finally1 the operation is finished by beating down the edge of the tube that has been raised a little by the preceding pass4 ,if this edge is already somewhat deteriorated1 or if it is not very thick1 tightness may be had by means of rings4 ,the use of rings should be avoided as much as possible1 because they diminish the section of the tubes1 and render the cleaning of their interior more difficult4 ,they should only be employed as an exception1 and should be considered as an unavoidable evil4 ,even in old boilers1 in which the holes have become oval1 they should be considered only as a means of rendering a small number of tubes tight4 #b4 ,,removal ,,of ,,worn-,,out ,,tubes4 ,the tubes are taken out independently of one another through the front tube-plate1 after an incision has been made with a chisel through the part of the tube that is fixed into the back plate4 ,when the holes in the front tube-plate are not greater in diameter than the external diameter of the tube1 and the latter is incrusted1 this process becomes very difficult1 and the use of it often completely spoils the tube4 ,in fact1 we can only remove the tube by live force1 and for this purpose we either use the shock of a heavy body or mechanical apparatus upon whose arrangement ,i shall not dwell4 ,in all cases the holes of the tube-plate are injured4 ,the edge of these must1 in fact1 detach the scale from the tube before the latter can be removed from the boiler1 and1 when a little of this scale remains adherent1 it produces grooves in the hole1 which render it very difficult later on to make the new tube tight4 ,it is consequently preferable to cut the tubes immediately back of the plates by means of a special apparatus consisting of a cone provided with a small circular steel saw4 ,this operation should be begun at the bottom of the boiler near the blow-off plug1 and be continued in advancing toward the top4 ,the cut tubes fall to the bottom of the boiler1 and are removed through the blow-off hole of the front tube-plate4 ,the pieces of tube that remain in the plate are afterward easily removed by cutting them with a chisel4 ,if there are but few tubes to be removed1 a passage is made for them toward the blow-off plug by removing a few of the tubes beneath4 ,when the tubes to be removed are not too far from the plug1 this method is very satisfactory4 ,even though there were a few more tubes removed1 the cost of such removal would be more than compensated for1 because this method is cheaper1 and preserves the tubes and plates1 and because the boiler1 by receiving a larger number of clean tubes1 will afterward utilize the fuel better4 #c4 ,,repair ,,of ,,tubes ,,in ,,service1 ,,and ,,putting ,,them ,,in ,,place ,,again4 ,either when the removed tubes are to be employed anew1 or when they are to be classed as old material1 it is equally necessary to free them from the incrustation that covers them4 ,the methods employed vary according to the shop4 ,the cleaning of tubes by beating or scraping the incrustation is very difficult1 and requires much time4 ,in some shops the tubes are dipped into an acid bath4 ,in this way only the incrustation composed of carbonate of lime is dissolved1 that into the composition of which sulphuric acid enters not being attacked4 ,in some large shops there are iron drums in which the tubes are placed4 ,when these drums are revolved the incrustation becomes partially detached1 but very rarely completely1 and it is always necessary to finish the work by hand4 ,it also happens that the bits of scale that become detached and that remain between the tubes produce grooves therein2 besides1 the cost of installing these drums is quite high4 ,per contra1 the writer has seen a1 as yet1 little known method employed in the shops of the ,berlin-,hamburg ,railway1 one that he has used himself1 that he has introduced into several shops1 and that he can recommend as the best4 ,the tube to be cleaned is submitted to a rotary motion around its longitudinal axis4 ,the workman grasps it with a sort of wooden pincers whose jaws are provided with coarsely toothed steel plates1 and1 pressing the legs of this more or less tightly1 slides it slowly along the tube4 ,the incrustation is thus reduced to dust1 and the tube1 after the operation1 is absolutely clean4 ,the apparatus used for revolving the tubes is shown in ,figs4 #a to #c4 ,it consists of quite a short shaft1 which revolves in two pillow-blocks and receives its motion through pulleys4 ,outside of the bearing to the right1 this shaft terminates in a cone provided with channels whose diameter is proportioned to that of the tubes4 ,the tube to be cleaned is firmly fixed upon the cone1 and provided at its other extremity with a plug that serves to center it4 ,as the cleaning is accompanied with much dust1 it must be done in open air or in a special shop4 ,at the same time1 a classification is made of the damaged tubes that can no longer be employed1 except as ends of the tubes that may be employed in shorter boilers1 and of those that are entirely unserviceable4 ,every time a tube is removed it loses #gj to #hj mm4 of its length in the two cuttings4 ,when we have locomotives that are provided with shorter boilers1 we have a direct use for the removed tubes1 but if the contrary is the case the tubes must be lengthened4 ,such elongation is effected in three ways1 viz41 by drawing them out1 by soldering copper ends to them1 and by uniting iron ends to them with a hammer4--,f4 ,w4 ,eichholz1 in ,organ fur die ,fortschritte des ,eisenbahnwesens4 ,,grulet',s ,,screw ,,for ,,raising ,,water4 ,the ,french ,agricultural ,machnery ,company has recently made a very interesting application of the screw for raising water for submersion and irrigation1 and1 to our knowledge1 it is the first of its kind4 ,it is only necessary to examine the accompanying cut and observe the dimensions of the machine 7which was constructed according to plans of ,mr4 ,grulet7 to recognize the fact that we have here a really practical application4 ,the screw1 which constitutes the principal peculiarity of the system1 has six blades1 with a pitch of #j4dfe m4 ,on making #baj revolutions per minute it is capable of raising about #dce liters 7#ie gallons7 per second to a height of #a4b m 7about #d feet74 ,the shaft that drives it revolves in a bearing which is bolted to a cross piece that is affixed to the cylindrical chamber4 ,this latter consists of a cast iron case that is easily taken apart1 and of a strong cylinder of iron plate whose upper extremity is connected1 by means of riveted angle iron1 with the bottom of the sluice4 ,in the interior of the cylinder there are two cones1 whose bases embrace the hub of the screw in such a way as to obtain a continuous superposition of the layers of liquid1 and prevent bodies in suspension from penetrating between the rubbing surfaces of the bearing4 ,one of the cones is made of iron plate1 and is connected with the principal cylinder by four radiating braces and small angle irons1 and the other is cast in a single piece with the box of the pivot4 ,the rotary axis is guided above by two pillow blocks held by the cross pieces of a frame that is riveted to the sides of the sluice4 ,finally1 this latter terminates in a hinged gate which regulates the flow of the water4 ,two beams that rest upon the sides of a stream will suffice in most cases to support the entire affair4 ,the mechanical duty of the apparatus is estimated at about #fe per cent4 ,in the apparatus put up by ,mr4 ,grulet1 the motive power is furnished by a portable #aj ,h4,p4 engine4 ,the boiler is a return flame one1 with movable fire place1 and the steam cylinder has a diameter of #j4b m4 7#h inches7 for a piston stroke of #j4c m4 7about #ab inches74 ,before the apparatus was finally put in place it was sent to the last exhibition at ,carcassonne1 where it attracted very much attention from visitors4 ,its great regularity in working was particularly remarked4 ,this quality1 and the simplicity of its construction and the ease with which it may be put in place1 are valuable features in apparatus that are designed to be looked after by inexperienced persons1 and to operate in open air far from repair shops4--,revue ,industrielle4 ,illustration3 ,,grulet',s ,,screw ,,for ,,raising ,,water4 ,,on ,,various ,,toning ,,baths4#aa ,by ,w4 ,m4 ,,ashman4 #aa ,a communication to the ,london and ,provincial ,photographic ,association4 ,in alkaline toning with borax or acetate of soda1 the first consideration is to free the paper as much as possible from the excess of silver nitrate remaining therein over and above the quantity used in the production of the print2 this is termed washing away the free silver4 ,that operation is satisfactorily performed by soaking the prints in a few changes of clean soft water1 usually four1 or until the water is no longer opalescent when tested with a few grains of salt4 ,the washing water so obtained is collected in the manner described to you by ,mr4 ,f4 ,w4 ,hart1 and precipitated with dilute hydrochloric acid4 ,the vessel employed should be scrupulously clean1 either earthenware1 porcelain1 or wood answering the purpose4 ,experiment #a4--,the treatment of the prints is sometimes followed by passing them into a dilute solution of sodium acetate or ordinary common salt1 about one per cent41 such as here shown1 and stirring them about for five minutes1 when it will be seen they have assumed a brick-red color1 the object of which is threefold3 ,first1 the fibers become charged with a substance which acts as a chlorine absorbent1 a necessary property to be mentioned further on4 ,secondly1 a definite color is insured to start with1 thus obviating the possibility of mistaking fresh prints in the toning bath for those which have become purple by reason of the deposited gold1 an important consideration when dealing with fumed paper4 ,thirdly1 the last trace of free nitrate of silver is removed1 thereby preventing a too rapid decomposition of the toning bath4 ,theoretically considered1 it is proper that the last trace of silver nitrate should be removed2 but those who are engaged in the daily practice of commercial work do not insist upon the strict observance of such a rule in all cases4 ,an especial exception is permitted and advocated when dealing with prints from weak or underexposed negatives1 this class being found to yield richer tones by not washing any of the free silver out4 ,the plan of soaking prints in a solution of sodium acetate was originally recommended1 in lieu of washing1 by a member of this ,association1 ,mr4 ,a4 ,l4 ,henderson1 as long ago as #ahfa1 the following being an outline of the method suggested by him3 ,slightly overprinted proofs were soaked in a bath composed of ,sodium acetate #bdj grains4 ,water #aj ounces4 ,the unwashed proofs were moved about in this solution at least ten minutes1 in order to convert all the free silver nitrate into acetate of silver4 ,after slight rinsing in clean water the proofs were toned with ,gold terchloride #d grains4 ,sodium acetate #bdj ,water #aj ounces4 ,among the advantages claimed was an entire absence from mealiness1 a defect1 you will remember1 we now avoid by the adoption of ammoniacal fuming4 ,guide-books to the practice of printing usually recommended three rapid washings2 the decomposing action thus set up by the quantity of free silver remaining in the paper materially quickens the speed of toning4 ,to prevent a too rapid deposition of gold some printers prefer adding a small quantity of common salt to the toning bath1 which turns the prints sufficiently red and acts in some respects equal to an intermediary bath4 ,preserved papers--containing1 as they generally do1 a certain proportion of free acid--are liable to give some trouble in toning1 owing to the retarding action of the acid present4 ,when this occurs1 it is in a great measure overcome by the use of an intermediate bath of an alkaline character and sufficient strength to neutralize the acid4 ,either the carbonates of ammonia or soda are found useful for this purpose1 and ,i cannot do better than quote the one mentioned by ,mr4 ,frederick ,york1 which1 it will be remembered1 is composed of ,washing soda #a ounce4 ,water #a gallon4 ,prints treated in the manner described are ready for toning by the alkaline method to be dealt with later on4 ,this brings us to the consideration of toning baths generally4 ,the properties of toning baths vary somewhat according to the mode of preparation4 ,the term toning1 as we understand it1 implies a certain change of color brought about by chemical means1 such as the deposition of a stable metal upon one that is easily affected by the atmosphere--electrolysis1 in fact4 ,evidently ,mr4 ,w4 ,h4 ,fox ,talbot was the first to use the toning bath in connection with paper photography1 although he does not seem to have made much headway with his process at first2 for it is recorded that from ,january1 #ahci1 the date when ,mr4 ,talbot communicated his discovery to the ,royal ,society1 until #ahde very little improvement took place4 ,these early paper pictures1 be it remembered1 were designated photogenic drawings4 ,talbotype was not patented for some time afterward4 ,in the year #ahde1 however1 it was found that steeping the paper in terchloride of gold vastly improved the results4 ,it was not until #ahec that albumen took any part in the production of prints1 the honor of its introduction being ascribed to ,mr4 ,henry ,pollock1 although it seems that ,m4 ,le ,gray1 of ,paris1 about that time was producing stereoscopic pictures on albumenized paper4 ,to ,m4 ,le ,gray is due the credit of introducing gold toning in lieu of sulphur4 ,the first toning then was performed by the decomposition of hypo41 and known as sulphur toning1 by which fine black tones were obtained upon the addition of an acid1 such as acetic1 sulphuric1 or other suitable oxidizing substance to the hypo41 gold taking no part in this process4 ,unfortunately1 prints so treated are said to be the least permanent of any2 but of that ,i can bring no actual proof1 never having employed the process4 ,experiment #b4--,toning by ,sulphur4--,we have an unwashed silver print here in a twenty per cent4 solution of hypo41 and to that we now add a few drops of slightly dilute sulphuric acid4 ,it will be seen that a straw-colored substance is immediately liberated1 which is sulphur in an exceedingly fine state of division1 and this becomes attached to the print4 ,toning action goes on1 through the silver image being tarnished1 or1 more correctly1 converted into sulphide of silver4 ,this liberation of sulphur may be expressed by the following equation3 ,hypo4 ,sulphuric ,acid ,na#b,s#b,o#c ,h#b,,so#d ,glauber ,salts ,water ,sulphur ,dioxide ,sulphur4 ,na#b,,so#d ,h#b,o ,,so#b ,s4 ,with respect to the reaction which takes place when toning a silver image with sulphur1 ,i will quote a few lines from the parent work of reference for nearly all recent writers1 namely1 ,hardwich's ,photographic ,chemistry1 wherein we find the following paragraph3 ,it is well known that articles of silver plate become darkened by exposure to the fumes of sulphur1 or to those of sulphureted hydrogen1 of which minute traces are always present in the atmosphere4 ,if the stopper of a bottle of sulphureted hydrogen water be removed1 and a simply-fixed photographic positive suspended over it1 the picture will lose its characteristic red tone1 and become nearly black4 ,the black color is even more intense than an experienced chemist would have anticipated1 because analysis teaches us that the actual quantity of silver present in a photographic picture on paper is infinitesimally small2 and it is well known that sulphide of silver1 although of a deep brown color1 approaching to black when in mass1 exhibits a pale yellow tint in thin layers1 so that a mere film of silver converted into sulphide possesses very little depth of color4 ,to explain the difficulty it has been suggested that the toning action of sulphur on a red print is probably due to the production of a sub-sulphide possessing an intense colorific power1 like the sub-oxide and sub-chloride of silver4 ,when the toned picture is subjected to the further action of sulphur1 is converted into the ordinary protosulphide of silver1 and becomes yellow and faded4 ,the toning baths following the sulphur method were principally mixtures of gold terchloride and hypo4 ,this latter substance was found to be a solvent of certain silver compounds by the ,rev4 ,j4 ,b4 ,reade1 in #ahci1 ,mr4 ,talbot having previously fixed his prints with common salt4 ,prints1 too1 were fixed first in some cases1 and toned afterward1 washing away the free silver being more or less practiced in the mixed hypo4 and gold and the sulphur toning processes4 ,when fixing was employed before toning1 it was usual to soak washed prints in a twenty per cent4 solution of hypo4 for a period of ten minutes1 or until the soluble silver salts were removed1 the resulting color being a disagreeable yellowish-brown4 ,to improve the result so obtained the prints were passed into a solution of-- ,gold terchloride #aj grains4 ,water #bj ounces4 ,when toning action quickly followed1 the yellow color giving place to that of a dark sepia tint4 ,from this stage to that of mixing these two substances together was only a natural sequence1 and effected a diminution of gold to the extent of one-fourth1 as will be seen by the following recognized formula3 ,hypo4 #g ounces4 ,water #bj ,when dissolved1 add-- ,gold terchloride #e grains4 ,dissolved in water #bj ounces4 ,after mixing1 a clear solution should result4 ,the sel d'or process followed1 and was expected to give still better results4 ,it was found1 however1 that the solutions would not keep2 and as a considerable quantity of the gold salt was needed1 it caused experimenters to search for a less expensive method4 ,one decided point in its favor was the circumstance that prints suffered no loss of intensity during the operation1 as they do in the case of all other toning methods4 ,briefly3 the prints were well washed to extract free silver1 and1 after soaking five minutes in salt and water1 they were passed into an alkaline solution composed of-- ,liquid ammonia #fj minims4 ,water #bj ounces4 ,here they became very red4 ,after washing in clean water the surface was flooded with a toning solution composed of ,double hyposulphite of gold and sodium 7sel d'or7 grain4 ,hypo #a ,water #a ounce4 ,upon the print assuming a purple-gray color it was withdrawn and fixed in a sixteen per cent4 solution of hypo4 to dissolve the unacted upon silver chloride4 ,gold1 when in a fine state of subdivision1 is of a rich purple color4 ,the layer obtained by deposition upon a silver image is very finely divided2 hence the color4 ,the only object in continuing the toning action beyond the stage at which a good surface color has been reached is to obtain a deposit of sufficient density to completely neutralize the red color of the organic silver image beneath2 therefore1 it is preferable1 in forming a judgment of toning action1 to examine proofs by transmitted light rather than by reflected only4 ,before dealing with the various formul for alkaline toning ,i should like to step out of the golden track to say a few words on platinum tetracloride1 ,pt,cl#d4 ,experiment #c4--,platinum ,toning4--,the value of a platinum salt as a toning agent for silver images has been thoroughly demonstrated before you by ,mr4 ,henderson1 when he initiated us into the secrets of ceramic photography4 ,my trials with this salt as a toning agent for paper proofs have only been partially successful4 ,by that ,i mean that toning does take place when a dilute solution is employed1 but the action is too tardy for demonstration here to-night1 since anything like a black tone could not be obtained under half an hour4 ,you will observe that the surface becomes covered with chloride1 showing the necessity for copious washing4 ,yellow or discolored prints are bleached when toned in this bath1 the whites becoming very pure4 ,the formula here given is capable of producing a very good shade of brown in less time1 and should be permanent1 since platinum is a metal practically unaffected by the atmosphere2 and ,i think there is good reason to suppose that if a thin coating of platinum could be deposited on the silver image1 the protection offered would be more economical as well as stable4 ,something has already been done in this direction1 but not in recent years4 ,the following is the composition we are now using3 ,platinum tetrachloride1 sirupy solution1 color of old ,east ,india sherry #e minims4 ,hydrochloric acid #aej ,water #bj ounces4 ,wash away the free silver thoroughly1 warm the toning solution to #gj ,fahr41 and fix in a twenty per cent4 hypo4 bath4 ,mr4 ,a4 ,watt1 in the second volume of the ,news1 gives a formula which runs as follows3 ,solution of platinum #cj minims4 ,hypo4 #c grains4 ,hydrochloric acid #e minims4 ,water #e ounces4 ,this bath is said to act instantly1 but ,i have not had an opportunity to test it4 ,the strength of the platinum solution here given is indefinite1 but any of our experimental members can soon ascertain the amount of dilution necessary to obtain the most favorable results4 ,alkaline ,toning4--,owing to the bleaching action which occurs in toning silver prints with gold1 which is slightly acid1 certain experiments were made1 and it was found that bleaching increased in proportion to the quantity of hydrochloric acid added4 ,now1 in the action of toning chlorine is disengaged1 and in order to render this powerful bleaching agent inert it has been proposed to introduce a substance capable of combining with it1 and thus1 in absorbing it1 prevent undue loss of vigor4 ,to obtain this a slightly alkaline toning bath became a necessity1 and to ,mr4 ,waterhouse we are indebted for the introduction of the alkaline salts 7,hardwich74 ,here is an example3 ,experiment #d4 ,sodium carbonate 7,na#b;,,hco#c7 #e grains4 ,auric terchloride 7,au,cl#c7 #a grain4 ,water #aj ounces4 ,instead of the dry bicarbonate we will use a saturated solution4 ,in this as well as the following experiments we shall tone three prints of the same subject1 viz41 ordinary1 fumed1 and preserved4 ,mr4 ,maxwell ,lyte has written on and investigated the properties of toning solutions a great deal more than most men1 and we find the following emanating from ,mr4 ,lyte3 ,sesquichloride of gold #ae grains4 ,phosphate of soda #cjj ,distilled water #a pints4 ,and in the same communication it is mentioned that #ahj grains of borax may be substituted for the phosphate with a like result4 ,therefore it will be seen that a borax toning bath is not of recent discovery1 although it does not appear to have been quoted in many formul for at least a dozen years after its publication4 ,after the publication of ,mr4 ,lyte's formul it was found that other salts behaved similarly2 and among the first suggested we found sodium acetate1 the qualities of which1 extolled by the introducer1 ,mr4 ,hannaford1 have since been verified by the whole photographic world4 ,here is one of the ordinary formul3 ,experiment #e4 ,gold terchloride #a grain4 ,sodium acetate #aj chloride #aj ,hot water #bj ounces4 ,mix twenty-four hours before use4 ,neutralize with chalk or whitening 7carbonate of lime74 ,the name of ,m4 ,le ,gray must be mentioned as the originator of the lime and gold toning bath2 although the original formul differ somewhat from the one now used1 the results are identical4 ,the original formul consisted first in washing away a portion of the free silver by soaking the proofs for a few minutes in two changes of water1 then submitting them to the action of an auriferous bath1 composed of ,terchloride of gold1 #a per cent4 solution #a part4 ,hyperchloride of lime 7white powder7 #c ,distilled water #a1jjj ,the action was complete in ten to fifteen minutes1 when the prints required washing in two changes of water to free them from the chloride of lime remaining in the fibers previous to fixing in one to six of hypo4 ,if the tone were satisfactory at the expiration of fifteen minutes1 the ordinary washing could be proceeded with2 if not1 the proofs were submitted to a final bath composed of3 ,gold terchloride #b parts4 ,hypo4 #bjj ,distilled water #a1bjj ,m4 ,le ,gray says3 ,the proof ought not to be left in this bath less than fifteen minutes1 as that is the minimum time necessary to insure the permanency of the picture2 but it may be allowed to remain in it for as much longer as is requisite for obtaining the desired tone4 ,efficient washing in warm and cold waters completed the operation4 ,should any of our provincial members experience a difficulty in obtaining calcium chloride for their experiments1 it can be easily made by causing dilute #g to #c hydrochloric acid to react on common whitening1 and when neutral filter and set aside for the crystals to separate out4 ,experiment #f4--,the uranium and gold toning bath has many friends4 ,the tones are said to be richer and to economize gold1 while it is very easy to work4 ,i am unable to give the author's name1 but ,i can present a formula which has worked well in my hands4 ,after washing away the free silver tone in the following mixture3 ,no4 #a4 ,one grain acid solution of gold terchloride #a ounce4 ,water #g ounces4 ,neutralize with sufficient of a twenty per cent4 solution of sodium carb4 7,na#b;,,hco#c74 ,no4 #b4 ,three grain solution of uranium nitrate #a ounce4 ,water #g ounces4 ,neutralize as in ,no4 #a4 ,warm each to #gj ,fahr41 and mix4 ,the bath is then ready for use4 ,it can be used repeatedly if desired by acidifying with citric acid and neutralizing before use2 but nothing is gained by using it a second time4 ,there are methods of toning which resemble more or less those which have occupied our attention to-night2 among them may be mentioned the tungstate bath1 likewise citrate of soda4 ,the vermilion bath1 too1 might afford sufficient matter alone for a lecturette4 ,if some one experienced with it could be induced to bring it before us1 ,i am sure it would prove interesting4 ,,coating ,,plates ,,with ,,gelatine ,,emulsion4 ,to coat plates perfectly1 says ,h4 ,s4 ,starnes in ,british ,jour4 of ,photography1 ,i found the following points were necessary3 #a4 ,that a certain quantity of emulsion should be flowed in one even stream all over the plate1 instead of pouring the emulsion in a pool in the center of the plate and then dispersing it over the whole surface2 because in the latter mode of coating large plates the gelatine is apt to commence setting before it is equally distributed1 and an unequally coated plate is the result4 #b4 ,the plate ought to be put on the leveling-table before coating1 and not be moved before the gelatine is set2 because in the dull light of the dark room it is so difficult to prevent the emulsion running off the plate when putting it down on the leveling-table4 #c4 ,i found that if the emulsion be rubbed 7so to speak7 on to the glass there is much less chance of frilling1 etc41 than if it were poured on4 ,i think it is because in the former case the gelatine is in firmer contact with the glass4 ,when the gelatine is poured on to the plate the cold glass instantly chills it1 and by the time the emulsion has reached the edges of the plate it has so far set as to have partially lost its power of adhesion to the smooth surface of the glass4 ,illustration3 ,fig4 #a4--,showing melted emulsion in coater ready for coating4 ,two or three years ago1 when it was the practice to warm the plates before coating1 ,i found from a series of experiments ,i then made that when a plate was warmed before being coated the emulsion commenced setting on the surface of the film1 and of course in setting contracted1 thereby leaving a partial vacuum between the film and the glass4 ,on development frilling was the consequence4 ,i found1 however1 that1 when pouring the same emulsion on cold glass1 on the portion of the plate where it was poured on1 the film instantly chilled and commenced to contract on to the glass1 and it never frilled there2 but toward the edges of the plate1 as the emulsion had commenced to chill before they were covered1 the film was not in such perfect contact with the glass4 ,any person can try the experiment by first coating a plate in the ordinary way1 and on the second plate just pour a small pool of emulsion on the center2 let both dry1 and he will then see after exposure which frills the easier on development4 ,illustration3 ,fig4 #b4--,showing emulsion flowing through the slit on to the glass4 ,after a series of experiments ,i found that by brushing a substratum of emulsion on to the cold plate 7with a brush made by binding a strip of wash-leather at the end of a strip of glass71 and then pouring the full quantity of emulsion on to the substratum 7for quarter-plates ,i used a small silver teaspoon1 which held sufficient to cover that size of plate71 ,i found ,i could coat plates far better and quicker and as easily as when coating with collodion1 and ,i got over the difficulties of having frilling plates4 ,when only a few small plates are required--such as for experimental purposes--,i believe this method is as quick and good as any2 but when several dozen plates are wanted1 any plan of coating them separately takes a long time4 ,with my plate-coater ,i can coat a dozen plates in about the time ,i formerly took to coat one4 ,when coating a number1 ,i thought it would be best to lay them in rows on the leveling-shelves and draw the receptacle containing the emulsion over them1 rather than keep the latter a fixture and run the plates under it either on an endless band or sliding shelves2 because by the first mode the plates can be fixed close together1 and the emulsion is less likely to get between them4 ,the coater is a species of wooden tray 7of which the diagrams show the section71 having a small slit in one of the bottom edges through which the emulsion passes in one even wave the whole width of the plate4 ,the width of the coater is the same as that of the plate1 though one six and a half inches wide can be used for either half or whole plates4 ,illustration3 ,fig4 #c4 ,i find the best way of making it1 so as to get the slit an equal opening the whole length of it1 is to put the back1 bottom1 and two sides together first1 as in ,fig4 #c4 ,then by putting a piece of very thin paper 7,a ,b7 on the angle piece when the front piece of wood is put tight down on the paper and fixed in its place1 and the paper is drawn out1 it will be found that the slit is very even4 ,in one coater ,i made ,i had the slit a little too wide an opening1 and to reduce it ,i glued a piece of muslin over it4 ,this ,i found was a great improvement1 as it not only acted as a strainer1 but it checked and caused a more even flow of the emulsion over the plate4 ,i varnished the wood and muslin 7except over the slit7 with black ,japan4 ,to coat the plates ,i put them close together in rows on the leveling-shelf1 as shown below3 ,illustration3 ,fig4 #d4 ,a is a thin1 narrow ledge of wood4 ,b ,b ,b are thin pieces of wood1 in the center of each of which is a small slot and thumb-screw4 ,the plates are pressed against ,a by the pieces of wood1 ,b1 and the thumb-screws are then fastened4 ,the plates are thus kept from slipping about4 ,all this1 of course1 can be done in ordinary white light4 ,the light is then made non-actinic2 the melted emulsion is poured into the reservoir of the coater1 which is put to the left hand edge of the outer row of plates4 ,it is then lifted up on edge1 as in ,fig4 #b1 and drawn slowly over the row of plates1 and so on until the whole of the rows are coated4 ,of course when not coating plates it is kept in a horizontal position1 as in ,fig #a4 ,the emulsion on the plates is allowed to set without being disturbed2 the shelf is then slipped into the drying-box until the plates are dry1 so that they are not touched from the time they are coated until they are dry and ready for packing4 ,i am at present engaged in making a modification of this coater to hold a much larger quantity of emulsion at one time1 when a large number of plates require to be coated4 ,it is something the shape of a flat teapot4 ,illustration3 ,fig4 #e4--;,a ,a is a piece of curved glass4 ,b a piece of coarse ground flat glass1 ground side uppermost1 sliding in two grooves in the wooden side4 ,c is the handle fixed to the wooden back4 ,a piece of thin paper is placed on the curved glass1 and the ground glass pushed close up and fixed by two small wedges1 ,d4 ,the paper is then slipped out1 leaving a narrow1 even opening between the two glasses4 ,the width of this opening can be varied by using thicker paper if the plates require to be coated with a thicker film4 ,by using this form the coater can be more easily cleaned1 as the ground glass can be slipped right out at the back1 and probably in passing from the opening to the plates over the curved glass the wave of the emulsion will be equalized as well as when passing through the muslin4 ,,iodo-,,chloride ,,of ,,silver ,,emulsion4 ,by ,v4 ,,schumann4 ,in a recent paper in the ,wochenblatt1 says the ,photographic ,news1 this investigator relates his experience of gelatine emulsion containing chloride and iodide of silver4 ,gelatine films containing pure chloride of silver can only be used in the camera in exceptional cases2 if1 however1 iodide be added1 the resulting iodo-chloride films answer most of the purposes of a gelatino-bromide plate4 ,it may be remarked that with gelatino-chloride emulsion an image is easily developed with pyro or oxalate2 but unfortunately1 fogging is very liable to set in4 ,on strongly diluting the developing solution and adding a large proportion of bromide1 it is possible to obtain a clear deposit1 but the image is so thin that it is quite useless for practical purposes4 ,gelatino-iodide films possess totally different properties4 ,the development is extremely slow1 without any tendency to fog2 thus the addition of a restrainer should be avoided4 ,iodo-chloride emulsion can be prepared either by dissolving the chloride and iodide salts in the gelatine solution1 and then adding by degrees the silver nitrate2 or by making two separate emulsions of chloride and iodide of silver1 and then mixing the two after the washing process4 ,it should be noted that the properties of a compound or a mixture of the two haloids are very different4 ,a negative of the spectrum impressed on an iodo-chloride film1 prepared by mixing the two emulsions1 shows two colored deposits4 ,the red end of the spectrum as far as the ,g line is reproduced in the negative as a red tone1 while that part of the spectrum from ,g extending to the violet appears as a grayish violet deposit4 ,when using ,stolze's potash developer1 the difference of the two tones on the negative appears even more marked4 ,experiments were instituted to determine the most suitable proportion of the silver haloids to be suspended in the emulsion4 ,for this purpose three emulsions were prepared according to the following formul3 ,no4 #a4--;,,iodo-,,chloride ,,emulsion4 ,a4--,ammonium chloride #j4fd gramme4 ,potassium iodide #j4je ,gelatine #a4e ,water #ae c4 c4 ,b4--,silver nitrate #a4ee gramme4 ,water #ae c4 c4 ,no4 #b4--,same as ,no4 #a4 but with #j4ae potassium iodide instead of #j4je2 and #a4fe silver nitrate instead of #a4ee4 ,no4 #c4--,same as ,no4 #a1 but with #j4fd potassium iodide instead of #j4je2 and #b4ad silver nitrate instead of #a4ee4 ,to prepare the emulsion1 ,a and ,b were heated in a water bath and then mixed slowly1 with thorough shaking4 ,the mixture1 after an hour's cooking1 was allowed to stand over night2 the emulsion was next washed for seventy-two hours1 and after slightly diluting1 at once poured over the plates4 ,the emulsions prepared according to formul #a and #b transmit blue light1 which1 however1 is much brighter than that exhibited by gelatino-bromide emulsion4 ,no4 #c emulsion transmits an orange light4 ,previous to cooking the emulsion1 a small quantity from each sample was spread on a glass plate1 and1 with the films prepared from the fully digested emulsion1 were placed in sunlight4 ,the unripe emulsion darkened much more quickly than that which had been digested4 ,the colors of the exposed films prepared according to ,nos4 #a and #b were chocolate1 and there was very little difference between the tones of the ripe and unripe emulsion4 ,with the plates made by ,no4 #c formula there was1 however1 a great difference of color noticeable2 thus1 while the unripe emulsion yielded a deposit not unlike that of ,nos4 #a and #b1 the films prepared from the ripe emulsion assumed a grayish green color1 which did not alter even after some weeks' exposure to daylight4 ,,apparatus ,,for ,,saturating ,,water ,,with ,,sulphurous ,,acid4 ,messrs4 ,a4 ,boake ,co41 of ,stratford1 ,london1 ,england1 have devised a convenient apparatus for charging water with sulphurous acid which is useful in the making of photographic developers4 ,the following description has been furnished by the firm3 ,the figure shows one of the siphons connected with a very convenient form of apparatus for preparing a solution of sulphurous acid in water1 or of sulphites1 as may be required4 ,the siphons are easy to manage1 the flow of gaseous acid being regulated with the greatest nicety by simply turning the milled head shown in the engraving1 the liquid acid being gradually converted into gas as the pressure is relieved4 ,there is1 moreover1 no danger attending the use of this simple apparatus2 sulphurous acid exerting at ordinary temperatures a pressure of about #cj pounds on the square inch1 while each siphon is carefully tested under a pressure of #bjj pounds on the square inch before being sent out4 ,illustration3 ,,apparatus ,,for ,,saturating ,,water ,,with ,,sulphurous ,,acid4 ,in preparing a solution1 say1 of sulphurous acid in water1 the ground stopper carrying the tubes for passing the gas should be removed from the glass jar in immediate connection with the siphon1 and two-thirds filled with distilled water2 the stopper is then to be replaced1 and the second glass jar half filled with caustic soda solution4 ,the soda solution is used to absorb any sulphurous acid not dissolved by the distilled water1 and so prevent the escape of this irritating gas into the air4 ,solution of sulphite of soda1 and also of bisulphite1 can be prepared in a similar way1 substituting only pure caustic soda solution for the distilled water employed in the case of preparing the solution of sulphurous acid2 but we must rather devise the purchase of the pure solid forms of these salts specially prepared1 and put up by us in one-pound stoppered bottles for use in photography2 these preparations can be obtained either direct from the manufacturers or from any wholesale chemical firm4 ,the siphons may be obtained either separately or already connected with the absorbing jars4 ,it may be mentioned that these siphons contain about two and a half pounds of liquefied sulphurous acid1 and can be refilled when required2 but those requiring larger quantities can obtain the acid compound in copper drums4 ,the ,photographic ,news says3 ,it will be noticed that ,messrs4 ,boake say there is no danger attending the use of the siphons1 as the glass vessels are tested at a much greater pressure than that ordinarily exerted by the condensed sulphurous acid2 but our readers must remember that a blow against a hard substance may cause the glass to become fractured1 and that under these circumstances the bursting of a siphon might cause a serious injury4 ,still1 if proper care is exercised1 there need be no accident2 but we would suggest that the condensed acid should always be kept in the coolest place available1 as the pressure it exerts becomes much greater when the temperature is raised4 ,the above caution is necessary1 as a bare statement that there is no danger may cause persons to handle the siphons without reasonable care4 ,the risk is precisely analogous to that attending the use and handling of bottles containing ordinary aerated waters1 only the irritating nature of the sulphurous acid must be taken into account4 ,instances have occurred in which serious injury has resulted from the bursting of a bottle of soda water2 but few1 if any1 are deterred from the use of soda water or lemonade on this account4 ,,determination ,,of ,,tannin4 ,by ,e4 ,,johanson4 ,the precipitation of tannin by a solution of gelatin is effected more completely and in a better condition for filtration if1 besides ammonium chloride1 as proposed by ,schulze and ,lehmann1 there is also added a small quantity of chromium sulphate or of chrome-alum4 ,the author proceeds in the same manner as ,lehmann1 but he adds to #ajj c4c4 of the solution containing sal-ammoniac from #e to #h drops of a solution containing #a part chromium sulphate in #be parts of water4 ,in order to ascertain the end of the reaction1 he filters small quantities into two test glasses of equal width1 adds to the one a few drops of a solution of gelatin1 observing if the two liquids1 when held up against a sheet of black glazed paper1 appear opaque or transparent4 ,as long as a precipitate is formed1 these portions and the washings of the little filters are poured back to the main quantity4 ,if acetic or tartaric acid is present1 the liquid should be neutralized before proceeding to the determination4 ,johanson points out that1 though this method gives good results with the tannin of galls and of oak-bark1 an extract of coffee gives no precipitate with solution of gelatin1 so that caffeo-tannic acid cannot be determined in this manner4 ,this shows that only quantities of tannin of one and the same kind can be compared with each other4 ,,the ,,incomplete ,,combustion ,,of ,,gases4 ,by ,,harold ,b4 ,,dixon1 ,m4,a4 ,abstract of a paper read before the ,chemistry ,section of the ,british ,association at ,montreal4 ,the author gave a resume of the work he had done in continuation of the researches of ,bunsen1 ,e4 von ,meyer1 ,horstmann1 and other chemists1 on the division of oxygen when exploded with excess of hydrogen and carbonic oxide4 ,the following are the general conclusions arrived at3 #a4 ,no alteration per saltum occurs in the ratio of the products of combustion4 ,the experiments made completely confirm ,horstmann's conclusion2 ,bunsen's earlier experiments being vitiated by the presence of aqueous vapor in the eudiometer4 #b4 ,a dry mixture of carbonic oxide and oxygen does not explode when an electric spark is passed through it4 ,the union of carbonic oxide is effected indirectly by steam4 ,a mere trace of steam renders the admixture of carbonic oxide and oxygen explosive4 ,the steam undergoes a series of alternate reductions and oxidations1 acting as a carrier of oxygen to the carbonic oxide4 ,with a very small quantity of steam the oxidation of carbonic oxide takes place slowly2 as the quantity of steam is increased1 the rapidity of explosion increases4 #c4 ,when a mixture of dry carbonic oxide and hydrogen is exploded with a quantity of oxygen insufficient for complete combustion1 the ratio of the carbonic acid to the steam formed depends upon the shape of the vessel and the pressure under which the gases are fired4 ,by continually increasing the initial pressure1 a point is reached where no further increase in the pressure affects the products of the reaction4 ,at and above this critical pressure the result was found to be independent of the length of the column of gases exploded4 ,the larger the quantity of oxygen used1 the lower the critical pressure was found to be4 #d4 ,when dry mixtures of carbonic oxide and hydrogen in varying proportions are exploded above their critical pressures with oxygen insufficient for complete combustion1 an equilibrium is established between two opposite chemical changes represented by the equations3 7,i47 ,,co ,h#b,o ,,co#b ,h#b4 7,,ii47 ,,co#b ,h#b ,,co ,h#b,o4 ,at the end of the reaction the product of the carbonic oxide and steam molecules is equal to the product of the carbonic acid and hydrogen molecules multiplied by a coefficient of affinity4 ,this result agrees with ,horstmann's conclusion4 ,but ,hortsmann considers that the coefficient varies with the relative mass of oxygen taken4 #e4 ,a small difference in the initial temperature at which the gases are fired makes a considerable difference in the products of the reaction4 ,this difference is due to the condensation of steam by the sides of the vessel during the explosion1 and its consequent removal from the sphere of action during the chemical change4 ,when the gases are exploded at an initial temperature sufficiently high to prevent any condensation of steam during the progress of the reaction1 the coefficient of affinity is found to be constant whatever the quantity of oxygen used--provided only the quantity of hydrogen is more than double the quantity of oxygen4 #f4 ,the presence of an inert gas1 such as nitrogen1 by diminishing the intensity of the reaction1 favors the formation of carbonic acid in preference to steam4 ,when the hydrogen taken is less than double the oxygen1 the excess of oxygen cannot react with any of the three other gases present--carbonic oxide1 carbonic acid1 and steam--but has to wait until an equal volume of steam is reduced to hydrogen by the carbonic oxide4 ,the excess of inert oxygen has the same effect as inert nitrogen in favoring the formation of carbonic acid4 ,the variations in the coefficient of affinity found by ,hortsmann with different quantities of oxygen are due partly to this cause1 but chiefly to the varying amounts of steam condensed by the cold eudiometer during the reaction taking place in different experiments4 #g4 ,as a general result of these experiments it is shown that1 when a mixture of dry carbonic oxide and hydrogen is exploded with oxygen insufficient for complete combustion1 at a temperature at which no condensation of steam can take place during the reaction1 and at a temperature greater than the critical pressure1 an equilibrium between two opposite chemical changes is established1 which is independent of the mass of oxygen taken1 so long as this quantity is less than half the hydrogen4 ,within these limits the law of mass is completely verified for the gaseous system composed of carbonic oxide1 carbonic acid1 hydrogen1 and steam at a high temperature4 ,,herbst',s ,,method ,,of ,,filling4 ,demonstrated by ,,dr4 ,g4 ,c4 ,,cludius1 ,grenoble1 ,france4#ab #ab ,translated from the ,revue ,odontologique1 for the ,dental ,cosmos4 ,at the ,july meeting of the ,odontological ,society of ,france1 ,dr4 ,cludius1 from ,grenoble1 made the following demonstration of a new method of gold filling1 saying3 ,we feel the necessity of making the operation of filling teeth with gold easier1 if possible1 especially in difficult cases1 in order to lessen the fatigue of the operator1 as well as to prevent the suffering of the patient1 during hours without interruption1 under the ceaseless blows of the mallet4 ,the remedy has been sought in new forms of material1 like sponge and crystal gold4 ,these have not given any help in the performance of good operations1 but have rather facilitated poor work4 ,we are not in need of varieties in the forms of gold1 but we ought to try and improve its manipulation1 and this has recently been done in a novel manner by ,dr4 ,herbst1 whose rotation method has been mentioned in the dental journals within only a few months2 and yet it seemed necessary that this great invention1 made in ,bremen1 should take its way by ,america to come to us4 ,in the ,january meeting of the ,odontological ,society of ,new ,york1 ,dr4 ,bdecker mentioned it for the first time1 describing the excellence of fillings made by ,dr4 ,herbst in less than half the time that any mallet work would have required1 and he expressed his intention of going to study the method with the inventor4 ,thinking that ,i was yet nearer to ,bremen1 ,i went thither1 and found there ,dr4 ,w4 ,d4 ,miller1 who had come on the same errand4 ,mr4 ,brasseur had also written to ,dr4 ,herbst1 and it is by his 7,mr4 ,b4's7 invitation that ,i came to ,paris to show you what ,i have learned in ,bremen4 ,to-morrow morning ,i shall show the method in the mouths of patients at the ,dental ,college of ,france4 ,dr4 ,herbst did not patent his new method1 to which may be given the name of rotation gold filling4 ,all he desires is that every one may try the system1 and he feels himself already largely paid by the acknowledgments he is daily receiving4 ,he proves that by his way of rotation one is able to adapt the gold more perfectly to the walls of the cavity than by any other means hitherto employed4 ,one can thus work gold in the very weakest teeth1 because there is no force employed1 yet the gold is as much condensed as by any mallet known4 ,illustration ,the new instruments are very simple1 and you may find them in the dental depots4 ,one can easily prepare them for himself--at least the principal one1 ,no4 #e--;by putting a broken burr in the hand-piece and holding it like a pen for writing until the rotating end of the burr is ground to a roof-like shape1 on a dry ,arkansas stone4 ,nos4 #a1 #b1 #c1 and #d are smooth burnishers1 and help to fix the first layers of gold in large fillings4 ,they are afterward used as finishers1 ,nos4 #i to #ag are finishing burnishers1 and ,no4 #ah is a needle-point finisher4 ,the cavity is to be prepared in the usual way1 but retaining points are very much less needed than for other methods4 ,take1 for instance1 a central cavity in a molar--and1 moreover1 the fundamental idea of this system is to transform all cavities to be filled into central cavities4 ,now fix several cylinders1 of a size proportioned to the cavity1 with a common plugger1 and then take ,no4 #b1 or #c1 or #d1 and by a slow rotation polish the gold against the walls4 ,if the gold does not stick directly1 put in more cylinders with the plugger1 and recommence the condensation with the burnisher4 ,on this first layer of gold a second one is to be made to adhere2 but the polished surface prevents1 and here ,no4 #e finds employment in quick rotation and interrupted touches until the polish is gone4 7,i may here remark that the gold is condensed by this rotation and without pressure in a very remarkable way47 ,for large fillings1 ,no4 #e is to have proportionate points1#ac which1 if too fine1 will make holes in the gold1 and the pressure is to be intermittent1 in order to avoid the development of heat1 which would be painful and irritating to the pulp4 #ac ,in the cuts1 ,nos4 #f1 #g1 and #h are proportionate modifications of ,no4 #e4 ,all the instruments by use get gilded1 and will not work longer without tearing out the gold2 but this inconvenience may be prevented by occasionally rubbing them while in rotation upon a piece of tin4 ,the filling of the cavity is continued in the way above described4 ,let us now take the case of two incisors with lateral cavities approximating one another4 ,the two cavities1 prepared as usual1 are treated as if one1 and the gold is at the same time introduced into both cavities1 fixing some cylinders in the four corners by rotation of the proper burnishers1 and condensation with ,no4 #e1 until they are filled1 so that there appears to be a single mass of gold4 ,no4 #ah is then pushed with regular rotation between the teeth until the mass is quite separated1 so that thin files1 and disks1 and tapes may be employed in finishing the fillings4 ,in filling similar cavities between the second bicuspid and first molar1 after they are properly prepared1 place a matrix and fill one cavity with shellac to retain the matrix1 and distribute the resistance1 and then fill the other like a central cavity1 beginning at the cervical border1 and pressing especially against the matrix at that point1 work toward and finish at the middle of the crown4 ,having filled the first one1 remove the shellac and fill the other in the same way4 ,the rotation and the pressure1 if intermittent1 do not produce heat--at least1 not more than will render the gold cohesive4 ,dr4 ,herbst filled for me two molars1 carious to the cervical border1 and very sensitive there1 for which reason they had for years been filled with plastics1 because ,i was afraid of perforation if retaining points were made1 without which gold filling by malleting would not have been possible2 and ,i was too nervous to sit three or four hours in the chair4 ,dr4 ,herbst filled both teeth by rotation1 without retaining points1 in a little more than one hour4 ,several gentlemen present have seen them and observed the severe tests to which ,mr4 ,brasseur subjected them1 and ,i may add that notwithstanding the great sensitiveness of the dentine and the proximity of the pulps1 ,i felt not the least inconvenience from heat1 and my own patients bear like testimony4 ,we will now split a crown filled in the hand1 and you see that the gold is pressed into the smallest depressions of the interior surface1 and is so uniformly condensed as to resemble an ingot1 impossible to separate in pieces1 yet you may note the different stages of the rotation4 ,i saw ,dr4 ,herbst fill six cavities--some of them large ones--in front teeth1 taking altogether at the same sitting about one hour4 ,it would be difficult to precisely describe the manipulation requisite for the great variety of cases presenting in practice1 but ,i have explained to you in theory the typical ones in the hope of stimulating you to try this method of filling by rotation1 which ,i look upon as one of the most ingenious modes yet given to our profession4 ,the results are splendid1 and the operator will thereby save much time and prevent great suffering on the part of the patient4 ,,dr4 ,,koch',s ,,berlin ,,lecture ,,on ,,cholera ,,and ,,the ,,comma ,,bacillus4 ,an important conference upon cholera was held in ,berlin1 at the ,imperial ,board of ,health1 on the evening of ,july #bf4 ,there were present ,drs4 ,von ,bergman1 ,coler1 ,eulenberg1 ,b4 ,frankel1 ,gaffky1 ,hirsch1 ,koch1 ,leyden1 ,s4 ,neumann1 ,pistor1 ,schubert1 ,skrezcka1 ,struck1 ,virchow1 and ,wollfhugel4 ,the conference had been called at the instance of the ,berlin ,medical ,society1 whose ,president1 ,professor ,virchow1 explained that it was thought advisable ,dr4 ,koch should in the first instance give a demonstration of his work before a smaller body than the whole ,society1 so that the proceedings might be fully reported in the medical press4 ,he mentioned that ,herr ,director ,lucanus and ,president ,sydow had expressed their regret at being unable to be present1 as well as many others1 including ,drs4 ,von ,lauer1 ,von ,frerichs1 ,mehlhausen1 and ,kersandt4 ,dr4 ,koch first showed various specimens of the bacilli and their method of preparation 7see ,berliner ,klinische ,wochenschrift1 ,august #d74 ,this resembles that for the tubercle bacillus1 viz41 drying on a cover glass and staining with fuchsin or methyl-olin4 ,koch then gave a history of his work while in ,egypt and ,india4 ,his post-mortem examinations led him to believe that the intestines were the nidus of the disease4 ,at first his microscopical examinations were unsatisfactory1 but finally he got fresh dejecta and acute cases1 and then discovered the comma bacillus4 ,this1 he said1 is smaller than the tubercle bacillus1 being only about half or at most two-thirds the size of the latter1 but much more plump1 thicker1 and slightly curved4 ,as a rule1 the curve is no more than that of a comma 7171 but sometimes it assumes a semicircular shape1 and he has seen it forming a double curve like an ,s2 these two variations from the normal being suggestive of the junction of two individual bacilli4 ,in cultures there always appears a remarkably free development of comma-shaped bacilli4 ,these bacilli often grow out to form long threads1 not in the manner of anthrax bacilli1 nor with a simple undulating form1 but assuming the shape of delicate long spirals--a corkscrew shape--reminding one very forcibly of the spirochte of relapsing fever4 ,indeed1 it would be difficult to distinguish the two if placed side by side4 ,on account of this developmental change1 he doubted if the cholera organism should be ranked with bacilli2 it is rather a transitional form between the bacillus and the spirillum4 ,possibly it is true spirillum1 portions of which appear in the comma shape1 much as in other spirilla1 e4 g41 spirilla undula1 which do not always form complete spirals1 but consist only of more or less curved rods4 ,the comma bacilli thrive well in meat infusion1 growing in it with great rapidity4 ,by examining microscopically a drop of this broth culture the bacilli are seen in active movement1 swarming at the margins of the drop1 interspersed with the spiral threads1 which are also apparently mobile4 ,they grow also in other fluids1 e4 g41 very abundantly in milk1 without coagulating it or changing its appearance4 ,also in blood serum they grow very richly4 ,another good nutrient medium is gelatine1 wherein the comma bacilli form colonies of a perfectly characteristic kind1 different from those of any other form of bacteria4 ,the colony when very young appears as a pale and small spot1 not completely spherical as other bacterial colonies in gelatine are wont to be1 but with a more or less irregular1 protruding1 or jagged contour4 ,it also very soon takes on a somewhat granular appearance4 ,as the colony increases the granular character becomes more marked1 until it seems to be made up of highly refractile granules1 like a mass of particles of glass4 ,in its further growth the gelatine is liquefied in the vicinity of the colony1 which at the same time sinks down deeper into the gelatine mass1 and makes a small thread-like excavation in the gelatine1 in the center of which the colony appears as a small white point4 ,this again is peculiar2 it is never seen1 at least so marked1 with any other bacterium4 ,and a similar appearance is produced when gelatine is inoculated with a pure culture of this bacillus1 the gelatine liquefying at the seat of inoculation1 and the small colony continually enlarging2 but above it there occurs the excavated spot1 like a bubble of air floating over the bacillary colony4 ,it gives the impression that the bacillus growth not only liquefies the gelatine1 but causes a rapid evaporation of the fluid so formed4 ,many bacteria also have the power of so liquefying gelatine with which they are inoculated1 but never do they produce such an excavation with the bladder like cavity on the surface4 ,another peculiarity was the slowness with which the gelatine liquefied1 and the narrow limits of this liquefaction in the case of a gelatine disk4 ,cultures of the comma bacillus were also made in agar-agar jelly1 which is not liquefied by them4 ,on potato these bacilli grow like those of glanders1 forming a grayish-brown layer on the surface4 ,the comma bacilli thrive best at temperatures between #cj and #dj ,c41 but they are not very sensitive to low temperatures1 their growth not being prevented until #ag or #af ,c4 is reached4 ,in this respect they agree with anthrax bacilli4 ,koch made an experiment to ascertain whether a very low temperature not merely checked development1 but killed them1 and subjected the comma bacilli to a temperature of -#aj ,c4 ,they were then completely frozen1 but yet retained vitality1 growing in gelatine afterward4 ,other experiments1 by excluding air from the gelatine cultures1 or placing them under an exhausted bell-jar1 or in an atmosphere of carbonic acid1 went to prove that they required air and oxygen for their growth2 but the deprivation did not kill them1 since on removing them from these conditions they again began to grow4 ,the growth of these bacilli is exceptionally rapid1 quickly attaining its height1 and after a brief stationary period as quickly terminating4 ,the dying bacilli lose their shape1 sometimes appearing shriveled1 sometimes swollen1 and then staining very slightly or not at all4 ,the special features of their vegetation are best seen when substances which also contain other forms of bacteria are taken1 e4 g41 the intestinal contents or choleraic evacuations mixed with moistened earth or linen and kept damp4 ,a most important statement was that the comma bacillus seems to be killed by the bacteria of putrefaction1 and consequently agents that destroy the latter organisms without the former may really do injury1 by removing from the cholera bacillus an impediment to its growth4 ,as for destructive agents to the bacillus1 he found it killed by solutions in the following proportions3 oil of peppermint1 #a in #b1jjj2 sulphate of copper1 #a in #b1ejj 7a remedy much employed1 but how much would really be needed merely to hinder the growth of the bacilli in the intestine672 quinine1 #a in #e1jjj2 and sublimate1 #a in #ajj1jjj4 ,in contrast with the foregoing measure for preventing the growth of these bacilli is the striking fact that they are readily killed by drying4 ,this fact is proved by merely drying a small drop of material containing the bacilli on a cover glass1 and then placing this over some of the fluid on a glass slide4 ,with anthrax bacilli vitality is retained for nearly a week2 whereas1 the comma bacillus appears to be killed in a very short time4 ,dr4 ,koch having found and cultivated the comma bacillus and ascertained its distinctive character1 next proceeded to investigate its relation to cholera4 ,in all there were now about one hundred cases of cholera in which the bacillus had been found1 while it was never found in connection with other diseases4 ,three different views1 said the speaker1 as to its relation to the cholera process are tenable3 #a4 ,that the disease favors the growth of these bacilli by affording them a suitable soil4 ,if so1 it would mean that the bacillus in question is most widely diffused1 since it has been found in such different regions as ,egypt1 ,india1 and ,france2 whereas the contrary is the case1 for the bacilli do not occur in other diseases1 nor in the healthy1 nor apart from human beings in localities most favorable to bacterial life4 ,they only appear with the cholera4 #b4 ,it might be said that cholera produces conditions leading to a change in form and properties of the numerous intestinal bacteria1 a pure hypothesis2 the only instance of such a conversion refers to a change of physiological and pathogenic action1 and not of form4 ,anthrax bacilli under certain conditions lose their pathogenic power1 but undergo no change in shape2 and that is an instance of a loss of pathogenic properties1 while there is no analogy to support the view of the harmless intestinal bacteria becoming the deadly cholera bacilli4 ,the more bacterial morphology is studied1 the more certain it is that bacteria are constant in their form2 moreover1 the comma bacillus retains its special characters unchanged through many generations of culture4 #c4 ,lastly1 there is the view that the cholera process and the comma bacilli are intimately related1 and there is no other conceivable relation but that the bacilli precede the disease and excite it4 ,for my own part1 said ,dr4 ,koch1 the matter is proved that the comma bacilli are the cause of cholera4 ,dr4 ,koch then described his attempts to inoculate lower animals with the bacillus1 and explained the cause of his failure in the natural immunity of the animals against the disease4 ,in advocating the local ,indian origin of the disease he said3 ,that the virus can be reproduced and multiplied outside the body is apparent1 since the bacillus can be cultivated artificially1 and its growth is not affected by comparatively low temperatures4 ,probably it does not grow in streams and rivers1 where1 owing to the current1 a sufficient concentration of nutrient substance does not occur2 but in stagnant water and at the mouths of drains1 etc41 vegetable and animal refuse may accumulate and afford the necessary nutriment4 ,thus is explained the propagation of cholera by the subsoil water1 and the increase of epidemics with the sinking of its level1 which lessens the flow and diminishes the amount of surface water4 ,admitting the dependence of cholera upon this micro-organism it is impossible to conceive the disease having an autochthonous origin in any particular place2 for a bacillus must obey the laws of vegetable life1 and have an antecedent2 and since the comma bacillus does not belong to the widely diffused micro-organisms1 it must have a limited habitat4 ,therefore1 the occurrence of cholera on the delta of the ,nile does not depend on its resemblance to the delta of the ,ganges2 but the disease must have been imported there as it is into ,europe4 ,it was once thought that an outbreak in ,poland had a local origin until it was discovered to have been introduced from ,russia4 ,again1 about ten years ago1 there was a sudden outbreak at ,hamar 7,syria71 thought to be an instance of local origin1 but erroneously1 as shown by a statement of ,lortet1 who told ,koch1 when at ,lyons1 that the epidemic had been introduced into ,hamar1 where he was at the time1 by ,turkish soldiers from ,djeddah4 ,all great epidemics of cholera began in ,south ,bengal1 where the conditions for the development and growth of the bacillus are most perfect4--,med4 ,record4 ,,local ,,an,,sthesia ,,by ,,the ,,hydrochlorate ,,of ,,cocaine4 ,by ,r4 ,j4 ,,levis1 ,m4,d41 ,surgeon to the ,pennsylvania ,hospital and to the ,jefferson ,medical ,college ,hospital4 ,the notes of a few cases of the use of the hydrochlorate of cocaine will illustrate its perfect efficiency in some and its apparent inertness in others1 and may help toward its proper application and general appreciation4 ,in a double extraction of hard cataract there was no pain produced by the graspings of the conjunctiva in the fixation of the eyes1 in the corneal incisions1 and in the iridectomies4 ,a #d per centum solution was freely brushed over the entire conjunctival surface three times1 at intervals of ten minutes1 and the operations were commenced in forty minutes after the first application4 ,no irritation was produced1 and the only sensation described was that of numbness and hardness4 ,the entire conjunctival surface seemed insensible to repeated pinching with the fixation forceps4 ,in a single extraction of hard cataract a #d per centum solution was brushed over the ocular and palpebral conjunctiva1 with the eyelids freely everted4 ,three applications were made at intervals of ten minutes1 and the operation was performed at the lapse of twenty-five minutes4 ,the patient asserted decidedly that she felt no pain whatever4 ,preparatory to the operation for uterine procidentia and rectocele1 the vaginal and labial mucous surface was wiped dry1 and a #d per centum solution of the hydrochlorate of cocaine was thoroughly brushed over it4 ,the sensitiveness was tested at three intervals of ten minutes each1 and the application was repeated three times4 ,there appeared to be at no time any decided loss of painful sensibility1 and the operation was finally performed under the ansthesia of sulphuric ether4 ,for the removal of a rather large tarsal tumor1 the ocular and palpebral conjunctiva and the exterior of the eyelids were brushed with the solution as previously used1 at intervals of ten minutes1 and the excision was performed at the lapse of forty minutes4 ,the operation seemed to be as painful to the patient as if performed without an attempt at ansthesia4 ,for the operation for lachrymal obstruction the application was made in the same manner and at the same intervals4 ,the slitting of the punctum and caniculus gave no pain1 but the passage of the dilating probe down the lachrymal canal seemed to produce some uneasiness4 ,prior to applying nitric acid as a caustic to a syphilitic ulcer on the tongue1 the same manner and number of applications were repeated1 the tongue having been wiped dry and held protruding between the teeth4 ,no pain was produced on the thoroughly benumbed tongue4--,med4 ,news4 ,,on ,,sewage ,,disposal4#ad ,by ,professor ,,henry ,,robinson4 #ad ,by ,professor ,henry ,robinson4 ,paper read ,oct4 #b1 #ahhd1 at the ,congress of the ,institute held at ,dublin4--,building ,news4 ,the outcome of several public inquiries which have taken place during the last year or two1 and of much valuable data derivable from other sources1 establishes1 we think1 a well marked advance with reference to sewage disposal2 and it may be of use1 as well as of interest1 if we lay before this ,congress the conclusions which1 we conceive1 are deducible therefrom4 ,we propose to deal with the subject under the following heads3 #a4 ,sewage disposal on land4 #b4 ,sewage disposal by chemical treatment4 #c4 ,sewage disposal by discharge into a tidal river1 or into the sea1 without treatment4 #a4 ,,sewage ,,disposal ,,on ,,land4 ,the object of dealing with sewage on land may be taken as twofold1 namely1 to purify it 7which is the sanitary object71 and to utilize its manurial products 7which is the agricultural object74 ,where want of skill or where prejudice has existed1 these two have not been properly separated1 and the results have been in many cases unfavorable to sewage disposal on land from either of the before mentioned points of view4 ,it has been regarded as an axiom that clay land cannot be employed to clarify sewage4 ,this is true when it is proposed to pour the sewage on it as if the land were porous4 ,very recent experience1 however1 has led to clay land being converted from an impervious to a pervious condition1 by which it has been successfully utilized4 ,this is effected by digging out the clay to a depth of about #f ft41 burning it into ballast and replacing it in layers interposed with an occasional layer of open alluvial soil1 the whole area being well drained with a free outlet for the effluent4 ,we have successfully carried this plan out1 and with this result1 that whereas it was not possible previously to clarify the sewage of #ajj people to an acre of clay land1 the prepared filtration area has been able to continuously clarify the sewage of about #a1ejj people to the acre4 ,the cost of converting clay land into this form of filter may be taken as varying from #gej per acre to #a1jjj per acre1 according to local circumstances4 ,one area which we have just completed has cost #a1jjj per acre4 ,before sewage is passed on to these filters 7or on to land7 it should be strained so as to remove the larger particles4 ,the best arrangement for this purpose is to pass the sewage upward through a straining medium 7not downward71 and to run the solids from the bottom of the straining tank on to a low lying piece of land for digging in as they are run out4 ,where such a filtration area is made to form part of a sewage farm it acts as a safety valve1 and enables the land and crops to have a rest when they do not require further irrigation2 at the same time the process of purification is not interrupted4 ,if open1 porous land is available for sewage purification1 and if it can be drained #f ft4 deep to a good free subsoil1 so that the effluent can get readily away1 we find that the sewage of from #fjj to #gjj people can be dealt with on each acre per annum with both good agricultural and sanitary results4 ,in our address as ,president of the ,engineering and ,architectural ,section of the ,congress of this ,institute at ,newcastle upon ,tyne1 in #ahhb1 we directed attention to the important investigation which had been conducted by ,mr4 ,r4 ,warrington1 of ,rothamsted1 the result of which was to show the action which goes on in the soil when sewage is passed through it4 ,further information which the same observer has published since that date is of equal value1 and deserves to be read by all who have to advise in regard to sewage disposal on land4 ,the process of nitrification 7as it is termed71 which he has so fully investigated1 consists in the conversion into nitrates 7which serve to nourish plant life7 of the organic matter in sewage4 ,this takes place by the action of a living ferment of the bacteria family1 which is created by and feeds on the impurities in sewage1 and these organisms both consume the impurities and convert them into nitrates4 ,the action of living agents thus brings about the oxidation of the organic matter in sewage1 just as worms1 larv1 fungi1 and insects feed on the vegetable matter in the soil1 increasing the amount of nitrogenous material in it4 ,experience during the past year or two has proved the feasibility of preserving green crops in a succulent state by compressing them in silos1 so that they can be utilized for cattle fodder in the winter4 ,this system deserves notice in connection with sewage farming1 as we are of opinion that it will prove a valuable means of getting over the well known practical difficulty which is experienced of finding a market for the large amount of green crop which is produced by sewage irrigation4 ,in speaking of this system the term silo is applied to the artificial chamber or receptacle for green crops 7such as grass1 vetches1 clover1 etc474 ,the term silage is applied to the crop thus treated1 and the term ensilage is applied to the process of making silage4 ,the details of the construction of silos cannot be referred to here1 beyond stating that what is required is to construct a pit or chamber either in the form of an excavation in the ground1 with a brick or other lining1 or by building it above the ground4 ,the object is to enable the green crop to be deposited in an air and water tight chamber1 in which pressure can be applied to the crop to compress it4 ,this is effected in some cases by well treading the crop after it is laid in the silo1 and then spreading layers of earth to about a couple of feet1 and pressing the covering well down4 ,another way is to construct the silo with a movable covering of the exact size and shape of its interior4 ,this cover is raised and lowered by suitable chains and rollers4 ,after the crop is placed in the silo1 the cover is lowered and weighted so that a thorough compressing is effected2 the weight applied giving about #bjj lb4 or so per square foot of surface4 ,salt is sometimes added as the crop is placed in the silo4 ,a crop thus dealt with is stored for months2 when the silo is opened the fodder is found preserved1 and in a state readily taken to by cattle4 ,it is desirable to choose the site for the silos so that the fodder is preserved somewhere near the place of consumption2 also to lay out the works so that as little handling as possible is required4 ,for instance1 the silo should be on sidelong ground1 so that the crop can be carted and tipped at a high level1 and the silage taken out for use at a lower level4 ,,ii4 ,,sewage ,,disposal ,,by ,,chemical ,,treatment4 ,in the last edition of our book on ,sewage ,disposal1 in speaking of precipitation we said that the purification of sewage by chemicals has been the subject of misapprehension1 owing to the extravagant advantages which have been claimed for the system by its advocates4 ,this is even more true now than it was two years ago1 inasmuch as in the recent scheme for dealing with the sewage of the ,thames ,valley chemical treatment per se was relied on to produce from the sewage of a future population of #cej1jjj an effluent at all times fit to be discharged at one point into the river ,thames above ,london2 but the ,parliamentary ,committee rejected it4 ,one part of the report of this ,committee deserves attention1 when speaking of sewage treatment by chemicals4 ,it is as follows3 ,your committee believe that in these cases the process of filtering the chemically purified effluent through earth ought1 if possible1 to be adopted1 which was not provided for in the scheme under their consideration4 ,this opinion is exactly in accordance with our experience1 and is that which we have held throughout4 ,it is at the root of the whole matter1 because efforts are made by those interested in chemical processes to attain as high a standard of purity as possible with the attendant heavy expense of chemicals4 ,experience shows that it is impossible at all times and seasons to be sure of a constant and uniformly high standard of purity1 and that chemical works should be supplemented by a filtration area1 however small4 ,the addition of this1 however1 enables a lower standard of effluent from the precipitation tanks to be admissible1 and this can be attained with very simple and inexpensive chemicals4 ,in the course of our practice we have had to advise as to the majority of the processes1 and to design the works for their being carried into operation4 ,we have found that the cost of such works complete varies from #j4jia to #j4aff pound per head of the population1 and that the average cost of the works at several towns which we have been connected with is #j4abc pound per head4 ,this figure may be conveniently followed by that of the cost of treatment1 which we find varies from #j4jcf to #j4aaj pound per head per annum1 and an average of several places gives #j4jf pound per head per annum4 ,the above figures apply only to places where the very highest standard was sought to be attained1 but our more recent experience leads us to modify the arrangement of the works and the cost of treatment1 so as to rely on filtration of the effluent as an important factor4 ,we estimate that under these conditions the cost of the works complete would be about #j4jge pound per head1 and the cost of treatment #j4jd pound per head per annum4 ,the disposal of the sludge has always been a difficulty in these works1 but this is now overcome in two ways3 either by digging it into the ground1 as is done at ,birmingham now1 or by pressing it into cakes in filter presses4 ,it is found at ,birmingham that one ton of sludge with #ij per cent4 of moisture is produced from #a1jjj people4 ,there the lime process is used4 ,we have found that about one ton to #b1jjj people is produced where a salt of alumina or iron is used with the lime4 ,at ,birmingham the sludge is dug into the land adjoining the works1 and it is found that one square yard of land will take one ton of sludge with #ij per cent4 of moisture once in three years1 which results in three yards of land being required to be provided for each ton of sludge4 ,this system of digging in sludge is successfully carried out as regards freedom from nuisance4 ,where land is not available to dig in the sludge1 it is necessary to make it portable for removal and disposal away from where it is produced4 ,this is best effected by filter presses4 ,appliances are made for this purpose1 by which the sludge is pressed to a consistency of about #ej per cent4 of moisture4 ,the cost of effecting this is about #j4jjg pound per head per annum4 ,it is found in practice that where the sludge is produced by straining the solids from sewage before passing it on to land for purification1 it requires a little lime to enable the press to work well4 ,about two barrow loads of lime for each ton of pressed sludge suffices4 ,it has been thought that the cost of precipitation would be covered1 and even a profit gained1 by the sale of the sludge4 ,this hope1 however1 is not nearer realization now than it was in the time1 now gone past1 when chemical processes were relied on to turn sewage from a profitless into a profitable commodity4 ,there is1 consequently1 less justification now than there was at that time for adopting a precipitation system for sewage disposal4 ,it is entirely a question of carefully considering the engineering and financial points involved1 regardless of the sanguine representations of interested or enthusiastic advocates of any particular system4 ,as the estimated manurial value of the sludge which is precipitated from sewage by the addition of chemicals does not seem to be capable of realization1 we think that probably the reason may be found in the fact that the chemicals arrest that process of decomposition which is essential to the conversion of the organic matters into nitrates for vegetation to utilize4 ,this explanation will be understood in the light of what we have already described in regard to nitrification4 ,if this view is correct1 it would follow that the more completely and permanently the sludge is deodorized by the chemicals1 the less capable is it of passing through the necessary stages of decomposition by which its manurial value can be realized4 ,as mistakes are constantly being made in regard to the weights of sludge with varying degrees of moisture1 the following table may be useful3 ,tons4 ,per cent4 ,tons4 ,per cent4 #ajj of sludge with #ij of moisture #ej with #hj #ajj #cc4c #gj #ajj #be #fj #ajj #bj #ej #ajj #af4f #dj #ajj #ad4c #cj #ajj #ab4e #bj #ajj #aa4gf #ae ,,iii4 ,,sewage ,,disposal ,,by ,,discharge ,,into ,,river ,,or ,,sea4 ,we will next deal with the conditions which should be fulfilled where it is sought to utilize a river or the sea into which to cast the sewage of a town4 ,if it can be ascertained beyond question that at the proposed point of discharge the currents at all times will carry the sewage right away1 and will not at the same time produce mischief at a distance 7which is often omitted from the consideration71 then that arrangement may be accepted as a good one4 ,this1 however1 seldom occurs4 ,a river has been looked upon by manufacturers and local authorities as the natural carrier of their refuse from their district4 ,this view has been persevered in1 in spite of the ,river ,pollution ,prevention ,act of #ahgf1 which is practically a dead letter4 ,the public1 however1 who use a river either for pleasure purposes or for obtaining their water supply1 have of late years grown more and more united in their efforts to stop this abuse2 and there is no doubt that these efforts will eventually succeed4 ,in a paper which we read last year at the ,congress at ,glasgow1 we pointed out the steps that were necessary to be taken to render this act operative1 and we refer our hearers to that paper if they wish to follow the matter further4 ,the effect of discharging sewage matter into a river has been the subject of much controversy among chemists4 ,some allege most positively that the injurious properties in the sewage are indestructible4 ,this has led to alarmists demanding that under no circumstances ought sewage to pass untreated into a river4 ,we have given considerable attention to this vexed question1 as it requires to be grasped by any engineer who has to advise on the selection of sewer outfalls1 and it appears to us that the balance of evidence is against the alarmists4 ,every river has a certain power of oxidizing impurities in proportion to the extent of oxidation of the river itself4 ,besides this1 there are the powerful purifying influences exercised by the plants and animalcules which exist in rivers4 ,it has been ascertained that entomostraca consume dead animal matter2 and where this is wanting they do not live1 but where it is in abundance they thrive4 ,it follows1 then1 these minute animals exercise an important function in absorbing sewage impurities4 ,they multiply prodigiously in these impurities1 and are both created by them and fed upon them1 converting foul and dangerous matters into harmless ones1 in a similar way to that which we have referred to as nitrification when speaking of the action of bacteria in the soil4 ,considering that these organisms arise from and are fed on concentrated filth1 it is obvious that they cannot live when the conditions favorable to their existence disappear4 ,this would be the case when the sewage is discharged into a large volume of water with a different temperature to that which suits them1 and with powerful oxidizing influences at work4 ,these conditions1 added to the difficulty they must experience to find their natural food--namely1 concentrated sewage--where the sewage matter becomes so greatly diluted1 accounts for the fact that in a short run of a good river sewage impurities largely disappear4 ,the action of weeds and plants also aids purification to a very large extent4 ,minute plants1 such as confervoid alg and the like1 also assist in oxygenating the river1 as when exposed to light they decompose carbonic acid1 and liberate oxygen4 ,the practical question which has to be answered in every case where sewage is proposed to be discharged into a river requires to be approached from two points4 ,the first is whether a nuisance will be caused at the spot to which objection would be taken4 ,if this is likely to be the case1 then the fact that the sewage will get purified in a short run of the river does not meet the objection4 ,the second point requires a careful consideration of the condition of the river1 both from an engineering as well as from a chemical and biological point of view4 ,decisions on these matters have too often been arrived at in a rough and ready way4 ,they require skillful treatment1 as the interests--both commercial and hygienic--which are affected are too great to permit of them being dealt with by any who are not well informed and careful4 ,the general conclusions which we deduce from our observations are as follows3 #a4 ,that chemical precipitation is not so necessary now as it was considered to be a few years ago1 in cases where land for irrigation is not procurable4 #b4 ,that the efforts to profitably remove the manurial elements from sewage by chemicals not having been successful1 the system should be adopted per se only where a filtration area cannot be obtained4 #c4 ,that the success which has attended the construction of filtration areas where the land is clayey1 and the successful results which have been obtained from a combined straining of sewage and of subsequent filtration through small areas of artificial filters1 point to the adoption of one or other of these systems in many cases where chemical treatment would previously have been advised4 #d4 ,that the injurious effects of passing untreated sewage into a river depend upon not merely the relative volumes of the sewage and the river1 but chiefly upon the power of the river to oxidize the sewage1 which power is in proportion to the extent of oxidation of the river itself4 ,,new ,,york ,,city ,,street ,,cars4 ,an article in the local news columns of the ,tribune says3 ,the loud outcry made a few years ago against the old fashioned plush covered spring cushions1 then used in street car for seats and backs1 caused them to be removed and set car builders at work to make a car that would be light1 healthy1 and comfortable4 ,the general plan of perforated wooden seats with plain backs has been adopted by all the companies4 ,they are covered with a fine quality of heavy ,axminster carpet during the winter1 and in the summer nearly all the cars have only wooden seats and backs4 ,open cars are used on a number of routes during the summer1 and this is conducive to the health of passengers4 ,the only particular difference in the furniture of the cars is the mats used on the floor4 ,seven of the lines use sectional wooden mats of plain or ornamental design1 while three retain cocoa mats4 ,wooden mats are the easiest to clean4 ,cocoa mats retain moisture on damp or rainy days1 and emit a musty odor4 ,there are four sets for each car1 and they are changed every trip on rainy days4 ,the ,first and ,second ,avenue routes1 under one management run #aej cars2 the ,third ,avenue1 #ahj2 the ,fourth1 #ge2 the ,sixth1 #hh2 the ,broadway and ,seventh1 #ace2 the ,eighth and ,ninth1 #afj2 and the ,tenth1 #abj4 ,at the stables of each the same general arrangement for cleaning cars is used1 while the details only are different1 being regulated by the judgment and experience of superintendents4 ,from six to fifteen men are employed for cleaning cars by the different companies4 ,after every round trip that a car makes1 it is taken to the stable1 the mats are taken off the floor1 and two men with brooms and specially constructed brushes give it a thorough sweeping and brushing4 ,after a car makes its last trip at night1 it is run upon what is termed the washstand1 which is a large turn table surrounded by hydrants4 ,everything movable is taken out of it1 and water is played from a hose on the inside and outside1 while four men with scrubbing brushes and stiff brooms remove whatever dirt has accumulated during the day4 ,after this operation the car is run upon a side track1 and two men dry the inside and polish the windows4 ,while passengers find fault with the untidiness of street cars1 superintendents have a word also of complaint against passengers4 ,if men would not convert a car into a spittoon for the reception of cigar stumps1 tobacco spit1 and quids1 and a garbage box for nut-shells1 fruit rinds1 cores1 and pits1 the remnants of lunches and old papers1 it would be much easier to keep up a cleanly appearance4 ,section #afg of the ,sanitary ,code1 which provides that no soiled article of clothing or bedding shall be carried on street cars1 except on the front platform1 is strictly enforced by all the companies1 and it is worth a conductor's position if he is proved derelict in this respect4 ,nearly all the car companies build their own cars1 and all have repair shops at their stables1 and as soon as a car is damaged by a collision it is sent at once to the shop and repaired4 ,men are detailed to keep a strict watch over all the working parts of cars4 ,no metal or plate has yet been found of which to make a hand railing that will keep bright and untarnished4 ,many experiments have been tried1 but the hardest plate that can be obtained will not stand the friction of the hands longer than two months1 before the plated metal will show through4 ,cars are painted and varnished at least once a year4 ,the various parts of the car last different periods4 ,the wheels average about eighteen months on long routes2 on short routes1 about two years4 ,steps and platforms last about five years4 ,there is no particular limit for the floors and framework1 as they are but little worn4 ,cars are frequently built up from an old floor or framework1 but at the end of about fifteen years there is but little left of the original car4 ,,rings ,,of ,,smoke4 ,illustration3 ,,fig4 #a--;,,apparatus ,,for ,,producing ,,rings ,,of ,,smoke4 ,when1 by means of a tube of from #b to #e millimeters in diameter1 we gently blow tobacco smoke against a wet pane of glass1 we produce very fugitive rings4 ,if we operate with a closed vessel the rings are fixed1 the current being itself uniform4 ,but the experiment that shows the phenomenon perfectly is the one that consists in rendering the current automatic by means of an aspirator--an arrangement analogous to that devised by ,mr4 ,nickles for analyzing the flame of a candle4 ,a tapering glass tube or1 better1 a metallic blow pipe traverses a cork which hermetically closes a large bottle having a cock beneath and filled with water 7,fig4 #a74 ,the nozzle of the blow pipe entering the center of the flame1 and the cock being open1 the liquid flows1 and a column of white smoke descends vertically to the surface of the water1 where it forms several concentric rings whose relief soon increases with the thickness of the heavy smoke1 which finds no exit4 ,these rings have a diameter so much the greater in proportion as the current is stronger 7,fig4 #b74 ,unfortunately1 the number of the rings soon diminishes in measure as the stratum of smoke that remains upon the surface of the water becomes thicker4 ,finally1 there remains but a single ring1 which has a thickness in the center of more than #j4jae m4 7,fig4 #c74 ,illustration3 ,,figs4 #b ,,to #e4--;,,different ,,aspects ,,of ,,rings ,,of ,,smoke4 ,instead of the smoke of a candle1 we may employ that of a cigar or of a tobacco pipe4 ,we thus avoid a deposit of fatty matter1 which1 in the first case1 soon clogs up the tube1 if it is too fine a one1 and thus puts a stop to the experiment4 ,several circumstances are known under which rings or crowns are produced4 7#a7 ,for example1 in the spontaneous combustion of phosphureted hydrogen1 the resulting white vapors of phosphuric acid rise1 and roll round in horizontal white crowns when the air is calm 7,fig4 #d74 ,these crowns1 whose diameter keeps on increasing1 end by separating into strips that dissolve in the humidity of the air4 7#b7 ,the crowns that we sometimes observe in calm weather around cannons at the moment of firing have the same origin1 although they are of a different nature1 and spread horizontally to a certain distance4 ,with vertical howitzers the crowns are horizontal1 and very beautiful when seen from beneath1 since they rise vertically4 7#c7 ,as well known1 a cardboard box having two apertures in the center of two opposite sides1 when filled with smoke and struck upon one of these sides1 allows the escape through the opposite aperture of curling rings of smoke4 7#d7 ,steam escaping into the open air1 through the intermittence of a vertical eduction pipe1 sometimes makes its exit in the form of circular or elliptical crowns4--,la ,nature4 ,,an ,,improved ,,hyacinth ,,glass4 ,the hyacinth is a native of the ,east4 ,when it was introduced into ,england1 in #aeif1 only four varieties of it were known1 but the ,dutch gardeners soon made wonderful progress in its culture1 and1 along toward the end of the sixteenth century1 had produced at least two thousand varieties4 ,this plant is well adapted for house decoration in winter1 when flowers are rare4 ,its culture requires but little care4 ,when the bulbs have taken root in a dark place they are gradually brought into the light1 and placed where the temperature is moderate4 ,illustration3 ,,fig4 #a4--;,,hyacinth ,,glass4 ,,fig4 #b4--;,,details4 ,is a regular changing of the water favorable to the development of this plant8 ,many florists doubt it1 and it is often recommended not to change the water1 but only to replace that which has been lost through evaporation4 ,others are of a contrary opinion1 and assert that the less favorable results that are obtained when the water is changed are merely due the fact that the roots are injured when the plant is taken out of the glass4 ,with the old style of glasses it has always been difficult to renew the water regularly and keep the glass clean1 but this inconvenience has disappeared in the glasses invented by ,mr4 ,j4 ,c4 ,schmidt1 of ,erfurth4 ,fig4 #a represents one of these glasses1 and ,fig4 #b shows the details4 ,as may be seen1 the tube1 a1 which contains the bulb1 may be removed from the glass1 b1 without the plant being touched or its roots disturbed4 ,the glass1 b1 may thus be easily cleaned and filled with fresh water as often as necessary4--,science et ,nature4 ,,the ,,botanical ,,club ,,of ,,the ,,american ,,association4 ,the meeting of the ,american ,association last year at ,minneapolis attracted a larger attendance of botanists than usual4 ,without much consultation1 a meeting of those interested in botany was called1 a president and a secretary were chosen1 and discussions1 short communications1 and papers upon botanical subjects listened to4 ,the ,botanical ,club was thus inaugurated2 and before the close of the session it was decided to do what was possible to secure a larger attendance of botanists at the next gathering in ,philadelphia4 ,although during the interim the prospect of a good attendance at the ,philadelphia meeting had been fair1 the most sanguine were surprised to find that1 as early as ,monday preceding the opening1 a number of botanists had arrived in the city2 and by the following day a larger gathering could have been assembled than the total attendance at ,minneapolis4 ,the first meeting of the club1 of which several were held between ,friday and ,wednesday1 was responded to by an attendance of about thirty--a little below the average attendance for the subsequent meetings4 ,prof4 ,w4 ,j4 ,beal1 of ,lansing1 ,mich41 the president1 took the chair2 and ,prof4 ,j4 ,c4 ,arthur1 of ,geneva1 ,n4 ,y41 was appointed secretary to fill the vacancy caused by the absence of ,professor ,coulter4 ,a paper by ,dr4 ,n4 ,l4 ,britton1 of ,new ,york1 on the composition and distribution of the flora of ,new ,jersey1 was read4 ,the surface-features of the ,state were given1 and the corresponding vegetation described4 ,the work of cataloguing the plants is being done under the supervision of the ,state geological survey4 ,the list at present has reached the very large total of nearly fifty-five hundred4 ,prof4 ,c4 ,r4 ,barnes1 of ,la ,fayette1 ,ind41 spoke of the course of the fibro-vascular bundles in the leaf-branches of ,pinus sylvestris4 ,the two needle-leaves at the end of each short lateral axis contain each a paired bundle4 ,the question at issue was whether this structure represented one or a pair of bundles1 or whether it might not be a segment of the fibro-vascular ring of the stem4 ,a study of the early stages shows that the first change in the stem is to divide the fibro-vascular ring into halves at right angles to the plane of the leaves2 and subsequently these divide again1 sending one branch of each to each leaf4 ,the paper led to much discussion by ,professors ,buckhout1 ,macloskie1 and others4 ,dr4 ,bessey1 of ,ames1 ,ia41 described the opening of the flowers of ,desmodium sessilifolium4 ,they expand partially in the usual manner1 then remain stationary till a particular sensitive spot at the base of the vexillum is touched by an insect1 when the wings and keel descend with a jerk1 the stamens are released1 and the insect dusted with pollen4 ,professor ,mackloskie1 of ,princeton1 ,n4 ,j41 described the method of cross-fertilization of ,geranium maculatum by bumblebees4 ,professor ,dudley1 of ,ithaca1 ,n4 ,y41 spoke of the torsion of stems of ,eleocharis rostellata1 and also on the protogynous character of some species of ,myriophyllum4 ,mr4 ,william ,h4 ,seaman1 of ,washington1 ,d4 ,c41 advocated the use of rather thick oblique sections in studying the structure of the fibro-vascular bundle--a method that called forth a very strong protest4 ,professor ,w4 ,j4 ,beal gave a paper concerning the manner in which certain seeds bury themselves beneath the soil1 which was discussed by ,professors ,bessey1 ,rothrock1 and others4 ,a paper by ,prof4 ,w4 ,r4 ,lazenby1 of ,columbus1 ,o41 on the prolificacy of certain weedy plants1 embraced careful estimates of the average number of seeds produced by individual plants among various kinds of weeds4 ,dr4 ,j4 ,t4 ,rothrock1 of ,philadelphia1 addressed the club on some phases of microscopic work1 alluding particularly to microscopic work1 alluding particularly to micro-photography1 its importance to the investigator1 and the ease of execution4 ,dr4 ,asa ,gray called attention to the interesting discovery of ,mr4 ,meehan regarding the mode of exposing the pollen in the common sunflower4 ,he had found that1 contrary to the teachings of the text books1 the pistil and stamens develop together until reaching full length1 when the filaments rapidly shorten1 and the anther tube is retracted1 exposing the style covered with pollen1 the further changes being the same as usually stated4 ,this ,mr4 ,meehan construed to be a device for self-fertilization2 while ,dr4 ,gray showed that1 although bees carried pollen from one flower to another of the same head1 they also carried it from head to head1 which constituted crossing in the fullest sense4 ,an interesting discussion followed1 in which ,professor ,beal suggested that an excellent experiment would be to cover up the heads and ascertain if any fertile seeds were produced4 ,dr4 ,gray thought it very likely there would2 for1 when cross-fertilization is not effected1 self-fertilization often takes place4 ,mrs4 ,wolcott had proved this to be so2 for1 in covering up the flowers to keep birds away1 she found that plenty of seeds were formed4 ,dr4 ,george ,vasey1 of ,washington1 gave some notes on the vegetation of the arid plains1 which was followed by observations on the curvature of stems of conifers by ,dr4 ,bessey1 in which he noted the bending of stems one1 two1 and even three years old4 ,mr4 ,,thomas ,,meehan discussed the relationship of ,helianthus annuns and ,h4 lenticularis2 showing that there was a constant difference in the form of the corollas1 the former being campanulate1 and the latter tubular4 ,the two are treated as one species in ,gray's ,synoptic ,flora of ,north ,america2 the one being considered a cultivated form of the other1 a view from which the speaker dissented4 ,mr4 ,meehan then spoke upon the fertilization of composites2 concluding that the arrangements were such as to favor self-fertilization1 which is opposed to the generally accepted view4 ,prof4 ,l4 ,m4 ,underwood1 of ,syracuse1 ,n4 ,y41 gave some statistics concerning the ,north-,american ,hepaticae4 ,of the two hundred and thirty-one species found north of ,mexico1 a hundred and twenty are pecular to ,america2 fully one-half the latter are not represented in any public or private herbarium in this country4 ,in a paper on the nature of gumming1 or gummosis1 in fruit-trees1 ,prof4 ,j4 ,c4 ,arthur detailed experiments from which the conclusion had been reached that it was due to a deorganization of the cell-walls of the tree through the influence of some fungus1 but not necessarily of a specific one4 ,it had been produced experimentally by the bacteria of pear-blight and by ,monilia fructigenum1 the fruit-rot fungus2 although the most common cause is doubtless the ,coryneum1 first described by ,oudemans in ,hedwigia4 ,at the final meeting the ,committee on ,postal ,matters then gave its report4 ,this committee was appointed at ,minneapolis to inquire into the various obstructions which the postal authorities throw in the way of exchanging specimens of dried plants4 ,the efforts of the committee had been directed toward securing the passage of specimens bearing the customary written label at fourth-class rates of postage4 ,the ,decision of the ,postmaster-,general was read1 stating that the present law could not be construed to permit the passage of specimens with written labels except at letter-rates1 but expressing a willingness to bring the matter1 at the proper time1 to the attention of ,congress1 the ,canadian authorities1 and the congress of the ,universal ,postal ,union4 ,some discussion followed2 and a motion was carried to continue the committee1 and also instructing the president and secretary of the club to draft resolutions to be presented to the section of biology1 in order to still further promote the objects in view4 ,these resolutions were acted upon by the biological section on the following day4 ,dr4 ,bessey was chosen president1 and ,professor ,arthur secretary1 for the next year4 ,besides the reading of papers1 the club took several excursions4 ,on ,saturday they went to the pine-barrens of ,new ,jersey1 about fifty participating4 ,on ,monday a party visited the ballast-grounds during the morning1 and upon their return inspected the library and herbarium of ,mr4 ,i4 ,c4 ,martindale1 of ,camden1 ,n4 ,j4 ,in the evening of the same day the ,botanical section of the ,philadelphia ,academy of ,science entertained the club1 the ,torrey ,botanical ,club of ,new-,york ,city1 and other invited guests1 at the rooms of the ,academy4 ,about three hundred were present1 and a thoroughly enjoyable time experienced4 ,on the afternoon of ,tuesday the club and its friends1 in all about eighty1 made an excursion to the ,bartram ,gardens1 one of the most interesting historical spots to botanists in this country2 and the club then adjourned4 ,in reviewing the attendance of botanists in ,philadelphia1 and the work of the ,botanical ,club1 there is much reason for congratulation4 ,about a hundred entered their names on the register of the club as botanists1 or about eight per cent4 of the total attendance1 one-half of whom are widely known for their attainments in the science4 ,there was no lack of interesting papers and free discussion4 ,besides the important measures already referred to1 the club was instrumental in securing the appointment of a permanent committee of the ,association to encourage researches on the health and diseases of plants4 ,but1 above all1 the augmented facilities for intercourse and acquaintanceship1 and the impulse imparted to individual workers1 through the influence of the club1 are a sufficient raison d'tre1 and a promise of usefulness of the future4--,science4 ,,petroleum ,,wells4 ,the theory of artesian and of spouting petroleum wells is entirely different4 ,while the latter owe their operation to an internal pressure1 due to gases accumulated within a confined space1 the former are due to the pressure of a liquid which is flowing--a pressure caused by a sheet of water of unequal height2 and they spout with so much the more force in proportion as the difference of level between the orifice and starting point of the sheet of water is greater4 ,petroleum reservoirs1 or pockets1 contain1 along with the petroleum1 gases1 salt water1 sand1 and foreign substances of varying nature4 ,the liquids and gases in these pockets are often submitted to very great pressure4 ,if we make an aperture in the pocket1 there will occur1 by reason of the tension1 and according to the location of the aperture1 a sudden exit of gas1 petroleum1 salt water1 etc4 ,yet it may happen that as the sounding well has been bored through the upper part of the pocket1 where the gases are accumulated1 only the latter will make their exit without any trace of petroleum4 ,under such circumstances the appearance of inflammable gases at the surface indicates pretty certainly the presence of inflammable liquids in the region explored1 and will justify further exploration or the fitting of suction pumps to the well holes4 ,it will be understood that a natural flow of petroleum will occur only so long as the pressure is sufficient1 and that a pocket may cease to give mineral oil spontaneously1 even though it may still contain large quantities of it4 ,this is the reason why at present spouting wells are not abandoned when they cease to operate1 but are worked by lift pumps4 ,the three diagrams1 #a1 #b1 and #c1 will give an idea of the different configurations that petroleum pockets may present4 ,in ,no4 #a1 as the well hole reaches the summit of the gas chamber1 the gases alone will be forced to the surface by reason of the internal pressure1 and not the slightest trace of petroleum will accompany them4 ,in ,no4 #b1 as the well ends at the side of the pocket1 only a portion of the petroleum--that which is included between the dotted lines--will come to the surface4 ,in ,no4 #c1 as the well ends at the lowest extremity of the pocket1 nearly the entire contents of the latter will be forced out naturally4 ,it results from this that in petroleum exploitation the sudden appearance and disappearance of the spouting in no wise proves that the pocket is exhausted4--,science et ,nature4 ,illustration3 ,,configuration ,,of ,,petroleum ,,pockets4 ,,aluminum ,,and ,,its ,,alloys4 ,symbol1 ,al4 ,equivalent1 old1 #ac4g2 new4 #bg4di4 ,specific gravity1 cast1 #b4df4 ,hammered1 #b4fg4 ,specific heat1 #j4badc1 ,heat conductivity1 #j4ff on silver scale #ajj4 ,melting point1 #a1bej or #a1efj ,fah41 according to different authorities4 ,a shining1 white1 sonorous metal1 having a shade between silver and platinum4 ,it is malleable and ductile1 does not oxidize when exposed to dry or moist air1 and is not chemically affected by hot or cold water4 ,sulphureted hydrogen gas1 which so readily tarnishes silver1 has no action upon this metal4 ,having but one defect in its uses as a pure metal 7difficulty in soldering71 it enters largely as an alloy of other metals1 making the baser metals more valuable in resisting oxidation1 and as a good as well as cheap imitation of the precious metals4 ,its power to ameliorate the condition of the alloys of copper1 zinc1 tin1 iron1 nickel1 silver1 gold1 and platinum by portions sometimes less than a thousandth part is beautifully illustrated in the elegant articles of tableware1 bric a brac1 and ornamental hardware now coming upon the commercial market4 ,its uses in the mechanic arts in the various forms of bronzes in filling a long wanted requirement of combined ductility1 strength1 sonorousness1 and freedom from oxidation1 thus giving to its alloys a high value for articles of house hardware1 carriage and harness trimmings1 quick running machinery1 journal bearings1 propeller blades1 and artillery4 ,piano wires made from its alloys will vibrate ten seconds longer than the best now in use4 ,for the kitchen and for articles for the toilet1 there is no more beautiful and cleanly ware4 ,an alloy of silver #bj and aluminum #hj parts by weight1 for nautical and other instruments1 is without a rival in beauty and lightness2 the sea air does not tarnish it4 ,the aluminum-silver alloys are more valuable than pure silver for table service2 its wares will not be destroyed by the constant polishing that wears out our plate1 and holds an immunity from the destructive effects of the fatty and acetic acids4 ,for watch cases it wears cleaner than pure silver1 and for watch movements it is far superior to the brass and nickel or ,german silver heretofore used4 ,an alloy is now made in ,france that has elastic qualities equal to steel for watch springs1 and with the valuable property of being free from magnetic effect4 ,the aluminum bronzes1 when combined with five per cent4 of gold1 have all the beauty1 finish1 and durability of color of eighteen carat gold2 they are entering largely into the manufacture of watch cases and jewelry4 ,the composition most approved is made of copper #he1 aluminum #aj1 gold #e1 parts by weight4 ,this can be soldered with any of the jeweler's solders of gold1 silver1 and zinc in the usual way4 ,the most important alloy1 aluminum bronze1 is composed of aluminum #aj parts1 copper #ij parts by weight2 specific gravity1 #g4g4 ,it has a pale gold color1 harder than ordinary bronze1 takes a fine polish1 is malleable and ductile1 but when rolled into sheets requires annealing at every third passage through the rolls1 and when drawn into wire must be frequently annealed4 ,it may be forged cold or hot1 and can be drawn in tubes4 ,in wire it has a tensile strength of #ajj1jjj lb4 ,this alloy is often found to be brittle at the first mixing1 but becomes ductile after remelting4 ,it is softened while being worked by plunging in water at a low red heat4 ,the ,parisian gold colored alloy is made of aluminum #aj4g1 copper1 #hi4c1 by weight2 used much for cheap ,french jewelry4 ,a non-oxidizable alloy in a moist atmosphere3 ,aluminum1 #be1 iron #ge #be per cent4 aluminum4 ,a hard bright alloy1 with the properties of silver3 ,silver #e 7by weight72 aluminum #ie #e per cent4 aluminum4 ,the silver alloys with aluminum bronze1 as represented in the four following atomic formulas1 are of a rich gold color1 and well adapted for jewelry1 watch cases1 etc43 ,cu ,al ,ag ,ag #bd 7,al ,cu#f7 #j4iahj #j4jfaf #j4jbjc ,ag #bd 7,al ,cu#g7 #j4ibda #j4jegj #j4jahh ,ag #bd 7,al ,cu#h7 #j4iccj #j4jejd #j4jaff ,ag #bd 7,al ,cu#i7 #j4idjj #j4jdej #j4jaej ,the figures being proportional weights4 ,a cheap alloy for journal boxes and machinery may be made by substituting zinc for silver in the following atomic proportions3 ,cu ,al ,zn ,zn #b7;,al ,cu#f7 #j4hfdc #j4jfbb #j4jgcd ,zn #b7;,al ,cu#i7 #j4ijec #j4jdce #j4jeab ,zn #b7;,al ,cu#ab7 #j4ibgc #j4jccc #j4jcid ,this is subject to considerable shrinkage in casting1 but is tenacious1 and when drawn into wire has a tensile strength of ninety to one hundred thousand pounds4 ,the following alloys1 in which iron enters as a third element1 are well adapted for gun metal1 being hard1 tenacious1 laminable1 and ductile3 ,cu ,al ,fe ,fe 7,al ,cu#ae7 #j4ibjc #j4jbfg #j4jecj ,fe 7,al ,cu#i7 #j4icii #j4jddf #j4jadi ,also a four-element alloy of ,cu ,al ,zn ,fe #a4 ,fe ,zn 7,al ,cu#ab7 #j4hchf #j4jcje #j4jgab #j4jfjj #b4 ,fe ,zn 7,al ,cu#ae7 #j4hfff #j4jbdi #j4jehh #j4jdif ,the tensile strength of the above alloys as drawn wire is #hb1jjj pounds for the first1 and #ajg1jjj pounds for the second4 ,all of the alloys in which zinc or zinc and iron enter in place of silver1 the color is affected and the luster diminished4 ,with nickel and platinum for the third element1 we have3 ,cu ,al ,ni ,ni #f 7,al ,cu#f7 #j4iabi #j4jfcd #j4jbcg ,pl #ba 7,al ,cu#f7 #j4iaag #j4jfef #j4jbbe ,those alloys into which platinum is introduced are less affected by acids than those in which silver takes the place of platinum2 platinum producing a higher luster than silver4 ,in the alloys of aluminum bronze with the more difficultly fusible metals1 it is preferable to fuse the bronze first1 then add the other metal in small shavings or wire2 by this means the less fusible metal absorbs the other without raising the heat of the furnace excessively4 ,add the least fusible metal last1 a little at a time1 allowing the heat of the melted metal to fall by degrees1 which prevents boiling and evaporation4 ,the crucibles for mixing the alloys should be of plumbago lined with a paste of lime4 ,avoid sand crucibles1 as silicium may be reduced and absorbed by the aluminum1 inducing brittleness4 ,if found brittle1 remelt with cryolite as a flux1 or stir the melted metal or alloy with a hard wood stick that has been slightly charred4 ,in adding aluminum to the copper1 cut it in small pieces and push it to the bottom of the crucible with a dry1 hard wood stick split so as to hold the pieces4 ,sodium chloride 7common salt7 calcined to evaporate the water1 and caustic soda with pulverized charcoal1 may be used as a flux for pure aluminum4 ,avoid borax as a flux1 as its metal may suffer reduction1 making the aluminum brittle4 ,aluminum will alloy with tin alone1 but is liable to separate on refusion4 ,does not alloy with lead4 ,bismuth1 even in minute quantity1 makes these alloys brittle4 ,the ,east ,indian steel called wootz is1 according to analysis1 alloyed with aluminum4 ,no reliable solder has yet been found for pure aluminum that will flow freely under the blow pipe or from a soldering iron4 ,a process recently adopted in ,france is to plate the parts to be united with alloys of tin #e1 aluminum #a1 upon which tin solder will flow4 ,these proportions may be slightly varied to suit requirements for hardness4 ,harder solders to be used with a blowpipe may be made with alloys of zinc1 tin1 and aluminum4 ,aluminum is now made at the works of ,m4 ,deville1 at ,javelle1 near ,paris1 and at ,salindres1 ,france2 also at ,birmingham1 ,england4 ,the product of late has reached the value of #bj1jjj annually in ,europe4 ,it has been claimed to be made in ,philadelphia at a reduced cost4 ,the present price in ,new ,york is #a4be per oz4 ,as its bulk is over four times as great as silver1 its comparative cost is but one-third that of silver--a point not often considered when the price is quoted4 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 #c4ej1 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 ,publishers1 #cfa ,broadway1 ,new ,york1 ,n4 ,y4 99 99 99 99 99 ,,table ,,of ,,contents4 ,,page ,i4 ,,chemistry ,,and ,,metallurgy4--,determination of ,tannin4--,by ,e4 ,,johanson4 #gdeh ,the ,incomplete ,combustion of ,gases4--,by ,h4 ,b4 ,dixon4--,abstract of paper read before the ,british ,association at ,montreal4 #gdeh ,aluminum and its ,alloys4 #gdfb ,,ii4 ,,engineering ,,and ,,mechanics4--,the ,new ,dam at ,suresnes4--,with engraving4 #gdec ,brarey's ,aeronautical ,machine4--,with engraving4 #gdec ,raising of the ,fallen ,girder of the ,douarnenez ,viaduct4--#b engravings4 #gded ,improved ,wire ,testing ,machine4--,with engraving4 #gded ,improved ,doubling and ,laying ,machine4--,with engraving4 #gded ,boiler ,tubes4 #gdee ,improved ,ladle ,carriage4--#b figures4 #gdee ,the ,repair of ,boiler ,tubes4--#aa figures4 #gdee ,grulet's ,screw for ,raising ,water4--#a engraving4 #gdef ,,iii4 ,,technology4--,on ,various ,toning ,baths4--,several experiments4--,by ,w4 ,m4 ,,ashman4 #gdef ,coating ,plates with ,gelatine ,emulsion4--#e figures4 #gdeg ,iodo-chloride of ,silver ,emulsion4--,by ,v4 ,,schumann #gdeh ,apparatus for ,saturating ,water with ,sulphurous ,acid4--#a engraving4 #gdeh ,,iv4 ,,physics1 ,,electricity4 ,,etc4--,the ,wave ,theory of ,light4--,by ,,sir ,,wm4 ,,thomson4--,sound and light due to wave vibrations4--,difference between vibrations of light and sound4--,radiant heat4--,solar spectrum4--,luminiferous ether4--,how to measure wave lengths of light and the frequency of vibrations4--,with diagrams4 #gddh ,the ,limitations of ,submarine ,telegraphy4 #gdej ,williams' ,system of ,coast ,defense by ,electrical ,torpedoes4--,full page of figures4 #gdea ,new ,electric ,gas ,lighter4--#b figures4 #gdeb ,insulators for ,telegraph and ,telephone ,lines4--#i figures4 #gdeb ,electric ,light in ,theaters4 #gdeb ,rings of ,smoke4--#e figures4 #gdfa ,v4 ,,architecture4--,the ,new ,technical ,high ,school at ,berlin4--,with engraving4 #gddg ,the ,new ,university ,buildings at ,strassburg4--#b engravings4 #gddg ,,vi4 ,,botany1 ,,etc4--,an ,improved ,hyacinth ,glass4 #gdfa ,the ,botanical ,club of the ,american ,association4 #gdfa ,,vii4 ,,hygiene1 ,,medicine1 ,,etc4--,herbst's ,method of ,filling4--,demonstrated by ,dr4 ,g4 ,c4 ,,cludins4 #gdei ,dr4 ,koch's ,berlin ,lecture on ,cholera and the ,comma ,bacillus4 #gdei ,local ,ansthesia by the ,hydrochlorate of ,cocaine4--,by ,r4 ,j4 ,,levis1 ,m4,d4 #gdei ,on ,sewage ,disposal on ,land1 by ,chemical ,treatment1 and by ,discharge into ,river or ,sea4--,by ,prof4 ,h4 ,,robinson #gdfj ,,viii4 ,,miscellaneous4--,new ,york ,city ,street ,cars4 #gdfj ,petroleum ,wells4 #gdfb 99 99 99 99 99 ,,patents4 ,in connection with the ,scientific ,american1 ,messrs4 ,,munn ,,co4 are ,solicitors of ,american and ,foreign ,patents1 have had #ci years' experience1 and now have the largest establishment in the world4 ,patents are obtained on the best terms4 ,a special notice is made in the ,scientific ,american of all ,inventions patented through this ,agency1 with the name and residence of the ,patentee4 ,by the immense circulation thus given1 public attention is directed to the merits of the new patent1 and sales or introduction often easily effected4 ,any person who has made a new discovery or invention can ascertain1 free of charge1 whether a patent can probably be obtained1 by writing to ,,munn ,,co4 ,we also send free our ,hand ,book about the ,patent ,laws1 ,patents1 ,caveats1 ,trade ,marks1 their costs1 and how procured4 ,address ,,munn ,,co44 #cfa ,broadway1 ,new ,york4 ,branch ,office1 cor4 ,f and #gth ,sts41 ,washington1 ,d4 ,c4 ,transcriber's ,note3 ,inconsistent spelling and hyphenation are as in the original4