ESTABLISHED 1845. VARNISHES. DETROIT MICH. Frontage on Lieb St. 200 Ft. MOSES BIGELOW & CO., NEWARK, N. J. RAILWAY VARNISHES. THE Railway Purchasing Agent. Devoted to the Interests of the Purchasing Department of Railways. Volume 4. CHICAGO, AUGUST, 1881. Is published on the 15th of every month, and is intended for circulation among all who are in terested in any way in buying for or selling to railways. It is the sole medium of publication of the proceedings and discussions of the Railroad Purchasing Agents' Association of the United States and Canada, and will contain all of the official notices of that organization. Communications on subjects within the scope of this paper are solicited. Subscription price, One Dollar and fifty cents ($1.50) per year, payable in advence. Advertising rates given on application. ADDRESS: RAILWAY PURCHASING AGENT, 182 and 184 Dearborn Street, CHICAGO, ILL. H. W. MCNEILL has been appointed superintendent of the mining and fuel department of the Chicago, Milwaukee & St. Paul, and will have charge of the supply and distribution of fuel on the company's lines. H. C. NUTT, late Purchasing Agent of the Atlantic & Pacific, has been elected president of the company. D. B. Sibley, for some years in the purchasing department of the Chicago, Burlington & Quincy, has been appointed Purchasing Agent of the Atlantic & Pacific, with headquarters in Chicago. THE Philadelphia, Wilmington & Baltimore having passed under the control of the Pennsylvania, the purchasing department is now under Enoch Lewis, Purchasing Agent of the latter company. Known and Unknown Facts About Belting. A. B. Couch in American Machinist: An engine or water-wheel is to deliver a known amount of power through a belt. Its velocity being given, what should be its width? atmospheric pressure, appreciate the sim- When the actual force to be transmitted Rules laid down by some engineers Others make the force transmitted di- Three forces are principally concerned First, its tension on the driving side. No. 8. or one-third of the ascertained breaking strength of the laced joinings of single leather belts, and the co-efficient of useful friction at six-tenths of that established for sliding friction, by their own experiments as well as those of Morin. It was found that, with equal arcs of contact, the adhesion did not materially differ on pulleys of 12, 24, or 42 inches diameter. Their experiments, as well as a number of practical examples cited, confirm their theoretical conclusions. The results are summarized in the following table, which gives for arcs of contact from one-quarter to three-quarters of the circumference, the net force which should be transmitted for each inch in width of single leather belt: The single leather belt, laced, is in such general use that its strength must be taken as the basis in the arrangement of general machinery. Mr. Towne found It is necessary first to inquire what ten- the strength of riveted belts to be about sion can be continuously applied to the 80 per cent. greater. A few have been driving side without injury. The ques-known to last a long time under tensions tion will then stand: What other and twice as great as those indicated by the less tension applied to the slack side will above table. But tensions one-third An elevator, a pump, a Daniels planer, produce an adhesion at least equal to the greater than those of the table are about or a brick machine is to be driven by a difference between the two tensions? as high as can be applied to single riveted belt under given conditions. Required, in The subject has been investigated math-belts of average quality without unequal each case, the necessary and sufficientematically by Rankine, and experimentally stretching and consequent loss of durawidth of belt. by Morin and others. A paper contributed The numerous interesting articles on to the Journal of the Franklin Institute, belting in the columns of the American | of January, 1868, by Mr. Robert Briggs, Machinist within the past few months have been rather comparative than positive in scope, and have seemed to stop short of the main point. The inquirer may know whether a 6-inch belt will do any more work than a 3-inch one, and if not, why not. He may be familiar with gives the result of some investigations bility. There is a lack of reliable information as to belt transmission with small pulleys and at high speeds beyond the fact that the centrifugal force and imperfect flexibility cause loss of adhesion. Any systematic expression of the quantity of loss would hardly be possible, but some careThe greater or driving tension was ful and intelligent experiments in that ditaken at about 67 pounds per inch wide, I rection would be valuable. Luminous Paint. [An address before the New York Academy of Sciences, May 23, 1881, by President Henry Morton, Stevens' Institute of Technology, Hoboken, N. J.]. LADIES AND GENTLEMEN --I have been asked this evening to say something on the subject of "Optical Phosphorescence." This particular variety of phosphorescence I have known something of for many years and it gives me pleas ure to accede to the request of your committee and to say what I can of the matter. The term phosphorescence covers a great many phenomena, and therefore we must restrict it in the present case by the limiting word “optical" to distinguish it from chemical or ordinary phophores cence. between about 1/36000 of an inch for red to Ordinary light is produced by develop-4000 of an inch for violet. ing, directly or indirectly, vibratory motions. For example, we see it directly when a blacksmith strikes a piece of iron with his hammer on an anvil until he makes it red hot. Here at the beginning, In the first instance, the idea of phos-recognize as simply heat. Gradually, by phorescence comes from the action of the blow after blow, quicker motions are added to these slower ones and the iron becomes element or substance, phosphorus, which hotter and hotter until at last sufficiently of course is very familiar to every one. quick vibrations are produced to be sensible as light. Again, our more usual source of heat is obtained by chemical combination, as for example, in ordinary combustion such as the burning of a candle. Here the vibrations are set up by the impact of the atoms of oxygen in the air as they are dashed against others of carbon and hydrogen in the material of the candle as it burns. This body is indeed one which not only tle heat indeed. In order that I may give you some idea of how remarkable this phenomena is, I shall need to explain a little as to the general properties of light, and I shall have to say some things that may seem very trite to many of you, but those who are familiar with the subject must excuse me if I repeat what is well known to them for the benefit of others. To begin then, with a consideration of what light is. Light is not a substance. If we suppose that light was a substance, it would make a great many things seem plain but would be entirely at variance with other facts. Light is not a substance, but a condition of energy. It is a peculiar variety of motion. Light and heat are merely very slight modifications of motion. Light and heat consist in motion and these motions are distinguished by their various rates. These impacts, brought about by chemical attraction, produce the vibrations of heat and light in that case. motions of heat. But, as a matter of fact, The reason why we see objects of all colors in daylight is simply that the white sunlight contains waves of all these lengths, and thus a red object finds red waves which it can reflect while absorbing all others, and a green object finds green waves which it reflects while absorbing the rest. But, you may ask, how do we perceive these waves, and how do they move from place to place? To answer this I must put a great strain upon your trust in my word and in that of scientific men generally. I must ask you to believe that all space and most matter is pervaded by a substance vastly lighter than air, through which we walk, and which passes freely through us without the slightest sensation or resistance, through which the rarest cloudlike comet can rush at lightning speed and show no retardation. Yet more, I must ask you to believe that this infinitely rare and unresisting fluid is also possessed of such hardness, rigidity and elastic stiffness that steel is by comparison pasty and the diamond soft. Yes, this is what we assume the luminiferous ether to be, which carries the motions of light and heat. Now you will perceive how unjust is the common impression that we scientific men lack the virtue of fath, for when you reflect that the subject of light is one about which we know most, and that these con We see something of it in the slow com-ditions of the luminiferous ether are unibustion of ordinary phosphorus, to which I have already referred. This, when glowing in the dark, emits a notabie amount of light, accompanied by very little heat, and we see the same thing done by the firefly and like insects. It is this action of phosphorus which has given the name to the class of phenomena under consideration this evening, though they differ from the action of phosphorus in that they do not involve any chemical action. Before going further, however, I must explain more fully about the different colors of light and their relations to each other, to heat and to the wave theory about which I have already spoken. Thus, going upward from the long or low rays of invisible heat (we call them We will say that the whole range of mo- low by analogy with music, where the tion is like and may be compared with the long sound waves constitute the bass or range of sound on a piano. The bass notes low notes, and the short waves make the represent heat only. The middle notes treble or high notes), we first come in represent heat and light, and the upper light upon the red, which are the longest notes represent those that are not only of the rays perceived as light; then comes luminous but have special power in affect-yellow, shorter; then green, shorter still; versally accepted, you will perceive what incredible things we can accept if they are only scientific. In this respect, indeed, I think our strength of belief might even be a good example to some theologians. Such, however, is the accepted view in reference to light, and it is believed to be the various waves in this rare but rigid ether which carry into our eyes the vibrations of light and into our bodies those of heat. Most natural substances have no power whatever of modifying these waves as regards their length. This red book looks red to you, not because it can turn any longer or shorter waves into red ones, but only because it reflects red waves if they fall upon it. If the light which now falls on it contained no red waves it would look black, no matter how bright was the illuminating light. There are, however, a large class of bodies, most of them of recent discovery or production, which will give one fixed color of light, no matter what is the light wave falling on them, provided only it is shorter than their special color. Thus one of the most brilliant of them "Fluorescene,' a dye-stuff lately made from coal tar products, gives out a beautiful green light when light of any shorter wave, say blue, indigo or violet falls on it. So there are others giving out red light, like "Naphthalene rose," under like conditions. This action is, however, of very brief duration; in less than 1/500 of a second after the blue light ceases to fall, the green color of Fluorescene will disappear. There are others, however, which are able to keep up the action, or, as it were, store up and continuously maintain the vibratory motion. Thus, for example, sulphide of calcium, when light falls thereon, vibrates to that light and continues thus to vibrate after the exciting light has been removed. none of them are as brilliant as when the It will also be seen in this connection how important a part japan plays in car The peculiar efficiency of this paint is painting, as well in the priming as in the undoubtedly due to an accurate regulation colors. It is not second in importance of the temperature and time of heating this even to the white lead or oil. You want mixture. This paint has been patented in no barytes in your lead, no fish, cottonEngland, and is there known as Balmain's seed or mineral oil in your paint, and you luminous paint. If an object is coated must have a reliable and perfect japan. It with this luminous paint, it may then be is essentially a chemical combination and covered with some of the most brilliant its essential qualities are (1) Its chemical tints, painted over in transparent var-equivalents must be perfectly neutralized, nishes, and these colors, while they show so that no reaction shall take place on beby exterior light brilliantly, will entirely ing mixed with paints or colors. (2) Its disappear when the object becomes self- drying properties must be so nicely balluminous in the dark. The paint will re- anced that it will not curdle on contact tain its sensitiveness so long as the me- with oils in the paints. This may be dium or vehicle that carries the luminous referred to its chemical properties and powder remains unimpaired, and a short might have been included in the exposure to any strong light renders it former specification. (3) It must have a luminous for a very considerable time. good body, and (4) readily assimilate with oil or any other vehicle which may be employed in the mixing or grinding of paints. The best is made from shellac as a base. But there are cheap shellacs and cheap ways of making japan. For it is sold in the market at all prices from 50 cents up. I owe no apology for cautioning buyers and painters against the trash under the name of japan, which is put upon the market. If you have not the means or time to test them, buy of a responsible manufacturer, of a house that cannot afford to sell its reputation for the paltry profits which would come from the supply of the whole demand. Color manufacturers of any repute make their own japans for the mixing and grinding of their own colors which require this vehicle, and it is safe to buy of them for they would not dare risk their valuable colors in a poor japan or varnish for vehicle. PAINTS AND PAINTING, [A paper read before the Master Car Builders' In this respect it resembles the action of most hot bodies. For instance, we place a vessel of water before a hot fire, and the heat vibration from the fire will gradually communicate motion to the vessel of water until it becomes, as we say, very hot. It simply means that the particles are vibrat[Continued from April Number.] ing to a certain degree and extent. Now, Now let us look at the rationale of this if we take this vessel of hot water away process. It will be seen that, besides the from the fire into a cold place, it will con-litharge in the prepared oil, there is prestinue for a notable time to give out heat-ent in every coat the hard drying japan, in other words, to emit again the heat vibrations which it has taken up from the fire. Something like this is probably the condition of the phosphorescent body. There is, perhaps, also another action analogous to that involved in what we call latent heat. If a block of ice is melted into water, a certain amount of heat disappears as heat; being used up in converting the ice into water; it has effected a certain change in the arrangement of the particles of the ice by which the latter has become water. Now, when the particles fall back into their original position, or, in other words, when the water freezes again, the same amount of heat motion is given out, and this we call the latent heat. Similarly when a phosphorescent body is exposed to light, this light will produce in the arrangement of its particles those changes which afterward will be reversed, and in this act of reversal, as the particles fall back into their original positions, they will develop light motions or vibrations. The substance constituting this paint is one long known to possess such a property, though it was never made so perfect as at present, and therefore was never applicable in the same way. It was first described by an English chemist named Canton, about the year 1768, and it is known in the old chemical books as "Canton's Phosphorus." Specimens of this preparation, sealed in glass and bearing date 1760, are still in existence, and appear as sensitive as the recently prepared material. It could be produced by heating various forms of lime, such as limestones, oyster shells, and the like, with sulphur in a closed vessel, and, under different conditions, will show various colors, though and every coat is made flat by excess of Secondly. We see an excess of turpen- 2. COLORING OR PAINTING.-We have now reached the third point in our grouping of topics, that of coloring in the process of painting. I must necessarily be very general as to this step. The color is applied in not less than two coats, frequently three or more, whether it is done by mixing before application, or whether it is done by glazing where two colors are applied the the other, or by stippling. For the reasons which I have already given, oil must be sparingly used, and other one upon on the hand it should not set too quickly. Work the color quickly, evenly, and brush out well. The same cautions apply here as in the case of the priming coats, as to time for thorough drying between the several coats. It must not be forgotten that it is to be finished by a coat of hard-drying varnish, as a protection to the whole. It must, therefore, be a hard-dried, solid and permanent coating. A great deal is said about elastic coats of paint. In fact no such term is properly applicable to paint, as applied to coach and fine car work. It may be soft and elastic when put on, and may remain so for some time, depending upon its drying perty, but it must eventually dry and |