Volume 34 (1877) (434 pages)

January 6, 1877.], MINING AND SCIENTIFIC PRESS ae Mechanica ‘P RoareEss. Rules for Tempering Steel. The fron Age gives some rules to be observed in tempering, 1. The steel should be very hard before tempering. If the articles to be tempered are not properly hardened at first it will be time and Jabor lost to temper them. 2. The heat for tempering should not be too suddenly applied. The slower the heating the tougher and stronger the steel, 3. The most careful and experienced workman is liable to be deceived in the color of the and consequently in the temperature in imperfect light or at twilight. 4. Where water is used for plunging the steel in, the less freuently it is changed the better, provided it deel not get greasy. The temperature to which the steel should be raised for various purposes is shown by the color of theyateel when heated. Lancets, which must be very hard, in order that they may be ground to a keen edge, are tempered to the faint yellow tinge, equal to 430° F., while razors and surgical knives, which must be leas easily broken, are tempered to the straw yellow, equal to 450° F. Pen knives are temred upon an iron plate over the fire, the Piades being laid upon it on their-backs until they have acquired the full yellow color, equal to 470° F. Cold chisels and large shears for cutting iron, must stand rougher usage, and are therefore tempered to a brown yellow, equal to 490° B., while the brown, with purple spots, equal to 510° F., marks the tempering heat for axes and plane irons, Table knives are heated till they acquire a purple color, equal to 530° F., in order to let them down to the proper temper, and articles in which great elasticity is required, such as swords and watch springs, are tempered to a bright blue, equal to 550° F., while saws are brought to the highest tempering heat at which the dark blue color shows itself. This temperature, about 600° F., is that * at which oil boils and flames, so that a bath of oil is very frequently used in tempering, the articles being immersed in it and the temperature ascertained either by a thermometer, or by the volume and color of the smoke which rises from the oil. Some tools are annealed by plunging them into oil heated to 400° F., and allowing them to cool down in it. Small steel tools, after being hardened by chilling in water, are coated with tallow heated over a flame till the: tallow begins to smoke, and then stuck into cold tallow. rge steclimpléments are let down to the proper temper by being heated in a kind of oven known as a mutile, A Note on Files. Prof. J. E. Sweet, of Cornell University mechanical school, in one of his recent lectures, gave his students the following note on files, as reported in the Polytechnic: Hach tile should have a well-fitted handle; and for a given purpose . know of nothing more utterly unsuited than the tangs or shanks of files as universally made. By remodeling the tangs of our entire lot_ of files, I hope, during the term, to show and convince you that there is a good form as well as a bad one; although I feel sure that a quarter of a century at least will be required, (our graduates holding prominent position) before a general move can be made to change the wrong for the right. As they are now made, they are expensive to forge by hand, and very ditticult to forge by machinery, There is no tool by which a proper hole can be made in the handle; nor can there, while they are of all sizes and degrees of taper, be such a tool made. Besides, the tangs will not, even if put in in the best manner, stay in the handle as they should. There is no more sense or economy in changing a file handle every time one wants to change 4 file, than there would be in so changing a hammer handle; and if the tangs were of such form that when a handle was put on it would stay, workmen would no more think of shifting the one than changing the other. That the part of the tang next the file where the handle is. protected by the ferule, should he tapering to give it strength, is all right; but that the part back of the terule should be parallel, or nearly so, and. of such size that it will drive tightly within a standard sized hole, is in my opinion the true form. The handle, to be used a long time without cramping the hand, should have a good deal of convex surface and very little, if any, of concave; and there should be no beads or ornaments, The wood from which they are made should be thoroughly seasoned, or the ferules threaded on as. a nut is screwed upon a bolt. Gas pipe, threaded on the inside and cut into short lengths, makes durable ferules, Tiles are cut their whole length, and to use only a small portion in the center sacrifices half their value. ‘The best practice is to run their entire length at each stroke, running them ata steady uniform speed—not too fast; and to exert sufficient pressure to make them cut from end to end. If a file is run too fast, or allowed to slip over, it wears away the teeth; a pretty well worn file will cut if held to the work with sufficient pressure; and for steel (unless the file is made specially for it, with obtuse teeth), it will endure more if used first on softer metal. The teeth of a new file are rapidly broken off, unless nsed with care. ake Welding. We recently printed a paragraph on welding as viewed by an English va ic. We seat that this statement has called up some controversy. At a recent meeting of the Foremen’s Association, Mr. George Newcombe made a “dead set” against certain opi which had been expressed on the subject at various discussions of the Iron and Steel Institute. He considered that they were quite. mistaken as to the conditions necessary to secure good welding, from au erroneous notion of what was actually done, or sought to be done. He maintained that the sand was only necessary asa refractory agent to prevent the conduction of the heat, and had no use whatever as a means of cementing the pieces of iron under the process of welding. Mr. Howson defended his opinion by asserting that the melted silicate promoted welding by preventing oxide forming ‘on the metal and so barring the way to an intimate homogeneous weld, It turned out, however, that each was looking at the matter too exclusively from his own peculiar standpoint Mr. Newcombe arguing as a smith, and Mr. Howson as a manufacturer; for the slag undoubtedly is necessary for protection in puddling, Mr. Head, as usual, made a dash at first principles, and considered the reason of the matter lay in the answer to the question, What is welding? Probably they world never arrive at a solution of the nature of this particular form of the cohesive power of attraction. All they were likely to be successful in was in finding out the proper conditions. It was a question they were all Feely interested in, and very much worth studying. The permeation of hot iron by carbonic oxide aad carbonic acid was also discussed with reference to the blisters in plate iron 80 annoying to manufacturers, some suggesting that they were formed by carbonic oxide, intercepted by the rolled skin, and others that they were caused by the generation of carbonic acid, the balance of opinion being in favor of their being ‘‘hottled-up” beads of carbonic oxide. Towards the conclusion, an ironmaster present made the very wise remark that the masters might very often be benefited by taking a lesson from their workmen. New Way of Making Miners’ Picks. An Englishman has devised an improvement in the manufacture of miners’ picks which is thus described: Jn the first place a rod, bar or plate, consisting internally of steel, and externally of iron, is formed by making a pile, and rolling or drawing down the pile into rods, bars, or plates, of the section required, having the inner core of steel embraced, as it were, by a wrapper of iron. For such tools as miners’ picks a compound bar of the above description is made, and cut into the lengths required for each tool; one or both ends of each length are afterwards sheared, cut or forged, or otherwise drawn down or shaped to a point or working edge or face, which is then hardened or tempered, The barat mid-length or elsewhere may be split longitudinally and opened out to allow of its being attached to a handle, or other means of attaching it to a handle may be adopted. Picks constructed in the manner above described may be made lighter and stiffer than picks constructed in the ordinary manner, and will, in addition, when a cast-steel core is used, possess the principal advantages of picks formed entirely of cast-steel, without the disadvantages which sometimes tell against the use of such tools, The steel will also be protected in manufacture, and also when the ends of the’ pick are reheated at the time of dressing or sharpening in the ordinary way. If by repeated sharpening the iron be found to overrun the point of extremity, some of the iron may be removed by paring or otherwise, and the extremity may be upset to facilitate doing so. Make your [yventions Known.—Inventors and others having new machinery and implements to describe, should have cuts of them made. The Newark Advertiser, speaking of this matter, says: ‘‘It is hardly possible to introduce successfully an improvement in machinery of any class without the aid of a good engraying. It not only serves to show at a glance the valuable features of the machine, more effectually than the longest verbal description can do, but it also constitutes the very best method of advertising an invention, its attractive appearance securing the attention of the reader, while a column of reading matter might be overlooked.” All of which is true, and cannot be too strongly impressed upon the minds of those who have new mechanical inventions which they wish to introduce to the public. New Rarway Carrrace.—A French company is now building a special type of carnage for service on the little railway between Bayonne and Biarritz. The designer is M. Carimantraud. The framework is entirely in iron; in spite of their large size the weight of the carriages is relatively small; the panels of the body are made of thin slips of wood, eovered on both sides with varnished canvas. There is a covered upper story and an interior staircase; each carriage is arranged for three classes, and has a goods department and smoking platform as well. The open spaces are as large as possible, to permit good views being taken. Petroleum is used for lighting; the lamps’ are so arranged as to give light to the interior and at the same time show the signals. Each carriage, all full, accommodates ninety-two passengers, Soientiric Process. Caterpillars in Coal. At the last ordinary meeting of the Derby Naturalists’ Society, the Colliery Guardian says that Mr. A. H. Stokes produced a caterpillar which had*been presented to him as a ‘‘find” in the coal, 61 conte deep, at High Moor, Eckington. The man from whom he obtained it stated that, on splitting a piece of coal in the ordinary course of his labor, he discovered the insect curled up inside, and it being of a “blood-red color” it so alarmed him and others that, at first, they did not dare touch it. Eventually it was secured and taken to the daylight, where it proyed its mortality by deyouring voraciously some leaves. Although the spirit in which the insect had been preserved had tampered very much with the delicate epidermis, and had thus destroyed the coloring, yet it was soon recognized as the larvie of the goat moth (Cossus ligniparda), the larva of which is supposed to be the “‘cossus” of the ancient Romans, by whom it was esteemed a great table delicacy. The insect appeared to be ‘full fed,” and quite ready to form its cocoon, and this would actount for the position in which it was found. How it came down the mine it is, of course, impossible to say. The ordinary home of the insect is in the wood of willow trees, where the pupe are sometimes found, and it may have descended in the timber used in the mine, or it may have descended unobserved on some of the men’s clothing. Some persons might doubt the ability of an insect to eat its way into coal. On this point, fortunately, we have ample evidence, A zentleman once placed some of these larve in a box, which he deposited upon the piano, He was rather surprised the next morning on finding that these industrious biters had gnawed their way through the box into the piano, and had evidently gone on a voyage of discovery into the interior, Prof. H the Zoologist (vol. viii., iP 2,897,) says: ‘‘I placed half a dozen caterpillars of the goat moth in a glass jar, with sawdust and a piece of willow, and covered the mouth with sheet lead, which was perforated with an awl to admit the air. Three of the caterpillars were to-day crawling on the floor, and, on examining the jar, I found that they had effected their escape by gnawing the lead, having enlarged two of the perforations sufficiently to enable them to pass out of their prison.” Now, an insect which can eat its way through lead and through walnut wood would not make a difficulty over a iece of coal. The larve of different species of ieranura are similarly powerful in the jaw, and Mr. Stokes’s insect was at first taken for one of this order, enslow, writing to Spectra of the Planets. Some researches by M. Vogel on the spectra of planets, undertaken in view of a prize question proposed by the Copenhagen Academy in 1873, which gained the prize, have been published in Poggendorf’s Annalen. The following isa short resume of them: The spectroscope shows the light of the planets to be in general’ reflected solar light. ‘The principal Fraunhofer lines are found in the light of the brightest. The idea of a light proper to Jupiter and Saturn, as explaining their peculiar whiteness, seems unfounded; for the presence in the spectra of these planets of lines and bands of absorption, identical with those produced by our atmosphere, seems to prove the existence of aqueous vapors in the gaseous envelopes of these planets, and it is difficult to suppose the temperature of their surface high enough to cause an emission of light. The solar and planetary spectra differs in that the latter have absorption bands, more or less intense, in the less refrangible parts ; and these may be attributed to the atmospheres of the planets. The further the star is from the sun, the more preponderating is the influence of this atmosphere. The interior planets, Mercury and Venus, have only very weak absorption bands in the red and yellow, which are coincident with lines produced by passage of light through our atmosphere. Mars presents the same bands, but more marked. In the spectra of Jupiter and Saturn, there is, besides these’ bands, a very intense band in the red, and all the more refrangible part (violet and blue) is greatly weakened, without bands being distinguishable. Lastly, the spectra of Uranus and Neptune are crossed eyerywhere with broad and intense absorption bands. Murber oF Scren‘tists.—The Chicago Times says: Late news from New Guinea conveys the intellgence that two persons engaged in making scientific collections on that island were lately murdered by the natives. The one was a Dr. James of the United States, the other a Swede, his companion, who had been some time with him exploring Gule island. The two had gone in their large boat to the eastside of Hall sound to shoot birds of paradise, when they were attacked by three canoes and both were killed. The native crew managed to get away in the boat and carried the news of the sad calamity to Cape York. Only a fortnight before the notice of his death reached England Dr. James’s, first collections arrived there, and the excellent way in which they were preserved, together with the careful notes accompanying them, betoken that science has lost a promising «auxiliary through his untimely decease, The Moon’s Motion. : ~ The reduction of the star occultations observed at the transit of Venus stations, for the purpose of determining their longitude, renders _necessary an investigation of the errors of the moon's place, as given in the Nautical Almanac for the eriod during which the work was in progress. uch an investigation, says the Independent, has just been published by Protecaur Newcomb, as art IIT of the papers issued by the Transit of Venus Commission. It appears, in the first nei that, on the whole, the moon has forthe: ast 14 or 15 years been falling continually behind the place indicated by the tables. In 1864 the tabular and observed positions were sensibly accordant; but in 1874 the moon waa on the average .94” (about 11 miles) behind computation. In respect to this Professor Newcomb remarks: ‘‘The sudden alteration of nearly one second per annum in the mean motion of the moom seems to me one of the most extraordi-. nary of astronomical phenomena; but as I have discussed it in several papers during the last five years, I shall do no more here than call. attention to its continuance, and to the impos: sibility of representing it by any small number of periodic terms, without introducing discordances into the longitude during previous years,” The explanation suggested in the papers referred to is that there may have been an actual change in the rapidity of the earth’s rotation, the length of the day having recently shortened something like 1-400 of a second, in consequence, probably, of some geological movement of the crust of the eae, Another result, hardly less startling to mathematical astronomers, is the discovery of a new inequality in the moon’s motion, amounting to about 1,5” each way. Itmay be either an inequality of the eccentricity and perigee with a ecbal of 16% years, or merely of the moon’s longitude with a period of 27.4 days. No theoretical explanation of this irregularity has been reached, According to Prof. N., the only apparent cause to which it can be attributed is the attraction of some of the planets. The whole discussion is throughly worked out and the paper is one of great interest and importance to astronomers, ‘ Cause of Error in a Thermometer. Mr. H. C. Russel publishes notes on some remarkable errors in thermometers recorded at Sydney observatory, 1876, For upwards of five years the same hygrometer has been in use at the observatory, The dry bulb is. small, only 0.3 inches in diameter, and the instrument, up to February 26th, had always given very satis: factory readings, tested by those of a standard which hangs only 3 inches from it. The difference in the readings was usually 0.2° to 0.3°. On that day the maximum shade temperature rose to 96.4" about noon; at 3 P. mM. the dry bulb and standard read 83,7°, and at 9 PB. Mm. 68,9° and 69°. Next morning they read 69.6° and 69,8". As this was Sunday, they were not read again until 9 4. mM. on the 28th, when the dry bulb read 87.3", and the standard, 64.9°, showing a difference of 22.4°, It was at once thought that the glass was cracked, and let in the air, but as no erack could be seen, after careful examination, it was determined to continue the reading, The author had always found before that if a thermometer cracks in the bulb the mercury rises till the tube is full, and he expected it would be so in this case though he could see no crack. The result, however, was that the difference steadily decreased, at first at the rate of 1° each day, and in 35 days the difference had fall@h to less than 0.5°, or almost to its normal condition, Between April 7th and 17th it rose again, then fell. On the 3d of May, and again on the 7th, sudden rises took place; since then the difference has been diminishing, except a slight rise on May 21st and 22d. hen very closely examined with the microscope, a very small piece of colored glass is to be seen in the bulb, as if lead had been reduced by the blowpipe, and on one side of the bulb a mark is visible, as if there was a minute quantity of water between the mercury and the glass at one spot, CimaAric CHANGES IN Russia.—The winters in Russia are becoming colder eyery year, and the summers hotter, more dry and less fruitful, owing, as is clearly stated by Livingston, to the destruction. of the woodlands which formerly abounded in the southern districts. The cleaying of these lands has caused such an enormous evaporation, that many once capacious watercourses have become mere swamps or are completely dry. The Dnieper becomes every day more shallow, and its tributaries are no longer worthy of the name of streams. The question of replanting has frequently been agitated, but the dried condition of the earth in many places in Southern Russia makes it a great difficulty. Energetic measures, however, are about being adopted to overcome this difficulty by scientific means. SipERsPHTHITEe,—This is the name of a new iron amalgam which is composed of 65 parts iron, 23 nickel, 4 tungsten, 5 aluminum, 5 copper. It resists sulphureted hydrogen, is not attacked by vegetable acids, and only slightly by mineral acids. Itis really more useful than standard silver, which it can be produced at a cost not exceeding that of German silver. For alloys which have to be silver-plated to prevent oxidation, the inoxidizable iron, as the above is called, is stated to be a perfectly successful substitute.

January 6, 1877.], MINING AND SCIENTIFIC PRESS ae Mechanica ‘P RoareEss. Rules for Tempering Steel. The fron Age gives some rules to be observed in tempering, 1. The steel should be very hard before tempering. If the articles to be tempered are not properly hardened at first it will be time and Jabor lost to temper them. 2. The heat for tempering should not be too suddenly applied. The slower the heating the tougher and stronger the steel, 3. The most careful and experienced workman is liable to be deceived in the color of the and consequently in the temperature in imperfect light or at twilight. 4. Where water is used for plunging the steel in, the less freuently it is changed the better, provided it deel not get greasy. The temperature to which the steel should be raised for various purposes is shown by the color of theyateel when heated. Lancets, which must be very hard, in order that they may be ground to a keen edge, are tempered to the faint yellow tinge, equal to 430° F., while razors and surgical knives, which must be leas easily broken, are tempered to the straw yellow, equal to 450° F. Pen knives are temred upon an iron plate over the fire, the Piades being laid upon it on their-backs until they have acquired the full yellow color, equal to 470° F. Cold chisels and large shears for cutting iron, must stand rougher usage, and are therefore tempered to a brown yellow, equal to 490° B., while the brown, with purple spots, equal to 510° F., marks the tempering heat for axes and plane irons, Table knives are heated till they acquire a purple color, equal to 530° F., in order to let them down to the proper temper, and articles in which great elasticity is required, such as swords and watch springs, are tempered to a bright blue, equal to 550° F., while saws are brought to the highest tempering heat at which the dark blue color shows itself. This temperature, about 600° F., is that * at which oil boils and flames, so that a bath of oil is very frequently used in tempering, the articles being immersed in it and the temperature ascertained either by a thermometer, or by the volume and color of the smoke which rises from the oil. Some tools are annealed by plunging them into oil heated to 400° F., and allowing them to cool down in it. Small steel tools, after being hardened by chilling in water, are coated with tallow heated over a flame till the: tallow begins to smoke, and then stuck into cold tallow. rge steclimpléments are let down to the proper temper by being heated in a kind of oven known as a mutile, A Note on Files. Prof. J. E. Sweet, of Cornell University mechanical school, in one of his recent lectures, gave his students the following note on files, as reported in the Polytechnic: Hach tile should have a well-fitted handle; and for a given purpose . know of nothing more utterly unsuited than the tangs or shanks of files as universally made. By remodeling the tangs of our entire lot_ of files, I hope, during the term, to show and convince you that there is a good form as well as a bad one; although I feel sure that a quarter of a century at least will be required, (our graduates holding prominent position) before a general move can be made to change the wrong for the right. As they are now made, they are expensive to forge by hand, and very ditticult to forge by machinery, There is no tool by which a proper hole can be made in the handle; nor can there, while they are of all sizes and degrees of taper, be such a tool made. Besides, the tangs will not, even if put in in the best manner, stay in the handle as they should. There is no more sense or economy in changing a file handle every time one wants to change 4 file, than there would be in so changing a hammer handle; and if the tangs were of such form that when a handle was put on it would stay, workmen would no more think of shifting the one than changing the other. That the part of the tang next the file where the handle is. protected by the ferule, should he tapering to give it strength, is all right; but that the part back of the terule should be parallel, or nearly so, and. of such size that it will drive tightly within a standard sized hole, is in my opinion the true form. The handle, to be used a long time without cramping the hand, should have a good deal of convex surface and very little, if any, of concave; and there should be no beads or ornaments, The wood from which they are made should be thoroughly seasoned, or the ferules threaded on as. a nut is screwed upon a bolt. Gas pipe, threaded on the inside and cut into short lengths, makes durable ferules, Tiles are cut their whole length, and to use only a small portion in the center sacrifices half their value. ‘The best practice is to run their entire length at each stroke, running them ata steady uniform speed—not too fast; and to exert sufficient pressure to make them cut from end to end. If a file is run too fast, or allowed to slip over, it wears away the teeth; a pretty well worn file will cut if held to the work with sufficient pressure; and for steel (unless the file is made specially for it, with obtuse teeth), it will endure more if used first on softer metal. The teeth of a new file are rapidly broken off, unless nsed with care. ake Welding. We recently printed a paragraph on welding as viewed by an English va ic. We seat that this statement has called up some controversy. At a recent meeting of the Foremen’s Association, Mr. George Newcombe made a “dead set” against certain opi which had been expressed on the subject at various discussions of the Iron and Steel Institute. He considered that they were quite. mistaken as to the conditions necessary to secure good welding, from au erroneous notion of what was actually done, or sought to be done. He maintained that the sand was only necessary asa refractory agent to prevent the conduction of the heat, and had no use whatever as a means of cementing the pieces of iron under the process of welding. Mr. Howson defended his opinion by asserting that the melted silicate promoted welding by preventing oxide forming ‘on the metal and so barring the way to an intimate homogeneous weld, It turned out, however, that each was looking at the matter too exclusively from his own peculiar standpoint Mr. Newcombe arguing as a smith, and Mr. Howson as a manufacturer; for the slag undoubtedly is necessary for protection in puddling, Mr. Head, as usual, made a dash at first principles, and considered the reason of the matter lay in the answer to the question, What is welding? Probably they world never arrive at a solution of the nature of this particular form of the cohesive power of attraction. All they were likely to be successful in was in finding out the proper conditions. It was a question they were all Feely interested in, and very much worth studying. The permeation of hot iron by carbonic oxide aad carbonic acid was also discussed with reference to the blisters in plate iron 80 annoying to manufacturers, some suggesting that they were formed by carbonic oxide, intercepted by the rolled skin, and others that they were caused by the generation of carbonic acid, the balance of opinion being in favor of their being ‘‘hottled-up” beads of carbonic oxide. Towards the conclusion, an ironmaster present made the very wise remark that the masters might very often be benefited by taking a lesson from their workmen. New Way of Making Miners’ Picks. An Englishman has devised an improvement in the manufacture of miners’ picks which is thus described: Jn the first place a rod, bar or plate, consisting internally of steel, and externally of iron, is formed by making a pile, and rolling or drawing down the pile into rods, bars, or plates, of the section required, having the inner core of steel embraced, as it were, by a wrapper of iron. For such tools as miners’ picks a compound bar of the above description is made, and cut into the lengths required for each tool; one or both ends of each length are afterwards sheared, cut or forged, or otherwise drawn down or shaped to a point or working edge or face, which is then hardened or tempered, The barat mid-length or elsewhere may be split longitudinally and opened out to allow of its being attached to a handle, or other means of attaching it to a handle may be adopted. Picks constructed in the manner above described may be made lighter and stiffer than picks constructed in the ordinary manner, and will, in addition, when a cast-steel core is used, possess the principal advantages of picks formed entirely of cast-steel, without the disadvantages which sometimes tell against the use of such tools, The steel will also be protected in manufacture, and also when the ends of the’ pick are reheated at the time of dressing or sharpening in the ordinary way. If by repeated sharpening the iron be found to overrun the point of extremity, some of the iron may be removed by paring or otherwise, and the extremity may be upset to facilitate doing so. Make your [yventions Known.—Inventors and others having new machinery and implements to describe, should have cuts of them made. The Newark Advertiser, speaking of this matter, says: ‘‘It is hardly possible to introduce successfully an improvement in machinery of any class without the aid of a good engraying. It not only serves to show at a glance the valuable features of the machine, more effectually than the longest verbal description can do, but it also constitutes the very best method of advertising an invention, its attractive appearance securing the attention of the reader, while a column of reading matter might be overlooked.” All of which is true, and cannot be too strongly impressed upon the minds of those who have new mechanical inventions which they wish to introduce to the public. New Rarway Carrrace.—A French company is now building a special type of carnage for service on the little railway between Bayonne and Biarritz. The designer is M. Carimantraud. The framework is entirely in iron; in spite of their large size the weight of the carriages is relatively small; the panels of the body are made of thin slips of wood, eovered on both sides with varnished canvas. There is a covered upper story and an interior staircase; each carriage is arranged for three classes, and has a goods department and smoking platform as well. The open spaces are as large as possible, to permit good views being taken. Petroleum is used for lighting; the lamps’ are so arranged as to give light to the interior and at the same time show the signals. Each carriage, all full, accommodates ninety-two passengers, Soientiric Process. Caterpillars in Coal. At the last ordinary meeting of the Derby Naturalists’ Society, the Colliery Guardian says that Mr. A. H. Stokes produced a caterpillar which had*been presented to him as a ‘‘find” in the coal, 61 conte deep, at High Moor, Eckington. The man from whom he obtained it stated that, on splitting a piece of coal in the ordinary course of his labor, he discovered the insect curled up inside, and it being of a “blood-red color” it so alarmed him and others that, at first, they did not dare touch it. Eventually it was secured and taken to the daylight, where it proyed its mortality by deyouring voraciously

some leaves. Although the spirit in which the insect had been preserved had tampered very much with the delicate epidermis, and had thus destroyed the coloring, yet it was soon recognized as the larvie of the goat moth (Cossus ligniparda), the larva of which is supposed to be the “‘cossus” of the ancient Romans, by whom it was esteemed a great table delicacy. The insect appeared to be ‘full fed,” and quite ready to form its cocoon, and this would actount for the position in which it was found. How it came down the mine it is, of course, impossible to say. The ordinary home of the insect is in the wood of willow trees, where the pupe are sometimes found, and it may have descended in the timber used in the mine, or it may have descended unobserved on some of the men’s clothing. Some persons might doubt the ability of an insect to eat its way into coal. On this point, fortunately, we have ample evidence, A zentleman once placed some of these larve in a box, which he deposited upon the piano, He was rather surprised the next morning on finding that these industrious biters had gnawed their way through the box into the piano, and had evidently gone on a voyage of discovery into the interior, Prof. H the Zoologist (vol. viii., iP 2,897,) says: ‘‘I placed half a dozen caterpillars of the goat moth in a glass jar, with sawdust and a piece of willow, and covered the mouth with sheet lead, which was perforated with an awl to admit the air. Three of the caterpillars were to-day crawling on the floor, and, on examining the jar, I found that they had effected their escape by gnawing the lead, having enlarged two of the perforations sufficiently to enable them to pass out of their prison.” Now, an insect which can eat its way through lead and through walnut wood would not make a difficulty over a iece of coal. The larve of different species of ieranura are similarly powerful in the jaw, and Mr. Stokes’s insect was at first taken for one of this order, enslow, writing to Spectra of the Planets. Some researches by M. Vogel on the spectra of planets, undertaken in view of a prize question proposed by the Copenhagen Academy in 1873, which gained the prize, have been published in Poggendorf’s Annalen. The following isa short resume of them: The spectroscope shows the light of the planets to be in general’ reflected solar light. ‘The principal Fraunhofer lines are found in the light of the brightest. The idea of a light proper to Jupiter and Saturn, as explaining their peculiar whiteness, seems unfounded; for the presence in the spectra of these planets of lines and bands of absorption, identical with those produced by our atmosphere, seems to prove the existence of aqueous vapors in the gaseous envelopes of these planets, and it is difficult to suppose the temperature of their surface high enough to cause an emission of light. The solar and planetary spectra differs in that the latter have absorption bands, more or less intense, in the less refrangible parts ; and these may be attributed to the atmospheres of the planets. The further the star is from the sun, the more preponderating is the influence of this atmosphere. The interior planets, Mercury and Venus, have only very weak absorption bands in the red and yellow, which are coincident with lines produced by passage of light through our atmosphere. Mars presents the same bands, but more marked. In the spectra of Jupiter and Saturn, there is, besides these’ bands, a very intense band in the red, and all the more refrangible part (violet and blue) is greatly weakened, without bands being distinguishable. Lastly, the spectra of Uranus and Neptune are crossed eyerywhere with broad and intense absorption bands. Murber oF Scren‘tists.—The Chicago Times says: Late news from New Guinea conveys the intellgence that two persons engaged in making scientific collections on that island were lately murdered by the natives. The one was a Dr. James of the United States, the other a Swede, his companion, who had been some time with him exploring Gule island. The two had gone in their large boat to the eastside of Hall sound to shoot birds of paradise, when they were attacked by three canoes and both were killed. The native crew managed to get away in the boat and carried the news of the sad calamity to Cape York. Only a fortnight before the notice of his death reached England Dr. James’s, first collections arrived there, and the excellent way in which they were preserved, together with the careful notes accompanying them, betoken that science has lost a promising «auxiliary through his untimely decease, The Moon’s Motion. : ~ The reduction of the star occultations observed at the transit of Venus stations, for the purpose of determining their longitude, renders _necessary an investigation of the errors of the moon's place, as given in the Nautical Almanac for the eriod during which the work was in progress. uch an investigation, says the Independent, has just been published by Protecaur Newcomb, as art IIT of the papers issued by the Transit of Venus Commission. It appears, in the first nei that, on the whole, the moon has forthe: ast 14 or 15 years been falling continually behind the place indicated by the tables. In 1864 the tabular and observed positions were sensibly accordant; but in 1874 the moon waa on the average .94” (about 11 miles) behind computation. In respect to this Professor Newcomb remarks: ‘‘The sudden alteration of nearly one second per annum in the mean motion of the moom seems to me one of the most extraordi-. nary of astronomical phenomena; but as I have discussed it in several papers during the last five years, I shall do no more here than call. attention to its continuance, and to the impos: sibility of representing it by any small number of periodic terms, without introducing discordances into the longitude during previous years,” The explanation suggested in the papers referred to is that there may have been an actual change in the rapidity of the earth’s rotation, the length of the day having recently shortened something like 1-400 of a second, in consequence, probably, of some geological movement of the crust of the eae, Another result, hardly less startling to mathematical astronomers, is the discovery of a new inequality in the moon’s motion, amounting to about 1,5” each way. Itmay be either an inequality of the eccentricity and perigee with a ecbal of 16% years, or merely of the moon’s longitude with a period of 27.4 days. No theoretical explanation of this irregularity has been reached, According to Prof. N., the only apparent cause to which it can be attributed is the attraction of some of the planets. The whole discussion is throughly worked out and the paper is one of great interest and importance to astronomers, ‘ Cause of Error in a Thermometer. Mr. H. C. Russel publishes notes on some remarkable errors in thermometers recorded at Sydney observatory, 1876, For upwards of five years the same hygrometer has been in use at the observatory, The dry bulb is. small, only 0.3 inches in diameter, and the instrument, up to February 26th, had always given very satis: factory readings, tested by those of a standard which hangs only 3 inches from it. The difference in the readings was usually 0.2° to 0.3°. On that day the maximum shade temperature rose to 96.4" about noon; at 3 P. mM. the dry bulb and standard read 83,7°, and at 9 PB. Mm. 68,9° and 69°. Next morning they read 69.6° and 69,8". As this was Sunday, they were not read again until 9 4. mM. on the 28th, when the dry bulb read 87.3", and the standard, 64.9°, showing a difference of 22.4°, It was at once thought that the glass was cracked, and let in the air, but as no erack could be seen, after careful examination, it was determined to continue the reading, The author had always found before that if a thermometer cracks in the bulb the mercury rises till the tube is full, and he expected it would be so in this case though he could see no crack. The result, however, was that the difference steadily decreased, at first at the rate of 1° each day, and in 35 days the difference had fall@h to less than 0.5°, or almost to its normal condition, Between April 7th and 17th it rose again, then fell. On the 3d of May, and again on the 7th, sudden rises took place; since then the difference has been diminishing, except a slight rise on May 21st and 22d. hen very closely examined with the microscope, a very small piece of colored glass is to be seen in the bulb, as if lead had been reduced by the blowpipe, and on one side of the bulb a mark is visible, as if there was a minute quantity of water between the mercury and the glass at one spot, CimaAric CHANGES IN Russia.—The winters in Russia are becoming colder eyery year, and the summers hotter, more dry and less fruitful, owing, as is clearly stated by Livingston, to the destruction. of the woodlands which formerly abounded in the southern districts. The cleaying of these lands has caused such an enormous evaporation, that many once capacious watercourses have become mere swamps or are completely dry. The Dnieper becomes every day more shallow, and its tributaries are no longer worthy of the name of streams. The question of replanting has frequently been agitated, but the dried condition of the earth in many places in Southern Russia makes it a great difficulty. Energetic measures, however, are about being adopted to overcome this difficulty by scientific means. SipERsPHTHITEe,—This is the name of a new iron amalgam which is composed of 65 parts iron, 23 nickel, 4 tungsten, 5 aluminum, 5 copper. It resists sulphureted hydrogen, is not attacked by vegetable acids, and only slightly by mineral acids. Itis really more useful than standard silver, which it can be produced at a cost not exceeding that of German silver. For alloys which have to be silver-plated to prevent oxidation, the inoxidizable iron, as the above is called, is stated to be a perfectly successful substitute.