Volume 24 (1872) (424 pages)

May 25, 1872.] SCIENTIFIC PRESS. 323 poe §oleNTiFic Proaress. Relations of Calorific Power of Combustibles to Composition. During tho Inst session of tho New York Lyeoum of Natural History, a discussion arose on tho ahovo subject, iu which the present writer startled most of tho members present by annonucing his conviction of the total fallacy of the provalent mode of calculating hypothetically tho calorific value of 2 coal or other comhustible, from its e¢lemeutary constitation. Ho eluiiued that, iu believing that tho samo elemeuts ina complex mixture, as well as ina homogeneous compound, oveu when preseut iu tho samo centesimal proportions, must neods ive the same heat ou completo combustion, we ignore all the well-founded and accepted views of moleenlar dyuamics and thormo-chemistry. As the prodncts of complete combustion of carho-liydrogen materials were always molecularly ideutical—that is, carhouic acid and water —the materials themselves must have had identical molecular constitution origiually, in order to exert the samo amount of internal disturbanco, while falling into the same new molecular arrangemeut. He cited many known facts to snpport his views, which gavo rise to somo discussion, and aroused especial opposition from the distinguished Presideut of the Lycoum, Dr. Nowberry, whoremarked that if Professor Wurtz holieved ho could substantiate these revolutionary ideas, he shonld not panee, night or day, bnt devoto himsolf exclnsivcly to the task, tho importance of the eubject being nnsurpassed by auy other in tho rango of science ! With thie pronmble, we introduce the following extract from a report of recent communication of Schenrer-Kestuer and Meunier to the Academy of Sciences, ou tho Heat of Comhuetiou of Lignites: ‘«Lignite, the anthors fonnd, is distinguished from coal also iuthis particular—that tho later emits a far greater quantity of heat than that dno to the combnstion of its elenients (carhon and hydrogen). Attention is again called to tho fact that it is impossible to judge of sthe value of a fnel according to its clemmentary composition; all calculations hased upon euch data are quite fallacions, and the authors prove this conclnsively by referring especially to oue of the eamples of lignite they investigated.””— American Gas-Light Journal, Carnonizep Sewace.—Mr. Hickey is engaged in India, says Engincering, in testing the efficacy of his invention of preserving scwage by carbonization. Tho main features of Mr. Hickey’s plau are that he collects the gases evolved during carbonization, which he proposes to make available for town illumination, while the coke which remains has heen found to he a most excellent deodorizer, and, mixed with the ammoniacal Kquors collected from the gas retorts, it also forms a valuable manure. The production of gas for Hghting pnrpoees hy the carbonization of ordure is not a novelty, but dates ne far back as 1686. But whether it will ever he found practicable to illuminate towns with gae produced from their sewers is very doubtful. Mr. Hickey’s experiments show that gas and coke can easily be msde by his process, but the pecnuiary succees of the manufacture is not yet scttled. Tho gas has an illuminating power of ouly 24% caudlee. TnansaiTTED Raprant Heat.—The questiou whether equal areas at different points of the solar surface, transmit equal energy towards the earth has not been eatisfactorily answered. The author of Mechanique Celeste, finding by obeervation that eqnal areas do not transmit eqnal energies (the ceutral regions transmitting, in opposition to his reasoning, much greater intensity than those near the border) explains the matter hy showing that the solsr atmosphere retards the paseage of the rays cansing a great diminution of the encrgy of the radiant heat projected towards the earth. Capt. Jobn Eriesson, in a series of ingenious experiments with incandescent spheree, described in full in Engineering, shows the inaccuracy of this theory. Far Founp my Breer Yeast.—Iu an article by Dr. Vogel, rend before the Academy of Science, in Munieh, after referring to the fact that sil eereals contain a larger or smaller qnantity of fatty matter, which is an essential constituent of the grain, the author describes at length his experiments made for the purpose of extracting, by the means of ether, the fat contained in heer yeast, an oil boiling at about 200° Centigrade, specifie gravity equal to 0.901; decomposed when heated above 300° Centigrade, and yielding acrolcin. The quantity of this oil fouud in one Kter of the yeast amounts to from 0.2 to 0.3 drams. It appears that this oil is, in most respecte, eimilar to the fatty matter in barley. Evreor or Extreme Corp on Sxow.—Dr Kane, the arctic explorer, recorded the very striking and euggestive fact that snow, at a temperature of forty degrees below zero, F., loees much of its anti-fractional quality. He found it nearly as difficult to draw, slede upon such enow as upon eand, Discovery or A New Pruanet.—Prof. James ©. Watson, of Ann Arbor, Mich., writes to the Journal of Science, that he discovered a new planet, on the night of April 4th, in the eonstellation Virgo. The planet shines like a star of the eleyouth magnitude, Presenvation or Woon.—Gen. Haupt contrihutes to tho May Van Nostrand, a review of tho chief procusses proposed for tho preservatien of wood, and adds eomoe deductions of his own. From his experimeuts aud in vestigations ho concludes: 1, Thatso long as tho cells of wood are ocenpied hy air and moistnre, no preservative e0lutious can bo iutroduced, aud the expnision of ftir and moisture iuust be the first step in any effective process for preserving timher froin decay. 2. That water can ho expelled by a loug coutiuned application of heat, but air ouly by expausion iu a vacuum, and tho comhiaation of heat aud vacuum will eecure the wiost rapid expansion of both water and air, 3. That the preservative Hid must ho introdnced while tho cells nro empty, consequently the process must he carricd on in vacuo. 4. That no pressure, however great, applied externally to the swfaco of timber, eau forco any fluid iuto the interior so long as air or water is contuiued in the cclls. When air aloue is present there may bo penetration to a limited oxtent superficially, hut water is practically incomprossible. If, howover, the pressure is applied at one end ouly of a stick, as iu the Boucher‘e process, a fluid may be forced through and exude from the other cud. Groxootcan Success.—An iustance of complete suecese in scarch founded on geological indications has just ocenrred in Swedeu. An extensive coal bed of unusual depth iu Europe, aud of excelleut quality, has been discovered at Raus, in Schonen, by horing on the strength of evidence afforded hy the Kthologieal formation existiug there. At first the promises were uot satisfactorily fulfilled. Eleven strata of coal, indeod, were pierced hy going down 566 fect; but none of these were more than a foot or so in thickuess. Five feet further a bed was peuetrated over eight feet thick. Other horiugs prove tho oxistenco of coal of great extent. ‘he shares of the eompauy at ouce rose 700 per ceut ahove their par value,— Ex. Penuyian Annquiries.—The Geological musoum of the University of Rome has received from King Victor Emauuel a magnificent collection of Peruvian antiqnities, comprising a number of silver vases, eome extremely curious musical iustruments, a colored garment made from the hark of trees, and eome arrows and lancee. Theee last are notehed, ornamented with feathers, and have wooden heade, ehowiug that thoy helong to tho period when the use of iron was unknown. The whole of theso ariicles were found in a bed of guano, and evidently date from the earliest antiquity. Bomer Incrusration.— Expcrimente have been tried with favorable results, itis said, at Vienna on Bérenger’s plan of treating feed water for boilers. The water is softened hy a eolution of lime and forced through a particular kind of filter, which retains the generated precipitate. There is no uecessity for waitiug for tho settling of the precipitate. From 10 to 15 filters, each of 0.1 cubic metre capacity, eoften ahout 410 cubie metree of water per day. Ant Monuments.—M. Demctrio Salazaro, the Iuspector of the National Musenm, at Naples, is about to publish, in thirty parts, at fifteen shillings each, a seriee of photographs and ehromo-lithographe of the Art Monuments of Southern Italy, from the fourth to the thirteenth century. This is the first great attempt of its kind, and is intended to show the growth and development of Italian art from its earliest ries. Tue vacancy at-the British Geological Survey office, cansed by-the death of Sw Roderick I. Murchison, has heen filled up by the appointment of Professor Andrew Cromhie Rumsay, L.L.D., F.R.5., as director-general. Professor Ramsay hae for many years heen director of the Geological Survey and Profeesor of Geology in the Royal Sehool of Minee. A RemaRraBLe Miygrau.—A. Frenzel writes of a mineral,which forme in the winter in the Himmelfahrt mine at Freiberg, but vauishes in the spring, when the weather begine to grow warm, or damp, though it forms 334 metree helow the surface. An analysis gave Magnesia...... co eno canogee 16.53 Sulphuricacid. WOU eae se oe Tux Spectroscopic Assoeiation of Italy is the title of a new society, the main object of which will be ‘‘to enrich science, by the aid of the spectroscope, with new discoveriee upon the physical constitution of the suu.”’ The first number of the Memoirs of the Society hae already been published. Xynownrre, which ie prepared by the action of nitric acid on woody fibre, is made into a sheeting or tissuo impermeable to water, which may be used as a suhstitute for india-rubber in the manufacture of all water-proof articlee. Repeaten spectroscopie measurements made last year by Professors Zollner and Vogel, in Germany, show that the velocity of rotation of the sun on its own axie is at the rate of six hundred and sixty miles an hour. Cane-suGAR when exposed to light in sealed tubee ie conyerted into grape-sugar or glucose. The eolution should be os concentrated ae possible. MecHaN ICAL Progress Economy of the Hot Blast, The first practical application of tho hot blast was mado iu 1828 or 1829 by J. B. Neilson, an Englishmau. Mr. N. and his colleaynes after determining the great value of tho invention for smelting ores, expeeted to seo it generally employed for all furnace operations; but the result has been that practically, it is almost exclusively confined to smelting the orcs of iron, Tho earliest carefully recorded experiments with tho hot hlust wero made at tho Clydo Iron works, with the following result:— Forthoyonrecmtcressses+s. 1829 1831 3833 ‘Temporatary of blast. Cold ahr EF, Gl2*F. Coal used per ton of i: As coke. As coke. In raw stato. For fusion, owt. hs St 40 For hvating air, raw coal. nil For blowing onginus, coal. 20 153 8 n 59 wy 7 From this it would appear that heating the air with 5 ewt. of coal had saved 47 ewt. of fnel in the furnace, and 8 evwt. similarly applied had beeu followed with au ecouomy of 93 ewt., or ahove 69 per cent. Besides this advautage the mako wae iucreased by more than one-third, and a blowiug eugine, which only supplied three furuaccs with cold blast, was equal to four when the air wae heated. The iron trade hesitated somewhat in creditthat the heat generated from 8 cwt. of fuel burnt outside the furnace, should be able to perform the duty of o very much larger weight burnt inside. Some writers on tho metallurgy of irou, wheu speakiug of the advantages of Neilson’s system, have not perhaps beeu sufficiently careful in drawiug a distiuction betwcon the saving directly due to ite application and that arising iu a collateral manner from its use. Looking at the question, however, in its commercial sense, the figures and lauguage quoted from the work of Dufrenoy justified the character he gave to it. Puddling Steel Rails. The Flushing and North Side Railway Company with its leased roads will have laid, hy the let of July ucxt, 40 miles of oteel track. The rails are of puddled oteel, with partly iron flangee and vertically piled. . The advantages claimed for these rails are:— perfect safety agaiust breaking, nota single rail of this kind haviug been broken duriug twelve years’ use in Germany and four years use in this conntry, greater strength and enduranec than can he obtaiued from steel-capped raile. The valuo of the worn-out puddled-steel rails is higher in proportion to first cost than that of cast-eteel raile, or iron rails with cast-steel caps, which cannot be re-rolled, but must be recast. The only disadvautage of the pnddled-steel rails is that a percentage of them may give out in the weld after a wear ahout equal to that of the life of three common iron rails. Thisis only a disadvantage in comparison to full steel or ingot rails, which have no welds, and therefore cannot failin the same manner. Setting aeide the greater safety of the welded steel rails, the question of economy in the use of either chicfly depends ou their respective first cost, on their wearing qualities, and on their market value as scrap when worn out. The solutiou of this question will depend more or less on the individual experience of the consumers, especially of those who have tried the different kinds of steel rails. ° Lele RarinoapD y Improvement.—A Pennsylvauia engineer, named Wilder, has recently hit upon an idea which, if carried out as it deserves to be, will do much toward increasing tho efficiency and enhancing the economy of railroads. It providee for the laying of two narrow gauge tracks, eide by side, with a epace between the inner raile equal to the ordinary gauge of four feet eight inches. Thus three possible gauges will be furnished on the same line, all of which it is proposed to use. Tor freight, the narrow gauge will be ueed at a safe rate of specd, while for passenger travel, and a high rate of speed, the broad gauge will be used, the cars being mounted on four lines of wheels. This, he contends, will preveut oecillatiou, thereby inereasing safety. He calculates by this system, and the increased weight of engines, it will permit of a rate of speed being attained ae high as a hundred miles an hour. No doubt a greatly iucreased speed may be attained by eueh a device, hut when a train of cars is made to trayel a hundred miles an hour, the material of which they are constructed and their manner of coustruction must be somewhat modified from their present material and form. Punntine py PetroteuM.—It ie asserted by the French technical journals that the experiment of using petroleum as fuelin the puddling furnace which has been in progress iu a large iron producing estahlishment during the past three months, has proved itself to be vory succeseful. In poiut of couvenience, efficiencyand in the euperior qnality of the iron prodnccd, it is asserted that petroleum affords the best fuel that has yet beeu employed. Burnt Iron and Steel. W. M. Williams has given the result of some iuquiries into the causes of this phenomeuon, to the Chemical Society of London. After some remarks upou the physical characteristics of iron and steel eo damaged, he assorta that he fonnd in all the samples of hurnt iron which ho has subjected to examination, particles of hlack oxide more or less abuudantly distributed throughout the mass. Theso are, however, absent in burnt steel, The method which he suggests of quickly detectiug such damage, is to tako a sinall quantity of fresh borings or filings from the subjected metal, cover them with diInted nitrie acid. As tho iron diseolves, the free oxide separates and remains suspeuded in the liquid, rendering it dark in color. These particles shortly disappear, aud are thus to be distinguished from separated carbon. No such discoloration tukce place with good iron. The cause of the hurning of iron he explsins as follows: As soon as tho small quantity of carbon is removed from tho heated mass hy oxidation, this procees exteuds to the iron itself— not ouly upon the surfaco, but into the interior. The higher tho temperaturo, and the longer the exposure, the greater is the quantity of carhon necessary to protect the iron. The best iron is that iu which carbon is bronght to tho lowest possible proportion, without oxidation of the iron. Burnt steel the author considers to be steel which has, by reheating, lost some of its carhon by oxidation, and by suddeu sohdification has had the resulting carbonic oxide imprisoned iu theinterior of its mass, The well known permeahility of irou for certain gaeee renders snch a proccss not difficult to understand. The structure and properties of “ burnt iron and etcel,’’ are therefore ‘‘ caused by the presence of intermingled particles of combustion products breaking the continuity of the metal. ‘The carbon is hurnt in the case of the hurut steel, the iron itself in the hurnt iron. Tue TurnIne PRopeLLer.—As a gun recoils when fired, or ae the progress of a rocket is kept np by the recoil arising from the efflux of the gases geuerated hy the ignition of the compositiou with which the rocket is filled, eo the progrees of a veeeel driven by the turbiue propeller ie kept up hy the recoil arising from the efflux in a eternward direction of a stream of water, kept up by the action of a contrifugal pump or turbine, driven by a steam engine, drawing water from the sea and dischargiug it sternwards, in a continuous stream, through a bent pipe or nozzle, at a high velocity, The turbine propeller was iuvented eome years ago, and attracted snfficient attention to secure a competitive trial by the British Government in 1867, with ecrew prepellers, Although the turbine did not equal (although not much behind) the screw, yet its performance at so early a stage cannot but he considered as very promising. Mr. A. Murray hss lately brought up the subject again in the Jour. 2. U.S. £, and urges further triale and inveetigations. It ie claimed that the turbine affords a higher per cent. of utilized power than the paddle or screw, which laet, all admit, lose a large amount of power, say 40 to 50 percent. at least, while centrifngal pumps of 40 to 50 horsepower, for raising water, have been found to utilize even as high ae 80 per cent., varying from that dowu to 50. But to determine this point satisfactorily further experiments are needed. Other pointe of superiority over the ecrew or paddle wheel claimed for the turhine are: the power of rapidly etopping the way of a vessel; great power over a heavy leak; freedom from the chance of internal injury or of fonling; nitility when the vessel is being driven by sails at the rate of 10 knots or more, (when the paddle or screw would be of little or no service, ) thus obtaining a greater speed than ever yet realized on the ocean; nesistance rendered to the veesel’s steerage; not being affected by the pitching or rolling of the vessel; nou-interference with any desired form of the ship for insuring good sailing properties; facility of bringing into action or discontinuing its nse, ete. Pressune IN Steam Borers.—The question as to whether the pressure in asteam boiler was equal or different at top and hottom, concerning which their eeeme to be eome difference of opinion amongst engiueers—though it is difficult, from the eimpKcity of the facts involved in considering the question, to see how a differeuce of opinion should exist—has neverthcless been experimentally determined by the Messrs. Hunter, at their establishment in this city. Au elbow was attached to the end of the blow-off pipe which eutered the mud-drum; into this a plng was screwed, and tapped to receive a half-inch pipe; to this a steam gange was attached and the cock opened. On comparing the indications of the ganges attached at top of boiler and to the top of drum, ae above deecribed, it wae fonnd that the pressure was greatest at the bottom, by a pound and a half, proving, as might readily have been predicted, that the pressure upon the bottom ofa boiler ie equal to the eteam proseure indicated above, plus the weight of a water column eqnal in hight to the difference in level hetween drum and surface of water in boiler, and in diameter to that actiug on the gauge.—Jour. Franklin Institute. Up to 1870 there were seventeen steel works in Great Britain. There are now nine steeltail mills in the United States, while two othere are building at Chicago and Springfield, Ill., and four others are projected at St. Louis, Milwaukee, Omaha, and two on the line of the Pacific Railroad.

May 25, 1872.] SCIENTIFIC PRESS. 323 poe §oleNTiFic Proaress. Relations of Calorific Power of Combustibles to Composition. During tho Inst session of tho New York Lyeoum of Natural History, a discussion arose on tho ahovo subject, iu which the present writer startled most of tho members present by annonucing his conviction of the total fallacy of the provalent mode of calculating hypothetically tho calorific value of 2 coal or other comhustible, from its e¢lemeutary constitation. Ho eluiiued that, iu believing that tho samo elemeuts ina complex mixture, as well as ina homogeneous compound, oveu when preseut iu tho samo centesimal proportions, must neods ive the same heat ou completo combustion, we ignore all the well-founded and accepted views of moleenlar dyuamics and thormo-chemistry. As the prodncts of complete combustion of carho-liydrogen materials were always molecularly ideutical—that is, carhouic acid and water —the materials themselves must have had identical molecular constitution origiually, in order to exert the samo amount of internal disturbanco, while falling into the same new molecular arrangemeut. He cited many known facts to snpport his views, which gavo rise to somo discussion, and aroused especial opposition from the distinguished Presideut of the Lycoum, Dr. Nowberry, whoremarked that if Professor Wurtz holieved ho could substantiate these revolutionary ideas, he shonld not panee, night or day, bnt devoto himsolf exclnsivcly to the task, tho importance of the eubject being nnsurpassed by auy other in tho rango of science ! With thie pronmble, we introduce the following extract from a report of recent communication of Schenrer-Kestuer and Meunier to the Academy of Sciences, ou tho Heat of Comhuetiou of Lignites: ‘«Lignite, the anthors fonnd, is distinguished from coal also iuthis particular—that tho later emits a far greater quantity of heat than that dno to the combnstion of its elenients (carhon and hydrogen). Attention is again called to tho fact that it is impossible to judge of sthe value of a fnel according to its clemmentary composition; all calculations hased upon euch data are quite fallacions, and the authors prove this conclnsively by referring especially to oue of the eamples of lignite they investigated.””— American Gas-Light Journal, Carnonizep Sewace.—Mr. Hickey is engaged in India, says Engincering, in testing the efficacy of his invention of preserving scwage by carbonization. Tho main features of Mr. Hickey’s plau are that he collects the gases evolved during carbonization, which he proposes to make available for town illumination, while the coke which remains has heen found to he a most excellent deodorizer, and, mixed with the ammoniacal Kquors collected from the gas retorts, it also forms a valuable manure. The production of gas for Hghting pnrpoees hy the carbonization of ordure is not a novelty, but dates ne far back as 1686. But whether it will ever he found practicable to illuminate towns with gae produced from their sewers is very doubtful. Mr. Hickey’s experiments show that gas and coke can easily be msde by his process, but the pecnuiary succees of the manufacture is not yet scttled. Tho gas has an illuminating power of ouly 24% caudlee. TnansaiTTED Raprant Heat.—The questiou whether equal areas at different points of the solar surface, transmit equal energy towards the earth has not been eatisfactorily answered. The author of Mechanique Celeste, finding by obeervation that eqnal areas do not transmit eqnal energies (the ceutral regions transmitting, in opposition to his reasoning, much greater intensity than those near the border) explains the matter hy showing that the solsr atmosphere retards the paseage of the rays cansing a great diminution of the encrgy of the radiant heat projected towards the earth. Capt. Jobn Eriesson, in a series of ingenious experiments with incandescent spheree, described in full in Engineering, shows the inaccuracy of this theory. Far Founp my Breer Yeast.—Iu an article by Dr. Vogel, rend before the Academy of Science, in Munieh, after referring to the fact that sil eereals contain a larger or smaller qnantity of fatty matter, which is an essential constituent of the grain, the author describes at length his experiments made for the purpose of extracting, by the means of ether, the fat contained in heer yeast, an oil boiling at about 200° Centigrade, specifie gravity equal to 0.901; decomposed when heated above 300° Centigrade, and yielding acrolcin. The quantity of this oil fouud in one Kter of the yeast amounts to from 0.2 to 0.3 drams. It appears that this oil is, in most respecte, eimilar to the fatty matter in barley. Evreor or Extreme Corp on Sxow.—Dr Kane, the arctic explorer, recorded the very striking and euggestive fact that snow, at a temperature of forty degrees below zero, F., loees much of its anti-fractional quality. He found it nearly as difficult to draw, slede upon such enow as upon eand, Discovery or A New Pruanet.—Prof. James ©. Watson, of Ann Arbor, Mich., writes to the Journal of Science, that he discovered a new planet, on the night of April 4th, in the eonstellation Virgo. The planet shines like a star of the eleyouth magnitude, Presenvation or Woon.—Gen. Haupt contrihutes to tho May Van Nostrand, a review of tho chief procusses proposed for tho preservatien of wood, and adds eomoe deductions of his own. From his experimeuts aud in vestigations ho concludes: 1, Thatso long as tho cells of wood are ocenpied hy air and moistnre, no preservative e0lutious can bo iutroduced, aud the expnision of ftir and moisture iuust be the first step in any effective process for preserving timher froin decay. 2. That water can ho expelled by a loug coutiuned application of heat, but air ouly by expausion iu a vacuum, and tho comhiaation of heat aud vacuum will eecure the wiost rapid expansion of both water and air, 3. That the preservative Hid must ho introdnced while tho cells nro empty, consequently the process must he carricd on in vacuo. 4. That no pressure, however great, applied externally to the swfaco of timber, eau forco any fluid iuto the interior so long as air or water is contuiued in the cclls. When air aloue is present there may bo penetration to a limited oxtent superficially, hut water is practically incomprossible. If, howover, the pressure is applied at one end ouly of a stick, as iu the Boucher‘e process, a fluid may be forced through and exude from the other cud. Groxootcan Success.—An iustance of complete suecese in scarch founded on geological indications has just ocenrred in Swedeu. An extensive coal bed of unusual depth iu Europe, aud of excelleut quality, has been discovered at Raus, in Schonen, by horing on the strength of evidence afforded hy the Kthologieal formation existiug there. At first the promises were uot satisfactorily fulfilled. Eleven strata of coal, indeod, were pierced hy going down 566 fect; but none of these were more than a foot or so in thickuess. Five feet further a bed was peuetrated over eight feet thick. Other horiugs prove tho oxistenco of coal of great extent. ‘he shares of the eompauy at ouce rose 700 per ceut ahove their par value,— Ex. Penuyian Annquiries.—The Geological musoum of the University of Rome has received from King Victor Emauuel a magnificent collection of Peruvian antiqnities, comprising a number of silver vases, eome extremely curious musical iustruments, a colored garment made from the hark of trees, and eome arrows and lancee. Theee last are notehed, ornamented with feathers, and have wooden heade, ehowiug that thoy helong to tho period when the use of iron was unknown. The whole of theso ariicles were found in a bed of guano, and evidently date from the earliest antiquity. Bomer Incrusration.— Expcrimente have been tried with favorable results, itis said, at Vienna on Bérenger’s plan of treating feed water for boilers. The water is softened hy a eolution of lime and forced through a particular kind of filter, which retains the generated precipitate. There is no uecessity for waitiug for tho settling of the precipitate. From 10 to 15 filters, each of 0.1 cubic metre capacity, eoften ahout 410 cubie metree of water per day. Ant Monuments.—M. Demctrio Salazaro, the Iuspector of the National Musenm, at Naples, is about to publish, in thirty parts, at fifteen shillings each, a seriee of photographs and ehromo-lithographe of the Art Monuments of Southern Italy, from the fourth to the thirteenth century. This is the first great attempt of its kind, and is intended to show the growth and development of Italian art from its earliest ries. Tue vacancy at-the British Geological Survey office, cansed by-the death of Sw Roderick I. Murchison, has heen filled up by the appointment of Professor Andrew Cromhie Rumsay, L.L.D., F.R.5., as director-general. Professor Ramsay hae for many years heen director of the Geological Survey and Profeesor of Geology in the Royal Sehool of Minee. A RemaRraBLe Miygrau.—A. Frenzel writes of a mineral,which forme in the winter in the Himmelfahrt mine at Freiberg, but vauishes in the spring, when the weather begine to grow warm, or damp, though it forms 334 metree helow the surface. An analysis gave Magnesia........... co eno canogee 16.53 Sulphuricacid.. WOU eae se oe Tux Spectroscopic Assoeiation of Italy is the title of a new society, the main object of which will be ‘‘to enrich science, by the aid of the spectroscope, with new discoveriee upon the physical constitution of the suu.”’ The first number of the Memoirs of the Society hae already been published. Xynownrre, which ie prepared by the action of nitric acid on woody fibre, is made into a sheeting or tissuo impermeable to water, which may be used as a suhstitute for india-rubber in the manufacture of all water-proof articlee. Repeaten spectroscopie measurements made last year by Professors Zollner and Vogel, in Germany, show that the velocity of rotation of the sun on its own axie is at the rate of six hundred and sixty miles an hour. Cane-suGAR when exposed to light in sealed tubee ie conyerted into grape-sugar or glucose. The eolution should be os concentrated ae possible. MecHaN ICAL Progress Economy of the Hot Blast, The first practical application of tho hot blast was mado iu 1828 or 1829 by J. B. Neilson, an Englishmau. Mr. N. and his colleaynes after determining the great value of tho invention for smelting ores, expeeted to seo it generally employed for all furnace operations; but the result has been that practically, it is almost exclusively confined to smelting the orcs of iron, Tho earliest carefully recorded experiments with tho hot hlust wero made at tho Clydo Iron

works, with the following result:— Forthoyonrecmtcressses+s. 1829 1831 3833 ‘Temporatary of blast. Cold ahr EF, Gl2*F. Coal used per ton of i: As coke. As coke. In raw stato. For fusion, owt. hs St 40 For hvating air, raw coal.. nil For blowing onginus, coal. 20 153 8 n 59 wy 7 From this it would appear that heating the air with 5 ewt. of coal had saved 47 ewt. of fnel in the furnace, and 8 evwt. similarly applied had beeu followed with au ecouomy of 93 ewt., or ahove 69 per cent. Besides this advautage the mako wae iucreased by more than one-third, and a blowiug eugine, which only supplied three furuaccs with cold blast, was equal to four when the air wae heated. The iron trade hesitated somewhat in creditthat the heat generated from 8 cwt. of fuel burnt outside the furnace, should be able to perform the duty of o very much larger weight burnt inside. Some writers on tho metallurgy of irou, wheu speakiug of the advantages of Neilson’s system, have not perhaps beeu sufficiently careful in drawiug a distiuction betwcon the saving directly due to ite application and that arising iu a collateral manner from its use. Looking at the question, however, in its commercial sense, the figures and lauguage quoted from the work of Dufrenoy justified the character he gave to it. Puddling Steel Rails. The Flushing and North Side Railway Company with its leased roads will have laid, hy the let of July ucxt, 40 miles of oteel track. The rails are of puddled oteel, with partly iron flangee and vertically piled. . The advantages claimed for these rails are:— perfect safety agaiust breaking, nota single rail of this kind haviug been broken duriug twelve years’ use in Germany and four years use in this conntry, greater strength and enduranec than can he obtaiued from steel-capped raile. The valuo of the worn-out puddled-steel rails is higher in proportion to first cost than that of cast-eteel raile, or iron rails with cast-steel caps, which cannot be re-rolled, but must be recast. The only disadvautage of the pnddled-steel rails is that a percentage of them may give out in the weld after a wear ahout equal to that of the life of three common iron rails. Thisis only a disadvantage in comparison to full steel or ingot rails, which have no welds, and therefore cannot failin the same manner. Setting aeide the greater safety of the welded steel rails, the question of economy in the use of either chicfly depends ou their respective first cost, on their wearing qualities, and on their market value as scrap when worn out. The solutiou of this question will depend more or less on the individual experience of the consumers, especially of those who have tried the different kinds of steel rails. ° Lele RarinoapD y Improvement.—A Pennsylvauia engineer, named Wilder, has recently hit upon an idea which, if carried out as it deserves to be, will do much toward increasing tho efficiency and enhancing the economy of railroads. It providee for the laying of two narrow gauge tracks, eide by side, with a epace between the inner raile equal to the ordinary gauge of four feet eight inches. Thus three possible gauges will be furnished on the same line, all of which it is proposed to use. Tor freight, the narrow gauge will be ueed at a safe rate of specd, while for passenger travel, and a high rate of speed, the broad gauge will be used, the cars being mounted on four lines of wheels. This, he contends, will preveut oecillatiou, thereby inereasing safety. He calculates by this system, and the increased weight of engines, it will permit of a rate of speed being attained ae high as a hundred miles an hour. No doubt a greatly iucreased speed may be attained by eueh a device, hut when a train of cars is made to trayel a hundred miles an hour, the material of which they are constructed and their manner of coustruction must be somewhat modified from their present material and form. Punntine py PetroteuM.—It ie asserted by the French technical journals that the experiment of using petroleum as fuelin the puddling furnace which has been in progress iu a large iron producing estahlishment during the past three months, has proved itself to be vory succeseful. In poiut of couvenience, efficiencyand in the euperior qnality of the iron prodnccd, it is asserted that petroleum affords the best fuel that has yet beeu employed. Burnt Iron and Steel. W. M. Williams has given the result of some iuquiries into the causes of this phenomeuon, to the Chemical Society of London. After some remarks upou the physical characteristics of iron and steel eo damaged, he assorta that he fonnd in all the samples of hurnt iron which ho has subjected to examination, particles of hlack oxide more or less abuudantly distributed throughout the mass. Theso are, however, absent in burnt steel, The method which he suggests of quickly detectiug such damage, is to tako a sinall quantity of fresh borings or filings from the subjected metal, cover them with diInted nitrie acid. As tho iron diseolves, the free oxide separates and remains suspeuded in the liquid, rendering it dark in color. These particles shortly disappear, aud are thus to be distinguished from separated carbon. No such discoloration tukce place with good iron. The cause of the hurning of iron he explsins as follows: As soon as tho small quantity of carbon is removed from tho heated mass hy oxidation, this procees exteuds to the iron itself— not ouly upon the surfaco, but into the interior. The higher tho temperaturo, and the longer the exposure, the greater is the quantity of carhon necessary to protect the iron. The best iron is that iu which carbon is bronght to tho lowest possible proportion, without oxidation of the iron. Burnt steel the author considers to be steel which has, by reheating, lost some of its carhon by oxidation, and by suddeu sohdification has had the resulting carbonic oxide imprisoned iu theinterior of its mass, The well known permeahility of irou for certain gaeee renders snch a proccss not difficult to understand. The structure and properties of “ burnt iron and etcel,’’ are therefore ‘‘ caused by the presence of intermingled particles of combustion products breaking the continuity of the metal. ‘The carbon is hurnt in the case of the hurut steel, the iron itself in the hurnt iron. Tue TurnIne PRopeLLer.—As a gun recoils when fired, or ae the progress of a rocket is kept np by the recoil arising from the efflux of the gases geuerated hy the ignition of the compositiou with which the rocket is filled, eo the progrees of a veeeel driven by the turbiue propeller ie kept up hy the recoil arising from the efflux in a eternward direction of a stream of water, kept up by the action of a contrifugal pump or turbine, driven by a steam engine, drawing water from the sea and dischargiug it sternwards, in a continuous stream, through a bent pipe or nozzle, at a high velocity, The turbine propeller was iuvented eome years ago, and attracted snfficient attention to secure a competitive trial by the British Government in 1867, with ecrew prepellers, Although the turbine did not equal (although not much behind) the screw, yet its performance at so early a stage cannot but he considered as very promising. Mr. A. Murray hss lately brought up the subject again in the Jour. 2. U.S. £, and urges further triale and inveetigations. It ie claimed that the turbine affords a higher per cent. of utilized power than the paddle or screw, which laet, all admit, lose a large amount of power, say 40 to 50 percent. at least, while centrifngal pumps of 40 to 50 horsepower, for raising water, have been found to utilize even as high ae 80 per cent., varying from that dowu to 50. But to determine this point satisfactorily further experiments are needed. Other pointe of superiority over the ecrew or paddle wheel claimed for the turhine are: the power of rapidly etopping the way of a vessel; great power over a heavy leak; freedom from the chance of internal injury or of fonling; nitility when the vessel is being driven by sails at the rate of 10 knots or more, (when the paddle or screw would be of little or no service, ) thus obtaining a greater speed than ever yet realized on the ocean; nesistance rendered to the veesel’s steerage; not being affected by the pitching or rolling of the vessel; nou-interference with any desired form of the ship for insuring good sailing properties; facility of bringing into action or discontinuing its nse, ete. Pressune IN Steam Borers.—The question as to whether the pressure in asteam boiler was equal or different at top and hottom, concerning which their eeeme to be eome difference of opinion amongst engiueers—though it is difficult, from the eimpKcity of the facts involved in considering the question, to see how a differeuce of opinion should exist—has neverthcless been experimentally determined by the Messrs. Hunter, at their establishment in this city. Au elbow was attached to the end of the blow-off pipe which eutered the mud-drum; into this a plng was screwed, and tapped to receive a half-inch pipe; to this a steam gange was attached and the cock opened. On comparing the indications of the ganges attached at top of boiler and to the top of drum, ae above deecribed, it wae fonnd that the pressure was greatest at the bottom, by a pound and a half, proving, as might readily have been predicted, that the pressure upon the bottom ofa boiler ie equal to the eteam proseure indicated above, plus the weight of a water column eqnal in hight to the difference in level hetween drum and surface of water in boiler, and in diameter to that actiug on the gauge.—Jour. Franklin Institute. Up to 1870 there were seventeen steel works in Great Britain. There are now nine steeltail mills in the United States, while two othere are building at Chicago and Springfield, Ill., and four others are projected at St. Louis, Milwaukee, Omaha, and two on the line of the Pacific Railroad.