Volume 35 (1877) (426 pages)

August #8, 1877.] MINING AND SCIENTIFIC PRESS 99 MecHanicat ey) Cd , ROGRESS, eS How a Brooch is Made. The jeweler’s art is one into which workmen in other erafta get but littlo insight. We havo been interested in reading an articlo written for the Polytechnic Review by Herman T. Wolf, on the practices of the manufacturing of jowclry, and wo quoto therefrom an accouut of the steps taken by the workmen to make a brooch, when twe pearls aad thirty-one diamonds, with necessary tools and materials, are furnished : The main points to be kept in viow are to show off the stones to the beat advantage, and, if they are perfect, to kave no more gold than is absolutely uccessary, so that their effect may not be marred. It will first be necessary for him to make the “settings” for the stones, For this purpose, he worka ont a piece of gold about three-sixteenths inch high and at the the bottom one-sixteenth inch thick. From this he hends the boxes for tho pearl and five upper stones. Of these he makes the scttings by scalloping them out, first from tho top and then from the bottom, and thcu solders the small frame under them fora finish. (The solder consists of gold of a lower grade, which, melting at a feos Hee, firmly unites the parts between which it flows.) Having dono this, he uoxt makes the ‘‘cluster.” Intoa pieco of gold aboutan iuch in diameter, and threo-cighths inch thick, he makes holea just so much smaller than tho stones as to allow setting. Next the outer edgo of the ‘‘cluster”’ is finished like a setting, aad acalloped ‘‘bizzle” and frame soldered under. Now he makes the mounting for the other diamonds, A frame like the contour is made, which is scalloped, and upon which a thick plate is soldered and into which the diamonds are afterwards carefully mounted. The ’* knife edgo wire” is nade from gold hent into the shape of the design and filed sharp at the top. Tho gold hand forthe enamel is so arranged that it can be secured after all the rest is finished, iu order that tbe entire work need not go through the enameling fire. The small shot aro made by melting particles of gold, which therehy assume a globular form and retain it upon cooling, And now all is ready for construction. This is done by placing the pieces upon a flat char. coal, applying borax and small pieces of finely cut solder to tho places where the pieces are to bo joined, and heating them by means of a gas jet and hlow pipe till the solder “runs.” After all the soldering has been completed the work is boiled in dilute sulphuric acid, to elean it of oxide and borax, carefully trued with files, all the fileemarks removed with a scraper and eimery paper, and the task is ready for polishing. This is done first by means of tripoli and oil, and afterward with rouge and alcohol. By means of gravers, rests for the stones are cut inte the settings, and the gold securely pressed over their edges, and the brooch is completed. In the manufacture of the so-called “ Etrusean ware,” the delicate wire ornamcntations aro all bent into shape first and then soldered onthe jewelry according to the design. The neat fine-gold-like appearance is produccd by immersing the jewelry for a few minutes in a boiling solution of muriatic acid three parts, saltpetre two parts, salt one part. This eats ont the alloy and brings the fine gold to the surface. Since it attacks copper more readily than silver, a finer effect is produced by alloying the gold with an excess of copper. A very praiseworthy attempt has of late been made to reproduce flowers in their natural colors and details; but, due to the amount of labor necessarily expended npon them, they command higher prices than is generally invested by the majority of purchasers. It is sincerely to he wished that they may gain the approval of the public. By the combination of platinum with red gold for seals, rings, and chains, mauy novel and very effective designs have beeu produceil. In making plain linked watch chains, the links are wrapped about a mandrel having the exact shape that they are expected to assnme. They are then cut apart at one end, hung together, and the joints soldered. Oxidized silver, so much in vogue a few years ago, is made hy treating silver with ammonic or potassic sulphide. Enamel is a fusible glass which is melted into cavities in the gold, made by cutting to some little depth with a graver. Niello, lately fallen almost entirely into disuse, is a hlack composition of gold, silver, eopper and lead heated together, and melted into a design prepared in the same manner as for enamel. The metal is then scraped and burnished, and produces the effect of a drawing in black upon a gold or silver ground. : Coupling Cars. The danger and disaster which always attend coupling cars by the existing-method has given inventors thought of ways by which the joint could be made without the insertion of the brakeman’s body between the moving cars. We read inan English exchange of the following device to meet the need: The object which has heen kept in view in this invention has been to save ‘‘life” and “time,” with as little cost to the owners of trucks, etc., as possible, and the principle which has been decided upon here is, that the couplings shall remain as they are with the ordinary link or chain, and the lstter to be handled from the sides of the cars, so dispeusing with the necessity of a man passing between the trucks for coupling or uncoupling urposes, To effect this the end link or couping link of each chain is gripped by a strong steel spring, whose other extremity is fixed toa horizontal bar, held loose by two eyes at each end of the truck. This bar hasacurved handle at one of its ends, by means of which the forementioned spring allows itself to be raised or lowered accordiug to requirement; since the end or connecting link is also fastened to the spring. it follows that by turning tho handle just named the conpling chain will also be raised or lowered aveording to the direction iu which the handle is Binet Owing, however, to the horizontal bar being also able to move laterally, it follows that by pulling or drawing the bar handle either towards or from you, the eud connectiug link will be clear of the hook, or ina vertical line with it. Consequently, tho lefthaud car coupled to the right, supposing it were required to uncouple that ear, all that is required would be for the shunter to seize the har handle and turn it to the right until the end connecting link had been raised ahove the hook, wheu he would pull the handle and har towards him, so as to get the link frec of the hook in its downward fall Having done this, he would lot loose the handle, when tho coupling chain of the left-hand car would assnme a similar position to that of tho right-haud car; Pltacally the converse of these operations would secure the re-coupling of the two cars, Rivets or Welds in Boilers. We havo formerly spoken of an investigation in progress as to the valne of welded boilcr shells. The verdict in the present case is in favor of riveted joints. In his last quarterly report, just issued, Mr. Lavington E. Heehe, tho chicf engineer of the Manchester Steam Users’ Association, makes the following remarks about welded boilers: One of the explosions referred to in the report sprung from a boiler welded at all the joints instead of being riveted. The association has always regardcd welded boilers with suspicion, and, as such boilers are being increasingly introduced for crano and portable purposes, it appeared desirahle to call attention to the untrustworthiness of such a mode of construction. When a hoiler is riveted, the strength of the seams can be known with considerable accuracy. The amount of metal lost hy the rivet holes can be calculated and allowed for, and what remains, provided that the work he put together with ordinary care, can be trusted. Such, however, is not the case with a welded joint. It is impeas to see into the heart of the weld and to now whether it is sound or not. The parts may he united simply at the surface, skiu deep, and no further, and though such joints ma: withstand the quiet strain of a hydranlic test they may yet fail in actual work. As soon as steain is got up in a boiler, it expands and contracts from alternate heating and cooling, and the flat surfaces breathe in and out according as the pressure falls or rises, This working of the parts soon finds out the weak places, and though a small crack may be all that is started at a weld in the first instance, as the working goes on the crack extends and grows from a small one to a large one till a serious rent results. Welds are, therefore, untrustworthy for those parts of a boiler in which the pressure of the steam acts internally and tends to tear the welds asunder, but welding may be safely adopted for the internal Hues on which the pressure of the steam acts externally and tends to keep the parts together. Boilers welded throughout, therefore, are not to he trusted, and the members are recommended to adopt those made with riveted joints instead. Iron Pavine.—By permission of the Commissioners of Sewers of the city of London, a portion of the new wood paving in Beech street has heen charged with iron (three cwt. to the square yard) by way of experiment. The object is to increase the durability of wood and preserve and protect it from heavy racking trate, and to test the practicability of securing emall hlocks of iron without framework, and so +s to deaden the uoise and counteract the other disadvantages of metal, as hitherto applied. Tbe ordinary wood paving blocks are beveled hy machinery on the upper and lower edges, and between each row is laid a row of cast-iron blocks of double-wedged scction thicker at the npper and lower surfaces than in the center, so as to fit niechanically hetween the beveled wood blocks, which on section are thicker in the center than at the npper ‘and lower surfaces. The iron hlocks weigh 16 pounds each, are rounded and serrated on surface for foothold, and perforated for grouting material, and are imhedded in sand on the ordinary concrete bed. The designer and patentee, Mr. Dennison (a London architect), states that the cost, though heavy at first, will not in the long run exceed either granite, wood or asphalte. Hoop Iron ror Crinines.—Mr. R. Leigh, England, bas taken out a patent for applying hoops to ceilings. The hoops are used in single lengths reaching hetween the joists like wooden laths, or they are first formed into squares or sheets, interlocked like wicker-work, or interlaced with wire or other material, and then nailed to the joists. The hoop iron is made of curved sections to increase its strength, wx ~ SCIENTIFIC ‘PRoGress. Electric Sparks as Bedfellows. Evrrors Press:—I havo several times this summer noticed a phenomenon, new in my experience, no account of which have 1 ever en in print, {[t is the oleetrie spark and light from the cotton shect and hedspread, When T ealled attention to it and showed the light to some fricnds in the eveuing, my landlady remarked that she hsd several times becn startled hy the crackliug sounds as the beds were stripped in the ‘‘morning making up.” Sho did not know how to acconnt for it. She eompared the sound to the hitting together of buttons ona string. But my practiced ear at onco detected the cece spark. TI first saw the light as 1 was gathering the sheet about my arms. Shaking and rubbing were tried frequently, hut not always producing light. Ono good experiment is to draw the hack of the finger nails quickly along the shect ur spread. Streaks of phosphorescent light follow each finger. The sparkle and light aro frequently shown on stripping the spread from the blanket or comfort. t is a well-known fact that dry silks or woolens will spark on a dry, frosty night, hut it was a now source of amusement to mo to sco a cotton sheet or spread sparkle like a cat’s back. 1 presume that this effect can he noticed anywhere, away from tho coast fogs, wheuever the thermometer rises abovo 90° during the day, — Jeicn Arrn, Auhurn, Cal. Prize for a New Sugar Extraction Pro cess, The General Council of Guadaloupe offers a prize of $20,000 to the inventor of a new process of extraction of juice of sugar cane or of sugar fabrication. This prize will be given to whoever obtains from the cane a yield of I+ per cent. sugar. The cost of application of the new process should not exceed 40 per cent. of the value realized. Experiments will continue four years, terminating June 30th, 1880, and will take place at Guadaloupe under the auspices of a government commission, All cost of transport, etc., must he defrayed by competitors, and applications, etc., must be addressed to the Director of the Interior, Basse Terre, Guadaloupe. The Setentifie American says: “The caae raised at Guadaloupe contains 18 per cent. sngar. Hitherto a percentage of 9.4 on an average has been obtained hy the ordinary factory machinery. Recently M. Ducharsaing has invented an imbibition process, tho details of which are not given in the legislative document before fis, hut which, it appears, increased the yield from 9.4 to 11.64 per cent. The inventor himself claims a greater advautage, YJand insists that the additional percentage of gain by his process is 2.33 iustead of 1.64. Even on the lower estimate, M. Ducharsaing’s invention was deemed sufficiently impoitant to warrant the awarding to him of a $20,000 prize. Tbe present preminm is therefore a second one, and the winner is called upon to make a still further improvement. The experiments must be conducted on at least 660,000 Ibs. of cane.” Something New about Oxygen. Recent investigations, says the Journal of Chemistry, have disclosed the singular fact that oxygen under high pressure rapidly destroys all living beings and organic compounds. varied phenomena of fermentation, in which the the chemical action depends upon the presence of living organisms, are completely arrested by the action of compressed oxygen, even if exerted for only a brief time; while fermentations due to dissolved matter, like diastase, perfectly resist the influence. M. Bert, to whom this curious discovery is due, has found a practical application of it in the field of physioloigeal research, The ripening of fruits is arrested by exposure to compressed oxygen, and hence it must arise from cellular evolution. The poison of the scorpion, on the other hand, whether liquid, or dried and redissolved in water, entirely resists the action of the eompressed gas. Such poisons evidently owe their power to chemical compounds akin to the vegetable alkaloids. Fresh vaccine mattcr, subjected for more than a week to oxygen under a pressure equal to fifty atmospheres, retained its virtue; from which it would appear that the active principal in vaccine matter is not certain living organisms or cells, as some have supposed. The virus of glanders, after similar treatment, quickly infected horses inoculated with it; and carhuncular blood, thongh freed from bacteria, was found to retain its dangerous properties after the same test. These must, therefore, he put in the same class with vaccine matter. If these results are contirmed by further investigations, the discovery is certainly a most important one, and will lead to the settlement of many disputed questions in physiological chemistry. . -) 2. eee A New Baromerer.—aA sensitive new batrometer has heen hrought hefore the Physical Society of St. Petershurg hy M. Gontkowski. The Knglish Mechanic says: In this apparatus a mercury column of invariable hight equilihrates almost the whole of the atmospheric pressure, and a column of petroleum oil completes the barometric colnamn. The barometer has at its All. each ear. upper end an enlargement, in which is fixed, with a plug, another tube 1.40m. in length. The two ends of this latter tuhe have been closed st the lamp, but a lateral slit is made in the part introduced into the enlargement of the first tuhe. This slit is covered with bladder skin, previously treated with benzine, and coated with a solution of gelatine in glycerine; it is tirmly attached about the tube by its two edges. Thus tbe hladder forms a partition, at ouce flexible and imperineable, between the mercury filling the first tube and its enlargementas far as the plug and the petroleum of the second. Experiments have shown that the resistance of this partition to flexure produces a loss of pressure less thsu 1-60thm. of mercury. The petrelenm is 15 times lighter than mercury, and does not emit of vapor of appreciablo tension at the ordiuary temperature, Testing Thermometers, Thvuso who are fsmiliar with English thermometers know that manufacturers offer for a small advance to furnish au instrument the accuracy of which is verified by the government otticer at Kew ohservatory. At the late meeting of the Royal Society, this officer gave some account of his work. The uumber of thermometers scut to be tested is increasing, there heing now some 3,000 annually. For greater accuracy and for saving timc, Mr. Galton devised the present apparatus. The thermometer frame is circular and will hold 40 at a time; the water iuto whicb they are placcd is in a cylinder of stout copper, two feet two inches highand four feet in diameter, and in the side is a slit one foot ten inches long and four and three-fourths iuches wide, which is glazcd, and through which the thermometers are read as they are passed round, The cylinder isan outer wooden case, and hetween the two is a packing of sawdust. The outer ease is also provided with a glazed slit to read through. The lid of the case has also a covering of sawdust in kamptulicon. The object of these precautions is to prevent the escape of heat aud maintain a fixed temperature during the testing. The regulation of the heating of the water before testing is effected by a eonnected coil of tubing at the side and a cluster of Bunsen burners. So well does this apparatus act that a long series of experiments made at different temperatures shows a variation of bnt a part of a degree, which is represented hy a figure in the second decimal place. It is still found to be impossihle to obviate differences of temperatures at different levels. This, however, is a great improvement on the old method. It takes only about four minutes to read a set. Telephonic Improvements. Prof. Bell, the inventor of the telephoue, lately married, and at the wedding reception there was an exhibition of the new invention. He has gone to Europe to experiment with the cables between England, France and Germany, prior to attacking the Atlantic lines, The latest form of Prof. Bell’s soleus says the Boston Transcript, has the whole machine, hoth for speaking into and hearing out of, reduced to the size and shape of an ordinary door knob. A shiny black piece of thin iron, the size of a three-cent piece, let into the surface of the mahogany knob, is what does the talking. Concealed in the wooden stem of the knob 1s the magnet, from which proceed the silk-covered wires which carry the viva voce message. There are two knobs, so that two may listen to a reply, or a single listener increase the amount of voice heard by holding one of the knobs to A common electric bell, operated by the saine wire, to call, completes the equipment. It is still wonderful, notwithstanding the increasing commonness of the telephone, to hear a superintendent or head of a house in the city makiug inquiries and giving orders to his foreman out at the mill or factory, 20 miles away, and receiving equally detailed answers and inquiries for instrnction in returns, such as coukl hardly have heen transmitted by the ‘*niano-playing” telegraph, so costly in time would conferences of that length have been. So large has the demand hecome, that the price for the use of the telephone, which the patentee does not sell, has just gone up from $10 to $30 a year. It seems to us, however, that the perfection of this most beautiful and important invention has yet further to go. Execrric lubumination ar Sra.—The English iron-clad Alexandra, supposed to be the finest afloat, has an electric lamp attached to its foremast. The Polytechnic says the cost of the lamp and the necessary electric appartus was £1,000, a sun which seems enormous at first, hut does not appear so very extravagant when we reflect that it is purposed to protecta ship the insurance of which amounts to £600,000. The electric light serves two purposes; first, as a beacon light to point out dangerous reefs of rock or sand; and second, as a protection against torpedo boats. The light is thrown out from all sides of the lamp, and illuminates such a large surface of the water that it would bealmost impossihle for a torpedo boat to aproach without detection; especially as the Hent falling upon the smoke would suffer such refraction as to make the hoat’s existence even more apparent than if the light had hut fallen onits surface, This latter function of the electric light is very important, since ships have heretofore found no protection against the attacks of the torpedo boat.

August #8, 1877.] MINING AND SCIENTIFIC PRESS 99 MecHanicat ey) Cd , ROGRESS, eS How a Brooch is Made. The jeweler’s art is one into which workmen in other erafta get but littlo insight. We havo been interested in reading an articlo written for the Polytechnic Review by Herman T. Wolf, on the practices of the manufacturing of jowclry, and wo quoto therefrom an accouut of the steps taken by the workmen to make a brooch, when twe pearls aad thirty-one diamonds, with necessary tools and materials, are furnished : The main points to be kept in viow are to show off the stones to the beat advantage, and, if they are perfect, to kave no more gold than is absolutely uccessary, so that their effect may not be marred. It will first be necessary for him to make the “settings” for the stones, For this purpose, he worka ont a piece of gold about three-sixteenths inch high and at the the bottom one-sixteenth inch thick. From this he hends the boxes for tho pearl and five upper stones. Of these he makes the scttings by scalloping them out, first from tho top and then from the bottom, and thcu solders the small frame under them fora finish. (The solder consists of gold of a lower grade, which, melting at a feos Hee, firmly unites the parts between which it flows.) Having dono this, he uoxt makes the ‘‘cluster.” Intoa pieco of gold aboutan iuch in diameter, and threo-cighths inch thick, he makes holea just so much smaller than tho stones as to allow setting. Next the outer edgo of the ‘‘cluster”’ is finished like a setting, aad acalloped ‘‘bizzle” and frame soldered under. Now he makes the mounting for the other diamonds, A frame like the contour is made, which is scalloped, and upon which a thick plate is soldered and into which the diamonds are afterwards carefully mounted. The ’* knife edgo wire” is nade from gold hent into the shape of the design and filed sharp at the top. Tho gold hand forthe enamel is so arranged that it can be secured after all the rest is finished, iu order that tbe entire work need not go through the enameling fire. The small shot aro made by melting particles of gold, which therehy assume a globular form and retain it upon cooling, And now all is ready for construction. This is done by placing the pieces upon a flat char. coal, applying borax and small pieces of finely cut solder to tho places where the pieces are to bo joined, and heating them by means of a gas jet and hlow pipe till the solder “runs.” After all the soldering has been completed the work is boiled in dilute sulphuric acid, to elean it of oxide and borax, carefully trued with files, all the fileemarks removed with a scraper and eimery paper, and the task is ready for polishing. This is done first by means of tripoli and oil, and afterward with rouge and alcohol. By means of gravers, rests for the stones are cut inte the settings, and the gold securely pressed over their edges, and the brooch is completed. In the manufacture of the so-called “ Etrusean ware,” the delicate wire ornamcntations aro all bent into shape first and then soldered onthe jewelry according to the design. The neat fine-gold-like appearance is produccd by immersing the jewelry for a few minutes in a boiling solution of muriatic acid three parts, saltpetre two parts, salt one part. This eats ont the alloy and brings the fine gold to the surface. Since it attacks copper more readily than silver, a finer effect is produced by alloying the gold with an excess of copper. A very praiseworthy attempt has of late been made to reproduce flowers in their natural colors and details; but, due to the amount of labor necessarily expended npon them, they command higher prices than is generally invested by the majority of purchasers. It is sincerely to he wished that they may gain the approval of the public. By the combination of platinum with red gold for seals, rings, and chains, mauy novel and very effective designs have beeu produceil. In making plain linked watch chains, the links are wrapped about a mandrel having the exact shape that they are expected to assnme. They are then cut apart at one end, hung together, and the joints soldered. Oxidized silver, so much in vogue a few years ago, is made hy treating silver with ammonic or potassic sulphide. Enamel is a fusible glass which is melted into cavities in the gold, made by cutting to some little depth with a graver. Niello, lately fallen almost entirely into disuse, is a hlack composition of gold, silver, eopper and lead heated together, and melted into a design prepared in the same manner as for enamel. The metal is then scraped and burnished, and produces the effect of a drawing in black upon a gold or silver ground. : Coupling Cars. The danger and disaster which always attend coupling cars by the existing-method has given inventors thought of ways by which the joint could be made without the insertion of the brakeman’s body between the moving cars. We read inan English exchange of the following device to meet the need: The object which has heen kept in view in this invention has been to save ‘‘life” and “time,” with as little cost to the owners of trucks, etc., as possible, and the principle which has been decided upon here is, that the couplings shall remain as they are with the ordinary link or chain, and the lstter to be handled from the sides of the cars, so dispeusing with the necessity of a man passing between the trucks for coupling or uncoupling urposes, To effect this the end link or couping link of each chain is gripped by a strong steel spring, whose other extremity is fixed toa horizontal bar, held loose by two eyes at each end of the truck. This bar hasacurved handle at one of its ends, by means of which the forementioned spring allows itself to be raised or lowered accordiug to requirement; since the end or connecting link is also fastened to the spring. it follows that by turning tho handle just named the conpling chain will also be raised or lowered aveording to the direction iu which the handle is Binet Owing, however, to the horizontal bar being also able to move laterally, it follows that by pulling or drawing the bar handle either towards or from you, the eud connectiug link will be clear of the hook, or ina vertical line with it. Consequently, tho lefthaud car coupled to the right, supposing it were required to uncouple that ear, all that is required would be for the shunter to seize the har handle and turn it to the right until the end connecting link had been raised ahove the hook, wheu he would pull the handle and har towards him, so as to get the link frec of the hook in its downward fall Having done this, he would lot loose the handle, when tho coupling chain of the left-hand car would assnme a similar position to that of tho right-haud car; Pltacally the converse of these operations would secure the re-coupling of the two cars, Rivets or Welds in Boilers. We havo formerly spoken of an investigation in progress as to the valne of welded boilcr shells. The verdict in the present case is in favor of riveted joints. In his last quarterly report, just issued, Mr. Lavington E. Heehe, tho chicf engineer of the Manchester Steam Users’ Association, makes the following remarks about welded boilers: One of the explosions referred to in the report sprung from a boiler welded at all the joints instead of being riveted. The association has always regardcd welded boilers with suspicion, and, as such boilers are being increasingly introduced for crano and portable purposes, it appeared desirahle to call attention to the untrustworthiness of such a mode of construction. When a hoiler is riveted, the strength of the seams can be known with considerable accuracy. The amount of metal lost hy the rivet holes can be calculated and allowed for, and what remains, provided that the work he put together with ordinary care, can be trusted. Such, however, is not the case with a welded joint. It is impeas to see into the heart of the weld and to now whether it is sound or not. The parts may he united simply at the surface, skiu deep, and no further, and though such joints ma: withstand the quiet strain of a hydranlic test they may yet fail in actual work. As soon as steain is got up in a boiler, it expands and contracts from alternate heating and cooling, and the flat surfaces breathe in and out according as the pressure falls or rises, This working of the parts soon finds out the weak places, and though a small crack may be all that is started at a weld in the first instance, as the working goes on the crack extends and grows from a small one to a large one till a serious rent results. Welds are, therefore, untrustworthy for those parts of a boiler in which the pressure of the steam acts internally and tends to tear the welds asunder, but welding may be safely adopted for the internal Hues on which the pressure of the steam acts externally and tends to keep the parts together. Boilers welded throughout, therefore, are not to he trusted, and the members are recommended to adopt those made with riveted joints instead. Iron Pavine.—By permission of the Commissioners of Sewers of the city of London, a portion of the new wood paving in Beech street has heen charged with iron (three cwt. to the square yard) by way of experiment. The object is to increase the durability of wood and preserve and protect it from heavy racking trate, and to test the practicability of securing emall hlocks of iron without framework, and so +s to deaden the uoise and counteract the other disadvantages of metal, as hitherto applied. Tbe ordinary wood paving blocks are beveled hy machinery on the upper and lower edges, and between each row is laid a row of cast-iron blocks of double-wedged scction thicker at the npper and lower surfaces than in the center, so as to fit niechanically hetween the beveled wood blocks, which on section are thicker in the center than at the npper ‘and lower surfaces. The iron hlocks weigh 16 pounds each, are rounded and serrated on surface for foothold, and perforated for grouting material, and are imhedded in sand on the ordinary concrete bed.

The designer and patentee, Mr. Dennison (a London architect), states that the cost, though heavy at first, will not in the long run exceed either granite, wood or asphalte. Hoop Iron ror Crinines.—Mr. R. Leigh, England, bas taken out a patent for applying hoops to ceilings. The hoops are used in single lengths reaching hetween the joists like wooden laths, or they are first formed into squares or sheets, interlocked like wicker-work, or interlaced with wire or other material, and then nailed to the joists. The hoop iron is made of curved sections to increase its strength, wx ~ SCIENTIFIC ‘PRoGress. Electric Sparks as Bedfellows. Evrrors Press:—I havo several times this summer noticed a phenomenon, new in my experience, no account of which have 1 ever en in print, {[t is the oleetrie spark and light from the cotton shect and hedspread, When T ealled attention to it and showed the light to some fricnds in the eveuing, my landlady remarked that she hsd several times becn startled hy the crackliug sounds as the beds were stripped in the ‘‘morning making up.” Sho did not know how to acconnt for it. She eompared the sound to the hitting together of buttons ona string. But my practiced ear at onco detected the cece spark. TI first saw the light as 1 was gathering the sheet about my arms. Shaking and rubbing were tried frequently, hut not always producing light. Ono good experiment is to draw the hack of the finger nails quickly along the shect ur spread. Streaks of phosphorescent light follow each finger. The sparkle and light aro frequently shown on stripping the spread from the blanket or comfort. t is a well-known fact that dry silks or woolens will spark on a dry, frosty night, hut it was a now source of amusement to mo to sco a cotton sheet or spread sparkle like a cat’s back. 1 presume that this effect can he noticed anywhere, away from tho coast fogs, wheuever the thermometer rises abovo 90° during the day, — Jeicn Arrn, Auhurn, Cal. Prize for a New Sugar Extraction Pro cess, The General Council of Guadaloupe offers a prize of $20,000 to the inventor of a new process of extraction of juice of sugar cane or of sugar fabrication. This prize will be given to whoever obtains from the cane a yield of I+ per cent. sugar. The cost of application of the new process should not exceed 40 per cent. of the value realized. Experiments will continue four years, terminating June 30th, 1880, and will take place at Guadaloupe under the auspices of a government commission, All cost of transport, etc., must he defrayed by competitors, and applications, etc., must be addressed to the Director of the Interior, Basse Terre, Guadaloupe. The Setentifie American says: “The caae raised at Guadaloupe contains 18 per cent. sngar. Hitherto a percentage of 9.4 on an average has been obtained hy the ordinary factory machinery. Recently M. Ducharsaing has invented an imbibition process, tho details of which are not given in the legislative document before fis, hut which, it appears, increased the yield from 9.4 to 11.64 per cent. The inventor himself claims a greater advautage, YJand insists that the additional percentage of gain by his process is 2.33 iustead of 1.64. Even on the lower estimate, M. Ducharsaing’s invention was deemed sufficiently impoitant to warrant the awarding to him of a $20,000 prize. Tbe present preminm is therefore a second one, and the winner is called upon to make a still further improvement. The experiments must be conducted on at least 660,000 Ibs. of cane.” Something New about Oxygen. Recent investigations, says the Journal of Chemistry, have disclosed the singular fact that oxygen under high pressure rapidly destroys all living beings and organic compounds. varied phenomena of fermentation, in which the the chemical action depends upon the presence of living organisms, are completely arrested by the action of compressed oxygen, even if exerted for only a brief time; while fermentations due to dissolved matter, like diastase, perfectly resist the influence. M. Bert, to whom this curious discovery is due, has found a practical application of it in the field of physioloigeal research, The ripening of fruits is arrested by exposure to compressed oxygen, and hence it must arise from cellular evolution. The poison of the scorpion, on the other hand, whether liquid, or dried and redissolved in water, entirely resists the action of the eompressed gas. Such poisons evidently owe their power to chemical compounds akin to the vegetable alkaloids. Fresh vaccine mattcr, subjected for more than a week to oxygen under a pressure equal to fifty atmospheres, retained its virtue; from which it would appear that the active principal in vaccine matter is not certain living organisms or cells, as some have supposed. The virus of glanders, after similar treatment, quickly infected horses inoculated with it; and carhuncular blood, thongh freed from bacteria, was found to retain its dangerous properties after the same test. These must, therefore, he put in the same class with vaccine matter. If these results are contirmed by further investigations, the discovery is certainly a most important one, and will lead to the settlement of many disputed questions in physiological chemistry. . -) 2. eee A New Baromerer.—aA sensitive new batrometer has heen hrought hefore the Physical Society of St. Petershurg hy M. Gontkowski. The Knglish Mechanic says: In this apparatus a mercury column of invariable hight equilihrates almost the whole of the atmospheric pressure, and a column of petroleum oil completes the barometric colnamn. The barometer has at its All. each ear. upper end an enlargement, in which is fixed, with a plug, another tube 1.40m. in length. The two ends of this latter tuhe have been closed st the lamp, but a lateral slit is made in the part introduced into the enlargement of the first tuhe. This slit is covered with bladder skin, previously treated with benzine, and coated with a solution of gelatine in glycerine; it is tirmly attached about the tube by its two edges. Thus tbe hladder forms a partition, at ouce flexible and imperineable, between the mercury filling the first tube and its enlargementas far as the plug and the petroleum of the second. Experiments have shown that the resistance of this partition to flexure produces a loss of pressure less thsu 1-60thm. of mercury. The petrelenm is 15 times lighter than mercury, and does not emit of vapor of appreciablo tension at the ordiuary temperature, Testing Thermometers, Thvuso who are fsmiliar with English thermometers know that manufacturers offer for a small advance to furnish au instrument the accuracy of which is verified by the government otticer at Kew ohservatory. At the late meeting of the Royal Society, this officer gave some account of his work. The uumber of thermometers scut to be tested is increasing, there heing now some 3,000 annually. For greater accuracy and for saving timc, Mr. Galton devised the present apparatus. The thermometer frame is circular and will hold 40 at a time; the water iuto whicb they are placcd is in a cylinder of stout copper, two feet two inches highand four feet in diameter, and in the side is a slit one foot ten inches long and four and three-fourths iuches wide, which is glazcd, and through which the thermometers are read as they are passed round, The cylinder isan outer wooden case, and hetween the two is a packing of sawdust. The outer ease is also provided with a glazed slit to read through. The lid of the case has also a covering of sawdust in kamptulicon. The object of these precautions is to prevent the escape of heat aud maintain a fixed temperature during the testing. The regulation of the heating of the water before testing is effected by a eonnected coil of tubing at the side and a cluster of Bunsen burners. So well does this apparatus act that a long series of experiments made at different temperatures shows a variation of bnt a part of a degree, which is represented hy a figure in the second decimal place. It is still found to be impossihle to obviate differences of temperatures at different levels. This, however, is a great improvement on the old method. It takes only about four minutes to read a set. Telephonic Improvements. Prof. Bell, the inventor of the telephoue, lately married, and at the wedding reception there was an exhibition of the new invention. He has gone to Europe to experiment with the cables between England, France and Germany, prior to attacking the Atlantic lines, The latest form of Prof. Bell’s soleus says the Boston Transcript, has the whole machine, hoth for speaking into and hearing out of, reduced to the size and shape of an ordinary door knob. A shiny black piece of thin iron, the size of a three-cent piece, let into the surface of the mahogany knob, is what does the talking. Concealed in the wooden stem of the knob 1s the magnet, from which proceed the silk-covered wires which carry the viva voce message. There are two knobs, so that two may listen to a reply, or a single listener increase the amount of voice heard by holding one of the knobs to A common electric bell, operated by the saine wire, to call, completes the equipment. It is still wonderful, notwithstanding the increasing commonness of the telephone, to hear a superintendent or head of a house in the city makiug inquiries and giving orders to his foreman out at the mill or factory, 20 miles away, and receiving equally detailed answers and inquiries for instrnction in returns, such as coukl hardly have heen transmitted by the ‘*niano-playing” telegraph, so costly in time would conferences of that length have been. So large has the demand hecome, that the price for the use of the telephone, which the patentee does not sell, has just gone up from $10 to $30 a year. It seems to us, however, that the perfection of this most beautiful and important invention has yet further to go. Execrric lubumination ar Sra.—The English iron-clad Alexandra, supposed to be the finest afloat, has an electric lamp attached to its foremast. The Polytechnic says the cost of the lamp and the necessary electric appartus was £1,000, a sun which seems enormous at first, hut does not appear so very extravagant when we reflect that it is purposed to protecta ship the insurance of which amounts to £600,000. The electric light serves two purposes; first, as a beacon light to point out dangerous reefs of rock or sand; and second, as a protection against torpedo boats. The light is thrown out from all sides of the lamp, and illuminates such a large surface of the water that it would bealmost impossihle for a torpedo boat to aproach without detection; especially as the Hent falling upon the smoke would suffer such refraction as to make the hoat’s existence even more apparent than if the light had hut fallen onits surface, This latter function of the electric light is very important, since ships have heretofore found no protection against the attacks of the torpedo boat.