Volume 39 (1879) (446 pages)

ly July 19, 1879.] 35 MINING AND SCIENTIFIC PRESS. CP ined yy Mecuanicat ‘PRoGREss. A Powerful Spectroscope. In the young science of spectroscopy, as in others, an important element of progress ia the improvement of iustruinents for dealing with the phenomeua presented, and many minds are engaged on this. A new spectroscope of remarkable power has just been brougbt to the notice of the French Academy by M. Thollon. Its ehief feature is the use of eulphide of carbon ptisms, which are closed laterally, not by plates with parallc} faces, hut by prisius of the form of Amici’s—i, e., having curved sides meeting at an angle, which, however, is much smaller than Amici’s prism, Tho rofringent angles of these prisms are in an opposito direction to that of the sulphide prism. ‘Two of these compound prisms are substitutsd by M. Tbollon for tho simple prisms in a spectroscope, which he formerly described to the academy. Without going into furthcr details, wo may eimply stato that an enormous dispersion is ohtainod; with a magnifying power of 15 to 20 times, the spectrum bae a length of 15 meters, ‘The angular distance of the D lines of sodium ie about 12’, whereas that produeed by M. Gassiot was only 3’ 6”. This instrumcnt should throw considerable light on the struoture of the spectrum, and M. Thollon has already noticed some intereetiny facts. The lines of sodium and magnesium present a dark nyclous passing into a nebulosity, which becomes gradually merged in the continuous spectrum. Many lines have heen split up, and all that have been thus resolved have been found to belong to two different snbstances. One of tbe hydrogen lines presents a nebulosity without a nucleus, M. Thollon remarks on, the magnificence of the spectrum of carbou from the electric arc, observed with the new instrument. Tho apectra of iron, copper, and magnesium in the same arc were also seen witb admirable clearness and brilliancy. These new epectroscopea have heen constructed for M. Tbollon by the able optician, M. Laurent. Tue Spityu MopHONE.—Tbe ephygmophone is a recent application of tbe telephone, and is an instrnment invented by Dr. Richardson, by which the movemente of the arterial pulse are transmitted iuto loud telepbonic eounds, In this apparatus the needle of a Pound’s sphygmograph is mado to traverso a metal or carbon plate which is connected with the zine pole of a Leclanche cell. To the metal etem of the sphygmograph is then attached one terminal of the telephone, the other terminal of the telepbone being connected with the opposite pole of the battery. When the whole is ready, tbe ephygmograpb is brought into use as if a tracing were about to be taken, and when the pulsation of the needle from the pulse-strokes is secured, the needle, which previously was beld back, is thrown over so as to make its point just touch the metal or carbon plate, and to traverse the plate to and fro witb each pulsation. In so moving, three sounds—one long and two ebort —are given from the telephone, which sounds correspond with the first, second and third events of sphygmographic reading. In fact, the pulse talks telephonically, and so loudly that when two cells are used the sounds can he beard by an audience of several hundred people. By extending the tolepbone wires, the sounds can also be conveyed long distances, so tbat a physician in his consulting-room migbt listen to the beart or pulse ofa patient lying in bed (speaking modestly as to distance) a mile or two away. Aw HrrecrivE Pian or Fire Sicnats.—The admirahle arrangement in tbis city for sending fire-alarms to the engine-houses and fire beadquarters is nowbere seen to better advantage than in tbe Broadway store of Lord & Taylor, which was the first large estahlishment connected with the fire-alarm telegraph. At two points on each floor are placed electrical ‘‘buttons” inclosed in small wooden cases witb glass fronts. If a fire occnrs the duty of the watchman is to break the glass and push the “button,” when an automatic machine on tbe fourth floor is immediately set in motion. This machine, . being connected with the fire-department wires, . communicates Lord & Taylor’s special signal to headquarters. Ina few seconds, the alarm has bsen repeated at the nearest engine-bouse, and a steam engine is on its way to the fire. Should the first alarm miscarry, the gong-alarm, which is always sent to the engine-houses 15 seconds after the first signal, serves to designate tbe locality of tbe tire.—New York Tribune. A Swiss Exursrrion.—Switzerland has appointed the year 1881 for an international exhibition of watches, jewelry, snuff hoxes and musical hoxes—a display in which the ancient republic may well call the rest of the world to eee what she can do. Tbis project adds another illustration to the recent tendency of international exhibitions, especially in smaller countries, torun to specialties. This will be the first exhibition of the sort in Switzerland. Tue Scientific American wants some ‘‘ wideawake California boy ” to invent a trap to catch . that troublesome squirrel, the gopber. This is} a personal affront. For every gopher in Cali: fornia there is a trap of some kind, the only) difficulty is to persuade the gopher to go into it. } Besides the gopher is not a sqnirrel. Has the! Scientific tried salt on their taile? Ecosomicat Steam Exciye.—The Corliss engine at the French exbibition of 1878 coneumed only one kilogramme (2.2 tb.) of coal per borse power per hour. A similar engine of 700 horse-power, constructed by M. Farcot, for the drainaye at Asnieres, consumes only six-tentbs asinuch. M. Tresca, in recommending, on bebalf of the committee of the French Academy, that the Montyon prize should bo awarded to the inventor ef this engine, stated three special advantages which it possessed. A form of construction which establisbes a great firmnees hetween tbe cylinder and the chief arbor, with tho least consumption of material; tbe separa. tiou of the oritices of admission and emission, to the great advantage of the psrmanence of temperature in tho stoam at its entrance into the cylinder; and a system of distribution commanded hy 2 central platform for the four opeuings by mcans of springs and came, which securo the opening and closing of tbe orifices, While claiming for Cave the principle of separation between the orifices and conduits of admission and escape, the committee consider that Corliss’ applications of the priuciple, the precision of action, and the economy of its engines entitled him to the Montyou prize of 1,000 francs, and the Academy awarded tbe prize accordingly, InsTRUMENT oF Resvusorration.—A Frenchman hae the credit of inventing an apparatus for aiding in the resuscitation of persons apparsntly drowned, or wbo from any other cause have been temporarily deprived of animation. It consists of a cylinder of sheet iron large enough to contain tbe body of an adult person. It is closed at one end, and tbe inanimate individual is inserted, feet foremost, in tbe receptacle as far as the neck, round wbicb tbere is placed a padded diapbragm, fastened to the cylinder so as to be air-tight. An air pump, attacbed to an opening in the tube, creates a partial vacuum, and the outer atmospbere, by its own pressure, forces its way into tbe lunge by the month and nostrils, which are left exposed. By areversed action of tbe pump the air is allowed to re-enter the cylinder, and respiration is thereby re-estahlisbed. A glass plate inserted in the iron casing enables tbe operator to watch the movements of the chest, which rises and falls as in life with tbe working’ of tbe pump. The action may be repeated, it is stated, 18 times in a minute, an. exact imitation of natural breatbing being thus produced. Ligntinc THE CapiroL By HLECTRIcITY.— The arrangements for lighting tbe capitol bnilding at Washington witha new electric light are nearly completed. The experiment has already been madein the Hall of the Houseof Representatives, and a single lightplaced on tbe front row of the reporters’ gallery and over tbe Speaker's chair made the whole hall so ligbt that priat could he easily read at tbe points furthest from the burner. The plan is to place four ligbts in the ball, and it is now believed tbat tbey will be a very great improvement upon tbe present arrangement of gas burners. Three electric machines have been purcbased under the appropriations for lightiug the interior of the building, and it isin contemplation to place another in position for tbe purpose of supplying a ligbt of vast power upon the top of the dome. It is claimed by theinventors thata burner can be constructed there which sball haveavery appreciable effect upon a large area of thecity. It is claimed that with the steam power of tbe heating and ventilating apparatus in eacb wing of tbe huilding, a dynamo-electric machine of 175,000 caudle power can be run. Tue New TRANSATLANTIC CABLE.—The cable steamer, Faraday, left Millwall at an early bour on Monday, and during the forenoon was safely moored abreast of Messrs. Siemens’ works at Charlton. The /araday is a powerful steamer of 4,900 tons, built at Newcastle in 1874 for Messrs. Siemens, and designed specially for laying cables, In the course of tbe afternoon she was surrounded by barges; those on tbe outside supplying her bunkers witb coal, arid those next to shore being employed in passing the cable into the steamer’s tanks. The new company, the official style of which is, ‘‘La Compagnie Francaise du Telegraphe de Paris a New York,” has opened offices in London for the transaction of executive husiness at 100 and 101, Greshain house, Old Broad etreet. The Furaday, having on board the ekore end and the Brest-Scilly section of the new cahle, was cleared at the London Custom-bouse on Tuesday nigbt for New York, and sailed for Brest the following morning. Her departure had been delayed, the wet weather having interfered witb tbe work of coiling the cable in the bunkers.—London Iron, June 21st, 1879. Tue Sourn ArricaN CaBLE.—The telegrapbic cahle to connect the European and Asiatic telegraphic systems with the Cape of Good Hope will be 4,000 miles long, extending from the Red Sea cahle, of Aden around Cape Guardafui and along the east coast of Africa to Port Natal, where it made a junction with the present land line to Cape Town. The cahle will be laid along the coast, tbe depth heing moderate along tbat side of the continent and the facility for repairing possible breakages has heen carefully ascertained. The cable will touch at Zanzibar, Mozambique, Sofala, Delagoa Bay, and thence to Durban as the submarine terminus, from which point the land telegraph becomes available to complete the circuit to Cape Town. The cost of construction and laying the cable is estimated at $7,500,000. The line from Durhan to Zanzibar is to be finisbed in July, and the , . whole cable by the middle of November, ® 6 SCIENTIFIC PROGRESS. A New Theory of the Earth's Magnetic Poles. From a study of tbe movement of tho compase-needle producing declination at Loudon, Mr. B. G. Jenkins, of the Royal Astrouomical Society, has become couvinced that tho various vicissitudes of the needle during the last 300 years can best be explaincd by the supposition of a etrong magnetic pole above the earth’s surface, and revolving around the geographic north pole in about 500 years. He finds four maynetic poles, as inaintained by Halley and Handsteen, to be neceasary to explain satisfactorily all the pbenomena of terrestrial magnotism, but he places these not in tho earth, but in tbo atmosphere, These poles he regards as the free ends of ae many broad magnetic belts, two extending from the vicinity of the nortb pole to the equator, tbe other two coming np from the eoutb pole to meet them, the horeal magnetism of the northern belts uniting witb tho austral magnetism of the eouthern belts along the magnetic equator, These hands he helieves to revolve at slow and unequal rates round the poles of tbe eartb, producing secnlar variations. Tt will he ohserved that Mr. Jenkine describes the magnetism of the northern hemisphere as “boreal.” Contrary to the current theory, he bolds that tbe north end of tbe compasa-needle is a true north pole, and tbat the facts observed are, when properly understood, in full accord witb the great magnetic truth that like poles repel and unlike poles attract. After submitting the evidence in favor of this view, Mr. Jenkins argues in thie wise: If the nortb end of the dipping needle is a eoutb pole, its pointing to the ground in Bootbia (where Sir James Ross located tbe eartb’s north magnetic pole) must be attributed to attraction. If it is attracted it is attracted by something either in the crust of the earth or at the center of the globe. If there is something in the earth’s crust which attracts tho needle in Bootbia, it ougbt to attract the needle in London. But tbe needle in London is attracted neither to tbe crust at Boothia nor to the earth’s center. The trutb is, Mr. Jenkins believes, that the north pole of tbe needle pointed to the ground almost perpendicularly in Bootbia because it was repelled by the true nortb magnetic pole in tbe atmospbere ahove tbat region when Sir James Ross was there 50 years ago. Furtber evidence as to the existence of the alleged magnetic belts above the earth’s surface ie promised. Meantime, it is of the first importance, Mr, Jenkins thinks, that it sbould be clearly eettled whether tbe magnetic pole remains in or above Boothia. According to bis calculation it should now be in latitude 72°, longitude £15°, in Prince Albert land.—Seientifie American. THE NEEDED Motor.—The demand to whicb we bave so often referred—a motor fitted for street railways—is felt in Europe, and the British Lords have been investigating the subject, and recommend the passage of a law permitting the nse of euch. They approve a locomotive worked by compressed air as more promising and desirable than any otber, and advocate the usc of steam engines in streets until a better discovery is made. The demand is for a simple power that can be attached to any car and that will draw it without fire. It is out of belief that science is stalled by soeimple a demand, Study has not been given tbe problem, An insured reward would eventually discover it, and release countless horses, reduce fares, increase speed and avert injuries. We claim au unequaled ingenuity, and apply it to telephones and improve stoves and shoe-hrushes, Here ie a call for it, and every day that call growe more urgent. Tbe wonder is that it has not been heeded, and that some slight machine or agent has not been found that will propel a car, a carriage, a sewing machine, a churn, turn a latbe, and be many men and borsee in one. Let us have this instead of new designs for perpetual motion and new combinations for an elixir, and fortunes will repay tbe invention.— North American. PETROLEUM AS FuEL.—Producers are gradually beginuing to use petroleum as fuel under boilers, and tbey find it cheaper by far tban coal, One large producer in the lower oil country, who is trying it, says that one barrel of oil a day witb tbe gas from the wells, gives him sufficient fuel under a boiler that is pumping three wells. Before using petroleum, he was hurning $2 worth of coal a day. In the Bradford region, the petroleum burner is heing introduced successfully, as well as in manufacturing establishments. But many hundred barrels per day more eould be consumed if producers would but interest themselves in thus aiding the consumption of their product. Thousands of harrels daily could be used in this way, with acorresponding benefit to producers in better prices.—Zx, THE EartH Betones to CuInA.—Dr, Schliemann haa found Chinese vases and gauze linen on Trojan soil, dating 1,200 years hefore Christ. They were on this coast in the fifth century, and arenow taking possession of it by right of prior discovery. Li-Fang-pao contends that the Hyperboreans were Chinamen, while here it is claimed that the Lepere are Chinamen. Magnetizing Molten Iron. Tn a letter to Dr. C. W. Siemens, and communicated by him to tbe British Society of Tolegraphic Engineers, Mr. E. Chernoff records a very curioue experiment: Believing that if it wote possible to magnotize white cast iron a magnet of greater permanence than any made of stee} would be obtained, Mr Chernoff cast some white refined iron in a mold, surrounded hy an electro-magnetic reel, along which a curreut was allowed to tlow during the process of casting, so that tbo fluid metal became magnetic, and cooled under the influonco of the magnetic current, The result so far justificd the expectation as to give a magnetized har of white cast iron; hut the form of the bar waa unlike what was expected. While pouring the metal into the mold and until tbe metal set, Mr. Chernoff ohscrved a singular agitation of the metal, whicb could not have proceeded from damp, as the mold was thoroughly dry. On cooling the har proved to be hollow, the cavity being symmstrical and extending about two-thirds the length of the bar. Tho metal was thinnest just opposite the center of the reel, where it did not excesd the thickness of writing paper. The agitation of the metal in cooling is accounted for by the repulsion of the molten metal toward the poles of the magnet. By casting under pressure it may be possible to obtain by thie metbod extremely permanent and powerful magnets of white iron. Possibly also this* experiment may lead to some useful modification of industrial processes for casting bollow cylinders without cores. Telephone an Instrument of the Present, There are said to be about 30,000 telephones now in service in this couutry, and only 500 in England—a fair sample of the greater quickness of the younger country to adopt new inventions. Prof. Wm. Ade Preece, an eminent Englisb electrician, recently said he did not tbink that the telepbone would be an iustrument of the future, and be largely adopted by the public; ‘*for although it had bsen largely adopted in America, we bad not the same necessity for it, for we bad a superahundance of messengers for all purpose, which the Americans had not,”— & ab Perhaps not. We must, bowever, give Prof. P. credit for his foresight. The telepbone, truly, will not be an instrument of the future, because in this country, at least, it is an instrument of the present, and as to England, refer to the following: Twelve sets of telephones have beeu sent out to Sir Garnet Wolseley, for use at the seat of war in South Africa. The great advantage of the telephone over the telegraph, is that tbe General can carry on confidential talk witb the officer at tbe district station, or a soldier can creep out toward tbe enemy’s lines and whisper back the information ae to position, A fino wire—tbe thinner the better—is all tbat is needed. This the soldier carries on a reel upon his back— a mile weighing only a few pounds, This will be tbe first time the telepbone has been nsed as an instrument of warfare. Artirician Sanpstonz.—Glaser’s Annalen contains a description of an improved inethod and apparatus for tbe manufacture of artificial sandstone, A thorough mixture of four to six parts of fine sand, and one part of slaked lime ie exposed for about three days to a high temperature and a pressure of more than three atmospheres, causing the forniation of a silicate of lime which acts as a cement, so that the mags, when cooled down to the ordinary temperature, hardens. This bardening process continues for some weeks hy exposure to the air, so that finally a product is obtained which is as hard and solid as good sandstone. The apparatus consists of a tank, into which the mixture is filled, and in which it is beated and stirred by a steam pipe, provided witb a numher of arms and rotated hy belting or gearing. Aftertbe mixture has reached the proper temperature the steain is cut off, and a second vessel, inclosing the tank on all sides, is put into communicatiun with the hoiler. By tbis meane tbe mass is heated for the period necessary. It is then run into a brick machine and shaped into the forms required. The process, it is claimed, effects great economy, especially for the manufacture of window sills, ete. The apparatus used is made large enough to produce 250 cubic feet of material in every charge—requiring, generally, tbree to four days. Gas anp Execrriciry.—After a full survey of the field the New York Times concludes that gas companies have heen driven from every stronghold except that of purely domeetic illuminating by the electric light, and that they may he driven from that before the year 1879 closes. There are four electric lamps claiming to meet the conditions of subdivision, namely, Edison’s, Holcombe’s, Werdermann’s and Faller’s, with one comprehensive method of subdivision, D’Ivernois’, and: one douhle-circuit generator, that of Mr. Keitb. Neither of these has yet been submitted to test on a comprehensive scale, hut all have done satisfactory work in the lahoratory, and one of them, Werdermann’s, has been tested in out-door experiments equivalent to street lighting. We have already referred to the fact that electricity and gas are not exclusives. A more perfect system of illumination will be introduced, and gas find otber and more appropriate uses than as a meane of illumination, ae cooking, heating, etc.

ly July 19, 1879.] 35 MINING AND SCIENTIFIC PRESS. CP ined yy Mecuanicat ‘PRoGREss. A Powerful Spectroscope. In the young science of spectroscopy, as in others, an important element of progress ia the improvement of iustruinents for dealing with the phenomeua presented, and many minds are engaged on this. A new spectroscope of remarkable power has just been brougbt to the notice of the French Academy by M. Thollon. Its ehief feature is the use of eulphide of carbon ptisms, which are closed laterally, not by plates with parallc} faces, hut by prisius of the form of Amici’s—i, e., having curved sides meeting at an angle, which, however, is much smaller than Amici’s prism, Tho rofringent angles of these prisms are in an opposito direction to that of the sulphide prism. ‘Two of these compound prisms are substitutsd by M. Tbollon for tho simple prisms in a spectroscope, which he formerly described to the academy. Without going into furthcr details, wo may eimply stato that an enormous dispersion is ohtainod; with a magnifying power of 15 to 20 times, the spectrum bae a length of 15 meters, ‘The angular distance of the D lines of sodium ie about 12’, whereas that produeed by M. Gassiot was only 3’ 6”. This instrumcnt should throw considerable light on the struoture of the spectrum, and M. Thollon has already noticed some intereetiny facts. The lines of sodium and magnesium present a dark nyclous passing into a nebulosity, which becomes gradually merged in the continuous spectrum. Many lines have heen split up, and all that have been thus resolved have been found to belong to two different snbstances. One of tbe hydrogen lines presents a nebulosity without a nucleus, M. Thollon remarks on, the magnificence of the spectrum of carbou from the electric arc, observed with the new instrument. Tho apectra of iron, copper, and magnesium in the same arc were also seen witb admirable clearness and brilliancy. These new epectroscopea have heen constructed for M. Tbollon by the able optician, M. Laurent. Tue Spityu MopHONE.—Tbe ephygmophone is a recent application of tbe telephone, and is an instrnment invented by Dr. Richardson, by which the movemente of the arterial pulse are transmitted iuto loud telepbonic eounds, In this apparatus the needle of a Pound’s sphygmograph is mado to traverso a metal or carbon plate which is connected with the zine pole of a Leclanche cell. To the metal etem of the sphygmograph is then attached one terminal of the telephone, the other terminal of the telepbone being connected with the opposite pole of the battery. When the whole is ready, tbe ephygmograpb is brought into use as if a tracing were about to be taken, and when the pulsation of the needle from the pulse-strokes is secured, the needle, which previously was beld back, is thrown over so as to make its point just touch the metal or carbon plate, and to traverse the plate to and fro witb each pulsation. In so moving, three sounds—one long and two ebort —are given from the telephone, which sounds correspond with the first, second and third events of sphygmographic reading. In fact, the pulse talks telephonically, and so loudly that when two cells are used the sounds can he beard by an audience of several hundred people. By extending the tolepbone wires, the sounds can also be conveyed long distances, so tbat a physician in his consulting-room migbt listen to the beart or pulse ofa patient lying in bed (speaking modestly as to distance) a mile or two away. Aw HrrecrivE Pian or Fire Sicnats.—The admirahle arrangement in tbis city for sending fire-alarms to the engine-houses and fire beadquarters is nowbere seen to better advantage than in tbe Broadway store of Lord & Taylor, which was the first large estahlishment connected with the fire-alarm telegraph. At two points on each floor are placed electrical ‘‘buttons” inclosed in small wooden cases witb glass fronts. If a fire occnrs the duty of the watchman is to break the glass and push the “button,” when an automatic machine on tbe fourth floor is immediately set in motion. This machine, . being connected with the fire-department wires, . communicates Lord & Taylor’s special signal to headquarters. Ina few seconds, the alarm has bsen repeated at the nearest engine-bouse, and a steam engine is on its way to the fire. Should the first alarm miscarry, the gong-alarm, which is always sent to the engine-houses 15 seconds after the first signal, serves to designate tbe locality of tbe tire.—New York Tribune. A Swiss Exursrrion.—Switzerland has appointed the year 1881 for an international exhibition of watches, jewelry, snuff hoxes and musical hoxes—a display in which the ancient republic may well call the rest of the world to eee what she can do. Tbis project adds another illustration to the recent tendency of international exhibitions, especially in smaller countries, torun to specialties. This will be the first exhibition of the sort in Switzerland. Tue Scientific American wants some ‘‘ wideawake California boy ” to invent a trap to catch . that troublesome squirrel, the gopber. This is} a personal affront. For every gopher in Cali: fornia there is a trap of some kind, the only) difficulty is to persuade the gopher to go into it. } Besides the gopher is not a sqnirrel. Has the! Scientific tried salt on their taile? Ecosomicat Steam Exciye.—The Corliss engine at the French exbibition of 1878 coneumed only one kilogramme (2.2 tb.) of coal per borse power per hour. A similar engine of 700 horse-power, constructed by M. Farcot, for the drainaye at Asnieres, consumes only six-tentbs asinuch. M. Tresca, in recommending, on bebalf of the committee of the French Academy, that the Montyon prize should bo awarded to the inventor ef this engine, stated three special advantages which it possessed. A form of construction which establisbes a great firmnees hetween tbe cylinder and the chief arbor, with tho least consumption of material; tbe separa. tiou of the oritices of admission and emission, to the great advantage of the psrmanence of temperature in tho stoam at its entrance into the cylinder; and a system of distribution commanded hy 2 central platform for the four opeuings by mcans of springs and came, which securo the opening and closing of tbe orifices, While claiming for Cave the principle of separation between the orifices and conduits of admission and escape, the committee consider that Corliss’ applications of the priuciple, the precision of action, and the economy of its engines entitled him to the Montyou prize of 1,000 francs, and the Academy awarded tbe prize accordingly, InsTRUMENT oF Resvusorration.—A Frenchman hae the credit of inventing an apparatus for aiding in the resuscitation of persons apparsntly drowned, or wbo from any other cause have been temporarily deprived of animation. It consists of a cylinder of sheet iron large enough to contain tbe body of an adult person. It is closed at one end, and tbe inanimate individual is inserted, feet foremost, in tbe receptacle as far as the neck, round wbicb tbere is placed a padded diapbragm, fastened to the cylinder so as to be air-tight. An air pump, attacbed to an opening in the tube, creates a partial vacuum, and the outer atmospbere, by its own pressure, forces its way into tbe lunge by the month and nostrils, which are left exposed. By areversed action of tbe pump the air is allowed to re-enter the cylinder, and respiration is thereby re-estahlisbed. A glass plate inserted in the iron casing enables tbe operator to watch the movements of the chest, which rises and falls as in life with tbe working’ of tbe pump. The action may be repeated, it is stated, 18 times in a minute, an. exact imitation of natural breatbing being thus produced. Ligntinc THE CapiroL By HLECTRIcITY.— The arrangements for lighting tbe capitol bnilding at Washington witha new electric light are nearly completed. The experiment has already been madein the Hall of the Houseof Representatives, and a single lightplaced on tbe front row of the reporters’ gallery and over tbe Speaker's chair made the whole hall so ligbt that priat could he easily read at tbe points furthest from the burner. The plan is to place four ligbts in the ball, and it is now believed tbat tbey will be a very great improvement upon tbe present arrangement of gas burners. Three electric machines have been purcbased under the appropriations for lightiug the interior of the building, and it isin contemplation to place another in position for tbe purpose of supplying a ligbt of vast power upon the top of the dome. It is claimed by theinventors thata burner can be constructed there which sball haveavery appreciable effect upon a large area of thecity. It is claimed that with the steam power of tbe heating and ventilating apparatus in eacb wing of tbe huilding, a dynamo-electric machine of 175,000 caudle power can be run. Tue New TRANSATLANTIC CABLE.—The cable steamer, Faraday, left Millwall at an early bour on Monday, and during the forenoon was safely moored abreast of Messrs. Siemens’ works at Charlton. The /araday is a powerful steamer of 4,900 tons, built at Newcastle in 1874 for Messrs. Siemens, and designed specially for laying cables, In the course of tbe afternoon she was surrounded by barges; those on tbe outside supplying her bunkers witb coal, arid those next to shore being employed in passing the cable into the steamer’s tanks. The new company, the official style of which is, ‘‘La Compagnie Francaise du Telegraphe de Paris a New York,” has opened offices in London for the transaction of executive husiness at 100 and 101, Greshain house, Old Broad etreet. The Furaday, having on board the ekore end and the Brest-Scilly section of the new cahle, was cleared at the London Custom-bouse on Tuesday nigbt for New York, and sailed for Brest the following morning. Her departure had been delayed, the wet weather having interfered witb tbe work of coiling the cable in the bunkers.—London Iron, June 21st, 1879. Tue Sourn ArricaN CaBLE.—The telegrapbic cahle to connect the European and Asiatic telegraphic systems with the Cape of Good Hope will be 4,000 miles long, extending from the Red Sea cahle, of Aden around Cape Guardafui and along the east coast of Africa to Port Natal, where it made a junction with the present land line to Cape Town. The cahle will be laid along the coast, tbe depth heing moderate along tbat side of the continent and the facility for repairing possible breakages has heen carefully ascertained. The cable will touch at Zanzibar, Mozambique, Sofala, Delagoa Bay, and thence to Durban as the submarine terminus, from which point the land telegraph becomes available to complete the circuit to Cape Town. The cost of construction and laying the cable is estimated at $7,500,000. The line from Durhan to Zanzibar is to be finisbed in July, and the , . whole cable by the middle of November, ® 6

SCIENTIFIC PROGRESS. A New Theory of the Earth's Magnetic Poles. From a study of tbe movement of tho compase-needle producing declination at Loudon, Mr. B. G. Jenkins, of the Royal Astrouomical Society, has become couvinced that tho various vicissitudes of the needle during the last 300 years can best be explaincd by the supposition of a etrong magnetic pole above the earth’s surface, and revolving around the geographic north pole in about 500 years. He finds four maynetic poles, as inaintained by Halley and Handsteen, to be neceasary to explain satisfactorily all the pbenomena of terrestrial magnotism, but he places these not in tho earth, but in tbo atmosphere, These poles he regards as the free ends of ae many broad magnetic belts, two extending from the vicinity of the nortb pole to the equator, tbe other two coming np from the eoutb pole to meet them, the horeal magnetism of the northern belts uniting witb tho austral magnetism of the eouthern belts along the magnetic equator, These hands he helieves to revolve at slow and unequal rates round the poles of tbe eartb, producing secnlar variations. Tt will he ohserved that Mr. Jenkine describes the magnetism of the northern hemisphere as “boreal.” Contrary to the current theory, he bolds that tbe north end of tbe compasa-needle is a true north pole, and tbat the facts observed are, when properly understood, in full accord witb the great magnetic truth that like poles repel and unlike poles attract. After submitting the evidence in favor of this view, Mr. Jenkins argues in thie wise: If the nortb end of the dipping needle is a eoutb pole, its pointing to the ground in Bootbia (where Sir James Ross located tbe eartb’s north magnetic pole) must be attributed to attraction. If it is attracted it is attracted by something either in the crust of the earth or at the center of the globe. If there is something in the earth’s crust which attracts tho needle in Bootbia, it ougbt to attract the needle in London. But tbe needle in London is attracted neither to tbe crust at Boothia nor to the earth’s center. The trutb is, Mr. Jenkins believes, that the north pole of tbe needle pointed to the ground almost perpendicularly in Bootbia because it was repelled by the true nortb magnetic pole in tbe atmospbere ahove tbat region when Sir James Ross was there 50 years ago. Furtber evidence as to the existence of the alleged magnetic belts above the earth’s surface ie promised. Meantime, it is of the first importance, Mr, Jenkins thinks, that it sbould be clearly eettled whether tbe magnetic pole remains in or above Boothia. According to bis calculation it should now be in latitude 72°, longitude £15°, in Prince Albert land.—Seientifie American. THE NEEDED Motor.—The demand to whicb we bave so often referred—a motor fitted for street railways—is felt in Europe, and the British Lords have been investigating the subject, and recommend the passage of a law permitting the nse of euch. They approve a locomotive worked by compressed air as more promising and desirable than any otber, and advocate the usc of steam engines in streets until a better discovery is made. The demand is for a simple power that can be attached to any car and that will draw it without fire. It is out of belief that science is stalled by soeimple a demand, Study has not been given tbe problem, An insured reward would eventually discover it, and release countless horses, reduce fares, increase speed and avert injuries. We claim au unequaled ingenuity, and apply it to telephones and improve stoves and shoe-hrushes, Here ie a call for it, and every day that call growe more urgent. Tbe wonder is that it has not been heeded, and that some slight machine or agent has not been found that will propel a car, a carriage, a sewing machine, a churn, turn a latbe, and be many men and borsee in one. Let us have this instead of new designs for perpetual motion and new combinations for an elixir, and fortunes will repay tbe invention.— North American. PETROLEUM AS FuEL.—Producers are gradually beginuing to use petroleum as fuel under boilers, and tbey find it cheaper by far tban coal, One large producer in the lower oil country, who is trying it, says that one barrel of oil a day witb tbe gas from the wells, gives him sufficient fuel under a boiler that is pumping three wells. Before using petroleum, he was hurning $2 worth of coal a day. In the Bradford region, the petroleum burner is heing introduced successfully, as well as in manufacturing establishments. But many hundred barrels per day more eould be consumed if producers would but interest themselves in thus aiding the consumption of their product. Thousands of harrels daily could be used in this way, with acorresponding benefit to producers in better prices.—Zx, THE EartH Betones to CuInA.—Dr, Schliemann haa found Chinese vases and gauze linen on Trojan soil, dating 1,200 years hefore Christ. They were on this coast in the fifth century, and arenow taking possession of it by right of prior discovery. Li-Fang-pao contends that the Hyperboreans were Chinamen, while here it is claimed that the Lepere are Chinamen. Magnetizing Molten Iron. Tn a letter to Dr. C. W. Siemens, and communicated by him to tbe British Society of Tolegraphic Engineers, Mr. E. Chernoff records a very curioue experiment: Believing that if it wote possible to magnotize white cast iron a magnet of greater permanence than any made of stee} would be obtained, Mr Chernoff cast some white refined iron in a mold, surrounded hy an electro-magnetic reel, along which a curreut was allowed to tlow during the process of casting, so that tbo fluid metal became magnetic, and cooled under the influonco of the magnetic current, The result so far justificd the expectation as to give a magnetized har of white cast iron; hut the form of the bar waa unlike what was expected. While pouring the metal into the mold and until tbe metal set, Mr. Chernoff ohscrved a singular agitation of the metal, whicb could not have proceeded from damp, as the mold was thoroughly dry. On cooling the har proved to be hollow, the cavity being symmstrical and extending about two-thirds the length of the bar. Tho metal was thinnest just opposite the center of the reel, where it did not excesd the thickness of writing paper. The agitation of the metal in cooling is accounted for by the repulsion of the molten metal toward the poles of the magnet. By casting under pressure it may be possible to obtain by thie metbod extremely permanent and powerful magnets of white iron. Possibly also this* experiment may lead to some useful modification of industrial processes for casting bollow cylinders without cores. Telephone an Instrument of the Present, There are said to be about 30,000 telephones now in service in this couutry, and only 500 in England—a fair sample of the greater quickness of the younger country to adopt new inventions. Prof. Wm. Ade Preece, an eminent Englisb electrician, recently said he did not tbink that the telepbone would be an iustrument of the future, and be largely adopted by the public; ‘*for although it had bsen largely adopted in America, we bad not the same necessity for it, for we bad a superahundance of messengers for all purpose, which the Americans had not,”— & ab Perhaps not. We must, bowever, give Prof. P. credit for his foresight. The telepbone, truly, will not be an instrument of the future, because in this country, at least, it is an instrument of the present, and as to England, refer to the following: Twelve sets of telephones have beeu sent out to Sir Garnet Wolseley, for use at the seat of war in South Africa. The great advantage of the telephone over the telegraph, is that tbe General can carry on confidential talk witb the officer at tbe district station, or a soldier can creep out toward tbe enemy’s lines and whisper back the information ae to position, A fino wire—tbe thinner the better—is all tbat is needed. This the soldier carries on a reel upon his back— a mile weighing only a few pounds, This will be tbe first time the telepbone has been nsed as an instrument of warfare. Artirician Sanpstonz.—Glaser’s Annalen contains a description of an improved inethod and apparatus for tbe manufacture of artificial sandstone, A thorough mixture of four to six parts of fine sand, and one part of slaked lime ie exposed for about three days to a high temperature and a pressure of more than three atmospheres, causing the forniation of a silicate of lime which acts as a cement, so that the mags, when cooled down to the ordinary temperature, hardens. This bardening process continues for some weeks hy exposure to the air, so that finally a product is obtained which is as hard and solid as good sandstone. The apparatus consists of a tank, into which the mixture is filled, and in which it is beated and stirred by a steam pipe, provided witb a numher of arms and rotated hy belting or gearing. Aftertbe mixture has reached the proper temperature the steain is cut off, and a second vessel, inclosing the tank on all sides, is put into communicatiun with the hoiler. By tbis meane tbe mass is heated for the period necessary. It is then run into a brick machine and shaped into the forms required. The process, it is claimed, effects great economy, especially for the manufacture of window sills, ete. The apparatus used is made large enough to produce 250 cubic feet of material in every charge—requiring, generally, tbree to four days. Gas anp Execrriciry.—After a full survey of the field the New York Times concludes that gas companies have heen driven from every stronghold except that of purely domeetic illuminating by the electric light, and that they may he driven from that before the year 1879 closes. There are four electric lamps claiming to meet the conditions of subdivision, namely, Edison’s, Holcombe’s, Werdermann’s and Faller’s, with one comprehensive method of subdivision, D’Ivernois’, and: one douhle-circuit generator, that of Mr. Keitb. Neither of these has yet been submitted to test on a comprehensive scale, hut all have done satisfactory work in the lahoratory, and one of them, Werdermann’s, has been tested in out-door experiments equivalent to street lighting. We have already referred to the fact that electricity and gas are not exclusives. A more perfect system of illumination will be introduced, and gas find otber and more appropriate uses than as a meane of illumination, ae cooking, heating, etc.