500 



SCIENCE. 



[Vol. XIII. No. 334 



be removed by distillation. If copper be used instead of zinc in 

 this process, aluminium bronze is obtained. Other fluxes than 

 those mentioned may be employed. 



— A submarine bridge is proposed between Sweden and Copen- 

 hagen by a Swedish engineer, Mr. Rudolph Littlejegrist. The 

 distance, according to The Engineering and Mining Journal, is 

 two and a half miles, and the proposed structure would join Elsi- 

 nore to Helsingborg by a bridge made up of one hundred feet spans, 

 carrying a single line of rails. It is to be submerged sufficiently to 

 allow ships to pass over it. The bridge would be incased in a 

 double tube, with an outer skin of iron and an inner one of steel, 

 and the space between the shells filled with concrete. It is fore- 

 seen that the outer shell might rust away in time ; but it is be- 

 lieved that the concrete would remain intact, and protect the steel. 

 The piers would be ordinary caissons, filled with concrete, and 

 placed one hundred feet apart. The tubes would rest on these 

 piers, and the girders would take a bearing on blocks inside the 

 tube immediately over the piers. The tube would be floated out in 

 one hundred feet lengths and lowered to place, and a massive 

 collar of concrete put over the joints. Pontoons, with legs at each 

 corner, worked by hydraulic rams, so as to give a stable platform, 

 would be used in sinking the tubes. The estimated cost of the 

 submerged work is about §3,500,000, not including the approaches. 



— According to the Mo7iiteur de la Ceramigne et de la Verrerie, 

 a method of electroplating glass and porcelain has been devised by 

 M. Hansen. The chief difficulty hitherto experienced has been to 

 obtain a conducting surface which would not prevent the proper 

 adherence of the metallic coating. M. Hansen uses chloride of 

 gold or of platinum dissolved in sulphuric ether, to which sulphur 

 dissolved in some heavy oil is added. This compound, after hav- 

 ing been slightly heated, possesses sufficient consistency to allow of 

 a film being laid on the glass with a brush. The object treated in 

 this way is then moderately heated in a mufHe until the sulphur 

 and chlorine are completely volatilized, the gold or platinum adher- 

 ing firmly to the surface. The best copper bath is two parts of 

 sulphate of copper to three of distilled water. In silver-plating, 

 seventeen parts of nitrate of silver and thirteen parts of cyanide of 

 potassium, dissolved in three hundred parts of water, are used. 

 For gold-plating, seven parts of gold are used, which are prefer- 

 ably dissolved in aqua regia, and precipitated by means of ammonia. 

 This precipitate, while still wet, is then placed in a warm solution, 

 consisting of nine parts of cyanide of potassium and ninety parts of 

 water. 



— We recently published an extract from Eiigineering, descrip- 

 tive of the use of the vvater-jet in sinking the wooden piles used in 

 the construction of the Calais harbor-works, in which the remark 

 was made, " We believe [the water-jet] had never been previously 

 used in this particular manner." In response to this, Mr. L. Y. 

 Schermerhorn, in a letter to Tlie Engineering and Building Record, 

 says that in 18S1 he compiled a paper giving, as far as known, the 

 history of the water-jet as an aid in engineering construction, which 

 was published by the Engineering Department of the United States 

 Army. From this paper it is clearly established that the use of the 

 water-jet in sinking both wooden bearing and sheet piles had been 

 applied in this country long previous to 1877, the date of its use at 

 Calais. In 1852, Lieut. George B. McClellan used the water-jet 

 for sinking piles in the gover-nment wharf at Decrows Point, Mata- 

 gorda Bay, Texas. In 1854, Lieut. W. H. Stevens made a similar 

 use of the water-jet in sinking sheet and bearing piles in the con- 

 struction of a jetty for the protection of Fort Livingston, La., and 

 for the foundations for lighthouses in the vicinity. In 1863, Mr. J. 

 W. Glenn placed five thousand wooden piles across the channel to 

 Mobile harbor, to prevent the entrance of the Federal fleet, by 

 pumping them down with a water-jet. In 1867-69, O. Chanute, 

 chief engineer of the Kansas City Bridge, used the water-jet for 

 sinking bearing piles. In 1868, T. J. Whitman, chief engineer of 

 the St. Louis water-works, applied the water-jet for sinking sheet 

 piles for the coffer-dam about the foundation of the engines. In 

 1872, Major P. C. Hains used the water-jet in sinking piles for 

 lighthouse foundations. In 1873, C. C. Martin, superintending 

 engineer New York and Brooklyn Bridge, sunk sheet piles by aid 

 of the water-jet. From the foregoing, it is evident that the water- 



jet had been used in this country by engineers for sinking bearing 

 and sheet piles nearly a quarter of a century previous to its use at 

 Calais. 



— According to the Japa?t Weekly Mail, an earthquake of a 

 most unusual character was recorded at 2h. 7m. 41s. p.m., on 

 Thursday, April 18, in the Seismological Observatory of the Im- 

 perial University, Tokio. The peculiarity lies, not in its violence, 

 but in the extreme slowness of its oscillations. The beginning of 

 the shock had all the characteristics of the ordinary earthquake ; 

 but gradually the motion augmented, until at a certain stage of the 

 shock it reached seventeen millimetres, but the ground swayed so 

 gently that the house did not vibrate visibly, nor were the senses 

 alive to it. It took from four to seven seconds to complete one 

 oscillation, — a most unusual phenomenon, and one never before 

 noted in the observatory. The motion was almost entirely con- 

 fined to the horizontal plane, and mostly south to north, but there 

 were a few vertical motions of equally slow periods. This state of 

 things lasted for ten minutes thirty-six seconds. Professor West of 

 the Engineering College observed the water in a small pond to 

 oscillate gently from north to south. At one time the water-level 

 fell about two inches on one side of the pond, and exposed the 

 bank, while a few seconds later the water immersed it nearly to 

 the same depth, exposing the opposite bank ; and this process con- 

 tinued for a quarter of an hour. " Slow oscillations of this nature 

 have been called ' earth-pulsations,' and these usually take place 

 where there is a destructive earthquake or a submarine disturbance 

 going on at a great distance. Earth-pulsations are known to have 

 caused slow oscillations of the water in lakes. From this fact it 

 may not be unreasonable to conjecture that a terrestrial or sub- 

 marine agitation of unusual magnitude has taken place somewhere. 

 The authorities of the Science College have sent to the Hydro- 

 graphical Bureau of the Naval Department, asking for information 

 as to the state of the tide and seas. It may be as well to remark 

 that it is not certain whether the maximum motion of seventeen 

 millimetres, as given by the seismograph, is perfectly accurate, 

 as it is very difficult to measure slow oscillation like this with ab- 

 solute certainty." It is now known as a fact that Vries Island, 

 outside Yokohama Bay, and possibly sixty miles off, was in a state 

 of violent volcanic eruption. 



— Naphtha is now much used as fuel in middle Russia. Last 

 year. 880,000 tons of it were sent up the Volga for fuel purposes ; 

 and it is expected that the export for the same purpose will this 

 year reach no less than one million tons. 



— The province of St. Petersburg is very rich in marshes covered 

 with a thick carpet of vegetation, which conceals water to the 

 depth of several feet, — sometimes twenty-five feet and more. 

 Small lakes and branches of rivers are continually being trans- 

 formed into such marshes ; and M. Tanfilieff, who has studied the 

 way in which the transformation goes on, comes to the following 

 conclusions {Mhnoires of the St. Petersburg Society of Naturalists, 

 vol. xix.), which are given in Nature : "The pioneers of the trans- 

 formation of a lake into a marsh invariably are flowering plants, 

 such as Me}iyanthes, Comarum, Cicuta, Equisctum, Carices, and 

 the like. Their roots and underground stems make a thickly 

 woven floating carpet, which soon totally conceals the water. The 

 Sphag7iuin invades this floating carpet, while the water beneath 

 becomes filled with debris of decaying plants, transformed later on 

 into peat-bog. In shallow basins the transformation goes on at a 

 much speedier rate, as their bottoms are invaded by plants, like 

 Phragmites and Scirpus lacustris, which reach a considerable 

 height, and thus supply, after their decay, a good deal of additional 

 material for the fiUing-up of the basin. A mass of smaller plants, 

 such as Leinna, Hydrocharis, Callitricke, Utricularia, Hypntim 

 fluitans, and several others, usually grow also amidst the rushes. 

 Of course, the streamlets which flow into the basin contribute also 

 to fill it up by bringing in sand and loam. As soon as the floating 

 carpet has reached a certain thickness, and the Sphagnum has 

 still more increased its bulk, various plants, such a.s Drosera, Vac- 

 cinium, Eriophorum, the dwarf birch, and other bushes, begin to 

 grow upon it, although the space beneath still remains filled with 

 water. As the Sphagnum does not grow upon ponds containing 

 a chalky water, its place in such ponds is mostly taken by the 



