The Russellville Democrat., 1880-01-08
POPULAR SCIENCE.

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 M. BouDAIBE, the engineer in charge of the preliminary surveys for flooding the dried-up lake beds of Algeria, esti- mates the cost of the proposed work at not exceeding 20000,0000f.
 TIE Nature says the French Minister of War has published a regulation for or ganizing optical telegraphy in time of peace. The several places on the French frontier are to be connected by post, and the apparatus is to be manpuvered by persons framed to keep records of com f munications sent and received This new service is to beplaced under the supervision of the Directer Of Aerial Communications, who has already com mand of the balloonists and the colom- bophilcs for carrier pigeons.
 THE Italian government has decided to construct the proposed observatory on Mount Etna, which will ba fitted for scismological as wei as for metoorolog- ical and astronomical observations. The building will be the property of tie uni versity of Catania. This will be the second loftiest observatory in the world, the United States signal station at Pikes Peak, i'll Colorado, at an elevation of IA ,336 feet, being the loftiest station, and indeed the loftiest inhabited building of any king in the world.
 NoTwITnsrASDIsG all that has been written on the subject, the use of ar- senic in dyes and coloring matters con- tinucs to be the cause of widespread mischief. We see by foreign journals that in France the prefect of the Depart ment du Noid has just issued q notice to bookbinders and others concerning the danger incurred by using the colors which have for their basis arsenic or copper. These are often employed in the coioring of paper, or the edges of books bound in green. In case of any accident arising from them, the binders are not only liable for civil damages, but for criminal offence.
 Ira small blt of camphor IS laid upon water, It begins turning and moving with great rapidily. If few grains of lycopodium or other light powder have been previously scattered on the water, they are drawn toward the camphor by eddies in an inverse direction. These phenomena were observed in 174S by Romion. Cassamar has, says Les Mondes, resumed the study of the question and adopted the views of Romen. He in stances the following critical experiment.: At the same time that the bits of cam phor are thrown upon the water, insert glass rod which has been rubbed with 1 flannel; the motion immediately stops. If the electricity is removed from the rod by rubbing it with tin-foil it loses the power of checking the eddies.
 REYSIER, the electrician, has come to the following conclusions regarding hy- dro-electric batteries The most power tul battery is the Bunsen. Ruhmkorf model, but it is inconyenient, deleteri- ous and expensive. The most economi- cal and constant is the Thomson, but it is costly and cumbrous. The most eonyen- tent would be well arranged rotary, l but the price would be high and the cost enormous A battery as powerful 1 as the Bunson, as economical as the l Thomson, and as convenient as a we'll arranged rotary one, would still be far | from suitable forelectric lighting. Hence l it is not at present among hydro-electric batteries that we have to look for the so- lution of domestic motor applicable to the present electric lamps.
 A PERSON in England having purchas- ed ring set with what purported to be a diamond, and having later discovered 1 that the same stone was a cape diamond, l entered suit at law to recover the money paid for the ring Judgment was given for the plaintiff on the evidence of sev- eral diamond dealers, who testified that l Cape diamonds are not to be regarded as ordinary diamonds, and that they lack the essential qualities of the Bra gillian stones, viz, lustre, hardness aad | color. A writer in Nature calls attention to this singular verdict, and expresses q hope that, when the case comes up for re-trial, the Judge will require some sci entific evidence, such as specific gravity or chemical composition, about Cape diamonds. iga 8saf1 ssne 1al@
 A useful method for the compression of fluid steel, invented by II R. Jones, of Pittsburg, was described by MT. Davis at the late meeting of the Iron and Steel Institute; held at a Liverpool En- gland. The process simply consists in admitting steam at high pressure to the top of the ingot mold immediately after the steel has been cured. A steam receiver, for the sake of convenenienee, is fixed to the side of the ingot crane, This receiver has a number of cocks cor responding with the number of molds India rubber pipes are provided to con duct the steam, ono end being perma- nently fixed to the receiver and the other by means of coupling attached tc the lid of the mold. In practice high CT pressure than from 80 to 15U pounds has not appeared to be necessary, and higher pressure is use in the case of mild steels. Under this pror ess the ingot are turned out free from porosity, anc with perfectly level top. The steam , besides consolidating the ingot, acts or end, cools the topof the ingot, and allow it to be conveyed to the relocating fur
 mace sooner than when the old process
 was used 5i3 bs ai
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