Democratic Sentinel, Volume 11, Number 21, Rensselaer, Jasper County, 24 June 1887 — SCIENTIFIC MISCELLANY. [ARTICLE]

SCIENTIFIC MISCELLANY.

A* electric signal apparatus on t French railway causes the blowing of • •team whistle upon a locomotive ap Broaching a danger signal. The engineej fe thus warned. This apparatus is found valuable in fogs and snow-storms, when ordinary signals often escape notice. The number of varieties of insects u rtetly greater than that of all other living creatures. The oak supports 450 •pedes of insects, and 200 are found in the pine. Humboldt, in 1849, calculated that between 150,000 and 170,000 species were preserved in collections, but recent estimates place the present number at about 750,000 species. It is a very general belief that great burial places exert a noxious influence, which must render the localities very unhealthy as places of residences This Mea is shown to be a mistaken one by the results of any inquiry into the sanitary condition of the cemeteries of Paris. The composition of the air in the cemeI cries is reported to be indistinguishable from that of arable lands. Concerning the moon’* effect on tides, the Astronomer Royal for Leland recently stated that, while the day is gradually lengthening through lunar action tides, the earth reacts on the moon •nd drives it away farther and farther. Looking backward, the moon must have been nearer and nearer tho earth, md at one epoch in the remote ages of the past—perhaps about 50,000,100 of years ago—the two bodies up st have been very close together, Chen the day was but three hours lon,v Instead of twenty-four. At that distant oeriod, the earth rotated once every three hours, and the moon revolved with it in the same time. So near was the moon jhat, if there had been oceans in those days as now, the tides must have been 216 times as great as at the present time; And, rising to an immense height, would have swept over the whole of England. Animal life in the Sahara is somewhat peculiar to the region, and, according to M. Vogt, the traveler is struck with the absence of all bright colors in the animals of the desert. As a rule, their hue approaches that of the ground, and the Adaptation is most remarkable in birds, reptiles, grasshoppers, etc. Black and white exist in some animals—for instance, the male ostrich—which have nothing to fear from enemies; and a •ingle exception to the rale occurs •ancxg insects the Coleoptera are nearly all black. To explain the existence in safety of these insects whose ?olor must make them conspicuous, M. Vogt, states that they feign death on the Approach of danger and in that state slosely resemble the excrements ol gazelles, goats, £ad sheep. This description, with their disagreeable odor, gives them Sufficient protection. The general color of the ground to the desert », of course that of sand. At the Crystal Palace, London, a •econd international electrical exhibition is to follow closely on the heels of the fast at Paris. The objects to be exhih ted are chiefly compared in thess elafises ; Apparatus used for the production and transmission of electricity Mid magnets, natural and artificial, mariners’ compasses ; lightning oonduc tors, and applications of electricity tc telegraphy and the transmission ol founds, to the production of heat, to lighting and the production of light, to the service of light-houses and signals, to apparatus giving warning to mines, railway? aal navigation, to military art, to tips arts, to electro-chemistry and chemical arts, to the production and transmission of motive power, the mechanical arts, to surgery and medicine, Co horology, to astronomy, to meteorology, tj ° geodesy, to agriculture, to apparat’xs for registering, and to domestic aces. It is expected that the exhibiiiua will prate matou ’’<>«. attrM&y* t* imarioan* ihac at Pwi*. the only cMvafry that women can afford to receive from men. in work, wages, and general conduct, is fair play, equal advantages, and equal wages, ho uouutn wil. ever ask of men other thaa » • tre:«t always as they treat f-sei. ■other.—Jftler O can. • <