The Arkansaw traveler., 1886-03-20
Compiled for TRE ARKANsAw TRAVELLER
 SCIENTIFIC MISCELLANY

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 A German metaliurgist has introduced an apparatus for pumping molten lead by steam pressure.
 A dicti mary for the scientific and tech. nical terms in all languages is projected by
 Prof Vilansva, and is endorsed by the Inter. national Geological Congress.
 Two F ench investigators have found that the germs of fermentation are rot de- stroyed or perceptbly affected by a pressure of 300 10 400 atmospheres continued for sev. eral days.
 The disco very of hitherto unknown lake in the Persian desert was announced at late meeting of the Vienna Geographical society. It is at least twenty five miles long. and from MohammedaH evidence appears ID have dried up after a previous existence, and t1 have again filled up at a quite recentdste.
 Giant Trees of Australia. a.-Evidence of the decay of forests in Australia is found in the present existence of a few trees far ex- ceedng in size any of those about them, and supposed to be survivors of departed race l ference, at height of thirty feet above the ground, was described at a late meeting of the Royal Society of New South Wales.
 Invisible Clouds.-ln the recent Eng- fish tests of lighthouse illuminants was brought out the curious fact-of great prac- tical as well as scientific interest-that re. markable changes in the transparency of the air occur without any visible haze or mist. Invisible clouds seemed to float by, obscur. ing the lights for time and it sometimes happened that while the distant French lights showed with unabated brilliancy the experimental lights, only mile and quar- ter away, had lost one-fourth to one-third their power.
 Lighting Power of Coai.-Franklin Institute tests indicate that one pound of coal burned under good boiler, yields | light ot about twenty candles by the incau- descs nt electric system. The same weigh, of coal gives from the naked arc light, ab 1u, Iss candles, only So candles being ordinarily available, on account of the shading of arc liPhis. The gas from one pound of bitum- | inous coal, yields fro I4 to r candles. the gre ater economy of fIel in els ctric lig1tingis offset by the increased expense for machinery | and attention.
 Variations in Granite. Prof Winchells comparative trials of the granites of New England aad Minnesota have shown some surprising differences in strength. Two inch unpublished cuoes were taken, and crushed between wooden cushions, the average strength of Minnesota granite was found to De 9+ 272 pounds, or 23,2I8 pounds per square inch; crushed between steel plates, the average strength was ro4 Boo pounds, or 2o2oo pounds to the square inch of surface. like number of spe c,mens of New gland granite gave an average strength of so7S5 pounds, or I4 759 pounds to the square Inch.
 An Archaeological Garden.-An ex. hibition is projected at Berlin to show the races of men and their habits, as animals are shown in geological gardens. In the exhibi- ton 1t is intended that representatives of various races shall permane ntly reside, while of such races as cannot stand the cold of the climate, representatives will be brought to Germany to reside during the summer. museum of obj cts pertaining to the different races will be established in connection. An attempt was once made at the Londoa Crys- tai palace to represent various peoples and their manner of living by means of models, but il was never carried very far.
 How Children Grow.-A rem arkable physiological discovery has been made by Rev. Mailing Hansen, principal of the Danish institution for the Deaf and Dumb. During period of three years, he has made fire quers careful measurements and weighings eff the r3o children under his charge, and has reached the COT clusion that the body does not increase evenly in bulk and height throughout the year, but that during some months the child accumulates bulk and re- mains stationary in height, while at another time there is growth in stature with compara. lively little increase in weight. lhese re- suits are confirmed by similar experiments in several smaller institutions in Denmark.
 Plaques of Mice.-At intervals of few years, the Brazilian colony of Lourenco sui fers from remarkable visitation of field mice, the latest of which in 1876. has just been described by pr. H. Voa Ihripg. These creatures. ordinarily not numero ous, appeared in enormous quantities, and in few days destroyed the fields of corn. potatoes, clover | oats, barley, gourds, pumpkins, and even weeds, actually damaging houses to con siderable extent and running furniture and clothing. The periodical occurrences of these plaques seems to be dae to the chief food supply of the mice, the seeds of the bamboo-grass. which a, regular interval. of < six to thirty years, natures over large terri tory, and then disappears. The field mice increase so rapidly that. if all the conditions which keep them in cheek were removed, . single pair would bear a progeny of ssooo individuals in . single summer. and every iiv- ing thing upon the earth would be consumed in half -doxen years.