The Arkansaw traveler., 1885-07-04
Compiled for TER ARxAxsAw TRAvxLwH.
 SCIENTIFIC MISCELLANY

specimens measuring s:cm :h.ee .c s;zA, inches in length-has been found in iron,
 Two French experimensers make tn. remarkable report that silicon, though upas. fectsd by temperature of 1870 degrees F
 volatilzes at sz4 degrees.
 The former prevalence of sub-tropica, climate in England is indicated by the rec.,, discovery in Cornwall of certain fossils of ,b. tertiary period of geology.
 Ire velocity of sound in ice has been determined by Trowbridge and McRae to h. about g goo feet per second, or about nina times the velocity of sound in the air.
 On Prussian plains where grass is nov unknown, and five out of every six years are generally rainless, the grass grew thick to the height of man sixty years ago. The change IS supposed to be an effect of the destruction of the vast forests which once covered the country 10 the northward.
 Dr. And:ee, of Leipzig, concludes tha, the American Indians in pre- Columbian times were unacquainted with the art of forginp iron, although they knew how to obtain and employ gold. silver, tin, copper, quicksilver. etc. He thinks that the great masonry work, of Peru may have been built with brorze tools
 ls has been shown experimentally tha, seed corn is rendered more valuable by be. ing slowly kiln-dried at high temperature. the corn so 'reated germinating in much colder weather than would otherwise be ,he case, while, on the other hand it may be ex. posed to much greater heat without losing its germinating power.
 A Growing World.-Drs. Kleiber and Keller, of St. Petersburg, have been studying the increase of the earth's mass from the ac. dition of meteors drawn from space. They have calculated that about 4so,ooo me,eors fall on the surface of the earth each hour. | and that the weight of the foreign material thus odded must be as much as 4o6o pounds hourly, or nearly sixty tons daily.
 Acclimatization in Africa. Stanley. the American explorer, believes equatorial Africa to be habitable fer Europeans and that, with due attention to diet and an occa. sonal holiday change, they may long retain | other hand, Fischer, a German traveller, re. gards Central Africa as entirely unsafe for Europeans at lower levels than 5000 ieet, and even at that altitude malaria must be ex. pected on rich land.
 Dimensions of Waves.-The extreme height reached by ocean waves, according 10 careful measurements by the Hydrographical Bureau, is from A. 10 1S feet, the average height of great waves being abou, 20 fee, During storms in the North Atlantic waves sometimes extend to length of 800 and 6oo feet, and last ten or eleven seconds while the largest wave observed is said to have had a length of half mite, and to nave taken a seconds to spend itself.
 Cartoons Chapges.-.At meeting of the Berlin Electrical society Dr. Aaron has exhibited specimens of vegetable carbon which had been transformed into electric conductors and made almost incompustib,e by energetic and prolonged heating in vacuum or in neutral atmosphere. These properties are so like those of graphi.e-the mineral carbon used in pencils-that the product may well be called artificial graphite, although 1t is not crystalline
 Are Our Latitudes Changing ?-Eleven stars have been selected for observation a, Lisbon and at Washington, to determine whether those places are changing in lati- tude. Each star will be observed fifteen or twenty times yearly, with the greatest possi- ole accuracy in recording its position. O. servations at Pulkowa have indicated di- intuition of about twenty-three feet in lati- tude between I843 and I872, and greater changes have been shown at other obserya- tories but it is by no means certain that these results are not due to errors of observation
 A Problem Solved Preliminary trials with an apparatus specially constructed for photographing the stars have been made at the Paris Observatory, during the past year The results have been SO satisfactory that Admiral Mouchez now declares the problem of making charts of the heavens, including all stars down to the fifteenth magnitude, 10 be solved. Photographic impressions of stars visible to the naked eye are taken with a minimum exposure of one-hundred,h 10 one-half of a second, while for the fain,est stars-tnose of the fifteenth and sixteenth magnitudes-an hour and a half or more is necessary.
 The Electricity of Rain.-The sugges. ton having been made that the ignition of petroleum tanks may sometimes be caused by sparks from the rain of thuader clouds, some interesting results obtained with an old f piece of apparatus have been called to mind In these experiments an electrometer showed that the drops of occasional showers are almost always more or less charged with electricity, and that it is only totally absent during foggy, moist days, and long storms The strongest charges were obtained during but the air even has given indications occasionally of an electric charge without any fall of rain.
 Sense-Points of the Skin.-Blix, of Up. sala, and Gutenberg. of Berlin, have observed