The Arkansaw traveler., 1886-03-27
Compiled for The ArknRsap Truueter. SCIENTIFIC MISCELLANY

ivy over house renders the interior eD. tirely free from moisture
 England has a new association in the Junior Engineering and Scientifc S,- ciety, to which no person over twenty. six years old is admitted
 The Malays, who frequently find an. cient stone axes in the soil, call them thunderstones," believing that they proceed from thunderbolts
 Birds, according to Mons. Desplat, evolve three times as much heat aS nam. mals, absorbing thrice as much oxygen and emitting thrice as much carbonic acid
 A member of the Royal Horticultural Society of London has observed that dahlias collect much dew on their leaves. the peach, rose and evening primro>r. very little; while the guince and mu.- berry are only very slightly wet.
 Major-General E. F. Burton has de- scrihed certain large yellow hornet, of India which dispose themselves in regu. lar circles upon their nest, with their heads to the center They thus appear like the spokes of yellow wheel and a nest of them is sometimes mistaken Tor a sunhower
 Thunder, Lightning and Rain Me teorologists have found that there can be no thunder and lightning without rain When thunder is heard beneath clear sky, the reports must either come from distant clouds or be the result of some other cause than discharge of electricity. Harvest or heat lightning Is produced by distant storm Thm. der seldom accompanies heat lightning the sound reaching only about twelve miles, while lightning is often seen hy reflection upon nearer clouds, at much greater distance
 Thickness of Clouds. II Toynbee, of the London Meteorological Society has arrived at the conclusion that clouds of less than 2000 feet in thickness are seldom accompanied by rain; and if they are it is very gentle consisting of minute drops. With thickness of between 2.000 and 4000 feet the size of the drops is moderate With increasing thickness comes in. creasing size of the drops and at the same time their temperature becomes lower, until, when the thickness k greater than 6,0O0 feet, hail is produced
 Plants of the Zones.-In a recent lee ture in London, Mir j. G. Baker est mated the total number of character istically tropical plants as from 4o"e to 50,000 The plants of the north temperate zone embrace about 2OOt9 species. The Arctic zone has less than 1000 species, while the higher mountain regions possibly furnish 2,000 more-a total of 5000 species of what gardeners call alpines, that is, plants specially adapted to cold, damp climate with q short summer, Mir Baker estimated that 46,0O0 species of plants are reprs- sented in the possessions of Great Britain.
 The Keen Eye of Science-A striking illustration of the value of the camera to astronomy is furnished by the recent discovery of new nebula near the star Maia in the Pleiades Until photo graphed at the Paris observatory thl> nebula had never been seen with the best glasses although it has since been detected with the great telescope of the Pulkova observatory. The emperor "i Brazil now announces his determination to cooperate at the Rio de Ianeiro "h- servatory, in the general project of pho tographing the entire heavens already begun at Paris with such unexpected success.
 Dust Explosions.-The investigations of the Prussian Firedamp commission have shown that many mine explosions attributed to fredamp, or outbursts of gas, are really due to fine coal dust, all kinds of dust appearing to be capable of exploding violently when ignited The experiments relative to this intlan' inability of coal dust were devised as nearly as possible in accordance with the conditions prevailing in practice and more than two hundred tests were made, explosions occurring in every case when an electric spark was pro duced in dust cloud.
 Locust Invasions.-The records of To- cust-plagues in the warm countries oi the east in modern as we'll as in ancient times, almost surpass belief Kirby and Spence mention an army of lOcu>ts I