The Arkansaw traveler., 1889-07-27
COMPILED FOE TIE ARxAHsAw TRAvxLnn
 SCIENTIFIC MISCELLANY.

Nasuralists and others are becoming considerably alarmed over the prospect of the carly extermina- tion of the kAngAroo.
 Dr. Foster, director of the University Ophthal- mic Clinique ct Breslau, believes that . common cause Of -dghtedness In the young s restric- ton of the circulation produced by the wearing of tight 6tting collars.
 Dr. ". J. BeAl, of the Michigan forestry com mission, counts seventy species Of indigenous trees growing wild In Michigan with three exotics escaped from cultivation; and of wild shrubs, l5O native and i've escaped exotics.
 At the Greenwich observatory I,O6s hours of sunshine were recorded in isss about 25O less than the average of the preceding eleven years and sss below that of 1887. The aggregate number of hours the sun was above the horizon was 4,466.
 In an improved method of wire making the wire is drawn cold successive pairs of rolls, each pair having greater speed than the pair pre- oedipg it. with an intervening friction clutch to graduate the speed of the rolls to the speed of the wire In process of rolling.
 French metallurgists have made the polariscope serve . thermometer. The color Of e mass of glowing metal varies according to Its temperature, and ray of the light when polArixed is rotated by plate of quarts to a degree dependent upon the color. The polariscope measures the degree of rotation, and gives c useful temperature scale.
 DEPORTATION AND CoMBus usrIox.-The singular fact has been pointed out that ton of sevcn.eighths inch dynamite cartridges, placed end to end and reaching about one mile, would Do consumed in about quarter of a second If . cartridge at each end were denotated, while If such train were sim- ply ignited its combustion would require several mil n tee.
 A NEw PIGMENT.-A pigment having the prop critics and appearance of Indian ink Is prepared In a simple manner by Mr. B. Piffard. An excess of camphor Is submitted to the action of strong sul- phuric acid for twenty -four hours, yielding red dish geatnous mass This Is heated until the sul- phurous acid and excess of camphor are expelled when the fine black pigment Is left.
 AN AUTOMATIC PHoroGRAPHER.-An ingenious French inventor has produced Q selfacting photo graphic apparatus. Argentine piece dropped
 in the slot of the machine sets in motion the neces sary series of operations the exposure being given after due warning upon one of four dials indicat- ing the progress of the work, and within i've min utes a finished picture :s turned out.
 A REMARKABLE PENpULUM-Th most perfectly operating pendulum ever constructed is probably that at the University of Glasgow. shot six teenth of an inch in diameter Is suspended by single fine silk fibre two feet long in glAss tube three -fourths of an inch In internal diameter the air being exhausted to about one ten- millionth. Starting with motion ofa quarter of an inch to either side of the center, the vibrations may be counted after . period of fourteen hours. ELECTRICITY DIRECT FROM WoRK-The accom- plishment of hitherto impossible feat-that of tansforming mechanical work direct into cleo tricity-is claimed by Prof Braun, of Tubingen. lie nas s0ccoc0cu n tnls Oy the us6 ot nlckei Wlfe wound into spirals. As the spiral Is elongated or compressed, . current of considerable strength Is generated, and this Is increased by putting in cir cult number of spirals. The experiments have given such positive results that the Anguine ex- perimenter Is hopeful of constructing useful gen. erator on this principles thing greatly to be desired, truly.
 CURIOUS COMPUTATOEs.-An electrical writer has calculated that the firing of small pistol sets free about 600 foot-pounds of energy, while a watch consumes about one 54-millionth Of 6 horse power the energy of the bullet being sufficient to keep the time for two years. An Edison telephone transmitter requires about a thouandth of the energy in a watch; it would therefore be worked for two thousand years on the energy exerted in the pistol A lightning flash of 300 900 volts and