The Montgomery advertiser., 1903-03-22
SCIENTIFIC MISCELLANY
NEW DUST FIGURES-WHITE LIGHT FOR DARK" ROOM.
A Promising Heater--An Imitation River-A Fast Growing Fish The Best Foods-The Secret
 of Magic Mirrors.

Curious figures are obtained by pr. w. J. Russell when magnesia dust or other of glass, copper, ebonite, cardboard or other material, the plate being about l2 degrees C. warmer than the air. The best retults are obtained when the dust gentis 1ettles over the plate during the cooling. The figures vary with the shape of the plate, usually showing radiations from the angles, and they are affected also by any neighboring object. such as an upright pin at the edge of the plate. or a piece of glass over 1t. After a week or a fortnight the dust figures become so adherent that they can be brushed gent ly without injury.
 Non-aetinic white light, first made known by a French photographer some years ago. Is produced by Altering sun- light through colorless solution of three parts of nickel chloride and one part of cobalt chloride, ultraviolet rays being absorbed by coating the containing yes sel with coilodion mixed with sulphate of qulnine slightly calculated with sulpnuric acid. Sensitive paper has been exposed to this filtered white light for week without change.
 The electric radiator of E. G. Rivers has a layer of finely powdered retort car bon held between enamelled Iron plates and kept in position by asbestos card board. copper strip Is led In at the center. with another at each end, and continuous current is passed from the center strip to the outer two. A cur rent of eight ampheres at 20 volts keeps a heating surface of 25 square feet at an average temperature Of 1SO degrees, F.
 An experienced rifieman has noticed that the position of a target appears to change from hour to hour during the the aim and sight-correction that will hit the bullS-eye at noon will nit 10 the left and above in the morning and to the right and below in the afternoon.
 A Laboratory of River Hydraulics, with an artificial river for studying the work of streams is A novel feature of the Technical Institute at Carlsruhe. The river" is a tank. with suitable inlets and outlet and a simple mechanism for varying the inclination. When the erect of the current in any channel Is to be investigated, a careful survey of DOT ton of the real river is first made. Then the tank is given the proper slope. and the natural conditions are reproduced on small scale, little bags of shot being used to consolidate the sand Of the banks and to represent either the stones of faced embankment or the boulders of Eravelly soil. The bottom is covered with two and a half inches of sand. In order that only the stage of flow desired may produce any effect upon the bed. the tank Is provided with means for carefully nll- ing before the outlet Is opened. and for emptying very slowly at the end of the experiment.
 The Parisian Idea of introducing cleo. tricity into billiards Is ingenious at least. In the center of the table is placed plate of some easily electrified substance, and the balls are of compressed pitch. the chalk The balls being influenced by the electrified plate, caroms are difficulA The player finds exercise for greater skin than ever, 1t Is claimed. and the new difficul- ties add Eest to the game.
 Observations on the growth of fishes are sought by returning to the water healthy specimens that have been weigh ed and tagged. Among the fishes .retaken in English waters last year were @ sea trout that had increased from three pounds to six in one year. a salmon that had risen from thirteen pounds to twen- ty-one in eighteen months and .- male salmon whose weight seems to have shown an extraordinary and astonishing growth from nineteen to thirty-thrSs hounds in thirty d@y&