We have now at Central University a singularly beauti ful experiment in operation, showing the motion of the earth. It has been contrived and successfully completed by Profes sor T. W. Tobin, who has charge of the department of chem istry and physics in the University. The apparatus may be briefl y described as follows: Upon an iron stand, about six feet in height, an exceedingly delicate pendulum is suspend ed; attached to the upper portion is some mechanism and a fi ne index needle. The

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... tus was brought to a state of perfect repose, and then the pendulum, by means of a fine silk, vibrated north and south. In the course of six minutes the index �howed that the normal relation between the pen· dulum and the earth had altered, and a longer in, terval in dicated an increased variation. In 1851 Foucault, a French scientist, reasoned �hat wh ile all bodies are governed by gra vity, independent motion is not: that in virtue of inertia, a body moved will continue in motion forever; so a pendulum once started in vibration will continue to oscillate in the same direction until gravity and the friction of the air bring it to a state of rest. The earth's revolution being a circle, there must be a vari able relation between the two motions, namely, the circle and the straight line of the pendulum's direction. The ap paratus now described shows this reiatioll. An experiment was made by Foucault in Paris with a pendulum over 200 feet long; a similar experiment at Bunker Hill and then at Yale College prove the principle: but the apparatus em ployed was cOdtly and cumbersome. The instrument at Central University is simple and' delicate, and is calculated to create interest in scientific clrcles.-Kentucky Registm', Riclvrrw nd, Ky. ••••• Hot Water Cor Tire Shrinking oC Wheels.