Fig. 3 represents the arrangement of the first stationary boiler of the new kind. The letters of reference will suffice to indicate the position of the principal parts of it, the forms of which may be varied according to the object for which the boiler is to be used. [Illustration: FIG. 3.--COMPLETE VIEW OF A SERPOLLET BOILER. 1. Exterior view. 2. Cross section. 3. Horizontal section at the height of the tube.] Messrs. Serpollet are occupied at present with studying the special arrangements which will be needed for connecting their boiler with a quadricycle, a torpedo boat, a stove, a locomotive, or a stationary machine of 10 horse power, and with rectangular parts. The inexplosibility of their boiler has been tested during an experiment made before the engineers of mines, on which occasion a manometer (steam gauge) graduated for a pressure of upward 200 kilogrammes per square centimeter was used, and the pressure raised far beyond the limits indicated. The result was that the hand of the manometer, being pressed against the walls of the box, became bent, and though the boiler was submitted to a pressure the degree of which it was impossible to measure, it was not changed in the slightest. Incrustation of the boiler is not to be feared, for, in consequence of the great velocity with which the steam circulates through the tube, the solid matter dissolved in the water becomes pulverized and is forced out, mechanically assisting to lubricate and polish the parts of the motor. The invention of Messrs. Serpollet is still too new to foretell all its possible applications, but their apparatus, in its present form, is exactly the steam generator which will be useful for producing a small motive force; while it will be necessary to wait until it has been ascertained, by further study, how the system can economically be used for high motive power. The most natural and immediate application of the invention seems to be its use for the electric lighting of restaurants, in which case one of the instantaneous vaporization tubes might be connected with stoves which remain lighted all day, and which might thus besides supply the necessary motive force to work a small dynamo charging some accumulators.--_E. Hospitalier, in La Nature._ * * * * * GAS LIGHTING BY HIGH-POWER BURNERS. In the course of a communication presented to the Societe Industrielle du Nord de la France by the manager of the Wazemmes Gas Company, he made the following remarks on gas lighting with high-power burners: