Lequeux-Wiesnegg Apparatus (Figs. 5, 6, and 7).--The apparatus represented in Fig. 5 is capable of being used in lecture courses. It consists of a tank, B, and a holder, A, which is provided at the top with a wide aperture closed by a hydraulic plug, F. When the apparatus is at the bottom of its travel and ready to be filled with acetylene, the plug, F, as well as the basket, D, and the bucket, E, are removed. The quantity of carbide necessary to fill the gasometer is introduced into the basket. After care has been taken to put a certain quantity of water into the gutter forming the hydraulic joint of the plug, F, the parts, E, D, F, are introduced into the tube, C, in operating rapidly enough to prevent the loss of gas. The holder immediately rises as a consequence of the production of acetylene. The gas redescends through a tube to the bottom of the tank and rises laterally in a column by serving as a guide to the holder and as a support to the cocks designed to send the gas to the points of utilization. A cock, H, placed at the lower part of the apparatus, permits of clearing the piping in case a condensation of water occurs. [Illustration: FIGS. 5, 6, AND 7.--LEQUEUX-WIESNEGG ACETYLENE APPARATUS.] The apparatus represented in Figs. 6 and 7 is continuous. It consists of an apparatus with two holders, that is to say, so arranged as to put the least liquid possible in contact with the gas produced, and to thus prevent absorptions and losses. This gasometer consists of a tank, A, of a movable holder, C, and of a stationary holder, B. The generator, E, is formed of a cylinder, at the bottom of which there is a bucket, F, designed for the reception of the greater part of the lime resulting from the reaction. It is closed by a cover, G, arranged with a simple or multiple joint, according to the precision that it is desired to obtain and that may reach 30 centimeters of water. The figure represents the holder at the bottom of its travel.