_Schrab carburator._—The idea of this apparatus is quite original. The jacket for cooling the motive cylinder is filled not with water but with the hydrocarbon to be vaporized. From thence it passes at a temperature of about 180° F. into a carburator containing several compartments, and through which pass part of the products of combustion; these gases passing through the already boiling liquid hydrocarbon become saturated with its vapour, but require admixture with air before they are capable of being exploded. The inventor states that the waste gases only take up 1/16 part of that which pure air would in passing through the hot liquid fuel, and thus explains the extraordinary economy of fuel which is obtained by these motors, only 1/16th of a litre of gasoline being necessary to produce one horse-power hour. This is a very remarkable result, and if it is correct places this combined plant in the foremost rank of carburetted air engines. _Meyer carburator._—This apparatus has the advantage of allowing heavier and cheaper oils to be used, at the same time completely volatilizing them. The heavy hydrocarbons are allowed to fall drop by drop into a steel chamber about eight centimetres diameter and four centimetres in height, heated by a flame. The vapour is produced at a high pressure, and escapes through a fine nozzle at high speed drawing the necessary air with it. Entering a reservoir this explosive mixture is prevented from returning by a check-valve. The apparatus is so arranged, that when the pressure in the reservoir has reached a certain point, the flame heating the vaporizer is turned down and prevents further explosive mixture being formed. The apparatus is therefore self-regulating, the supply of carburetted air being always proportional to the demand. _Delamare carburator._—M. Delamare-Deboutteville has devised a very compact carburator for use with his Simplex motor. Gasoline is contained in an upper vessel, from which it flows in a fine stream from a tap on to a horse-hair brush, and is there met by a similar stream of warm water coming from the water jacket of the cylinder. The heat obtained from this source tends to vaporize the hydrocarbon, and the two liquids fall together into a closed vessel. The gasoline rids itself of its impurities and floats on the surface of the water, which is withdrawn from underneath it by a siphon. The hydrocarbon vapour produced during the fall, and afterwards by the heat of the substratum of water, passes by a check-valve to the motor. It is found that the cleansing effect of the water renders the cylinder much less liable to become fouled by tarry products.