The electric generator is a static induction machine of very small size, and the arrangement of which will be understood by reference to Fig. 1, which gives a general view of the apparatus with a portion removed in order to show the relative position of the different parts, and to Fig. 2, which shows the latter detached. A is an ebonite cylinder containing the entire machine, and closed above by a cap of the same substance upon which is screwed the lighting rod. The cap is traversed by conducting wires which end in two contact springs that establish an electric communication with the lighting tube. Two inducting armatures of tin are cemented to the interior of the cylinder, A, and occupy, each of them, about a third of its circumference. The bottom of the cylinder, A, supports six contact springs, parallel with each other and constituting three distinct pairs which are properly connected, two by two, with the different parts of the rest of the apparatus. The movable or induced cylinder, B, of ebonite is provided with six equidistant and insulated thin sheets of tin of a width nearly equal to the interval which separates them. This cylinder is given a rapid rotary motion by means of a system of rack and gearing every time the button, F, is pressed. During the revolution of the cylinder the six insulated plates come successively into communication with the six springs, and these put them successively in communication, two by two, first with the fixed inducting armatures, second, with the conductors connected with the two points between which the spark is to pass, and, third, with each other. The apparatus operates, then, like Sir William Thomson's replenisher. It is only necessary for the armatures upon the cylinder, A, to be at the start at a difference of potential as small as desirable to suppose it, in order to have the play of the machine multiply the charge and soon give it sufficient tension to cross the interval that separates the two points fixed at the extremity of the lighting rod, G. From a technical point of view, the ingenious and new idea resides in the application of a multiplier of charges with which the priming and operation are always secured, provided the insulating parts are so dry that the losses due to dampness are inferior to the machine's power of production. This result, moreover, is easily attained by the use of a hermetically closed system, and of drying substances placed in that part of the cylinder which forms the handle of the apparatus. From a mechanical point of view, the lighter contains a series of practical and simple arrangements which make it an apparatus at once convenient, strong, and sufficiently perpetual, as regards duration, to partially justify the name that has been bestowed upon it by its inventor, Mr. J. Ullmann.--_La Nature_. INSULATORS FOR TELEGRAPH AND TELEPHONE LINES.