other cause at the high rate of speed that is necessary for economical working. The bearings are oiled by a small screw propeller, I, attached to the shaft. The oil in the drain pipes, D and F, and the oil tank, D, lies at a lower level than the screw, but the suction of the fan, K, raises it up into the stand pipe, H, over and around the screw, which gripes it and circulates it along the pipes to the bearings. The course of the oil is as follows: The oil is forced by the propeller, I, and oils the bearing, A. The greater part passes along the pipe, E, to the end bearing, C; some after oiling the bearing, C, drains back by the pipe, F, to the reservoir, D; the remaining oil passes along through the armature spindle, oils the bearings, B, and drains into the reservoir, D, from which the oil is again drawn along the pipe, G, into the stand pipe, H, by the suction of the fan, K. The suction of the fan is also connected to the diaphragm, L, and forms, with it and the spring, M, the principal part of the governor which actuates the throttle valve, V. Fig. 4 is the electrical control governor, which will be further described in connection with the dynamo. It acts directly upon the controlling diaphragm, L, by admitting or closing a large access of air to it, and thus exercises a controlling influence upon it. The dynamo which forms the other portion of the electric generator, Fig. 1, is coupled to the motor spindle by a square tube coupling fitted on to the square spindle ends. The armature is of the drum type. The body is built up of thin iron disks threaded on to the spindle and insulated from each other by tracing paper. This iron body is turned up and grooves milled out to receive the conducting wires. For pressures of 60 to 80 volts there are fifteen convolutions of wire, or 30 grooves. The wire starting at b, Fig. 6, is led a quarter of a turn spirally, c, round the cylindrical portion, a, then passing along a groove longitudinally is again led a quarter turn spirally, d, round the cylindrical portion, a, then through the end washer, and back similarly a quarter turn, e, then led along the diametrically opposite groove, and lastly a little over a quarter turn, f, back to g, where it is coupled to the next convolution. The commutator is formed of rings of sections. Each section is formed of short lengths. Each length is dovetailed and interlocked between conical steel rings. The whole is insulated with asbestos, and, when screwed up by the end nut, forms, with the steel bush, a compact whole. There are fifteen sections in the commutator, and each coupling is connected to a section. The whole armature is bound externally from end to end with brass or pianoforte steel wire. The magnets are of soft cast iron and of the horseshoe type. They are shunt-wound only.