The Electrical Review Volume 13

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1883 Excerpt: ...a mixture of soapsuds and olive oil. The sensibility of the apparatus was, besides, pretty evident, since the brake being loaded with 54 kilogrammes, the addition of a weight of 50 grammes was sufficient to upset equilibrium. The maximum work of the turbine working under the best conditions of speed, measured bv means of this apparatus, was found to be equal to 27 H.P. Calling P the load of the brake, N the number of revolutions per minute, and L the length of the arm of the lever, the work is expressed by the following formula: --r==--4500-'00349 Nfl P At Grenoble, the work received was measured by a brake of smaller dimensions, mounted on the pulley of the receiver. The arm of the lever being 0-815, the formula was r = 0-001138 np. They then proceeded as follows: --The turbine was started with the generator out of gear, i.e., turning only the loose pulley of the counter-shafting. The brake at Vizille was then put in equilibrium with a load, P, and N was counted. A weight, /?, was then placed on the Grenoble brake and the generator was put in gear. The equilibrium was destroyed: it was restored at Vizille, so as to reproduce exactly the speed, N0, of the axle of the brake, which was obtained within about one revolution. The load at Vizille became P1, and, when equilibrium was restored, the indications of the two brakes were observed simultaneously. With these conditions, it is evident that the work expended by the generator and the counter-shaft, or the gross motive work, is expressed by the formula: --Tb = 0-00349 (P-P'). In this equation it is taken for granted that the total energy furnished by the turbine does not vary during the experiment. In order to insure that this last condition was fulfilled, after each series of experiments, i.e...