. American engineer and railroad journal . , and soon developed an electricmotor weighing but 33 lbs. per horse power (primary bat-tery not included), which rotated an improved marine screwsome 2,400 turns per minute.* In 1886 he exhibited to the French Academy of Sciencesa new method of constructing geometrically accuratescrews by a process so simple that any workman cancarry it out, and that the cost is very much has also experimented, ever since 1867, with aerialscrews, and has reached the conclusion that for the latterthe best results are obtained when the pitch is equal to thed
. American engineer and railroad journal . , and soon developed an electricmotor weighing but 33 lbs. per horse power (primary bat-tery not included), which rotated an improved marine screwsome 2,400 turns per minute.* In 1886 he exhibited to the French Academy of Sciencesa new method of constructing geometrically accuratescrews by a process so simple that any workman cancarry it out, and that the cost is very much has also experimented, ever since 1867, with aerialscrews, and has reached the conclusion that for the latterthe best results are obtained when the pitch is equal to thediameter, or a little contrary to marine practice,where pitch is generally times the diameter. In 1887, at the Scientific Congress at Toulouse, and in1888, before the French Societe de Physique, M. Trouveexhibited the electric motor and aerial screw representedin fig. 35. The motor is the lightest ever built, weighingbut oz., and developing 868 foot-pounds per minute,or at the astonishing rate of I horse power for each Fig 35.—TROUVE—1886. lbs. weight. It is wholly of aluminum, except the mag-netic circuit, which is necessarily of very soft iron ; andthe armature is directly connected with a very light aerialscrew, geometrically perfect, whicli was constructed bythe process communicated to the French Academy of Sci-ences. This apparatus, upon being placed in one pan of a pairof scales, and connected with a source of electricity of 40Watts constant delivery, lightened itself of its entire weightby action upon the air. To make the experiment morestriking, M. Trouve then arranged it at the extremity of abalanced beam, as shown in the figure, connecting it withthe electric supply through the standard, the knife edgesand the beam. Then upon turning on the current, thescrew began to revolve, and the balanced beam rose fromthe position A B into the position A B , with the expendi-ture ot 868 foot-pounds per minute, which M. Troiize capable of raising i
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
