. Bulletin. Science. Figure 66.—Page's rotating motor. From American Journal of Science, 1838, vol. 35, p. 262. was a paddle wheel, where an armature was kept in constant motion by a commutator switching on a field to tease the armature ahead at the right time. The engines of Ritchie, Jacobi, Davenport, Davidson, and Froment were of this second form. After mid- century there was a further proliferation of electric motors, but no new basic types were introduced until the advent of AC power. In spite of the sanguine hopes of many of the early inventors, most scientists and engineers could not se
. Bulletin. Science. Figure 66.—Page's rotating motor. From American Journal of Science, 1838, vol. 35, p. 262. was a paddle wheel, where an armature was kept in constant motion by a commutator switching on a field to tease the armature ahead at the right time. The engines of Ritchie, Jacobi, Davenport, Davidson, and Froment were of this second form. After mid- century there was a further proliferation of electric motors, but no new basic types were introduced until the advent of AC power. In spite of the sanguine hopes of many of the early inventors, most scientists and engineers could not see any advantage in the use of electric power over that of steam. The greatest difficulty in the use of elec- tricity lay in the relatively high cost of production of electrical power in comparison with that of steam. Instead of consuming coal in a chemical reaction that produced heat and the expansion of water, one dissolved a metal in an acid in a chemical reaction. Figure 67.—Page's reciprocating motor. From American Journal of Science, 1838, vol. 35, p. 264. that produced an electrical current. Metals and acids were much more expensive than coal and water. A few engineers and scientists calculated just how much more expensive it was to produce an electrical current than it was to produce steam. In 1846 Scoresby and Joule '" estimated that an electric motor could raise 80 pounds a distance of 1 foot for each grain of zinc consumed, while the best Cornish steam engine would raise 143 pounds the same distance for each grain of coal that was burned. Page had estimated the cost of his 1850 motor as greater than that of the cheaper steam engines but less than that of the highest priced ;^ Robert Hunt made an even more adverse estimate than Scoresby and Joule had made when he calculated in 1850 that electrical power was 25 times more expensive than steam ;' Obviously the electric motor could not 1" William Scoresby and James Joule, "Experimen
Size: 1566px × 1596px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorunitedstatesdepto, bookcentury1900, booksubjectscience
