a Tig. 2. 



Figure 52. — Watkins' motors. From Philo- 

 sophical Magazine, 1838, vol. 12, pi. 4. 



to use his motor to drive a boat 28 feet long, 7)^ feet 

 wide and dravi'ing If^ feet of water. ^^ Carrying a 

 dozen or so officials of the Russian government, this 

 boat moved at the speed of 1}^ miles an hour on the 



Figure 53. — Jacobi's motor. From Sturgeon's 

 Annals of Electricity, 1837, vol. i, pi. 13. 



Neva river. The following year, using the same 

 motor, Jacobi found he could double the speed by 

 using 64 Grove cells with the same electrode area. 

 One suspects the fumes from the 64 cells probably 

 contributed as much to the dropping of the project 

 as did the breakdowns of the motor. 



The first inventor to build an electric motor able to 

 perform useful work was probably Thomas Davenport, 

 a blacksmith of Brandon, Vermont. ^^ In 1833 

 Davenport was so fascinated by the operation of one 

 of Henry's electromagnets that he bought one. By 

 July 1834 he had worked out a motor with a 7-inch 

 flywheel that rotated at a speed of 30 rpm. Using 

 a shunt-wound motor for drive, Davenport built a 

 motor on rails that is usually called his miniature 

 "train" (fig. 54). He had applied for a patent on his 

 electric motor in 1835, but the fire at the Patent 

 Office in Washington destroyed his application 



'Jacobi, op. cit. (footnote 52). 



92 Franklin L. Pope, "Tfie Inventors of the Electric Motor," 

 Electrical Engineer, 1891, vol. 11, pp. 1-5, 33-39, 65-71, 93-98, 

 125-130; Walter R. Davenport, Biography of Thomas Davenport, 

 Montpelier, Vermont, 1 929 ; Mary Somerville, Electromagnetism — 

 History of Davenport's Invention of the Application of E'ectromagnetism 

 to Machinery, New York, 1837. 



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