|"In this instrument, contrived by Dr. Page [in 1838], two electro-magnets of the U-form ... are firmly secured in a vertical position, the four poles appearing just above a small wooden table. The two armatures..., connected by a brass bar, move upon a horizontal axis in such a manner that while one is approaching the poles of the magnet over which it is placed, the other is receding from those of the other magnet. The brass bar is connected with one extremity of a horizontal beam, the other end of which communicates motion by means of a crank to a fly-wheel. On the axis of the flywheel ... is the break-piece. Each magnet being charged in succession, the armatures are attracted alternately, communicating a rapid reciprocating|
A prototype of this apparatus, made by Davis in July 1838, was used to power a drill used to drill the steel plates for gas burners. Page claimed that this was the first example of the mechanical application of electro-magnetism.
This apparatus is on loan from Vassar College to the Smithsonian.
The four examples below are probably by Palmer and Hall, the successor
company to Daniel Davis; the Harvard engine has a Palmer and Hall plate.
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