This is an article from Amateur Work Magazine Vol6 published in 1907.
"The following instructions for constructing a hammer actuated by electricity will be found useful in making any device in which a "sucking solenoid" is required. The sizes of the parts, the gauges and proportions of the wire given, are suitable for a small hammer capable of working off a 4 volt accumulator, or off a couple of quart size bichromate batteries, connected up in series; but by increasing the size and varying the amount and gauge of the wire used to wind the solenoid, the size of the hammer can be increased and the winding altered to accomodate the Â£. M. P., E.M.F., or " voltage "of the current supplied.http://chestofbooks.com/crafts/popular- ... ammer.html
"When the hammer is In its normal' position on the anvil, its weight drives the sliding contact down, so that it completes the circuit between itself and the two springs; the current circulates round the Solenoid, and the hammer is now slicked up into the tube. On reaching nearly to the top of its stroke the washer on the hammer catches in the upper arm of the sliding contact, thus raising it and breaking contact below. The 'hammer immediately falls, and in so doing its washer catches in the lower arm, driving down the slide and re-establishing the contact."
This is only if you are interested in solenoid motors...