he pushed with his hands against the ceiling, increasing the downward
pressure on the rod, which was only acted upon as a powerful spring
would have been, but still maintaining its perpendicular position
concentric to the inner surface of the helices. I held,' says the
reporter, 'an iron rod in my hand, with the end of which I touched
that of the suspended rod. I could not detach it by pulling or
jerking, and could only alter its position so as to cause the annular
space to become eccentric instead of concentric. The instant the
battery was disconnected, the rod fell to the floor with its full
force.'

By moving the wires from the battery up and down outside the pile of
helices, it was clear that an upward and downward movement of the rod
would follow, 'and that a shackle-bar attached from this oscillating
rod, and to a crank, would convert this reciprocating motion into a
continuous one.' To this contrivance the name of 'Jumper' was given,
of which one was exhibited, the helices weighing 800 lbs., and the rod
526 lbs.; and by the means above mentioned, it has been converted into
a working-engine, with a twelve-inch crank, and a fly-wheel of four
and a half feet in diameter. 'On the outside of the helices,' to quote
the description, 'was placed a line of pieces of metal, so arranged as
to render the attachment with the battery and its necessary
alternations performable by the engine itself. Before starting the
engine, I tied an arm of the fly-wheel, at one-third greater distance
from the centre than the length of the crank, to an upright beam of
twelve inches diameter, which formed part of the frame of the engine.
The cord used was the better kind of bed-cord, of great strength,
nearly three-eighths of an inch thick. This was passed twice round the
fly-wheel arm and post before being tied, and with pieces of
sole-leather intervening, to prevent the cord being cut by the corners