The electro-magnetic machine invented by Professor Page, has from time
to time been noticed in our Journal, and we have now to give a further
account of this interesting mechanism, as furnished by an American
periodical. It appears that several of these machines have lately been
submitted to critical examination by competent authority at
Washington, and with very favourable conclusions. The principle has
already been explained--namely, the alternate rising and falling of an
iron rod within a helix through which an electro-magnetic current is
made to pass: when the current is _on_, the rod rises, and remains, as
it were, self-suspended, equidistant from all parts of the surrounding
helix; and falls as soon as the current ceases by breaking contact
with the battery. The 'rod' of one of the machines submitted to the
examination weighs 350 lbs.: no sooner, however, was contact made,
than it rose into its position. 'Dr Page then stood on the top of the
rod, which not only sustained his weight, in addition to its own, but
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
of the post. Such a fixture, I am confident, would have held a five
horse-power steam-engine from starting, with full pressure of steam on
the piston, and no previous motion. Not so, however, with this engine,
for the breaking of the cord and contact with the battery occurred at
the same instant of time, leaving an impression in the beam to the
depth of the cord, despite the protection of the sole-leather.' The
engine continued to work in the most satisfactory manner; and Dr Page
attached a circular-saw, which was used in wood, to a depth of six
inches, and at a speed such as could be anticipated from the power
which we afterwards found the engine to possess.
Careful experiments made to test the power of the engine, shewed it to
be equal to seven horse nearly; and the estimate for consumption of
acid and use of zinc is twenty cents for each horse-power per day of
twenty-four hours. The escape of acid vapours from the batteries is an
evil that will have to be guarded against, to prevent the pernicious
effects produced in several electro-plating establishments, where the
health of the workmen has been seriously injured by the liberated
gases. This defect being overcome, Professor Page's electro-magnetic
engine may become highly valuable in engineering and manufacturing
processes. To quote the conclusions of the report--'the cost will be
less than that of a steam-engine of the same power: the weight will be
but one quarter, if boilers and contents be taken into account: the
expense of firemen and engineers is dispensed with: buildings, and
stocks of goods, and vessels may be more cheaply insured than when
steam-engines are used, as there could be no risk from explosion or
fire: the expenses are only active while the machine is positively in
action, whereas an ordinary steam-engine continues its expenses
whenever the fire is burning.
'Dr Page's engine, if used ten times during the day, of six minutes
each time, would have but one hour's expenses for the day; whereas a
steam-engine, under similar circumstances, would be subject to nearly
or quite the full expenses of fuel for twenty-four hours, or equal to
the expenses of continuous work.'