6 Charles Grafton Page. 
{this J daft Ist series, vol, xxxii,) he contrived several other 
rere of self-acting t breakers, one of which consisted of 
miniature vibra tated lever moved by the action of the current 
sal so limited and regulated in the extent of its motion by a 
set screw as to give it “the extremest rapidity of oscillation de- 
sired. The breaking of the circuit of a voltaic current by the 
action of the current itself was done some years previously in 
the electro-magnetic motor of Prof. Henry, already mentioned, 
but Prof. Page aces to have been the first to contemplate 
the availability of this mode of action to produce the extreme 
rapidity of siernation called for in these induction machines,* 
and to make and bring before the public a construction em- 
bodying this idea. This early instrument is, in this respect, 
the type of the self-acting ao now very generally 
used with the voltaic induction 
The discovery of the rematkable effect produced by substi- 
tuting iron wires fora solid iron bar in induction coils, was 
made by Sturgeon, by Bachoffner, and by Page, all indepen- 
dently of meh other, but the rent! 4 the ‘English te, 
soon manufactured in large numbers in this country. The 
cnly considerable improvements made since that time, apart 
om the eeeenenon by Ruhmkorff upon a greatly enlarged 
scale, are the invention by Fizeau of the condenser, as it i 
rather inaptly called, and Richie’s improved mode of iodine 
the secondary, or induction, coil of fine wire, as to divide, 
a st all possible injustice, we extract the following from Prof. 
Hany paper in Get xx, 1831, of this Jou urnal, as republished by Prof. Page in 
the American ig Seam ag Journal, vol. i illati 
electro-magnet o enry’s motor was “ about seven inches long, and movable on 
an axis at the center.” “If the tumblers be filled with strong diluted acid, the 
motion is at first apid and powerful, but it soon almost entirely ceases. 
partially filling the tumblers with weak aeid, and uan 
is 
Big 
tity of fresh acid, a uniform motion at the rate pra oan. Lapel five vibrations inamin- 9 
hour. 
ute, has been kept up for more than an 
