136 
A comparison between the power of the new machine 
and that of the 10 inch machine will show that while the 
current from the former fuses 12 feet of iron wire O'OTo of 
an inch in diameter, the current from the latter fuses only 
7 feet of wire 0'065 of an inch in diameter ; and is, con- 
sequently, only about half as powerful as that from the new 
machine. Besides this, the quantity of copper used in the 
construction of the new machine is about 3Jcwt., and of iron 
15cwt. ; while the weight of these metals in the 10 inch 
machine is 29cwt. and 60cwt. respectively. In other words, 
we have in the new machine a double amount of power, 
with less than one-fourth the amount of materials employed 
in the construction of the 10 inch machine. Another 
advantage possessed by the new machine is the great 
reduction of temperature in the armatures by their rapid 
motion through the air, which acts much more efficiently 
than the circulation of water through the magnet cylinder. 
By increasing the diameter of the electro-magnetic circles, 
conjointly with the number of electro-magnets and arma- 
tures, the angular velocity of the machine may be so 
diminished that it may be driven directly from the crank 
of a steam engine, concurrently with an increase of electric 
power proportionate to the number of electro-magnets and 
armatures in the electro-magnetic circles. 
In Ms paper “ On a Property of the Magneto-electric 
Current to Control and Render Synchronous the Rotations 
of the Armatures of a number of Electro-magnetic Induction 
Machines,”* the author stated that this property would be 
available when the machines were used for the electro-deposi- 
tion of metals from their solutions. It has, however, been 
found that the small resistance presented by depositing solu- 
tions to the passage of the currents, prevents this property 
from manifesting itself (in accordance with what the author 
* Proceedings of the Literary and Philosophical Society of Manchester, 
December 15th, 1868, 
