THE NEW ELECTRO-MAaNETIC MACHINES. 
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greatest brilliancy, as also did a splendid bluish line far in the 
violet portion, and probably due to the incandescence of the 
nitrogen of the air. 
When the carbons were placed horizontally between the 
actual terminals of the machine, without any reflector whatever, 
the light was diffused all over the room with the most agreeable 
softness, nothwith standing its intensity, and a modification of 
some such natural method would appear to be an excellent one 
for illuminating large squares and other public open spaces. 
Even in broad daylight Mr. Wilde’s electric light had the 
power of throwing the distinct and beautiful shadow of a 
burning wax candle on a screen upon the wall 50 feet distant, 
marking out with exquisite perfection the gaseous core of the 
flame, bordered by a bright outline of the section of the flame 
itself, whilst the small inner flame, at the extreme point of the 
wick, was also shown in darker shadow, outlined with a fainter 
line of light. It cast the shadow of the flame of burning 
magnesium as black as night upon a wall eight feet distant, an 
evidence unmistakeable of the superior intensity of the electric 
beam, for supposing the shadow to have been that of dense 
fumes within the flame, it must not be forgotten that one side 
of the magnesium fire was still throwing all its powerful rays 
upon the screen over its own shadow, produced by the more 
distant electric light. 
The heating power of the machine was shown by the fusion 
of a bar of iron, 15 inches in length, and more than a quarter of 
an inch thick ; whilst upwards of 7 feet of ordinary iron wire, 
such as is used for the fencing of fields, was brought to white- 
ness, and along its entire length tears of molten metal trickled 
fast and freely down, until the attenuated wire broke, and fell 
upon the floor. 
The most marvellous exhibition, however, was the actual 
fusion of a bar of platinum, 18 inches in length, and 0*21 
inch in diameter. The high temperature at which platinum 
can only be melted is very well known. Indeed, it is by the 
oxy-hydrogen blast alone that platinum can be commercially 
prepared. A bar of platinum, 030 in diameter, was afterwards 
fixed to the terminals, 9 inches apart, and maintained for a 
short period at incandescent whiteness, but fusion was not 
allowed to take place, the platinum being rather too expensive 
a material to play freely with. The bar thus experimented 
upon was in value about £25. 
Of the effect of the current from Mr. Wilde’s machine when 
sent through an induction-coil, some indication was given 
in the effects produced upon a large instrument which had 
been prepared by Mr. Ladd for a smaller electro-magnetic 
machine. This coil consisted of four miles of No. 27 copper wire, 
