New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1903-09-14
ALTVTyTu CONDUCTORS.

Few people realize 10 what extent aluminium
has recently been used in place of copper for
the transmission of electricity. Something of
a sensation was produced i'm 1900 when the
former metal was adopted for the new power
line betW cen Niagara and Buffalo. about twenty
miles in length: but little has been heard about
its subsequent introduction elsewhere. The in
formation which Alton u. Adams supplies in
The Engineering Magazine for September.
therefore affords more or less of a surprise.
At least half dozen other transmission lines
are mentioned, Of which two, in California
are respectively five and over seven times as
long as the one in Western New-York. At
the least calculation. fully a thousand tons
of aluminium have been devoted TO this service,
without counting the cables used for diStribut-
ing current to sub-statiops for railway opera
tons and electric lighting in other parts of the
country.
One can appreciate what a formidable COM
petitor the new candidate for favor is when he
makes a comparison Of its conductivity. weight
and cost with those of what was once the sole
resource OF the electrician. In tne.first Of these
particulars aluminium is inferior TO copper.
Hence an increase of 60 per cent in the size
of wire is needed for the performance of the
same work. However, only half as many
pounds Of the white metal are required as Of
the red because the latter bulk for bulk, is
more than three times heavy as the former.
When the price Of copper was over Il cents a
pound, aluminium at 81 cents was equally eco
nOmical. With the one at II cents and the
other selling for 80, the relation is the same.
The most trifiing increase in the cost of copper
or decrease in that of aluminium would make
the employment of the modern substitute dis
tinctly cheaper than that of the old favorite.
-
Of aluminium which commend it TO electrical
engineers. Inasmuch as a diminution in
weight may be secured by its use. the poles
may he placed further apart. or lighter arms
and pins used. In either ease, the construction
OF line would be made less expensive. With
aluminium the tendency of wires or cables 10
work loose from the insulators through vibra-
ton is diminished by the larger sag which It
is customary 10 allow. That provision results
from the fact that the expansion and contrac-
ton is little greater than with copper. Again,
the silent leakage of current from wire 10 wire
through tie air. with given voltage and vol
ume. is smaller with n big conductor than n
small one.
Two drawbacks TO the use Of aluminium have
been recognized. The increased surface Of a
wire gives the wind better hold on the ca bic.
when blowing at right angles to it. but the
trouble is Insignificant because guys or struts
are now used, which give additional security.
Protection from the fumes OF chemicals by
coating Of waterproof material is de-
sirable for short distances in the vicinity OF
certain factories. Although this necessity must
not be ignored. the precaution is a local not
general. observance. The incidental advantages
more than Offset the incidental disadvantages
apparently. and hence turn the scale in favor
OF aluminium when its price enables IL to com
pete with copper II is not hard to understand