Transmission of Power by Electricity. 
1879.] 
183 
IX. ON THE TRANSMISSION OF POWER 
BY MEANS OF ELECTRICITY. 
By Profs. Elihu Thomson and Edwin J. Houston, 
S HE statements recently made as to the size and cost of 
the cable that would be needed to convey the power 
of Niagara Falls to a distance of several hundred 
miles by electricity have induced the authors to write the 
present paper, in the hope that it may throw light upon this 
interesting subject. 
As an example of some of the statements alluded to we 
may cite the following, viz., that made by a certain electri- 
cian, who asserts that the thickness of the cable required to 
convey the current that could be produced by the power of 
Niagara would require more copper than exists in the enor- 
mous deposits in the region of Lake Superior. Another 
statement estimates the cost of the cable at about 60 dollars 
per lineal foot. 
As a matter of faCt, however, the thickness of the cable 
required to convey such power is of no particular moment. 
Fig. 1. 
Indeed it is possible, should it be deemed desirable, to con- 
vey the total power of Niagara, a distance of 500 miles or 
more , by a copper cable not exceeding one-half of an inch in 
thickness. This, however, is an extreme case, and the exi- 
gencies of practical working would not require such 
restrictions as to size. 
The following considerations will elucidate this matter : — 
Suppose two machines connected by a cable, of say 1 mile 
in length. One of these machines, as, for example, A, 
Fig. 1, is producing current by the expenditure of power ; 
the other machine, b, used as an electrical motor, is pro- 
ducing power, by the current transmitted to it from A, by 
