ees 
wm & 
20 W. H. WARREN. 
recently installed double centrifugal turbines of 900 to 1200 
horse power at 120 revolutions per minute. The head 
varies from 14 to 264 feet, and the volume from 4,230 to 
42,300 in an irregular manner, often without warning. 
The new turbines have each two wheels, of which the lower 
one is designed to work under the higher heads, and there 
are two sets of guides for each wheel, one above the other. 
The water flows in a direction parallel with the axis into 
each wheel, both from above and below, and leaves at the 
circumference in a radial direction. The wheel casing on 
both the upper and lower turbines is so arranged as to 
admit more pressure to the under side than the upper, in 
this way so far balancing the pressure that an overhead 
suspension bearing may be used. At Lyons there are 
22,000 HP. installed, for which Francis turbines are used. 
The water is takeil from the river Rhone above Lyons by 
a canal 114 miles long, the power house being about 13 
miles from the lower end; the canal varies in width from 
197 to 344 feet and is 84 feet deep in the shallowest part. 
The installation consists of eight 1,250 HP. turbines coupled 
to alternating current generators directly above them, with 
three 250 HP. turbines for exciting the fields of the alter- 
nators. The eight 1,500 HP. turbines have been added 
more recently, and are of the double type; they are designed 
to work efficiently with a greater fluctuation of head than 
the others, and are hydraulically balanced. The regulation 
is by Fink swinging gates, worked by a servomotor under 
oil pressure. 
In America a power plant of 57,000 HP. was completed 
last year at Sault Ste. Marie, Michigan, for the Lake Superior 
Power Company, at a cost of £800,000. Hach hydraulic 
unit is composed of four double turbines arranged horizon- 
tally, of 568 HP., and from 81 to 82% efficiency. The 
electric units consist of 400 KW. alternating and direct 
current Westinghouse generators. 
