June 



?•] 



SCIENCE. 



473 



mary generators, of which there are six, are adapted to the condi- 

 tions by a few mechanical changes from the standard pattern. 

 They are mounted on a heavy cast-iron base, and are provided 

 with an extended shaft and outer bearing. On the armature shaft, 

 and between two bearings, the Pelton wheel is mounted and en- 

 closed in a water-tight cover. The cut of the generator is made 

 from a photograph taken at the Brush Electric Company's works 



excellent forms of water-wheels, the Pelton was selected as best 

 adapted to work under the special circumstances. This wheel is 

 the outgrowth of the old hurdy-gurdy form, and, as will be seen 

 from the illustration, its buckets are provided with a very ingenious 

 wedge-shaped partition, by which the stream of water is divided, 

 and sweeps out through the curved sides in such a way as to pro- 

 duce a re-actionary effect in addition to the impact. By the pe- 



BRUSH DYNAMO, CHOLLAK MINE. 



at Cleveland, before shipment, and shows a pulley on the armature 

 shaft, arranged for testing-runsat the factory. The water-wheel is 

 attached to the armature shaft at the place occupied by this pulley, 

 and a coupling is provided for detaching this entire end of the 

 shaft carrying the wheel from the other end carrying the arma- 

 ture. 



These Brush generators are each of i3o-horse-po\ver capacity. 



culiar construction of the buckets, all the water is also thrown 

 down and out of the way of the wheel. The six Pelton wheels are 

 each 40 inches in diameter, are made of phosphor-bronze, and 

 weigh 220 pounds. They drive the generators at the rate of 900 

 revolutions per minute. The compact arrangeinent of combined 

 d) name generator and water-wheel makes it almost impossible for 

 the visitor to the underground chamber to realize the enormous 



BRUSH ELECTRIC MOTOR, EIGHTV HORSE-POWER, NEVADA MILL. 



and are compound wound for constant current. The electrical 

 curve from these machines is almost ideally perfect, and they re- 

 quire no regulator whatever. The current remains of constant 

 strength under all conditions of load. 



The head of water at the underground chamber is i,6Sofeet. It 

 has never before been attempted to run a water-wheel under such 

 enormous pressure. This was indeed one of the most serious 

 problems involved in this remarkable installation. From the various 



amount of power here at work. The machines are placed in par- 

 allel rows of three, and the swift-revolving armatures are all that 

 can be seen in motion as evidence of the Soo horse-power gener- 

 ated. The chamber is brilliantly lighted by 36 Swan incandescent 

 lamps, operated in multiple series from one of the Brush genera- 

 tors, and there are several of the same lamps in the inchne. Each 

 generator circuit is provided with a dead-beat ammeter of the 

 Brush pattern ; and a Brush voltmeter is also at hand, which is 



