Notes on Small Motors, 169 



PARTICULARS OF EXPERIMENTS. 



Time, nine p.m. 



Height above sea, 130 feet. 



Hydrostatic pressure by gauge, 75 lbs. 



Free discharge of pipe, 11*7 gals, per minute. 



Radius of turbine, 4^ inches. 



Best speed, 1300 revolutions per minute. 



Greatest power of turbine, 1800 ft. lbs. per minute. 



Consumption of water, 2*8 gals, per minute. 



Efficiency, 40 per cent. 



This comparatively low efficiency is probably due to the 

 small size and rude construction of the machine ; on a some- 

 what larger scale and well made it may reasonably be 

 expected to give at least 50 per cent. 



When all the machinery was disconnected the expenditure 

 of water was reduced by the automatic closing of the jet to 

 *75 gals, per minute. 



A similar experiment was tried with the jet fixed open, 

 when the turbine increased its speed to about 2000 revolu- 

 tions a minute, and discharged considerably over 3 gals, per 

 minute. 



Comparative Cost of Motive Power, as Derived from 

 Various Sources, the Price of Coal, Labour, and Gas in Mel- 

 bourne being taken as a basis of computation. 



Pence. 



1. Large marine engines of the most modern type, per 



million ft. lbs -20 



2. Stationary condensing engines of less than 100 indicated 



horse-power ... ... ... ... ... ... "35 



3. Non-condensing stationary engines of less than 50 indi- 



cated horse-power ... ... ... ... ... '45 



4. Large gas engines of the most improved type *90 



5. The above-mentioned turbine, as tested (water at Is. per 



1000 gals.) 18-5 



6. Manual labour at a crank-handle ... ... ... 55'0 



o 2 



