Manchester Memoirs^ Vol. xlii. ( 1 898), No. 0. 5 



(4) Two tanks, each capable of holding 60 tons of 

 water, one in the tower 11 6ft. above the floor, the other 

 15ft. below, connected by 4in. rising and falling mains, 

 each 500ft. long, passing through the laboratory in a 

 chase beneath the floor. The rising main includes a 

 special quadruple centrifugal pump, 2ft. above the floor, 

 capable of raising one ton a minute from the lower to 

 the upper tank, also a set of mercury balances in the 

 laboratory, showing the pressures in the rising and falling 

 mains and the levels in the two tanks. 



(5) A special quadruple vortex turbine supplied from 

 the falling main, and discharging into the lower tank, 

 capable of i H.P., and available for steady speed at all 

 parts of the laboratory. 



(6) A supply of power to the laboratory by an engine 

 and boiler, quite distinct from the experimental engine, 

 and distributed by convenient shafting always running. 



The existence of these appliances, with all their speciali- 

 ties, was largely owing to the interest in educational work 

 taken by Mr. William Mather, who, together with the 

 other members of the firm of Mather & Piatt, afforded 

 facilities to the author and inspired that enthusiasm in the 

 execution of the novel and special work which alone 

 rendered it possible. 



Of these appliances the brake is the centre of interest, 

 as it was in this that the work has been measured as well 

 as converted into heat. 



A description of this brake has already been published, 

 together with that of the engines,* and it is here only 

 described so far as is necessary for reference. 



The brake consists primarily (i) of a brake wheel i8in. 

 in diameter, fixed on the 4in. brake shaft by set-pins, so 

 that it revolves with the shaft {Fi^s. 2 and 3), (2) of 



* Triple Expansion Engines, by Professor Osborne Reynolds, Proc. Inst. 

 C.E., 1889-90. Part I., p. 18. 



