ON PADDLE WHEELS. 



129 



Log. H.P. = 2-18087 H.P. = 151-66. 



The nominal power of the engines is 220 h. p. at 22 revolutions per minute, therefore the 

 nominal power with only 15 revolutions is 150 h. p., so that in this case the calculated power 

 surpasses the nominal power by very little more than one per cent. In this calculation some 

 of the resistance has been neglected, viz., that on the arms and the edges of the floats, to 

 which should also be added the effect of the back water and the shock, the amount of which 

 we cannot at present estimate ; but as the engines are supposed to work above their nominal 

 power, and it is not known by how much, the above result may be very near the truth. 



The following is the calculation of the effective power according to the formula (2). 



Log. 



6 

 a 2 



P 

 at. 



0-77815 

 1-39794 

 0-88137 

 0-03120 



6a 2 pa = 3-08866 6 a 2 p a. =1226'5 



2 

 R* 



sin. a 



0.30103 



3-06357 



-1-94416 



2# 3 sin. a = 3'30876 2.R 3 sin. a =2035'9 



4 

 R 



sin. a =- 



0-60206 



1-02119 



1-76274 



-1-94416 



4R P 2 sm. a, = 3-33015 4Rp 2 sin. a=2138'7 



3 



r 2 



P 

 ft 



= 0-47712 

 = 1-80618 

 = 0-88137 

 =1-95215 



= 3-11682 



Log. 



q 



P 



ct, zzz 



0-47712 

 2-04238 

 0-88137 

 0-03120 



3.R 2 pa = 3-43207 3 R z p a =2704-4 



3 = 0-47712 



a = 0-69897 



p 2 = 1-76274 



a = 0-03120 



Sap 2 a, = 2-97003 



Sap 2 a, 



= 933-3 



3 

 R 



a 



P 

 sin. a 



0-47712 

 1-02119 

 0-69897 

 0-88137 

 -1-94416 



3 flap sin. a= 3'02281 3 JZapsin.a=1053-9 



2 

 R 



a 2 

 sin. a 



0-30103 



1-02119 



1-39794 



-1-94416 



=1308'6 



2.Ra 2 sin.a= 2-66432 2.Ra 2 sin.a= 461-7 



