ELASTIC RADIAL DEFORMATIONS OF FLYWHEELS. 281 
The values of F and AR at any speed are obtained by 
multiplying the above values by the square of the speed in 
revolutions per second. 
On inspection of the curves it will be seen that the 
observed and calculated values lie very close together for 
the three-armed wheel, while they are somewhat divergent 
for the other two wheels, the difference being greater for 
the higher speeds. The curve of calculated values is a 
parabola, whereas the curve of observed deflections is 
flatter than the parabola at low speeds and steeper at 
higher speeds. 
Three-armed Wheel, straight arms.—Fig. 10 gives a 
complete set of curves for one half of bay C of the three- 
armed wheel, points being taken 15° apart. Curves are 
also shewn for the centres of bays A and C and for the arm 
AB. The points B. 60° and arm AB shew considerable 
divergence from the corresponding points in bay C, a fact 
which cannot be accounted for by any variation in the 
dimensions of the wheel. The shape of the rim between 
the arm and centre of bay C for speeds ranging from 4 to 
14 revolutions per second is shewn in fig. 11. 
A series of experiments was carried out on the three- 
armed wheel, in which concentrated loads were applied in 
a radial direction to the centre of each bay while the wheel 
was stationary, the deflections at points 15° apart in each 
bay being noted as before. The load at each bay was 
applied by means of a loop of copper wire onthe rim. This 
loop was pulled in a radial horizontal direction by a piece 
of cord attached to it. The cord passed over a pulley sup- 
ported on roller bearin’s and was attached to a bucket in 
which weights were placed. In order that the deflection 
might be taken at each point, and at the same time to keep 
the load on the centre of the bay it was necessary to move 
the stands supporting the pulleys for each point under 
S -—Aug. 5,.1902. 
