1911-12.] The Elastic Strength of Flat Plates. 
357 
Results of Experiments on Circular Plates. 
Results for Deflection for Plates fixed at the Circumference and having 
uniform load upon their areas. ( All dimensions in inches and 
pounds.) 
& 
Diagram 2 is for plate A, and gives the theoretical and experimental 
deflection curves for a load of 20 lbs. per sq. in. It will be seen that the 
form of the two curves is almost identical, and as this was also conspicuous 
in the preliminary experiments, it will not be again referred to. The only 
point remaining for decision, with regard to deflection, is whether the 
deflection at the centre, as calculated from the equation, tallies with that 
found from experiment within small limits of experimental error. Diagram 
3 shows, therefore, deflection at the centre plotted against load, and as the 
result is in the nature of a straight line, it is sufficient proof that the 
deflection varies directly with the pressure. In Diagram 3 there is a 
pronounced intercept OB, amounting to ’005 in., which, being interpreted, 
