373 
1911-12.] The Elastic Strength of Flat Plates. 
a symmetrical form for the greatest stress at the ends of the short diameter, 
where 
a = half length of plate, 
b = half breadth of plate, 
t — thickness of plate, 
p = applied pressure. 
A comparison can thus be made between Grashof’s theoretical results 
and the results obtained directly from the curves. 
Tables for Graphical Analysis of Curvature for 
Rectangular and Square Plates. 
General Explanation . — In all cases readings are for one quadrant of 
the plate. These readings are usually the average of those for all the 
quadrants. Diagram 9 shows generally along what lines measurements 
are taken. In the tables to follow, the points are given by means of polar 
co-ordinates, the origin being taken at the centre of the plate. The 
direction of the line is in each case given by the tangent of the angle ; 
thus, in fig. 9, OA = tan _1 0°, OB = tan -1 - 25, OC = tan -1 *5, OK = tan -1 *7 5, 
etc. In rectangular plates the axis of reference is along the long 
diameter. 
[Table 
