198 
Mr Wimperis, Some Experiments upon Beams 
A formula of this type will be found to fit experimental results 
more nearly than the ordinary Eulerian equation, and as an example 
of its use the fourth and eighth columns of the table show values 
of P derived from the formula 
= 60,000 
10 + P‘ 
(Formula, 2.) 
Table II. 
Length of 
Strut in 
inches 
Maximum 
Load in lbs. 
(observed) 
Maximum 
Load in lbs. 
from Formula 1 
Maximum 
Load in lbs. 
from Formula 2 
Length of 
Strut in 
inches 
Maximum 
Load in lbs. 
(observed) 
Maximum 
Load in lbs. 
from Formula 1 , 
Maximum 
Load in lbs. 
from Formula 2 j 
71-9 
11-3 
12-3 
11-6 
11*0 
536 
523 
458 
60-0 
16-5 
17-6 
16-6 
10-0 
645 
634 
545 
48-0 
26 
27*5 
26-0 
9*0 
673 
784 
660 
42-0 
33 
36-1 
33*8 
8-0 
941 
1,010 
811 
36*0 
46 
49-0 
46-0 
7-0 
1,207 
1,290 
1,020 
30-0 
67 
70-4 
66*0 
6-0 
1,450 
1,760 
1,310 
24-0 
105 
110 
103 
5*0 
1,642 
2,540 
1,720 
18-0 
180 
196 
180 
4-0 
2,390 
3,960 
2,310 
14-9 
263 
285 
258 
3*0 
2,770 
7,050 
3,160 
120 
401 
440 
390 
2-0 
2,925 
15,900 
4,280 
This fits as well perhaps as any expression of this type would do. 
Even a modified formula of this form only gives results over a 
limited range owing again to the complexity of the phenomena ; 
one phenomenon for 3-inch and 2-inch struts, being the bursting 
of the conical ends under the great pressure applied. 
The table here given ranges from a strut length of 6 feet to 
one of 2 inches, and naturally such a variation in length tests any 
formula very severely. If the series had been split up into several 
