TESTING OF STRUTS. 295 



taking / as 36,0001bs., and a as ^Vry for I pillars, 



p = 36,000 x 6-5 



, t 4,300 



r 



= 197,0001bs. 

 = 92 tons. 

 Lastly, trying Euler's formula, where 



7T 2 . E. L. 



P-- /a 



= 7^. 30,000,000. 5-38 



4,300 



= 326,0001bs. 

 = 168 tons, 



a result far too large. For pillars whose ratio -r is 



K 



much below 150, Euler's formula is misleading. 



