OF THE IRK, LOCOMOTIVE ENGINE. 9521 
3 
But, in the rectangular beam, I= ; and the weight, W, 
being placed, at the middle of the beam, we have z= “ ; and, 
2 
Wa? 
therefore, Ce=ad= aye (1) 
Now, it is necessary to find the value of W, 
such that, if it be suspended gently from the point 
c, the beam will just break. 
Leal. ‘sy Wa ] 
R (24)7EI ’ 
At the point, c, =o; and, therefore, 
: Ss wee my oes 3Wa is 
and, in Art. 12, ER (2) Ebe 3 
2 
9 (12)*Sbe* 
and, W = 3a 
; which is the value of c, in Art. 11. 
And by substituting for W, in equation (1), we have 
Ce= 
» which is the value of 6, in Art. 11. 
Therefore, wea Oeee _ 4x32gS'abe 
Ww 
Ew 
& u=64 s\/ a nearly. 
w 
Supposing the tie-beams to be made of Riga fir; and taking 
