AS APPLIED TO WORKS OF CONSTRUCTION. 265 
‘ For rectangular sections we have by substituting for J its va_ue, 
VizZ., ay bd’. F 3 We 
. © = papa — Sreatest slope. 
3 
v= ins = greatest deflection. 
The modulus of elasticity derived from the experiments made 
at the Mint may be found from the formula Z = 
vbd* 
average of ten experiments gave a deflection of 1:2 inches 
with a weight applied at the centre of 1,437 bb. 
. Bae 
: a ee See ie 
£ x 12x 2 
In the experiments made on transverse elasticity by the 
Railway Bridges Inquiry Commission, the deflections were taken 
ing a graduated staff fixed 
5 
same as with the larger experiments made by the Railway Bridges 
quiry Commission, viz, # = 2,715,813 Ib., which may be taken 
as a mean result in calculating the deflection of large beams from 
the formula above referred to. 
The diagram of the Railway Bridges Inquiry Commission, fig. 
11, and those obtained by the author, one of which is shown (See 
fig. 3), shows that the deflections are nearly proportional to th 
loads producing them. 
wv 
wl 
S* p55 od 
