* 
Miscellaneous Intelligence. 297 
be “two-thirds of that which half a calibre in thickness would offer if 
outward. But the tension in cooling acts in the same direction, And 
this latter force far exceeds the former, if we remember Major Rodman’s 
n 
the way of casting large guns, was to cast them with a core. is core 
sides would lie in one groove, the other in the adjoining one, and the 
connecting part would bind the core together longitudinally. The diffi- 
culty of procuring this peculiar shaped wire led him at last to abandon 
t the gun, instead of facilitating it. Instead of the resistance op 
to the powder bei 
these guns it is less subject to wear than when it is the last part to cool, 
method, 
48 in the old 
