574 TRANSACTIONS OF SECTION G. 
part and the flying apart of the two pieces of the specimen is due to sudden 
release in compression. 
Lantern slides and kinematograph illustrations were given for cylindrical, 
hollow, square, and rectangular sections, as well as for the machine representing 
its operations. The projections, enormously enlarged, were made in a small 
fraction of the time required for the tests; so that the behaviour of the material 
was readily demonstrated. In the case of the wrought iron, the defects of the 
metal were made manifest, while the flow had the appearance of a turgid stream 
in motion. ; 
The author gratefully acknowledged the receipt of a Government grant from 
the Royal Society, which has made it possible to conduct experiments which 
there is every reason to expect will be not only of scientific interest, but also of 
value in engineering developments at present pending. 
