MancJiester Memoirs, Vol. hi. (19 12), No. 0. 5 



3. In this case the longitudinal cracks appeared under 

 a load of 3"36 tons. They spread upwards and 

 the specimen parted in sections, three to four 

 inches in width at the base, under a load of 472 

 tons or a vertical breaking stress of 481 lbs. per 

 sq. inch. There was no latitudinal crack. 



3a. This specimen was reinforced at the base, and 

 longitudinal cracks first appeared under a load 

 of 5 '2 tons, and spread from the top downwards 

 as the load increased. At the load of I2'32 tons, 

 giving a breaking stress of 1254*9 lbs. per sq. 

 inch, the specimen collapsed, shearing off at the 

 base, just above the level of the reinforcement, 

 leaving only the inner half of the thickness of 

 the base with the reinforcement standing. There 

 was no latitudinal crack. 



Having experimented on domes of three different 

 sizes, first without reinforcement, then with reinforcement 

 at the base to prevent spreading, I next decided to test 

 further specimens of the same size as before, but rein- 

 forced with wire rings both at the top and bottom to 

 prevent any spreading movement starting either at the 

 top or bottom with the results and the modes of rupture 

 described below. 



General mode of rupture of specimens reinforced 

 top and bottom. 

 Firstly. At some load cracks developed in meridian 

 planes round the middle of the dome, spreading 

 up and down as the load increased. 

 Second!)'. When the load was increased and before 

 the cracks had extended to the top or bottom, 

 rupture took place quite suddenly by an irregular 



