144 GASOMETERS. 



5 cwts. Its working-pressure will therefore be equal to a column of water 

 5j^ths of an inch high. 



The working pressure of the gasometer 87 feet 6 inches diameter, weighing 

 38 tons 10 cwt., will be found equal to a column of water 2^ths high, the area 

 of water- surf ace being 6013'2 feet. 



A gasometer 50 feet diameter, weighing 12 tons 18 cwt., will rise with a 

 pressure of 2^ths perpendicular head of water, and a gasometer 36 feet dia- 

 meter, weighing 6 tons 5 cwt., will work with a pressure equal to a head of 

 water 2Y^ths of an inch high. 



The weight of a cubic foot of river water is 62'5 pounds. 



