740 Report on the Exhibition of Implements, 
minute. The pumps are double-action, and deliver 2640 gallons per hour at 
any height. With india-rubber valves the water can be forced 24 yards 
vertically, and 28 yards horizontally. Hence it forms a powerful fire-engine. 
The action of the pump will be further understood by reference to the plan 
(Fig. 33). 
Fig. 33. — Plan of Mons. Nicolas Noel's Force-pump. 
A, Suction-valve under piston ; b, Suction-valve under ditto ; c. Passage 
from top of piston ; dd, Delivery valves. 
The merits of this pump are its simplicity, the durability 
of the valves, easy access to all parts, and perfect action ; the 
muddiest water does not cause it to choke. 
The universal pump for liquid manure, fire extinction, and 
watering purposes, is supplied, carriage-paid to London, for 
13Z. 15s., and comprises : — 
The pump, mounted on an iron two-wheeled carriage. 
2^ yards of spiral wire rubber-suction hose. 
2 brass unions, one bent union, and an iron strainer. 
4 yards of canvas delivery-hose, with brass double-union. 
1 deliverj-jet and fan-spreader for watering purposes. 
Mr. Thomas Adams, of West Gorton, Manchester, exhibited 
several spring safety-valves. I am indebted to Mr. Courtney for 
the following description, and to the exhibitors for the illus- 
tration, which shows a section of the valve and spring. 
The special feature as compared with the ordinary mushroom 
safety-valve is, that the head of the valve, instead of merely 
covering the valve-seating, is made to extend over the seating. 
This is well seen in the section. By this means, as soon as the 
steam pressure in the boiler has risen sufficiently to lift the 
valve, the escaping steam compresses on the outer ring, and, 
owing to the increased area exposed to the pressure of the steam, 
the valve is lifted still higher, thus rapidly relieving the boiler 
