Nov. 30, 1888.] 



SCIENTIFIC NEWS. 



549 



each room, and these pipes are connected with larger 

 vertical pipes which are supplied with water at pressure, 

 from the street main or from an overhead tank. The 

 sprinklers are attached to the horizontal pipes at distances 

 about ten feet apart, so that there is one for every 100 

 superficial feet of floor area. Thus a building 120 feet 



fastened at its lower extremity by solder which melts 

 at about 160 degs. F. An elastic seat is at the same 

 time pressed against the valve by the pressure of the 

 water, so that there is no leakage, and the greater the 

 water pressure the tighter is the valve closed. The 

 elastic seat not only serves to close the valve, but when 



Fig. 1. — Grinnell's Sprinkler in Position. 



long by 60 ft. wide, and four floors in height, should have 

 72 sprinklers in each room, or 288 for all the rooms. 

 The accompanying illustration (fig. 1) represents the 

 sprinkler as seen when not in action, and fig. 2 is a 

 sectional view of a sprinkler discharging water. Its 

 construction is at once simple and ingenious. A well- 

 fitting and specially contrived valve is held in position 

 by the curved lever shown in fig. 1, and this lever is 



the soldered joint of the lever begins to yield, the seat 

 moves simultaneously with the valve, to the extent of its 

 elasticity, and thus keeps the valve opening covered 

 until the soldered joint is completely severed. This is 

 a detail of much importance, for if a slight escape of 

 water were possible before the soldered joint were quite 

 broken the solder might be cooled and reset, and the 

 action of the sprinkler would be defeated. 



