CONSTRUCTION AND FTEE PROTECTION OF COTTON WAREHOUSES. 63 



CHEMICAL EXTINGUISHERS. 



Chemical extino-nishors are of two general types. One contains 

 a reservoii' of water with chemicals so arranged that, when the ex- 

 tingiiishei- is inverterl, tlie chemicals produce a reaction with result- 

 ing pressure which is capable of discharging the water with consid- 

 erable force. The other type of extinguisher generates a gas which 

 clings about the fire and does not support combustion. While both 

 types of extinguishers are of value in some cases, neither of them 

 should be depended upon for the cotton warehouse or compress, as 

 water barrels and pails are more satisfactory particularly where ig- 

 norant labor is employed. There is possibly some advantage in hav- 

 ing one 21-gallon extinguisher at the compress tower. 



YARD HYDRANT SYSTEM. 



An adequate system of yard hydrants fully equipped and main- 

 tained is one of the greatest assets of a warehouse plant. Unfor- 

 tunately, the value of the yard hydrant installation is often impaired 

 because the hydrants are not located x)rof)erly or because the equip- 

 ment has deteriorated. Hydrants should be housed with all equip- 

 ment ready for use as shown in figure 7. 



lieaviei- solution and the purpose of the treatment will be defeated. The data 

 given for calcium chloride is based upon the chemically fused product generally 

 used for refrigeration purposes. The tables are adapted from those given in 

 Van Nostrand's Chemical Annual. 



Treatment of water with so4ium chloride, or common salt. 



Sodium chloride per gallon solution. 



Freezing point. 



Fahrenheit. Centigrade 



Specific 



gravity 



at 59° F., 



15° C. 



Weight of 

 solution 



per 

 gallon. 



Density 



at 59° F., 



15° C. 



0.44 pound, or 7 ounces 



0.9 pound, or 15 ounces 



1.22 poimds, or 1 pound 4 oimces. 

 1.92 pounds, or 1 pound 15 ounces 

 2.5 pounds, or 2 pounds 8 ounces.. 



+ 25.4 

 + 18.6 

 + 12.2 

 + 6.9 

 + 1.0 



-3.7 

 - 7.4 

 -11.0 

 -13.9 

 -17.2 



1.037 



1.073 



1.1115 



1.150 



1.191 



8.7 

 9.0 

 9.3 

 9.6 

 9.9 



"B. 



5.2 



9.9 



14.5 



19.0 



23.3 



Treatment of tvater with calcium chloride (fused 75 per cent CaCh). 



Amoimtcalciumchloride per gallon of solu- 



Freezing point. 



Speeifle 



gravity 



at 68° F., 



20° G. 



Weight of 



solution 



per 



gallon. 



Density 



at6S°r., 



20° C. 



tion. 



Fahrenheit. 



Centigrade. 





+18.0 

 + 12.5 

 + 6.5 

 - 2.0 

 -12.5 



- 7.8 

 -10.8 

 -14.2 

 -18.9 

 -24.7 



1.1 

 1.125 

 1.15 

 1. 175 

 1.2 . 



9.2 

 9.4 

 9.6 

 9.8 

 10.0 



° B. 

 13.0 



1.83 poimds, or 1 pound 13 ounces 



16.0 

 19.0 



2..59 pounds, or 2 pounds 10 oimces 



21.3 

 24.0 







