1916] SURAL ENGINEERING. 689 



type. Of 117 fires 95 were dust explosions, and of 108 fires 82 originated back 

 of the cylinder or very near that point. "About 75 per cent of the occurrences 

 were assigned to the presence of static electricity and to smut explosions. 

 . . . The invesigations show conclusively that the presence of a hot box is 

 not essential in order that an explosion may take place. . . . 



"As a result of the investigations ... it is believed that a complete system 

 of electrical connection from all of the moving parts to a common wire, and 

 a thorough grounding of this common wire, will prevent a large percentage of 

 the fires that are due to the presence of static electricity and an explosive mix- 

 ture of smut dust and air." The use of a suction fan attached to the top of 

 the separator and near the cylinder w^hich exhausts from above the cylinder 

 and from below the fan is also advocated. 



An automatic fire extinguisher which was tested and found to be satisfactory 

 is also described. This consists essentially of a tank mounted on top of the 

 separator and containing a bottle of sulphuric acid and water containing soda. 

 Other accessories are a discharge pipe extending throughout the separator and 

 fitted with spray nozzles, a tripping mechanism, and a set of fuses mounted in 

 a wire line. 



" The presence of sufficient heat within the separator will melt one of the 

 fuses. This breaks the wire line, releasing the trigger, which frees the trip- 

 ping mechanism, causing a hammer within the tank to strike a blow sufficient 

 to break the bottle. The discharge of the sulphuric acid into the water con- 

 taining soda causes the formation of carbon dioxid, which generates sufficient 

 pressure to force the water through the discharge pipe and the nozzles to all 

 the crevices of the separator. . . . 



" The locations [of fuses] will vary with each machine, and must be selected 

 so that the fuses are sure to be reached by the flame or the heat, but not so 

 placed that the wire connecting them is likely to be broken by the straw or by 

 the moving parts of the separator. 



" The location of the nozzles depends upon the construction of the machine, 

 but the following points should be observed : 



" Locate one nozzle directly above the cylinder, if possible ; if not, place it 

 so that the beater will help diffuse the spray from that nozzle. Run the pipe 

 line along underneath the roof of the separator, with the nozzles pointing 

 downward. Install a sufficient number of nozzles along this line, and so locate 

 them that every chamber in the separator is thoroughly served by a nozzle. 

 Particular pains should be taken to serve dead air spaces, as it is in these that 

 dust is likely to accumulate. As the stacker end of the machine is less likely 

 to contain any closed chambers, it is probable that, in most types of machines, 

 the nozzles at this end may be 30 in. or more apart. The last nozzle along the 

 pipe line and within the separator should be just above the end of the shakers." 



Combination barns for prairie farms, A. R. Geeig and A. M. Shaw {Brit. 

 CoJumbia Dept. Lands, Forest Serv., Farm Build. Ser. Bui. 1 (1915), pp. 54. 

 figs. 21). — This bulletin describes and illustrates the structural details of four 

 combination barns and gives bills of materials. 



Dairy barns, ice and milk houses for prairie farms, A. R. Greig and A. 'M. 

 Shaw (Brit. Coltimbia Dept. Lands, Forest Serv., Farm Build. Ser. Bui. 2 

 {1915), pp. 66, figs. 20). — This bulletin describes and illustrates the structural 

 details of four dairy barns and two ice and milk houses. 



Beef cattle barns for prairie farms, A. R. Gbeig and A. M. Shaw {Brit. 

 Columbia Dept. Lands, Forest Serv., Farm Build. Ser. Bui. 3 {1915), pp. 53, 

 figs. 18). — This bulletin describes and diagrammatically illustrates a beef cattle 

 breeding barn, feeding shed, and feeding barn and discusses details of roof 

 framing, mangers, stalls, a portable grain table, and a portable feeder. 



