88 MARKET DAIRYING 



hinges by which the cover is fastened are attached to 

 these 2x4s, as shown in Fig. 39. 



A safety valve, set at ten pounds pressure, is inserted 

 through the top of the cover at the most convenient place. 

 A bell trap (see Fig. 58) placed in the bottom of the 

 sterilizer serves as an outlet for the condensed steam. 



The steam is admitted either through the sides or 

 through the bottom of the sterilizer, and both inlet and 

 outlet pipes should be laid in the concrete at the time the 

 sterilizer is being built. 



A false, perforated, metallic bottom is placed one inch 

 from the bottom of the sterilizer, on which all vessels are 

 placed in an inverted position. 



The following is an itemized statement of the cost of 

 the material used in the construction of this sterilizer, 

 whose inside dimensions are: length, 71-3 feet; width, 

 21-4 feet; depth, 21-3 feet. 



2 bbls. of Portland cement $5.20 



20 ft. of 2 X 4 studding 30 



no ft. of lYi tongue and grooved flooring, 31'^ wide 4.40 



4 hinges 40 



5 lbs. nails 20 



6 54-inch iron rods 2^/2 feet long 1.20 



3 hasps 30 



20 sq. ft. zinc ,1,75 



Ball and lever safety-valve i.oo 



3 pounds sheet asbestos 30 



Total $15.05 



Sterilizing Bottles. The most convenient way to 

 sterilize bottles is to place them in metallic cases like 

 that shown in Fig. 40. A reversing rack is placed over 

 the cases, which permits sterilizing the bottles in an in- 

 verted position. 



Importance of Keeping Vessels Inverted. It is not 



