A COMMERCIAL POINT OF VIEW. 



75 



These important deficiencies in air-tight jars for pre- 

 serving eggs have led me to invent a jar purposely for 

 egg preserving, and which jar is not only perfectly air- 

 tight, but it will show at a glance whether it is so, and 

 how long it remains so, by means of its patent pneumatic 

 self-indicating cap. I have every reason to believe that 

 these jars will remain air-tight for any number of years, 

 and that the eggs preserved in them will remain as fresh 

 as on the day they were laid, and fit for hatching and the 

 breakfast table. Now, although such jars can also be 

 made of glass, which would have the advantage of show- 

 ing the eggs, yet when it is considered that glass is liable 

 to crack when put into boiling water, particularly during 

 cold weather, it is my opinion that glazed stone ware is 

 preferable. 



PATENT PNEUMATIC SELF-INDICATING AIR-TIGHT JARS. 



Fig. 26. 



From the above sketch it will be seen that the jar has 

 two covers ; the inner is made of stone ware, with a ridge 



