206 AUTOBIOGRAPHY 



best seal we had yet found. Now, I believe, the 

 common practice is to keep the top of the silage 

 quite moist which forms a seal of semi-decayed 

 material two to four inches thick which is dis- 

 carded when the silo is opened. 



However, I was not yet content, for the silage 

 was at one time too acid and others too dry and 

 fire-fanged at the walls of the structure. So I 

 constructed a. cistern, of about seven tons capacity, 

 the walls of which were asphalted to make them 

 air-tight. When this was filled with roughage, 

 burning charcoal in a kettle was put into the top 

 of the silo and then the cover, which I had tried to 

 make air-tight, was put in place and overlaid with 

 about two feet of earth. This did not prove 

 enough better than the open method to justify the 

 large expense and the inconvenience in emptying 

 the silo. Next, I had made a galvanized iron 

 cylinder of five hundred to one thousand pounds 

 capacity, which would at least be air-tight, and I 

 filled it up with green corn. Then procuring two 

 cylinders of compressed carbonic acid gas, the air 

 in the little iron silo was forced out by forcing the 

 carbonic acid gas in the silo was thus filled with 

 green corn and a deadly gas. I had succeeded at 

 last for when the material came out it was ap- 

 parently in just the same state as when it went in. 



