INDUSTRIAL FUMIGATION AGAINST INSECTS 



29 



Figure 29. — Two outdoor fumigation vaults under one roof, built of brick, finished on 

 the inside with Keen's cement, and equipped with doors shutting against rubber 

 gaskets to prevent gas leakage. Note ventilators in roof to aid in ventilation when 

 lighter-than-air gas is used. (Photograph by Ferez Simmons.) 



Figure 30. — Outdoor structure built for fumigation of dried fruits. It is made of 

 hollow tile, plastered on the inside with Keen's cement, and equipped with a re- 

 frigerator-type door. Note funnel-shaped openings above the door, through which 

 a liquid fumigant can be poured into evaporating trays suspended from the ceiling 

 of the vault. (Photograph by Perez Simmons.) 



