The Campaign in Havana 249 



superior grade of pyrethrum powder per thousand 

 cubic feet of air space. Sulphur, in the form of 

 "flowers of sulphur," was used in the same pro- 

 portion. Where a probable leakage of fumes was 

 seen to be more or less unavoidable, the quantity of 

 fumigants was increased proportionally, and the 

 inspectors became quite expert in gauging the 

 amount required; as a matter of fact, they usually 

 erred on the side of safety. 



In loosely built houses, the wind velocity had to 

 be considered. Sometimes it was not advisable to 

 paper the entire wall area of a house to prevent the 

 leakage of fumes. Time was of value, and too 

 much moving around of laborers and the manipu- 

 lations incident to the papering might cause the 

 mosqiiitoes to fly away, so that it became neces- 

 sary to avoid any commotion that would result in 

 sending out of doors the very infected mosquito the 

 fumigation was intended to destroy. 



After all the sulphur pans were burning, and the 

 last door of the house was locked and sealed, a 

 notice was posted upon it stating the hour of 

 closing and that of reopening by the sanitary 

 department, and also that any person, other than 

 the inspector in charge, who opened the door 

 would be guilty of a misdemeanor and treated 

 accordingly. A laborer was detailed to watch 



