42 The Control of Mosquitoes 



the country becomes settled those living within a 

 half-mile or so will be malarial, and people passing 

 through the district will be affected similarly. 



It is not an economy to expedite construction in 

 such a manner. If a contract takes a long time to 

 execute and the laborers become infected by 

 Anopheles, created by the foreman's energetic 

 though short-sighted action, what of the reduced 

 energy or vital force of the workmen? Labor 

 receives a daily wage and any decrease of output 

 increases the cost of supervision. How does 

 the loss of the laborers' efficiency compare with the 

 saving made by neglecting proper care of the 

 natural watercourse? If all, or a large part, of 

 the force becomes infected what is the contractor's 

 monetary loss ? 



History shows that important contracts have 

 failed in the tropics, and in some cases the entire 

 project has had to be abandoned. The anti- 

 malaria campaign on the Isthmus showed exactly 

 how and why these failures happen, and also pro- 

 vided opportunity for the study that may assist 

 in determining the best and most economical 

 means of overcoming future diflficulties of similar 

 or related character. 



