170 MOSQUITO ERADICATION 



every reasonable precaution should be taken to guard against 

 fire. LePrince 1 recommends a 140°F. flash-test oil, if the oil 

 is to be stored near any valuable property. 

 LePrince 1 continues: 



"Oil stored in unsafe containers, as wooden barrels or improperly 

 covered tanks near railroad tracks, is very apt to catch fire. Small 

 quantities are usually shipped in wooden barrels and, if left exposed in 

 the sun, leakage occurs and danger from fire is increased. Provision 

 must be made for fire protection and precautions taken to avoid spilling 

 on the ground at or near the place of storage. Sufficient sand or loose 

 earth should be kept available close to where the oil is stored for use in 

 extinguishing a flame. Oil-storage houses and faucets of storage tanks 

 or barrels should be kept locked when not actually being used. No 

 smoking is to be allowed near them." 



As indicated above, barrels of oil should not be stored nor left 

 in any place where the sun can beat down upon them, since, not 

 only is the fire risk increased, but a very large quantity of oil is 

 likely to be lost. The warmth of the sun thins the oil, and some 

 of the barrels are almost certain to leak. The amount of oil that 

 may be lost in this manner is surprising. 



In case it is found necessary to distribute barrels of oil at 

 various places throughout the area of operations, care should be 

 taken to place the racks in the shade or else to cover them over. 



COSTS OF OILING 



So many factors enter into the situation that it is almost 

 impossible to give any rules to estimate the cost of oiling or even 

 the amount of oil to be used in any project. 



The weather is, perhaps, the most important factor in the case. 

 A given area may require twice or thrice the amount of oil and 

 labor one year as another, depending on the amount of rain-fall 

 and its distribution. Topography is also an important element, 

 as is soil-type. Again, the conduct of the campaign itself has an 

 effect upon oiling; if fish control and drainage are pushed, less 

 oiling will be required, and vice versa. 



The following figures,- taken from five different projects with 

 which the writer was connected, shows the wide fluctuations in 

 amount of oiling required, costs of oil and costs of applying oil, 

 even in places of approximately the same area: 



1 "Control of Malaria: Oiling as an Anti-mosquito Measure," U. S. 

 Public Health Service, 1915. 



