256 The Control of Mosquitoes 



ration of any liquid; the concavity causes the last 

 remaining portions of liquid to remain in the center 

 of the apparatus, where it is exposed to the hottest 

 part of the flame, and the convexity presented to the 

 flame permits the maximum effect of the latter for 

 evaporation. Inasmuch as it is made of galvanized 

 iron, hammered out of one piece, there are no joints 

 to leak, or solder to melt, and the form is eminently 

 suited for stacking a large number, one inside the 

 other, for transportation. 



The stand of galvanized iron, riveted into a cylindri- 

 cal shape, 6 inches in diameter, and 5}4 inches high. 

 Near the top is a row of holes through which the hot 

 air from the lamp escapes, forming a natural draft. 

 This hot air acts upon the campho-phenique that 

 may be near the edge of the pan, away from the direct 

 action of the flame, causing rapid evaporation at 

 this point as well as in the center of the pan, which 

 sets into the top of the stand. The stand is supported 

 on three iron legs two inches long in the clear, which 

 is turned outward at right angles at the bottom one- 

 half inch. This is done so that they may fit into 

 appropriate straps in the bottom of the safety pan, in 

 which the stand sets, to assure the correct placing 

 of the latter. 



The safety pan is also made of galvanized iron 

 eleven inches in diameter. In the bottom are three 

 straps into which the "turned out" part of the legs 

 of the stand fit. In the center of the safety pan there 

 is a ring one-half inch high, three inches in diameter, 

 into which the alcohol lamp fits. With the stand 

 confined in its proper place by straps, the lamp like- 

 wise placed in its ring, it will be seen that there is 

 no possibility of any portion of the apparatus occupy- 



