THE TOBACCO BEETLE. 45 
Two tests were made, one in which the room was heated by turning 
the steam into radiators, and one in which the entire basement of the , 
building was heated by admitting the live steam direct from the | 
boiler. Evaporation during the experiment was about 75 gallons per 
hour. 
The experiment in the room fitted with radiators was commenced 
on July 7, the temperature of the room being 85° F. Steam was 
turned on at 2 p. m.t_ All stages of the tobacco beetle were used in 
the experiment and were placed in cans of smoking and chewing 
tobacco in the middle of the room. Controls were kept for each lot. 
At 3.380 p. m. the temperature reached 100° F., and at 4.30 p. m. 
117° F. This temperature was held until 6 p. m. and then gradually 
lessened until 7 a. m., July 8, when it registered 89° F. The steam 
was again turned on and the temperature gradually increased until, 
at 10 a. m., it registered 188° F. This temperature was held until 
noon, when the experiment was ended. At different times some of 
the material was taken out and the boxes labeled and kept for later 
examination. Tobacco exposed for 24 hours at temperatures between 
100° and 117° F. when examined on July 8 was found to contain 
live adults, pupe, and larve. In all material kept in the room 
during the entire time, and which had been subjected to a tem- 
perature of 138° F. for 2 hours, all stages of the beetle were killed. 
In this experiment the air was dry. A hygrometer at 6 p. m. 
registered about 35° F. | 
_ In the second experiment the entire basement of the building was 
heated by live steam which was admitted directly through four 
half-inch nozzles. Three nozzles were fitted to the main steam pipe 
extending through the basement from end to end, and one nozzle 
fitted to the return pipe. Records of temperature were secured 
by means of self-recording thermometers placed in or near the 
packages of infested tobacco, which were divided into several lots 
and placed in different parts of the basement. The tobacco used 
in the experiment was badly infested with all stages of the beetle. 
The experiment was commenced at noon. The outside temperature 
in the shade was 92° F. A boiler pressure of 40 pounds was kept 
until noon of the following day, July 9, when the fire under the 
boiler was allowed to die out gradually to avoid too sudden cooling 
of the walls of the building. The tobacco used in the experiment 
was taken to Tampa, Fla., and kept under observation until July 
15. The results were as follows: At temperatures under 114° F., with 
exposures of 6, 12, and 18 hours, results were practically negative. Ex- 
posure at temperatures between 118° and 130° F. for 24 hours killed 
part of the different stages, but was not entirely effective. Mate- 
. 1 All references to clock time refer to standard time. 
