February, '15] HOWARD: PROGRESS OF ECONOMIC ENTOMOLOGY 



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can be used in the spray chamber as well as hydrant water. Bear in 

 mind if you know the absolute humidity and temperature of the air 

 as it leaves the humidifier or spray chamber, the thermostat in the 

 breeding chamber can be set so as to lower the humidity of the air as 

 it passes through the heating chamber. Of course, this increases the 

 temperature of the air. 



Mr. W. C. O'Kane: I would like to ask Mr. Dean how in summer, 

 when the atmosphere is saturated, he is going to maintain a low humid- 

 ity in his machine. 



Mr. G. a. Dean: Pass the air through cold water which will 

 give it a temperature within one degree of the water and then con- 

 dition the air in the heating chamber, by setting the thermostat in 

 the breeding chamber so as to heat or expand the air which will reduce 

 the humidity. If hydrant water is used I don't suppose the tempera- 

 ture would be much below 60 degrees. There would be no difficulty 

 whatever in maintaining a low humidity w^ith a high temperature. 



Mr. W. C. O'Kane: With a low temperature and low humidity. 



Mr. G. a. Dean: You cannot get a temperature in summer 

 lower than the water used in the spray chamber. If a temperature 

 lower than the hydrant water is desired you must use ice water or even 

 salty ice water. This will give you a low temperature, say perhaps 

 thirty degrees. Then if this air is heated, say to sixty or seventy 

 degrees in the heating chamber, it will be expanded and, of course, the 

 humidity will be lowered. It should be remembered that the appara- 

 tus is so constructed as to use the air from the breeding chamber, 

 which will enter the spray chamber already partly conditioned. 



President H. T. Fernald: We will now listen to a paper by Dr. 

 Howard. 



NOTES ON THE PROGRESS OF ECONOMIC ENTOMOLOGY 



By L. O. Howard 



When General W. G. LeDuc took office as United States Commis- 

 sioner of Agriculture July 1, 1877, just 37 years ago, the annual appro- 

 priation to the Department was $174,086.96, and there were 77 

 employees. The Department was in the main a statistical, correspon- 

 dence and seed distribution bureau. Virtually no research was being 

 carried on. The entomologist, with one assistant only, was engaged 

 almost entirely in the general museum work of the Department. In 

 the country at large there were no state experiment stations, and but 

 three state entomologists, Riley in Missouri, Thomas in Ilhnois, and 

 Fitch in New York, the last past his days of work. There were prac- 



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