50 MASS. EXPERIMENT STATION BULLETIN 388 



oxygen below 11 percent. The results obtained with the storage were, therefore,, 

 unsatisfactory, the fruit on removal being in about the same condition as fruit 

 kept at 32 degrees in a normal atmosphere. 



During the past summer the leak was stopped and a new cooling unit installed 

 with a sensitive thermostat. The room is now operating with an atmosphere 

 of 5 percent carbon dioxide and 2 percent oxygen. Results will not be available 

 until the room is opened in the spring. 



Frost Protection on Cranberry Bogs. (C. I. Gunness.) The wind machine 

 used for frost protection was moved to a dry bog in the spring of 1941. It was 

 operated both in the spring and in the fall. The results were in general unsatis- 

 factory in that protection was given over too small an area. 



Poultry House Investigation. (C. I. Gunness and \V. C. Sanctuary.) The 

 investigation on the operation of electric brooders in colony houses was con- 

 tinued during 1941. The purpose of the investigation was to see whether litter 

 could be kept dry in a brooder house through the use of soil heating cable. Very 

 wet sawdust litter was placed in the houses and while the litter in the house 

 equipped with soil cable was drier than in the others, it wa« not sufficiently dry to 

 be considered satisfactory. It was felt, however, that the litter was too wet at 

 the start to make a fair test of the effect of the soil cable. Good chicks were 

 reared in spite of the damp litter conditions. The test is being repeated this year. 



Ceiling temperatures were taken during the winter months of 1941 in insulated 

 and non-insulated pens through the use of thermocouples. Ventilation was 

 adjusted so as to keep the same temperature in insulated and uninsulated pens. 

 It was found that on cold nights the ceiling temperatures in insulated pens would 

 run one degree lower than air temperatures within the pen, while in uninsulated 

 pens the ceiling temperature would run 4.5 degrees lower than the air temperature. 

 This would indicate that insulated pens are more comfortable for the birds even 

 though there ma> be but slight difference in air temperatures. 



Observations taken during the late summer showed ceiling temperatures from 

 5 to 13 degrees higher in uninsulated pens than in insulated pens with equal air 

 temperatures. In sections where the black composition roof had been painted 

 with aluminum paint, the ceiling temperature in uninsulated pens was reduced 

 from 85 degrees to 82 degrees on the rear slope when compared with sections 

 which had not been painted. In insulated pens the aluminum paint produced a 

 difference of 3 degrees in ceiling temperatures on the rear slope. On the front 

 slope the black surface gave a ceiling temperature of 101 degrees in the unin- 

 sulated pens with a temperature of 92 under the aluminum paint. In the in- 

 sulated pen the black gave 88 degrees and the aluminum 85 degrees on the front 

 slope. 



DEPARTMENT OF ENTOMOLOGY 



Charles P. Alexander in Charge 



Investigation of Materials which Promise Value in Insect Control. 



Oil sprays for dormant applications. (A. 1. Bourne and W. D VVhitcomb.) 

 The early season of 1941 was unusual in many respects. March was character- 

 ized by cold, windy weather with the average temperature below normal and 

 snowfall above the average. April, however, was marked by abnormally high 

 temperature which persisted throughout the month and culminated in the peak of 

 90 degrees reached on the 20th. The transition from winter to spring was very 



