256 ANNUAL. REPORT OF THE Off. Doc. 



as far as possible, fences. Fig. 4 is a view of a Westchester county 

 fruit and poultry farm where 1,500 Vv'hite Leghorns are kept for 

 egg production. These are divided, approximately, into three flocks 

 of from four to six hundred each. These flocks are separated from 

 each other by six foot wire fences and each is given two or three 

 acres of orchard for range. The orchard furnishes shade, the in- 

 tervals between the trees permits growth of grass for green food, 

 and the fowls in return, furnish fertility to grow larger trees and 

 better fruit. On this farm the fowls were originally fenced off into 

 small flocks of 25 to 30 each, which made a tremendous outlay for 

 fences and made it well nigh impossible to spray the trees effec- 

 tively, the spray mixture quickly ruined the fences. Gradually 

 these fences were taken out and it was found that all the various 

 flocks returned to their own separate pens. It is well to remember 

 that the biggest bump in a hen's head is the bump of location. Com- 

 pare by contrast the expense of the yards, restricted runs, extra 

 labor, and the lack of shade in the poultry plant shown in Fig. 5. 



The problem which concerns all who operate incubators, is a 

 proper temperature at which to operate the machines. We have 

 tried a large number of experiments with the object in view of 

 determining the best temperature to run the machines during each 

 week of the hatch. We early discovered, that, in order to know 

 the temperature which the eggs were receiving in a given machine, 

 we must first decide how the thermometer should be placed. With 

 this object in view, we ran a large number of hatches with different 

 incubators, each of which contained three thermometers of differ- 

 ent types. One was suspended with the bulb slightly above the sur- 

 face of the eggs. One was placed with the bulb resting on fertile 

 eggs. The other was placed on the tray with the bulb between the 

 eggs. (See Fig. 6.) In each case these thermometers were placed 

 precisely according to the instructions of the manufacturer. The 

 actual result as shown by the reading of these thermometers dur- 

 ing the entire hatch was startling, see Fig. 7, which is a reproduc- 

 tion of one of the incubator records which we keep when we operate 

 each and all of onr machines. The top line represents the tempera- 

 ture reading of the hanging thermometer, the middle line the ther- 

 mometer resting on the eggs, the bottom line the thermometer that 

 was between the eggs. It will readily be seen that there was a net 

 difference between the reading of the hanging thermometer and the 

 thermometer between the eggs of three to four degrees during the 

 first two weeks of incubation which was gradually reduced during 

 the last week. It will readily be seen also that if a given ma- 

 chine were to be run at 103 degrees by the hanging thermometer, 

 the reading of the thermometer between the eggs would be 99 to 100 

 degrees. If, on the other hand, we were operating the incubator 

 by the thermometer between the eggs at 103 degrees, the hanging 

 thermometer would be running at 106 or 107 degrees. We have not 

 yet determined just what temperature a machine should be run 

 with each of these thermometers, but we have demonstrated that 

 with certain machines the hanging thermometer did not give suffi- 

 cient heat to get the chickens out until the 22nd or 23rd day, and 

 some of them not at all, particularly where the eggs were cooled to 

 any extent. We found, on the other hand, that where the tempera- 

 ture was run at 103 with the thermometer between the eggs, nearly 



