Incubation 



1857 



cooking purposes, they may be tested on the fourth or the fifth day. 

 Brown eggs are less easily tested, and it is usually advisable not to test 

 them before the sixth or the seventh day. 



In order to obtain the best results, the eggs should be tested first on 

 the seventh day of incubation and again on the fourteenth day. A common 

 method of testing is illustrated in Fig. 66. If the germs are strong and 

 the eggs have been properly incubated, only a few dead germs should be 

 found on testing the eggs a second time. It is better to do the testing 

 at night unless the room can be darkened during the day. A convenient 

 movable room for testing eggs either during the day or at night is easily 

 constructed at a low cost in the following way : The framework should be 

 made of 2 x 2 -inch lumber. The side and back walls should be made of 

 thin lumber down to about one and one half inch from the floor, and 

 these walls should be painted black on the inside. Heavy black cloth or 

 paper may be used in place of the 

 Itimber. Black cloth is preferable 

 to lumber for use in covering the 

 top, as the former will allow the heat 

 to escape. The size of the room is 

 governed by the space it is to occupy 

 and by the size of the egg trays. A 

 dark-colored window shade or a black 

 cloth curtain should be hung over 

 the entrance. A hole a little smaller 

 than an ordinary egg should be cut in 

 the rear wall of the room sufficiently 

 high and at the proper distance from 

 the side walls to be convenient in 

 testing eggs held in the right hand. 

 The work is less tiresome if this open- 

 ing is directly opposite the right arm, 

 and as low as possible without caus- 

 ing the operator to stoop. Brackets 

 for the egg trays should be placed 

 inside of the room along the sides, 

 and boards the width of the tray 

 should be placed on the brackets 



before the tray of eggs is placed on them in order to prevent the eggs 

 from cooHng too rapidly. A shelf is placed lower down in order to hold 

 the trays for the infertile eggs and those containing dead germs. On 

 the outside of the rear wall a third shelf should be provided for holding 

 the lamp that is used in testing. Any ordinary lamp that can be fitted 



Fig. 67. — Interior view of testing room: 

 I, Curtain rolled; 2, shelf and tray for 

 untested eggs; j, tray for infertile and 

 dead germ eggs 



117 



