IS 



say of a robin {Tardus migratorius). The grooves forming the 

 drilled surface should be cut with a chisel. Fig. 2 will suit the 

 generality of eggs, excepting those of very large birds and of 

 sea fowl, which usually lay eggs with a strong but soft shell. 

 The grooves may be cut either with a chisel or a j^/e, but if with 

 the latter, greater care will be requisite in its use. Fig. 3 is 

 intended for the largest eggs, and even some of the smaller ones 

 which have a chalky shell, such as Crotophaga. The grooves 

 are cut with a Jih. In the manufacture of all these drills the 

 greatest care is necessary that the grooves should lie parallel to 

 one another, and that their edges should be smooth. The smaller 

 the drill, the more acute should be the angle it forms at the 

 point. The drills may be fitted with handles or not according 

 to fancy. Those with handles are less likely than the others to 

 cramp the fingers of the performer, an inconvenience which often 

 causes breakages. 



N. B. A separate sketch is given with the enlarged views of 

 the end of a drill, in order to show more plainly the manner in 

 which the grooves should be cut. 



Figs. 4 and 5 represent blowpipes, for emptying eggs. They 



Fig. 7. 



Fig. 6. 



Half natural size. 



Natural size. 



