MEASURING SPECIMENS. 



73 



calipers can be used — a small size for the little eggs, 

 and a larger size for the big ones : though, unless the 

 calipers work very smoothly, accidents are likely to 

 happen. A more satisfactory method is to purchase 

 or make a machine with a sliding-bar, like a shoe- 



^^^^^^ 



A 



1 1 > j II 1} ' I' I ' I' ji i 



T 



Fig. 14. 



maker's foot-measure of diminutive proportions. 

 Having fitted the bars snugly to your egg, ascertain 

 the distance between the 1)ars by a i:>air of draughts- 

 man's dividers of the ordinary pattern, and find the 



I'I'IM'I 



I ' I ' I ' I ' r j ' r j ' I ' I ' I 



Fig. 15. 



number of inches and hundredths by comparing with 

 some standard rule ; unless, indeed, the measuring 

 stick, upon which your egg lies and the movable bar 

 slides, IS marked off in inches and hundredths of 

 an inch. It would be well to have a slight depres- 



