PROPAGATION 
to be constantly changing the regulator, 
which results in an uneven temperature 
in the machine. An uneven temperature 
is not conducive to good hatches. How- 
ever, if the manufacturer of the machine 
that you are using instructs you to lay 
the thermometer on top of the eggs, then 
I think it is best for you to do so. And 
I think it is a good practice for those who 
have had but little or no experience with 
incubators, even though the manufacturer 
does not so recommend; for while the bulb 
of the thermometer that lies on the eggs 
will always be the right height, the one 
with adjustable legs or the hanging ther- 
mometer is liable to be adjusted too high 
or too low by the novice to get good 
results. I have known persons who have 
had a great deal of experience with incu- 
bators to make such bad adjustments of 
their hanging and adjustable-leg thermom- 
eters that they got very poor results. The 
fact that eggs vary in size gives the ther- 
mometer that lies on top of the eggs an 
advantage over a hanging or suspended 
thermometer, for it is self-adjusting and 
will never be placed too high or too low 
to give good results. And if the eggs are 
4 47 
