Another has a very pretty appearance, glass 

 doors, etc., with thermostatic bar, single wall, 

 clock-work and battery ; dampers in the top to 

 open and close (often six or eight times in an hour), 

 lamp trips to lower the flame ; it is quite a piece of 

 machinery and quite likely to get out of order, 

 both the clock-work and the thermostatic bar, as 

 well as the battery. When these all work right it 

 gives very good results ; but it requires skill, 

 experience and a mechanical turn to operate this 

 class of machines successfully. 



Another has splendid arrangements for moisture 

 and ventilation ; but the thermostatic bar is affected 

 by the swelling and shrinking of the machine and 

 change of outside temperature ; in some climatesj 

 we find it almost impossible to control it in an 

 ordinary house. 



We have found where lamp trips are used the 

 wick becomes charred much quicker. 



Another kind has a tank to pour hot water into 

 above the eggs, which are placed in a drawer. 

 The water must be drawn out and heated every 

 day, sometimes several times in a day, and is not 

 reliable for profitable work . 



There are others which we might mention, but* 

 space forbids, nor is it necessary. 



Most of the so-called "self-regulating" incu- 

 bators that we have seen have to be governed ; 

 principally by the lamp and some judgment of the 

 operator. 



Example : We have a large room made of one- 

 inch boards, with a stove in it, which, in moderate 

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