548 DOMESTIC ANIMALS, DAIRYING, ETC. 



demand of the machine. This is very important, for sometimes it 

 happens that the operator is detained for some reason and can not 

 reach his machine at the proper hour, and in such a case the lamp 

 must contain oil enough for a few hours overtime. This reservoir 

 should be plain and smooth outside and inside. It should be well 

 made and well finished, having no rough projections or slivers of 

 metal or solder to catch the hands, the clothing, or the cleaning 

 cloths. Attached to this reservoir, or body of the lamp, should be 

 a good, strong handle large enough for the hand of the operator. 

 Better no handle at all than one that is slender, sharp-edged, flim- 

 sily attached, or too small for the use of more than one or two 

 fingers. Select a lamp with a handle that is broad, strong, smooth, 

 and firmly attached. The lamp is for use, and it should be built 

 to stand handling. It must be strong in order that it may be con- 

 venient. 



Burner. The burner is the very important part of the incu- 

 bator lamp. It should be made with the greatest regard to stability 

 and accuracy. The flat>wick tube is the most common, and, when 

 the burner is properly constructed, it answers every purpose. But 

 many manufacturers are careless about the quality of their burners, 

 and are sending out flimsy and poorly made articles that are diffi- 

 cult to manipulate and are imperfect in action. A little careless- 

 ness in selecting a burner has led to the condemnation of many a 

 good incubator. The burner should be made of good material, 

 such as brass or copper, and never of poor material, such as iron or 

 plated tin. The wheel or lever used in raising and lowering the 

 wick must be stout, large enough for its purpose, easy to find, and 

 must turn exactly and easily. Never waste any time upon a burner 

 that does not work promptly and readily, so far as the wick is con- 

 cerned. If it turns hard, or does not turn to the thirty-second of 

 an inch, it is useless and will cause trouble. 



The tube holding the wick should be strongly made of material 

 that will not break, spring, or bend, and it should be so adjusted to 

 the size of the wicks furnished with the outfit that the wick can 

 pass up and down freely without pinching or binding. On the 

 other hand, it should not be so large or loose as to allow the escape 

 of gas along the side of the wick. In one case the pinching of the 

 wick will interfere with capillary attraction, and in the other the 

 looseness of the wick will cause an uncertain or unsteady flame. 

 The wick tube should be perfectly true and smooth across the top. 

 A rough edge with notches, depressions, or projections of metal or 

 brazing will make it difficult to trim the wick; and a poorly 

 trimmed wick gives off an uncertain degree of heat. Alongside the 

 wick should be a small tube for the escape of surplus gas or vapors 

 from the reservoir, but this tube must never project above or even 

 to the top of the wick tube, for if it does it will interfere with trim- 

 ming and be likely to fill with cinder or soot. 



The space under the wick screen should -be wide open. The 

 hinge to the cap should be very strong and work freely to the fullest 

 extent. The snap, or catch, to the cap should have proper strength; 



