MOISTURE AND TEMPERATURE 239 



plied has never been definitely decided; both principles have 

 their advocates. Some machines are built with pans to hold 

 moist sand or water, others have none. Some machines are 

 built with a solid bottom, the idea being to conserve the moisture 

 within the eggs, and others are built with slatted bottoms, 

 through which there is a constant circulation of air. All types 

 are in general use, and all give equally good results. The ques- 

 tion of moisture is one that must be solved by the individual 

 operator. Common sense should tell us, however, to conform 

 in a general way to the instructions of the manufacturer. In- 

 cubators which are designed to use moisture pans seldom give 

 best results when operated without the pans. Similarly, the 

 non-moisture machines are seldom improved by the addition of 

 moisture pans. 



In the opinion of the writer there can be no set rule advanced 

 on the subject of moisture. That excessive evaporation is bad 

 for a hatch, there can be no doubt. And too much moisture will 

 ruin a hatch, also. It seems to be better to err upon the side of 

 too little than too much. But everything depends upon the 

 incubator, its location, the season of the year, climate and the 

 external atmosphere at the time of the hatch. If the weather 

 is extremely dry and hot, more evaporation will take place than 

 when the weather is cool and damp; this is only natural. An ex- 

 amination of the air cell in the egg by means of a candle will 

 reveal the exact condition of the contents. See chapter on test- 

 ing hatching eggs. 



Temperature. — ^An absolutely uniform temperature is not at all 

 necessary to success, and in fact, it is seldom obtainable. That 

 statement does riot mean the operator should disregard tempera- 

 ture or cease his vigilance. On the contrary he should aim to 

 keep the thermometer as near a certain degree as possible. The 

 point is this, variations of a degree or so either up or down, if 

 corrected within a reasonable length of time, will cause no dam- 

 age. The operator should aim to maintain a temperature of 

 I02>^ degrees for the entire hatch. If the temperature drops 

 to loo degrees or rises to 104^ degrees, no ill effects will result, 



