Mayhew 1952 Experimental April 1 Mallard E30 entire time the temperature varied only 1°C. The only difference from normal was the lack of the electric fan moving the air around the incubator during the 2 hour lapse of power. However, the temperature within the different humidity boxes didn't change. April 4 One chicken hatched this morning at 40% rel. humidity. The egg had gotten in by mistake with some extra small mallard eggs. April 7 Today I broke open all the remaining eggs from the original setting of 36 eggs on Feb. 29. The results are tabulated on page E . April 8 Today 7 eggs from farmer were set at 75%, 7 eggs at 65%. April 12 Today 102 Gibson eggs were set. 40% — 20 eggs 65% — 20 " 75% — 22 " 85% — 20 " 90% — 20 " April 14 Some eggs in the 75% box were seen to be pipped at 17:00 this afternoon. April 17 Today at 13:00 I broke open one of the pipped eggs, since mold was forming around the pipped area. The embryo was fully developed, but some of the yolk had not yet been absorbed. Dr. Armundson of the Poultry Husbandry Dept. looked at it, + said the bird had pipped too early.