Artificial Incubation

Abstract

IN the account of Mr. Llewelyn B. Atkinson's article on “The Scientific Principles of Artificial Incubation” (NATURE, February 21, p. 282), the author is quoted as saying that practically every type of incubator has the air too dry. If this is so, the number of eggs hatched should be dependent to some extent on the humidity of the outside air. That this is the case is we think borne out by the following. We took the percentages of fertile eggs hatched out at Fishponds Poultry Farm, Netley Abbey, and correlated the figures with the relative humidity deduced from the dry and wet bulb readings at Calshot, four and a half miles distant. The hatchings considered were from December 17, 1923, to March 12, 1924; there were hatchings on 26 days; the largest number of eggs hatched out on any one day was 95, the smallest two 37 and 60; the highest percentage of fertile eggs hatched on any one day was 93.2, the lowest 63.5. The readings at Calshot are those taken four times in the twenty-four hours, and we have taken them from the Daily Weather Report. The following values were found for the correlation coefficient between the percentages of hatchings and the mean relative humidity for various periods: