. Artificial incubation and incubators ... hermometer as nearly as possi-ble on a level with the top of the eggs. If it is laid on the eggs besure to have the stem or scale a little the highest—a very littlewill do, but it should never be perfectly level or with the bowl thehighest; if so, the weight of the mercury more than counteractsthe cohesion of the metal, which is all there is to draw it into thebulb as the temperature decreases, and the thermometer will mostlikely show a higher temperature than actually exists, and also,will not show any decrease in the heat of the drawer, if suchshoul
. Artificial incubation and incubators ... hermometer as nearly as possi-ble on a level with the top of the eggs. If it is laid on the eggs besure to have the stem or scale a little the highest—a very littlewill do, but it should never be perfectly level or with the bowl thehighest; if so, the weight of the mercury more than counteractsthe cohesion of the metal, which is all there is to draw it into thebulb as the temperature decreases, and the thermometer will mostlikely show a higher temperature than actually exists, and also,will not show any decrease in the heat of the drawer, if suchshould occur. CHAPTER IV. The Egg. Deeming that it is necessary to a full understanding of theprocess of Artificial Incubation, I shall give as briefly as possible,an account of the formation of the egg, and the mode and proba-ble time of impregnation. In the structure of the egg we have first the shell, which issufficiently porous to allow the process of respiration. Next is theshell-membrane, which is double, and composed of an outer thick. leathery membrane, (s. m. Fig. 1) and an inside thinner one (i. ) At the large, or butt end of the egg, between the shell andthe membrane, is the air-cell or air bubble (a, c. h.). In freshlylaid eggs this r.^ace is so thin as to be hardly discernible, it rapidlyincreases in size, however, as the white of the egg shrinks fromevaporation. 20 THE EGG. Next under the shell-membrane is the white of the egg or al-bumen, as it is called (w.). This is formed of numerous thinlayers of fluid albumen, which alternate in consistency, theseform a network of elastic character, completely surrounding andprotecting the yellow yolk (y. y.), which comes next, and in turnnearly encircles the white yolk (w. y.) The yellow yolk is also f orm_ed in several concentric layers, separated by very thin fluid of albumen. This white yolk has the appearance of a roundwhite spot of three-sixteenth to one-quarter inch diameter, con-nected by a funnel-shaped ope
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectincubat, bookyear1883
