Josh Zerin > wrote:
Interesting quote from "American Cookery", 1798:

Eggs--Clear, thin shell'd, longest oval and sharp ends are best; to
ascertain whether new or stale--hold to the light, if the white is
clear, the yolk regularly in the centre, they are good--but if
otherwise, they are stale The best possible method of ascertaining, is
to put them into water; if they lye on their bilge, they are good and
fresh--if they bob up an end they are stale, and if they rise they are
addled, proved, and of no use.