Magic oracle, or, Conjuror's guide (1850)
“ To make an egg stand on end on any polished surface seems very extraordinary, yet is to be done even on a looking glass; now, from the form of an egg, nothing is more liable to roll, and on nothing more than a looking-glass. To accomplish this trick, let the performer take an egg in his hand, and while he keeps talking and staring in the faces of his audience, give it two or three hearty shakes, this will break the yoke, which will sink to one end, and consequently make it more heavy, by which when it is settled, you may make it, with a steady hand, stand upon the glass. ”
