Children's toys, and some elementary lessons in general knowledge which they teach (1877)
Erle, T. W. (Twynihoe William), 1828-1908 · London : C. Kegan Paul · leaf 80
that the centre of gravity of any, and every, body is that point about which, if it be sup- ported, the whole mass will balance, and therefore rest quiet and contented. We have also seen that if this point be not supported, it will descend to as low a posi- tion as it can reach, travelling along… … Here we have a three-cornered board of the shape of a pyramid. Since it is of a regular figure, and of one uniform substance, its centre of gravity (leaving out of account its thickness which is so small as to be immaterial) will be at the middle of its surface. Set
Toys · Science
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
