Keely says that "''if a planet of 20,000 miles diameter, more or less, should have a displacement of all the material, with the exception of a crust 5,000 miles thick, leaving an intervening void between this crust and a center of the size of an ordinary billiard ball, it would then require a force as great to move this small center mass as it would to move the shell of 5,000 miles thickness. Moreover, this small central mass would carry the load of this crust forever, keeping it equidistant, and there could be no opposing power, however great, that could bring them together. The imagination staggers in contemplating the immense load which bears upon this point of center where weight ceases. This what we understand by a neutral center.’’" [The Neutral Center]