When the great earthquake of 1906 occurred and the whole surface of the earth along the line of the "Portola Fault" was in a tremor, it was estimated by scientific men that the swaying of the tall Spreckels Building carried the center of gravity beyond the base line many times during those fearful forty-eight seconds.
But when the building was erected, the wise builder "dug deep and laid the foundations" aright. The building has a steel frame and the frame does not rest upon the loose sand which underlies so much of San Francisco -- the architect pierced through the loose material at the surface and anchored the steel frame in great wells blasted from the solid rock and afterward filled in around the bases of the steel frame with cement.
When the 18th of April came, testing every man's work of what sort it was, the huge weight of the swaying building was held in place because it was founded upon a rock. It gripped that which was abiding.
written by Rev Chas. R. Brown, page 37 in One Thousand Evangelistic Illustrations, edited by Webb, A. (1924). New York: Harper & Brothers Publishers