This section is from the book "Light Science For Leisure Hours", by Richard A. Proctor. Also available from Amazon: Light Science for Leisure Hours, Second Series.

Assuming my theory to be correct, we have a means - rough, it may be, but not uninstructive - of determining the displacement of the centre of gravity of the earth's solid mass from the centre of figure. For, accepting one inch as the difference of barometric height at the two poles, it is easily calculated that this difference amounts to a difference of level of about 850 feet. In other words, the surface of the water at the south pole lies farther than the surface of the water at the north pole from the centre of gravity of the entire fluid and solid globe, by about 850 feet. Hence this centre of gravity must lie about 425 feet north of C (which is the centre of the bounding surface of the water). Now, it is evident that both the centre of gravity of the entire fluid and solid mass, and that of the solid mass, must lie much nearer to C than to C. Hence both these centres of gravity lie considerably within 400 feet of C, and Of lies considerably within 825 feet of C. Thus the centres of figure and the centres of gravity of the earth's solid mass, and of the entire fluid and solid mass are collected within a space less than one-eighth of mile in length - a distance almost evanescent in comparison with the dimensions of the earth's globe.

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