"There are two ways," said the doctor, "by which the polar compression of the earth has been found out. One is by the measurement of arcs on the earth's surface; the other is by experiments with pendulums or weights with regard to the earth's gravity at different places. The former of these methods is, perhaps, the more satisfactory. Measurements of arcs have been made on a very extensive scale in different parts of the world--in England, France, Lapland, Peru, and India. Mr. Ivory, who devoted himself for years to an exhaustive examination of the subject, has deduced that the equatorial radius of the earth is over 3962 miles, and the polar radius over 3949 miles. This makes the depression at either pole upward of thirteen miles. A depression of over thirteen miles, as you must plainly see, should produce strange results in the scenery at the poles. Of course, if there are mountains, no difference would be noticed between this and any other part of the earth's surface; but if there is water, why, we ought to expect some such state of things as More describes. The gravitation test has also been tried, with very nearly the same result. The surface of the earth at the equator, being farthest from the centre of gravity, indicates the least weight in bodies; but at the poles, where the surface is nearest the centre of gravity, there must be the greatest weight. It is found, in fact, that the weight of bodies increases in passing from the equator to the poles. By experiments made in this way the polar compression is ascertained to be the same as I have mentioned." "What effect would this have on the climate at the poles?" asked Oxenden.