Cosmos, Vol. 4

to solve, which rotates uniformly around a fixed axis. Since the time of Newton and Huygens, the most famous geometers In this context, "geometers" refers to mathematical physicists and astronomers. of the eighteenth century have been occupied with this solution. It is beneficial to constantly remember that everything great achieved through the intensity of mental power and the mathematical combination of ideas derives its value not merely from what has been discovered and integrated into science; but primarily from what this discovery has contributed to the development and strengthening of the analytical tool The "analytical tool" refers to the methods of calculus and mathematical analysis used to solve physical problems..

"The geometric figure of the Earth, as opposed to the physical one ³, determines that surface which the surface of the water would assume in a network of canals connected to the ocean, covering and crisscrossing the Earth everywhere. The geometric surface intersects perpendicularly the directions of the forces which are composed of all the attractions emanating from the individual particles of the Earth, combined with the centrifugal force corresponding to its rotational speed. ⁴ On the whole, it can only be regarded as very closely belonging to an elliptical spheroid of rotation; for irregularities in the distribution of mass in the interior of the Earth, given locally varying density, likewise produce irregularities in the geometric surface, which is the product of the total effect of unequally distributed elements. The physical surface is directly given by the actually existing surface of the solid and liquid on the outer crust of the Earth." Even if it is not improbable for geological reasons that accidental changes, which in