Note 43 — CANTO I. OURSELF!
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The foolish trash of Isaac Newton.
See Studies of Nature, by St Pierre, in which that scheming philosopher has, with wonderful adroitness, swept away the cobweb calculations of one Isaac Newton. Indeed, I never much admired the writings of the last mentioned gentleman, for the substantial reasons following.
In the first place, the inside of a man’s noddle must be better furnished than that of St Pierre, or he will never be able to comprehend them.
Secondly, it would be impossible to manufacture a system, like that of St Pierre, accounting for the various phenomena of nature, in a new and simple method, if one were obliged to proceed, like Newton, in his Principia, in a dull, plodding, mathematical manner, and prove, or even render probable, the things he asserts. But by taking some facts for granted, without proof, omitting to mention such as militate against a favorite theory, we may, with great facility, erect a splendid edifice of “airy nothings,” founded on hypotheses without foundation.
The said Isaac had taken it into his head that the earth’s equatorial was longer than its polar diameter. This, he surmised from the circumstance of a pendulum vibrating slower near the equator than near the pole, and from finding that the centrifugal force of the earth would not fully account for the difference between the time of the vibrations at Cayenne and at Paris.
This, with other reasons equally plausible, led him to suppose that the earth was flattened near the poles, in the form of an oblate spheroid, and that a degree of latitude would, of consequence, be greater near the pole than at the equator. Actual admeasurement coincided with that conclusion.
The abbe St Pierre, however, possessing a most laudable ambition to manufacture tides from polar ices, and thus to overturn Sir Isaac’s theory relative to the moon’s influence in producing those phenomena, and finding it somewhat convenient for that purpose to place his poles at a greater distance from the centre of gravity than the equator, accordingly took that liberty. He likewise had another substantial reason therefor. Unless his polar diameter was longer than his equatorial, the tides, being caused by the fusion of polar ices, must flow up hill.
He therefore drew a beautiful diagram with which a triangle would (according to the scheme of the author of The Loves of the Triangles, improved from Dr Darwin’s Loves of the Plants) certainly fall in love at first sight. (See page xxxiv. Pref. Studies of Nature.) In displaying his geometrical skill in this diagram, however, he took care to forget that there was some little difference between an oblong and an oblate spheroid.—That flattening the earth’s surface, either in a direction perpendicular or parallel to the poles, would increase the length of a degree of latitude by decreasing the earth’s convexity. That neither an oblate, nor an oblong spheroid was quite so spherical as a perfect sphere. This was very proper, because such facts would have been conclusive against his new Theory of the Tides.