The planet Neptune: an exposition and history / By J.P. Nichol.

  • John Pringle Nichol
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: The planet Neptune: an exposition and history / By J.P. Nichol. Source: Wellcome Collection.

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    so all globes in rotation, is a spheroid flattened at the poles, or bulging out—as if into an attached ring—at the equator. The determination of the precise shape of the Earth, being of consummate consequence to geographical science, several of the greatest of our European States have instituted vast triangulations—some of them in remote re¬ gions—that, by the sure methods of the Surveyor, this character of our globe might be defined. Results of high accuracy have undoubtedly been reached by such labours ; but with all their im¬ portance, they are not superior to intelligence, which on the same subject has reached us from the Moon. The motions of that orb are not what they would be, had the Earth been a perfect sphere. Certain deviations are caused by the influence of our equatorial protuberance: and these deviations •—measured by our modern instruments, whose pre¬ cision approaches to the marvellous—enable us, by inverse reasoning, to determine with undoubted exactness, how far the Earth deviates from a regu¬ lar globe. It is certainly unnecessary to accumu¬ late illustrations of a point concerning which the whole modern history of Astronomy is most rich and emphatic : let me conclude, therefore, with an allusion to that recent grand generalization of the