INDEX.

N.

"KtAtural Day, what, iii. 123. Philosophy, what,

* i. 4 n.

Nature , most of the Phænomena in, accounted for byAttraction and Repulsion, i. 39 n.

Needle , dipping, what, i. 42. Variations of its Decli-nation and Inclination, i. 46 n. Variation of ac-counted for, i. 44 n.

Nettleton, Dr. Table of Experiments for the Altitudeof Mercury in the Barometer, ii. 133.

Newcomen and Cowloy , their Contrivance for raisingWater by Steam, ii. 74 n.

Newjham’s Water-Engine with some Variation, ii. 45.Motion of the Water in, how effected, ii. 49. Wa-ter-Engine, greatest Artifice in the Contrivance of,ii. 69 n. Its Rationale, ibid. and 70 n.

Newton, Sir Isaac, his Manner of accounting for seve-ral subterranean Phænomena by Attraction of Co-hesion, i. 32. His Demonstration of the fundamentalPrinciples of Mechanics, i. 167 n. Experiments withGlobes to shew the retarding Power, i. 322 n. Ex-periments, Table of, i. 324 n. and 325 n. Theoryof the Tides, ii. 98 n. His Theorem for investi-gating the Rarefaction of the Air at any Altitude,ii. 144 m His Thermometer, ii. 18311. How con-structed, ibid. Opposed by Professor Euler, ii. 105 n«His Hypothesis about an elastic Medium rectified byleSicur and Jacquier, ii. 225 n. His Explanation ofthe Nature of Waves, ii. 229 n. More nicely deter-mines the Velocity of Light, ii. 275 n. Account'sfor the Porosity and Hardness of Glass, ii. 294 n.His Table of the Proportion of the Sines of Incidenceand Refraction in yellow Light, ii. 308 n. His Me-thod of determining the Refrangibility of several inter-mediate Rays, ii. 321 n. &seq. His Reasons for theReflection of Light, ii. 332 n. Fits of. easy Re-flection and Transmission proved by Experimentswith two Prisms, ii. 237 n. Definitions and Pre-cautions with regard to the Doctrine of Colours,ii. 354 n * & s e i- His elegant Demonstration of the

Imper-