I N D E X.

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Irregular Appearance of, and what, hi. 313 n. Ob-served in the Planets, ibid. Uses of, ibid. &s eq .spring , how caused, id. 191. Tides, Time of hap-pening, 11. 96.

£>nngr, how supplied with Water, ji. 5. Jo whatowing, ii. 8. See Fountains. Intermittino- and re-ciprocating, accounted, for, ii. n. ' S i ne 1 e hnwformed, ii. i 5 n. Three Sorts of, ii. l6 „ r*ciprocatmg, how produced, ii. 16 n. Qdd Phæno-menon of accounted for, ibid. Intermittino- ac-counted for, ii. 17 n. ? ■

Standard , universal, of Measure, what, i. 124 n,

Star, rising or setting cosmically, what, iii. 260. ' Ris-ing acronically, what, ibid. Rising and setting he-liacally, what, iii. 261. Why appear and disappear,in. 262 n. Fixed, Distance of, iii. 263. ApparentMagnitudes, to what owing, iii. 264 n. Nebulous,what, ibid. Twinkling of, to what owing, iii. 265n. Small ellipt.c apparent Motion of, ibid. Towhat owing, iii. 2669. fsf/ry.

Steam, Water raised by, ii. 7471, Rarity of,/ii. 7671.Steel, Manner of hardening, i. 79 n.

Stentorophonic Tube, why so called, ii. 246. Structureof explained, ii. 247 n.

Stereographic Projection of the Sphere, what, iii. 308 n.Strait, what, iii. 284.

Strings, musical, ii. 231. Elastic, the Motion andTope of accounted for, iii. 255 h. See Vibrations.Subterranean Phænomena accounted for, i. 37.

Sucking Pump, the common, explained, ii. 56 n.Summer, Middle of, when, iii. 189.

Sun, Revolution abput its Axis determined, ii. x 12 n.Demonstrative Proofs for its being the Centre of thetrue Mundane System, iii. 132, hfseq.' Nearer theEarth in Winter than Summer, iii. 143 n . Appa-rent Motion quicker, ibid. Eclipse of, how calcud

lated, iii. 192. Times of entering the Equinox de-termined, iii. 225. How appears to move round theEarth, iii. 186 its seq. ' -

Superficies, what, i. 6.*fSynodical Month, fee Moon.

Synthesis, in Natural Philosophy, i. 4 n .

e.. *