t 5 2 5 3 
Sextant, defcrlption of one contrived by Mr. Flamdeed, p. 3« Improvement made oa 
it, p. 4. 
Shale, various properties of, p. 186. 
Sbap-Water (WeEmoreland) may be rendered fimilar to Harrogate water by diffolvlng 
common fait in it, p. 178. 
Sharp , Abraham , (fervant to Mr. Flamfleed) encomiums on him, p. 5. An excellent 
maker of mathematical inftruments both in wood and brafs, p. 7. 
Shells , defeription of fbme minute Britifh fhells, p. 160. The frefh-water Nautilus, 
ibid. The fountain Helix, p. 165. The tender prickly Helix, p. 166. The fine 
ringed Turbo, p. 167. The oblong frefh-water Patella, p. 168. Gold {hells brought 
from the ^eft Indies fuppofed not to be fhells, but a fpecies of cochineal in its pupa 
Eate, p. 168. 
Smeaton , John , his Obfervations on the Graduation of Agronomical Inflruments, with 
an Explanation of Hindley’s Method of dividing Circles, p. 1. 
Snow, experiments refpedting freezing by mixing it with fpirit of nitre, p.242. Expe- 
riments with common and dephlogiEicated acids of nitre, p. 254. 
Soap, procefs for the making of it from diachylum, fea fait, and fpirit of wine, 
p. 158. 
SpeSlra, new experiments on, p. 313. Four kinds of, p. ibid. Of the a&ivlty of the 
retina in vifion, p. 314. From the defed of fenfibility, p. 317. Suppofed defeats 
in the eye from obferving fpedra, p. 318. From excefs of fenfibility, p. 320. Of dired 
ocular fpedra, p. 324. Of reverfe ocular fpedra, p. 327. MifceUaneous remarks, 
p. 333. Rules for determining before-hand the colours of all fpedra, p. 336. 
Conclufions, p. 347. 
Spirit of Wine , Obfervations on the affinities of fubftances in, p. 153. 
Stars, obfervations on, and a difeovery of the period of the variation of the light of 
the Ear marked £ by Bayer, near the head of Cephus, by Mr. Goodricke, p. 48. 
Obfervations by Mr. Pigott, p. 37. Obfervations on the variations of £ Lyrae, 
Algol, and ^ Perfei, p. 60. Obfervations and remarks on thofe Ears which the 
aEronomers of the laft century fuppofed to be changeable, p. 189. Catalogue of 
variable Ears, reduced to the beginning of 1786, with obfervations, p. 191. Obfer- 
vations on the famous Nova of 1572 in Cafliopea, p. 192. Obfervations on the 
0 Ced, p. 193. Obfervations on Algol, p. 194. Obfervations on Mayer’s N° 420, 
ibid. Obfervations on the variable, in Hydra, p. 195. Obfervations on the famous 
Nova of 1604 in Serpentarius, p.197. Obfervations of @ Lyrae, ibid. Obfervations 
on the Nova near the Swan’s head of 1670, p. 198. Obfervations on v> Antinoi, 
ibid. Obfervations on the variable, in the Swan’s neck, p. 199. Obfervations on the 
variable, in the Swan’s breaE, p. 201. Obfervation on the £ Cephei, p. 202. Obfer- 
vations on Hevelius’s 6th Cafliopea, p. 203. Obfervations on the 46th or f Andrc- 
medae, ibid. Obfervations on Flamfteed’s 50, 52 r Androinedae and Hevelius’s 
41 Andromedas, p.204. Obfervations on Tycho’s 20th Cefi, ibid. Obfervations on 
Y y y 2 FiamEeed* 
