C 5*7 1 
theodolites , improvements in the method of dividing them, p. 18. By Mr. Ramfden, 
ibid. 
thermometer, regider of, in 1785, at Lyndon in Rutland, p. 236. Additional obfer- 
vation on making a thermometer for meafuring the higher degrees of heat, p. 390. 
The difficulty of obtaining clays of the fame thermometrical properties, p. 398. 
The difficulty remedied by a mixture of alum earth, p. 402. 
Thompfon , Sir Benjamin , New Experiments upon Heat, p. 273. 
Torricellian Vacuum, experiments with, upon heat, p. 274. Diredions for making, p. 
27?. Not fo good a conductor of heat as the atraofpheric air, p, 286. 
7 ran/fi Inftrument, hidory of its origin and improvements, p. 7. 
Turbo, defcription of a newly difcovered Britiffi ffiell, called the fine-ringed Turbo, 
p. 1 5 ;. 
Turkey Stone, magnetical experiments on, 63, 
V, 
Ventotiene,. Ifland of, account of, p. 371. Some particulars of the birds there, p. 372* 
Account of fome Roman tiles found there, ibid. 
Vefuvius , fome particulars of the prefent date of, p. 365. Account of the eruption in 
November 1784, ibid. The appearance of the mountain altered, p. 369, A journal 
of its operations kept by Sir William Hamilton and Father Piaggi from Auguft 
1779 to the prefent time, p. 366. 
Vince , Samuel, a new method of finding fluents by continuation, p, 432. 
Vifion . See Eye. 
Vitriolic Acid, experiments on freezing, made with it, p, 263. 
Vitriol, Oil of experiments on freezing, by mixing it with fpirit of nitre, p. 269. 
Volcanos , rather of creative than deftru&ive powers, p. 378. Advice to young ©b- 
fervers of, p. 379. 
W. 
Waring , Edward, on infinite Series, p. 81. 
Water, properties of, when faturated with hepatic air, p. 141. Experiments On 
its power of codufling heat, p. 301. 
Watfon, Bp . of Landaff, Obfervations on the Sulphur Wells at Harrogate, p. 171. 
Weather, obfervatjons on, in 1785, p. 237. On the variations of feaions, p. 238. 
Wedgwood, Jofah, Additional Obfervations on making a Thermometer for meafuring 
the higher Degrees of Hear, p. 390. 
Whately, Thomas, Difle&ion of a Body dead of an extraordinary Introfufception, p. 306. 
4 White 3 
