[ 43 * 3 
Fire, conlidered as the caufe of heat, the only agent by which abfolute drynefs can be 
immediately produced, p. i. Fire capable of producing any required degree of 
compadinefs, as lavas abundantly Ihew, p. 5 5. The effects of fire on James’s pow- 
der, p. 318. Fire powerful in the change of the colour of bodies, p. 362. Fire the 
caufe of heat, p. 4 02 * 
Fixed air. See Air, 
Flints, rows of, in a chalk-pit near Ridlington in Rutland, p. 281. Flints about Rid- 
lington not fo black as thofe of the fouthern counties, but veined, ibid. 
Fyfi'eld, in Hampfhire, abilradof a regiiler of rain kept at, for the year 1789, p. 89. 
G. 
Geneva. Confiderations on the convenience of meafuring an arch of the meridian, and 
of the parallel of longitude, having the Obfervatory of Geneva for their common 
interfedtion, p. 106. Capelia, a liar of the hrft magnitude, culminates between the 
zeniths of Geneva and St. Jean Maurienne, p. 115. 
Geography . On the rate of travelling, as performed by camels; and its application as a 
fcale, to the purpofes of geography, p. 129. 
Giant's Canfevbay , many of its pillars confifl of fine-grained, dark-coloured whinflone, 
P- 5 1 ' 
Granite and bafaltes, obfervations on the affinity between, p. 48. Almoft all granites 
melt into a black glafs, p. 60. Granitic lavas are granite rocks fufed, p. 63. Mal- 
vern Hills, compofed of granite, p. 65. 
Greenwich , the longitude of Dunkirk from, deduced from triangular meafurement, fup- 
pofmg the earth to be an ellipfoid, p. 236. Longitude of Paris from Greenwich, 
ibid, 
H. 
Heat, at its maximum in a body, when it is incandefcent, p. 3, Heat caufed by 
fire, p. 402. 
Herfchel , Dr. on nebulous flars, p. 71. 
Home , Everard, on cerain horny excrefcences of the human body, p. 9$. 
Human body, obfervations on certain horny excrefcences of, p. 95. The cafe of 
Mrs. Lonfdale, p. 96. The cafe of Mrs. Allen, p. 98. 
Hydrahad Tabafheer, experiments on, p.369. Refembles Cacholong, ibid. 
Hygrometer , fundamental proportions for the conflrudtion of an, p. 1. Abfolute dry- 
nefs can only be produced by fire, ibid. Extreme moiflure can only be produced by 
means of water, ibid. 16. Obfervations on abfolute drynefs, p. 2. An liygrofcopic 
body cannot lofe any part of its moiflure, but by evaporation, ibid. Drynefs capable 
of fixation by lime, p. 3. An hygrofcopic body, which is brought to incandefcence, 
cannot contain any evaporable water, p. 9. The point of extreme moiflure of an 
hygrometer known by the excefs of water, p. 17. Obfervations on two diftin& 
claffes' 
