[ 493 ] 
rions for placing the machines, &c. ibid. Defcription of the drawing-board (fig. u 
Sab. XIII,), ibid. UFe of ditto, p. 367. How to draw all perpendicular lines at 
once, ibid. Defcription of the compound board (fig. 2. tab. XIV.), p. 368. Ufe 
o i ditto, ibid. The T Iquare, its ufefulnefs, p. 369. Defcription of the vertical- 
board (fig. 3. tab. XIV.), p. 368. Ufe of ditto, p. 370. 
Artificial Spring, account of one, by Erafmus Darwin, M. D. p. r. Old difufed well 
near the dottor’s houfe in Derbyffiire defcribed, p. 2. St. Alkmund’s well, its 
fituation^ ibid. A new fprjng difcovered, ibid. Method of preventing the 
mixture of the old water with the new, p. 3. And of trying the height of the 
new fpring, ibid. New water nearly of the fame properties with St. Alkmund’s 
well, p. 4. See Mountains. Increafe in quantity and quality, ibid. And why, 
p. 6. 
J/a Fcetida , defcription of a plant yielding it, in a letter from John Hope, M. D. p. 
36. General defcription, ibid — -38- The afa fetida plant not fatisfadorily known 
till Kaempfer defcribed it, p. 36. Letter from Dr. Pallas to Dr. Guthrie, with two 
of the plants, ibid. One of which planted in the Botanic Garden at Edinburgh, p. 
39. The juice feems to be of the fame nature with the officinal afa fcetida, ibid. 
Agronomical Obfervations, in two letters from M. Francis de Zach, Profeffor of Mathe- 
matics, and Member of the Royal Academies at Marfeilies, Dijon, and Lyons, p. 
s 3 /‘ Account of his obfervations of an eciipfe of the moon, made with Father le 
Fevre, Alhonomer at Lyons, in the Obfervatory called ait grand College, ibid. State 
of the Iky at the time of making the obfervation, ibid. Short telefcopes preferable 
to long ones in obfervxng eclipfes of the moon, p. 138. In eclipfes of 'the moon no 
greater exaftnefs than that of a minute can be obtained, ibid. Agreement between 
the Imperial Aftronomer, 1 ’Abbe Hell’s obfervations of the moon’s fpots made at 
Vienna, with thofe made by M. Meffier at Paris, ibid. Correfpondent altitudes of 
the fun taken with a quadrant of three-foot radius, in order to adjuft the pendulum- 
clock to apparent time, p. 139. Obiervations of the moon’s eciipfe the xSth of 
March, 1783, p. 142. Father le Fevre’s obfervations with a refleftor fifty-live inches 
focal length, p. 143. Obfervations of JupkeVs fateliites at Marfeilies, by M. Saint 
Jacques de Sylvabella, p, 144. Obfervation of the tranfn of Mercury, Nov. i 2 , 
1782, at Marfeilies, by the fame, p. t 5 i. and by M. Wallot, at the Royal Obferva- 
tory at Paris, ibid. Important remark upon the diameter of Mercury, p. 152. 
Averrbca Carambola, an account of the fenfitive quality, in a letter from Robert Bruce, 
M. D. p. 356. Is a fpecies of fenfitive plant, ibid. Is differently affeded by being 
touched in different manners, p. 356, 357. Method of confining the motion to a 
fingle leaf, p. 357. Effed of impreffing it by pundure, percuffion, or compreffion, 
ibid. Ditto on flicking a pin into the univerfal petiolus, p.358. On makings, 
compreffion with a pair of pincers on ditto, ibid. On the leaves being blown againft • 
each other, or the branches, ibid. Appearance of the leaves when ihaded from any 
difturbing caufe in the day-time, p. 359. The leaves naturally perform a more 
extenfive 
