[ 493 1 



tions for placing the macKInes, &cc. ibid. Defci/ption of the drawing-board (fig. i. 

 tab. XilL). ibid. Ufe of ditto, p. 367. Ho'.v to draw all perpendicular lines at 

 once, ibid. Defcription of the compound-boa'd (fig. 2. tab. XIV.), p. 368. Ufe 

 of ditto, ibid. The T fcjuare, its ulcfulnefs, p. 369. Defcription of tlie vertical- 

 board (fig. V tab. XIV.), p. 368. Ufe of ditto, p. 370. 



A'tifcial Springy account of one, by Erafnuis Darwin, M. D. p. 1, Old difufed well 

 near the doflor's houfe in Derbyftiire defcrlbed, p. 2. St. A'kmund's well, its 

 fituation, ibid. A new fpring difcovered, itiJ. 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. Alkmuad's 

 well, p. 4. See Mounta'ms. Increafe in quantity and quality, ibid. And why, 

 p. 6. 



Aja Fceuda^ defcription of a plant yielding it, in a letter from John Hope, M. D. p. 

 36. General defcription, ibid — 38. The afa fcetida plant not fatisfad'torily known 

 till Ksempfer 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, 

 iq. The juice feems to be of the fame nature with the officinal afa foetida, ibid. 



Aftronomical Obfervatiom, in two letters from M. Francis de Zach, Proieflbr of Mathe- 

 matics, and Member of the Royal Academies at Marfeilles, Dijon, and Lyons, p. 

 137. Account of his obfervations of an eciipfe of the moon, made with Father le 

 Fevre, Aftronomer at Lyons, in the Ohkxvsi'ioxy c?\\GdL au gra?ici College, ibid. State 

 of the fky at the time of making the obfervation, ibid. Short telefcopcs preferable 

 to long ones in obferving eclipfes of the moon, p. 13S. In eclipfes of the moon no 

 greater exadnefs than that of a minute can be obtained, ibid. Agreement between 

 the Imperial Aftronomer, I'Abbe Hell's obfervations of the moon's fpots made at 

 Vienna, with thofe made by M. Meffier at Parif, ibid. Correfpondent altitudes of 

 the fun taken with a quadrant of three-foot radius, in order to adjufl the pendulum- 

 clock to apparent time, p. 139. Obfervations of the moon's eciipfe the iSth of 

 March, 1783, p. 142. Father le Fevre's obfervations with a rcfleftor fifty-five inches 

 focal length, p. 143. Obfervations of Jupiter's fatellites at Marfeilles, by M. Saint 

 JaC']ues de Svlvabella, p. 144. Obfervation of the tranfit of Mercury, Nov. iz, 

 1782, at Marfeilles, by the fame, p. 151. and by M. Wallot, at the Royal Obferva- 

 torv at Paris, ibid. Important remark upon the diameter of Mercury, p. 152. 



Averrhca Cara/nbola, 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 affected by being 

 touched in different manners, p. 356, 357. Method of confining the motion to a 

 fingle leaf, p. 357. Effeft of impreffing it by pundlurc, percuffion, or compreffion, 

 ibid. Ditto on flicking a pin into the univerfal petlolus, p. 358. On making a 

 compreffion with a pair of pincers on ditto, ibid. On the leaves being blown again it 

 each other, or the branches, ibid. Appearance of the leaves when fhaded from any 

 dillarbing caufe in the day-time, p. 359. The leaves naturally perform a more 



extenfivitr 



