VOL. XXXV.] PHILOSOPHICAL TRANSACTIONS. 287 



Omitting the numbers according to the tables of Mr. Cassini, having already 

 shown that they are too great; the lieight of this mountain is nearly the same 

 with the celebrated Puy de Domme, where Mons. Perier observed the Mer- 

 cury, Sept. 19, 1648, at 23i inches. 



On Joch, a high mountain in the territory of Engelberg, where it borders 

 on the canton of Bern, full south of Zuric, the Mercury stood, June 23, 1706, 

 at 21i inches, which gives the height of that mountain, according to 



Mariotte 96 1 toises, or 5766 feet. 



Dr. Scheuchzer 987f 5926 



This mountain, though very high, is far from being the highest in that 

 neighbourhood ; for next to it there rises another called the Titlisberg, covered 

 with everlasting snow, which we may, on a moderate computation, pronounce 

 at least 1000 feet higher than the top of the Joch, and consequently one of 

 the highest in the country. 



On the Avicula, by the Italians called Monte del' Uccello, and by some 

 S. Bernard's mountain, from a chapel built in honour of that Saint, a high 

 mountain in Rhoetia, towards Italy, the Mercury was observed, July 30, 1707, 

 at 2244 inches, which give, according to 



Mariotte . • 707|- toises, or 4247 feet. 



Dr. Scheuchzer 727-^ 4363 



This height must be understood only of that part of the mountain which is 

 passed over by travellers, the mountain itself rising considerably above it, and 

 the Adula, or Aia^as'xxa; of Strabo, (Geog. lib. 3) of which the Avicula is only 

 a part, being still higher. The Rhenus posterior, or Hinder Rhein, and the 

 Moiiss, which at last loses itself in the Tesin, near Bellinzone, not much 

 above the entry of the Tesin into the lake of Locarno, arise on this mountain. 



At Santa Maria, on the Luckmannier Berg, by some S. Barnaby's mountain, 

 which is also a branch of the Adula, the Mercury stood Aug. 9, 1725, as on 

 the Avicula, at 22-fi inches, which shows the height of these two places to 

 be equal. 



In the Alp San Porta, near the source of the Hinder Rhein, Rhenus pos- 

 terior, 5-1- hours from Speluga, Spliigen in Rhoetia, the Mercury was observed, 

 July 29, 1707, at 214^ inches; where it stood likewise on the abovementioned 

 mountain Joch, whither the reader is referred for the height of this Alp. 



At Spliigen itself, the Mercury stood the same morning early, at 23-l inches; 

 which gave the elevation of Spliigen, according to Mariotte 644-^ toises, or 

 3865 feet, and according to Dr. Scheuchzer, 66] jr toises, or 397 1 feet. So 

 that the fall of the Rhine from the Alp aforesaid, to Spliigen, in 5J hours, 



