Mr. Alison's Ascent of the Peak of 'Teneriffe. 195 



The true height of (the ground at) Whitfield Hill is with- 

 out doubt the mean of the measurements, at Pickington Ridge 

 of 1349-8, and at Settronside of 1352-3,— or 1351 feet. The 

 consequent error at Bear's Head, amounting to the unprece- 

 dented quantity of 17 feet, appears utterly inexplicable. 

 Leeds, Feb. 14, 1830. John Nixon. 



XXXI. Narrative of an Excursion to the Summit of the Peak 

 of Teneriffe on the 23rd and 2^th of February 1829. By 

 Robert Edward Alison, Esq. 



[Continued from p. 145.] 



A T half-past five (thermometer 36°) I awoke my sleepy 

 "£*• guide, and in about an hour reached that part of the Peak 

 directly above Alia Vista Arriba, called Mai Pais. From what 

 I could observe during my two journeys thither, I consider 

 the diagonal line from the base to this point to be rather more 

 than a mile; but a person in ascending has considerably more 

 than that distance to go, from the serpentine direction he is 

 obliged to take in mounting. 



Mai Pais consists of large blocks of lava, heaped up together 

 in great confusion, sometimes forming deep hollows, or high 

 and dangerous banks. The lava is of various descriptions, but 

 generally similar to that of the two streams or branches before 

 mentioned ; and it appears to have run in a half-fluid state, 

 and to have broken into masses by cooling. 



We had made the ascent up to this point by the lights of 

 the bespangled vault above, and we here seated ourselves upon 

 a block of lava to wait for the rising of the sun. In a few 

 minutes a long and bright streak of light orange-colour began 

 to tinge the eastern part of the fleecy clouds below, which was 

 afterwards reflected on the mountains above us. This streak 

 increased in size and intensity, till Aurora with her rosy 

 fingers burst open the gates of the East, and the twinkling 

 lights of heaven immediately hid their diminished heads. The 

 rapid transition from darkness to light was most striking, from 

 the almost total absence of twilight. I was rather surprised at 

 this, as the evening before it was of much longer duration. I 

 suppose this was caused by the great refractive power of the 

 atmosphere, which was afterwards weakened in the morning, 

 by the vapour that was held in solution condensing, and the 

 air becoming dryer. 



The ascent over Mai Pais is not so laborious as the track 

 of pumice which we had previously been traversing; as we were 



2 C 2 obliged 



