248 Mr. Alison's Narrative of an Excursion to the 



P.S. — The nearest appulse of the D's northern border to 

 Aldebaran on the morning of the 6th of October, at Green- 

 wich, will be about 12"; this happens at 6 h 47 m 44 s . 



At Plymouth the D's northern disc will hide the star 

 24 m 39 s ; immersion at 6 h 16 m 17 s , and the emersion at 

 6 b 40 ra 56 s . The sun will rise at 5 h 27 m . The above is in 

 mean solar time, and according to the respective meridians. 



T. S. 



XL. Narrative of an Excursion to the Summit of the 'Peak 

 qfTeneriffe on the 2.3rd and ZMh of February 1829. By 

 Robert Edward Alison, Esq. 



[Continued from page 200.] 



A FTER resting an hour on the top of the Peak, we 

 ^* descended the cone in the short space of five minutes, 

 although it had cost us 30 in the ascent ; and in about an hour 

 we reached the Estancia. From the clearness of the atmo- 

 sphere there, we found the sun very hot, and although only 

 half-past eleven in the morning, the thermometer in the shade 

 stood at 76°, and in the sun at 97° ; but this heat was greatly 

 owing to the local situation of the Estancia, as an hour and a 

 half afterwards it was only 62°, at which point it generally 

 stood on the way back, till on entering the lower region of 

 the clouds it suddenly fell to 52°, and after to 49°, where it 

 remained until we left our cold and wet companions behind 

 us ; and six hours after leaving the Estancia we arrived safely 

 at the town of Orotava. 



It appears to me that the difficulty of the ascent to the top 

 of the Peak, has been greatly over-rated : from the great 

 steepness of the cone, and the loose nature of the surface, it 

 may present greater obstacles than the ascent of most of the 

 Andes ; but an excursion to the top of it, even at the unfavour- 

 able time of the year that I made it, cannot be compared to 

 the danger and fatigue of an ascent of Mont Blanc. Although 

 the extreme rarity of the air at first produced a slight feeling 

 of sickness, a considerable quickening of the pulse, and a slight 

 difficulty in breathing, yet these symptoms all went off after 

 I had been a few hours on the mountain. The greatest incon- 

 venience 1 felt was from a total want of appetite, and an in- 

 tolerable thirst which it appeared impossible to allay, for no 

 sooner had I taken any liquid, than it immediately returned. 

 It has been mentioned by some authors, that the heat of the 

 atmosphere decreases more rapidly the further you are re- 

 moved from the surface of the earth ; others contend that the 



decrement 



