Mr. Alison's Ascent of the Peak of Teneriffe. 23 



speed was not particularly entered, it could not be less than 

 at the rate of 2\ miles per hour. 



As these experiments were fairly made, and by horses of 

 the common breed used by farmers, and upon ploughs from 

 various counties, these numbers may be considered as a pretty 

 accurate measure of the force actually exerted by horses at 

 plough, and which they are able to do without injury for 

 many weeks ; — but it should be remembered, that if these 

 horses had been put out of their usual walking pace, the re- 

 sult would have been very different. The mean power of the 

 draught-horse, deduced from the above-mentioned experi- 

 ments, exceeds the calculated power from the highest formula 

 of Mr. Leslie. I am, Gentlemen, 



Your obedient servant, 



B. Bevan. 



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

 Teneriffe on the 23rd and 24>th of February 1829. By 

 Robert Edward Alison, Esq.* 



TT AVING frequently observed the rapid fall of the atmo- 

 -*--* spheric temperature when ascending from the sea-coast 

 of TenerhTe to an elevation of 1000 feet, and on the contrary 

 the very slow alteration at higher points, I was desirous of 

 ascertaining the proportional decrement of heat in the upper 

 regions. 



The ascent to the top of the Peak of Teneriffe is consi- 

 dered by the natives of the island as impracticable in the 

 winter season, on account of the snow and the supposed ex- 

 treme cold ; it is therefore seldom made before the month of 

 June, when it is free from snow: but I was not able to wait 

 for a more genial season, as I was in daily expectation of re- 

 turning to England; I therefore resolved to make the at- 

 tempt. 



On the 23rd of February, at 4 A.M., I left the Augustine 

 convent Orotuca, which is situated nearly 1100 feet above 

 the level of the sea. At the time of my departure the thermo- 

 meter stood at 56°'5, and there was a gentle breeze from the 

 N.N.W. 



After joining a stout active young peasant who was to act 

 as my guide, we entered the " Camino de C'rasna," which is 

 dignified by the name of a road, although, like almost all the 

 highways in the island, it is only a steep and uneven line of 



* Communicated by the Author. 



lava 



