AND PORTO SANTO. 47 



scene was soon changed ; the clouds advanced at first Hke vast 

 floating glaciers, but soon formed an entire sea, from which the 

 points of the peaks emerged Hke desert rocks and breakers. I did 

 not quit the summit until noon, when the thermometer stood at 

 49 in the shade, and at 80 in the sun ; De Saussure's hygrometer 

 remained at 57, for there was not a cloud above us ; and the elec- 

 trometer, armed vnth its conductor and elevated, was not affected 

 in the smallest degree. I made the height of the peak 6164 feet", 

 (or about 650 feet lower than the range of hills considered as the 

 base of the Peak of Teneriffe,) and I think it was impossible for 

 the day to be more favourable'. 



' Barom. 619.65, T. 9.45, T.d. 9.45 c. 49 F: in the turret of Mr. Veitch's house in 

 Funchal, 1 54 feet above the level of the sea, (allowing seven feet for the rise of the 

 tide at the syzygies, when the height of the turret was determined,) 770.70, T. 20.5, 

 T.d. 20.5 c. 69 F : T— T' = IB- 2; ^Jga x 2 (t + t') = 103" 2; correction for 

 latitude, 8"'. 



' For the Peak of Teneriffe to be visible from Ruivo, it would require the latter to 

 be upwards of 18,000 feet high. " M. Cordier mesura le Pic de Teneriffe, le 10 Avril, 

 1803, en employant un excellent barom^tre qu'il avoit fait bouillir la veille, et par un 

 temps tr^s-beau et tres-constant, qui se prolongea pendant un mois. Les instrumens 

 etoient places au vent du Pic, et la hauteur barometrique fut ramenee a la temp&-ature 



de I'air ambiant M. Cordier a tenu compte des petits changemens de 



niveau dans la cuvette, et ce physician, tres exerce aux mesures barometriques, a pris 

 toutes les precautions necessaires pour obtenir un resultat exact." M. Cordier's 

 observation, calculated by La Place's formula, gives 1920 toises, or 12,162 English feet. 

 Voyage de Humboldt, 1. 1, c. 3. In a MS. communication of Dr. Savignon's, (a 

 Spanish physician resident at Lagunae,) the summit of the Peak is stated to be 12,208 

 Enghsh feet, with the following observation : " Orotava stands 1042 feet above the 

 level of the sea ; the range of hills, which may be considered as the base on which the 

 Peak of Teneriffe rests, 6810 feet, and the base of the sugar loaf, 11,670 feet: these 

 heights are the result of a series of observations made by several intelligent gentlemen 

 of Teneriffe, and agree extremely well with those made by Baron Von Buch and 

 Professor Smith in 1815." I need not add, that Baron Von Buch (whose work I have 

 not yet seen), as a scientific traveller, is allowedly second only to Baron de Humboldt. 

 I merely mention these two barometrical observations, differing only forty-six feet in 

 a height of 12,000, because they seem to have escaped the attention they merit. See 

 Journal of Science for jNIarch, 1823, p. 79. 



