degrees of latitude makes this elevation much more sensibly felt; and in the winter there are few colder spots than the summit of the Sierra of Catorce. The mine of La Purisima is 390 feet higher than the town, and the Cerro de la Leona 1,110 feet; but the whole range is exposed almost equally to the cold winds from the north and north-west, which sweep across it at times with incredible violence. To the east there in no protection, as the descent towards the coast commences almost immediately; and to the west, between Catorce and that branch of the Sierra Madre upon which the mineral deposits of Zacatecas, Fresnillo, and Sombrerete are situated, there is not a single intervening ridge.
I have heard doubts expressed with regard to the accuracy of the measurements by which the height of Catorce has been ascertained; and from the numberless accidents to which a barometer is exposed, it is certainly possible that Captain Wylde may have been deceived in the result of his observations. Most people are of opinion that the elevation exceeds considerably the 7,760 feet at which he has rated it, and they justify this belief in the following manner. On leaving the valley of Mexico there is an immediate descent of 767 feet into the valley of Tula, and this continues to increase as you advance from Arroyo Sarco towards the Băxīŏ, Zĕlāyă being 1,138 feet, and Salamanca 1,707 feet below the level of the Capital. Guănăjūātŏ rises again, and is only 633 feet lower than Mexico; and although from Mărfīl
