uated in 12 deg. 3' 24'' south latitude, and 77 deg. 8' 30'' west longitude
from Greenwich. It may, however, be mentioned that the longitude from
Greenwich is very differently stated. In sea charts and Manuals of
Geography it is often marked 76 deg. 50'. Humboldt makes it 77 deg. 5' 5''; and
Malaspina 77 deg. 6' 45''. According to Ulloa it is 70 deg. 37' west of Cadiz.
The latitude is very generally fixed at 12 deg. 2' 3'' south. The height
above the level of the sea is also differently estimated. Rivero, in the
_Memorial de Ciencias Naturales_, I., 2, page 112, states it to be 154
metres, or 462 French feet. On another occasion he makes it 184-4/5
Castilian varas (each vara being equal to 33 inches English). He gives
the following account of heights, according to the barometer, between
Callao and Lima, in varas, viz., Callao, 00; Baquijano, 24-3/5; _La
Legua_, 50-2/5; Mirones, 94-3/20; Portada del Callao, 150; _Plaza de
Lima_, 184-4/5.

The first estimate given by Rivero is the most correct. Gay makes the
height of Lima, at the corner of the church of _Espiritu Santo_, 172.2
Castilian varas; but most of his heights are incorrectly stated.

The conical hill in the north-east of Lima, called Cerro de San
Cristoval, is, according to trigonometrical measurements, made in 1737,
by Don Jorge Juon, and De la Condamines, 312 varas higher than the Plaza
Mayor, or 134 toises above the sea; but one of the most exact
measurements is Pentland's, who found the height to be 1275 English
feet.

The average temperature during the hottest period of the year, from
December to March, is 25 deg. C. The medium temperature during the cold
season, from April to November, 17.5 deg. C. Highest rise of the hygrometer,
21.5 deg..

The low temperature of Lima at the distance of only twelve degrees from
the Equator is to be ascribed to the situation of the town, and the
prevailing atmospheric currents. The Cordilleras, rising at the distance
of only twenty-eight Spanish leagues east of the city, are crowned with
eternal snow; and on the west the sea is distant only two leagues. The
prevailing wind blows from the south-south-west. West winds are not very
common, though they sometimes blow with extraordinary violence for those
regions, and breaking on the surrounding mountains, they form
atmospheric whirlwinds, which diffuse alarm through the whole
population. In June, 1841, I had the opportunity of observing one of
these dreadful whirlwinds, whi