288 Geographical Collections. 
trict of Larecaja. Its height is 25,000 feet. It results from a trigonometrical 
measurement made on the borders of Titicaca, at the height of 12,760 feet: it 
also results from the determinations obtained at a less distance, of the portion of 
the mountain which rises above the line of eternal snow. Between the 13th and 
17th degrees, Mr. P. seldom found this line lower than 17,000 feet on the flanks 
of the eastern chain of the Peruvian Andes. * 
Between the parallel of the Hlimani and that of 21°, the eastern Cordillera 
does not offer a single summit which attains the limits of eternal snow, though 
several rise to 16,000 feet, and even higher, since the Cerro de Potosi, which 
belongs to this portion of the eastern chain, has 16,080 feet. At 21° 15’ occurs 
the Nevado de Chosolque, at 12 leagues N. W. of Tupica. But south of that 
latitude, Mr. P. met with several peaks covered with eternal snow. 
- The snow-clad mountains which are seen to the north of Cochabamba, under 
the latitude of 17° 23’, do not belong precisely to the eastern chain of the Cor- 
dillera, but to a transverse chain which detaches itself from the preceding, and 
prolongs itself to the east, across the fertile province of Cochabamba, lowering 
more and more. The Indian race of Yuracaraes inhabits the lower parts of this 
chain, which terminates in the immense plains of Chiquitos. The natives give 
it the name of Cordillera of Cochobamba: it separates the valley of Gupai-el- 
Grande from the beds of the Rio Beni and the Mamoré. 
( To be continued. ) 
Anomalous Rise in the Waters of Lake Leman, ( Lake Geneva, ) and the 
Rhone, in August and September 1629. Bib. Univ. T. xlii. p. 86.—The sin- 
gularity of the season which has just terminated, has given rise to a remarkable 
anomaly in the rise of the waters of Lake Leman, and of the Rhone, at its issue 
from the lake. These waters being essentially fed by the melting of the snows 
and ices of the mountains of Valais, ordinarily increase and decrease regularly 
with the temperature ; so that their maximum of height takes place almost always 
in August, and their minimum in February, without the rains having any re- 
markable influence upon this periodicity. This year the summer has not been 
very hot, and, at the same time, the months of August and September have offer- 
ed a greater quantity of rain than has been known to fall at that season for the last 
twenty-three years. It resulted from this, that the waters, after having attained 
their regular maximum on the Ist, 2d, and 3d of August, amounting only to 
113 inches above the mean height of the twenty-three preceding years, lowered 
in their regular course to 23 feet below that height on the 6th and 7th Septem. 
ber, and then, on the 29th of September, re-ascended 14 inches above the mean, 
thus giving in this month an oscillation of 163 inches, in a direction opposed to 
that of their annual course. 
Out of twenty-three years of observations made by Mr. Messaz, director of the 
hydraulic machine of Geneva, we only find one example of that anomaly, and _ 
that in a much less marked degree. In 1822, the waters attained their regular 
maximum the 6th and 7th of August, which was 23 inches above the mean: 
they descended the 29th of August to 163 inches above that same. mean, and 
then re-ascended rapidly to the 3d and 4th of September, when they attained 26 
inches. The oscillation was then only of 94 inches. It is true that it was very 
rapid. 
That we may be able to form a more correct idea of the value of these quanti- 
ties, we will mention, that in the twenty-three years of observations, the mean of 
the low and high water deviates 29 inches from the general mean ; that the max- 
* A singular result ; for at Quito, under the equator, the limit of snow is at 
2460 toises. Probably that, as in the interior of Asia, there is a radiation of 
caloric, arising from the elevated plains which surround the mountains.— Note 
of Mr. de Humboldt. 
