royal geographical society.

Feb. 12.--W. R.

Hamilton, President, in the chair.--The following papers were read:

-- 1. Extracts from a letter from Baron Alex. von Humboldt:

"Berlin, Jan. 10. 1838.

"I cannot sufficiently congratulate the Geographical Society in having found so excellent a traveller as M. Schomburgk--so much courage and so much devotedness.

His latest labours in Guayana, the ascent of the rivers Corentyn and Berbice, place him very high in my opinion; and this zone of hieroglyphic figures, sculptured in the rock, from Encamarada in 66° 50' west, even as far as the eastern limit of British Guayana, a distance of nearly 600 geographical miles, is an ethnographical phenomenon, which daily inereases in interest.

"The astronomical geography of Northern Asia will shortly be set right by the publication of the great works of M. Federoff, who has recently returned to St. Petersburg, after five years' absence.

Should I yet publish the detail of my own astronomical observations in Siberia, it will only be in order to fix more accurately the points where I have made observations on terrestrial magnetism.

I bespeak the same indulgence for these labours in Asia, that has formerly been shown to my travels in America.

"I learn, with the greatest satisfaction, that my letter to the Duke of Sussex, on the subject of magnetic observatories, has produced some useful results.

As we make observations here, both with the needle of Gambey, furnished with microscopes, and with the new apparatus of Gauss, furnished with a mirror, we have an opportunity of convincing ourselves more and more of the greater perfection of the latter apparatus, which, by degrees, will be employed in all our great observatories.

"As I think that this subject is not without importance to seamen, I beg you to invite the influential members of your Society, to be good enough to propagate Gauss's manner of observing in all new stations where intelligent persons can be found.

Points near the magnetic equator, and those which are in high latitudes in the southern hemisphere, as the Cape of Good Hope, Australia, Van Diemen's Land, &c., would be most desirable, if they would observe at the same epochs indicated by M. Gauss, and followed throughout the north of Asia, in Germany, Sweden, and Milan.

"The beautiful trigonometric levelling between the Black Sea and the Caspian, is at length finished.

There is depression, but a much less depression than Professor Parrot announced after his first barometric levelling by stations.

This always appeared to me probable, on account of the elevation of Kasan, and on account of some corresponding observations that I obtained during my journey to the Caspian.

"The levelling of Messrs. Fuss, Sabler, and Sawitch shows, that the level of the Caspian is about 105 English feet lower than that of the Black Sea."