324 QUARTERLY JOURNAL. 



Mean height of the continents above the surface of the sea : By 

 Baron von Humboldt. — Since immense and lofty chains of moun- 

 tains occupy our imaginations, by presenting themselves as evi- 

 dences of vast terrestrial revolutions, as the boundaries of climates, 

 as great water-sheds, or as the bearers of different vegetable worlds ; 

 it becomes so much thc3 more necessary to show, by a correct nu- 

 merical estimate of their volume, how small the whole quantity of 

 the elevated masses is in comparison with the area of entire coun- 

 tries. The mass of the Pyrenees, for example — a chain, the mean 

 height of whose summits, and the superficial extent of whose base, 

 are known bv accurate measurements — would, if distributed over 

 the area of France, increase the height of that country only 115 

 English feet. The mass of the eastern and western chains of the 

 Alps would, in the same manner, raise the height of the flat country 

 of Europe by only 21 "^ English feet. By means of a laborious inves- 

 tigation, which, from its very nature, only gives the upper limit, 

 i. e. a number which may be smaller, but can not be larger, I have 

 ascertained that the centre of gravity of the volume of the land 

 which rises above the present level of the sea, is situated at a height 

 of 671 and 748 English feet in Europe and North America, and 

 1131 '8 and 1151 English feet in Asia and South America.* These 

 calculations indicate the lowness of the northern regions ; the great 

 steppes of the plains of Siberia are counterbalanced by the enor- 

 mous swellings of the surface of Asia between lat. 28^° and 40°, 

 between the Himalaya, the northern Thibetian Kuen-Lun, and the 

 Sky mountains. We can, to a certain extent, determine, from the 

 estimated amounts, where the plutonic force of the interior of the 

 globe has operated with greatest power in elevating continental 

 masses. The mean height of the non-mountainous portion of France 

 does not exceed 512 English feet. 



[From the New- York Tribune, October 18.] 



AGRICULTURAL ITEMS. 



The Farmers' Club held its regular semi-monthly meeting 

 yesterday. The hour devoted to miscellaneous matters was fully 

 occupied. An interesting paper on guano, and its application to 

 plants, was read and commented on. It appears that the best method 

 of using guano for iiorlicultural purposes, is to dissolve one pint of 

 it in fcnir gallons of water, and use freely about the roots. A paper 

 was next read, translated by Mr. Meigs, from the Paris Horticultural 

 Review, on the palm and date tree, giving an account of the nu- 

 merous varieties ; and another paper by Mr. Renier, on the cultiva- 

 tion of the potato, with some interesting statements regarding the 



* The corresponding amount for the whole globe will consequently be somewhat 

 less than 1000 feet. 



