32 COSMOS. 



three timeS as great as the elevation of the highest ot our 

 mountains above the sea's level, but it is almost five times 

 as great as that of the eastern plateau of Thibet. 



We ought here to observe that the results of the earth's 

 compression, which have been obtained by mere measure- 

 ments of a degree, or by combinations of the former with 

 pendulum measurements, show far less* considerable differ- 

 ences in the amount of the equinoctial bulging than we 

 should have been disposed at first sight to conclude from the 

 fractional numbers. The difference of the polar compres- 

 sions (3-^0- and ^i-y) amounts to only about 7000 feet in the 

 difference of the major and minor axes, basing the calcula- 

 tion on both extreme numerical limits ; and this is not twice 

 the elevation of the small mountains of the Brocken and of 

 Vesuvius ; the difference being only about one tenth of the 

 bulging which would be yielded by a polar compression 



f -nnr 



As soon as it had been ascertained by more accurate meas- 

 urements of a degree, made at very different latitudes, that 



* It has often seemed to me as if the amount of the compression of 

 the earth was regarded as somewhat doubtful merely from our wisli 

 to attain an unnecessary degree of accuracy. If we take the values 

 of the compression at 75-!^-, ^-^j, -yJ-jj-, -^^, we find that the difference 

 of both radii is equal to 10,554, 10,1)05, 11,281, 11,684 toises, or 

 67,488, 69,554, 73,137, 74,714 feet. The fluctuation of 30 units in 

 the denominator produces only a fluctuation of 1130 toises, or 7126 

 feet, in the polar radius, an amount which, when compared with the 

 visible inequalities of the earth's surface, appears so very inconsid- 

 erable, that I am often surprised to find that the experiments coin- 

 cide within such closely approximating limits. Individual observa- 

 tions scattered over wide surfaces will indeed teach us little more than 

 what we already know, but it would be of considerable importance to 

 connect together all the measurements that have been made over the 

 entire surface of Europe, including in this calculation all astronomic- 

 ally determined points. (Bessel, in a letter addressed to myself, De- 

 cember, 1828.) Even if this plan were carried out, we should then 

 only know the form of that portion of the enrth, which may be re- 

 garded as a peninsular projection, extending westward, about sixty- 

 six and a half degrees from the great Asiatic Continent. The steppes 

 of Northern Asia, even the middle Kirghis steppe, a considerable por- 

 tion of which I have myself seen, are often interspersed with hills, 

 and in respect to uninterrupted levels, can not be compared with the 

 Pampas of Buenos Ayres, or the Llanos of Venezuela. The latter, 

 which are far removed" from all mountain chains, and consist immedi- 

 ately below the surface of secondaiy and tertiary strata, having a very 

 uniform and low degree of density, might, by differences in the results 

 of pendulum vibrations, yield very decisive conclusions in reference 

 to the local constitution of the deep internal strata of the earth. 

 Compare my Views of Nature, p. 2-8, 29-32. 



