ALTITUDES. 



297 



Many persons may desire that these altitudes should have been much more numerous. Others might have 

 been given, but I did not think it desirable further to encroach upon the text, especially as the contour map will 

 give a general idea of the altitude of every foot of land in the stal 



I should have been glad to reproduce Prof. Guyot's figures, as obtained by the mercurial barometer, for 

 comparison with those of the Geodetic Connection survey. It has been done only in a few cases on page 280. 

 His barometrical figures are usually nearly as reliable as those obtained by the measurement of vertical angles. 

 I have altered his figures of the heights of mountains in Warren, page 281, measured on the slope of Moosilauke 

 with a pocket level, and communicated privately to William Little, by the difference between the barometrical 

 and trigonometrical heights of Moosilauke. I have been disappointed in not receiving from Prof. Guyot answers 

 to several questions about his measurements, sent with the proofs of this chapter. Hence the reference to " note 

 beyond," on page 275, has no significance. 



R. S. Howe, engineer of the Northern Railroad, suggests the addition of the following statement to the end 

 of the second paragraph on page 249: " and an efficient means of noticing the orographical and other physical 

 peculiarities of the state, and placing within reach of the medical profession a record that may enable and induce 

 professional men in different localities to observe, record, and contrast the influence of elevation, if it has any, on 

 health and disease. Hitherto, latitude an J longitude have been the chief and almost the only conditions modify- 

 ing climate that have been taken into account in considering the influences on health; but the observations of 

 physicians and travellers present facts suggesting that altitude, to some extent, controls the type of diseases." 



Fig. 44. WHITE MOUNTAINS, FROM BRIDGE IN BERLIN, NEAR MILAN. 



VOL. I. 



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