MEMOIR OF GUYOT. 717 



one. Much rain, great distances, imperviable forests, delayed me two 

 months. I camped out twenty nights, spending a night on every one 

 of the highest summits, so as to have observations at the most favor- 

 able hours. The ridge of the Smoky Mountains I ran over from begin- 

 ning to end, viz, to the great gap through which the Little Tennessee 

 comes out of the mountains." 



Having thus far finished his study of the mountain system, a new 

 map of the whole Appalachian chain, made under his direction by his 

 nephew, Mr. Sandoz, was published in 1860, in the July number of 

 Petermaun's "Mittbeilungen." This map, with some emendations, was 

 republished in 1861, in volume xxxi (second series) of the American 

 Journal of Science, in illustration of an accompanying paper on the 

 Appalachian system. This paper, after a brief history of his work, pre- 

 sents his results in an orographic description of the mount^ain region 

 and an explanation of the laws which he had deduced, together with 

 tables of more than three hundred altitudes. 



His " thousands of measurements" in the Alps had prepared him for 

 accurate and thorough work here. As evidence of exactness, his 

 barometric measurement of Mt. Washington in 1851 gave for the height 

 6,291 feet; the measurements by spirit-level made by N. A. Godwin, 

 civil engineer, in 1852, gave 6,285 feet, and a similar levelling under the 

 direction of the Coast Survey in 1853 gave 6,293 feet. So, again, the 

 Black Dome of North Carolina, made 6,707 feet by him, was measured 

 with a spirit-level by Maj. J. C. Turner, civil engineer, setting out 

 from Guyot's point of departure, and the height made 6,711 feet. 



There was still left unmeasured the heights of the Catskill Mountain 

 range. In 1862 he went to work in this region, and continued it, as 

 before, during his summer and autumn vacation months until the close 

 of the summer of 1879, excepting the year 1871, when he took a trip to 

 California for Lis health and some barometric work in the Rocky Mount- 

 ains and the Coast Range. Gray's Peak, in Colorado, was one of the 

 heights ascended and measured — an easy walk for him, said the young 

 men of the party. 



The Catskill region, a plateau of "piled-up strata owing its mountain 

 forms chiefly to sculpturing waters," had its diBBculties. Although so 

 near New York and the Hudson River, and frequented each summer by 

 thousands of tourists, it was to a large extent, especially over the south- 

 western part, an untracked wilderness of forests. In several cases his 

 only chance for making his triangulation was by climbing to the tops 

 of the highest trees, and then there was difficulty in identifying the dis- 

 tant, featureless, forest-buried summits. Moreover, many peaks had 

 no names, and again the same name was often found to be used for 

 two or three diflerent peaks. He accomplished his work nevertheless, 

 and when finished had gratifying proof of his great accuracy in spite 

 of the difficulties. One point in the triangulation, the extreme western, 

 was in common, as he afterwards found, with that of the State survey 



