716 MEMOIR OF GUYOT. 



winter, and his long journeys in that inclement season were often over 

 unbroken roads and in the roughest of conveyances. 



Thus Guyot went almost immediately to work in his favorite fields, 

 laying the foundations not only for geographical education, but also for 

 geographical investigation, and for a national system of meteorological 

 observations and records. The national plan was not then inaugurated : 

 but the work thus carried forward under the Smithsonian Institution 

 was the initiator, in fact, of the United States Signal Service Bureau. 



In the summer of 1861 Guyot had occasion to visit Europe, and he 

 took advantage of the opportunity, observes Professor Henry, " to de- 

 termine, by his own observation, the relations of the standard barom- 

 eters used by the Smithsonian Institution with the most important 

 standards of the European observatories; and it is believed that these 

 comparisons establish a correspondence of the Eurojiean and American 

 standards within the narrow limit of one or two thousandths of an 

 inch."* 



Besides the general survey of Few York topography, Guyot carried 

 forward, during his leisure weeks of the summer and autumn, a study 

 of the altitudes and orography of the Appalachian chain, or the mount- 

 ain system of eastern North America, in which work he had encour- 

 agement from appropriations by the Smithsonian Institution. He com- 

 menced, as early as 1849, a barometric exploration of the White Mount- 

 ain system of New Hampshire, and continued his work at the North 

 until he had spent five years over New Hampshire, the Green Mount- 

 ains in Vermont, and the Adirondack s, and other parts of New York. 



From these more northern portions of the Appalachian system he 

 went to Virginia and North Carolina. In July of 1S5G he measured 

 barometrically twelve of the highest peaks of the Black Mountains in 

 North Carolina, all of them higher than the White Mountains of New 

 Hampshire. He was occupied with this southern parC of the system 

 from that time till late in the summer of 1860, when his measured 

 heights in that region of endless forests and great altitudes had in- 

 creased in number until they exceeded one hundred and eighty; how 

 much exceeded his paper does not say, as the altitudes determined in 

 1860 remain still unpublished. Besides these measurements, he made 

 his survey complete by extending a net- work of triangles over the area 

 (nearly 150 miles in length), so fixing the positions of the peaks and 

 ridges. 



In a letter of October 3, 1859, he writes, speaking of his work of that 

 season in the Smoky Mountains, 'Hhe culminating range of North Car- 

 olina": "My trip to the Smoky Mountains was a long and laborious 



*Professor Henry's report to the Regents of the Smitlisoniau Institution for the 

 year 1862. The observatories with which the comparisons were made were that of 

 Kew, then under the direction of Stanley ; that of Brussels, under Quetelet; that of 

 Berlin, under Encke, and that of Geneva, under Plantamour, -who had already com- 

 pared the Geneva barometer with that of the College de France and that of the Ob- 

 servatory of Paris. 



