NO. 12 SMITHSONIAN EXPLORATIONS, I917 29 



vail for 260 days per year, and skies not more than i/io cloudy 

 prevail over 300 days per year, at an elevation above 8,000 feet, with 

 sky of the deepest blue, the conditions are believed to be far the best 

 in the world for the study of the variability of the sun. 



It is now known that large fluctuations of the earth's temperature 

 and of barometric pressure, changes of the intensity of terrestrial 

 magnetism, variation of the numbers of sun spots and of the dis- 

 tribution of light over the sun's disk are all closely associated with 

 variations of the intensity of solar radiation. Even our understanding 

 of the variability of the stars is likely to be improved by the study of 

 solar changes. All these and other probable applications of its results 

 enhance the interest and value of the proposed Chilean expedition. 



GRASSES OF THE ADIRONDACK AND WHITE MOUNTAINS 



During the month of August, 1917, Mr. A. S. Hitchcock, sys- 

 tematic agrostologist in the Department of Agriculture and custodian 

 of the section of grasses of the division of Plants in the U. S. National 

 Museum, visited the Adirondacks in New York and the White Moun- 

 tains in New Hampshire for the purpose of studying their flora, 

 especially the grasses of the alpine summits. In the Adirondacks his 

 headquarters were at Lake Placid from which point excursions were 

 made to the summits of Whiteface and Mclntyre, the highest peaks in 

 the group with the exception of Mt. Marcy. It was impracticable 

 to reach Mt. Marcy without the use of a camp outfit. This peak rises 

 to a height of 5,344 feet but Mt. Mclntyre is nearly as high (5,112 

 feet). Both Mclntyre and Whiteface extend above the timber line 

 and support at the summit an alpine flora. 



The White Mountains reach a somewhat greater altitude than the 

 Adirondacks, Mt. Washington, the highest peak, being 6,293 feet. 

 In the Mt. Washington group there are several peaks whose summits 

 are above the timber line. The alpine flora of these peaks and of the 

 peaks of the Adirondacks are similar, and include plants that farther 

 north are found at a lower altitude or, in the Arctic regions, even at 

 sea level. 



Four days were spent investigating the flora of the peaks. The 

 ascent was commenced at Crystal Cascade on the east side, whence 

 the trail led up Tuckerman Ravine to the summit of Mt. Washington, 

 thence down to Lakes-of-the-Clouds where there is an Appalachian 

 Mountain Club hut for the accommodation of climbers. From here 

 the head of Oakes Gulf was explored. The second day was spent 

 along the trail from Lakes-of-the-Clouds to the Mt. Madison hut, 



