MONT BLANC. 



THE summit of this mountain is a ridge, nearly horizontal, lying east 

 and west; the slope at each extremity is inclined from 28 to 30 degrees ; 

 the south side between 15 and 20, and the north side about 45 or 50. 

 This ridge is so narrow as scarcely to allow two people to walk abreast, 

 especially at the west end, where it resembles the roof of a house. It is 

 wholly covered with snow, nor is any bare rock to be seen within 150 

 yards of the top. The surface of the snow is scaly, and, in some places, 

 covered with an icy crust, under which the snow is dusty, and without 

 consistence. The highest rocks are all granites, those on the east side 

 are all steatites, those on the south and the west contain a large quantity 

 of schoerl, and a little tapis corneus. Some of these, especially those 

 on the east, which are about 150 yards below the summit, seem to have 

 been lately shivered with lightning. Sir George Shuckburgh made the 

 height of Mont Blanc, by trigonometrical measurement, 15,973 English 

 feet, or nearly three miles above the level of the sea. M. de Saussure 

 found, by his electrometer, that the electricity of the air on the summit 

 of the mountain, was positive. Water boiled at 68,993 degrees of a 

 thermometer, which rises to 80 with the barometer, 27 French inches 

 high. The wind was north, and extremely piercing on the summit, but 

 southward of the ridge the temperature of the air was agreeable. The 

 experiments with lime water and with the caustic alkali, show that the air 

 was mixed with carbonic acid, or fixed air. Mont Blanc is the highest 

 of the Alps, and encompassed by those wonderful collections of snow 

 and ice, called the Glaciers. Of these glaciers there are five, which 

 extend almost to the plain of the vale of Chamouni, and are separated 

 by wild forests, corn fields, and rich meadows, so that immense tracts of 

 ice are blended with the highest cultivation, and perpetually succeed to 

 each other, in the most singular and striking vicissitude. All these 

 several valleys of ice, which lie chiefly in the hollows of the mountains, 

 and are some leagues in length, unite together at the foot of Mont 

 Blanc. 



The summit of these mountains was deemed inaccessible, before 

 Dr. Paccad, a physician of Chamouni, reached it, in August, 1786. 

 Soon after it was again successfully attempted by M. de Saussure, in 



B 



