ASCENT OF CHIMBOLtAZO. 147 



twenty steps before us ; and at half-past nine it was almost dark. As 

 we however felt secure of being able to accomplish our return by re- 

 tracking our own footsteps, we summoned new perseverance to our aid, 

 and kept constantly referring to the compass, in order to avoid a preci- 

 pice which we had formerly sighted. Yet a little higher and farther, 

 and then we became sensible that the elevation was less steep, that we 

 walked more easily, and could breathe with greater freedom, when, at 

 intervals, hollow detonations were heard. At first we attributed them 

 to explosions of Cotopaxi, but presently brilliant lightning announced 

 the raging of a storm far below us, — a storm such as only equatorial 

 regions ever know. Under the fearful impression that hail or snow 

 would efface the prints of our steps, and thus make us lose our way 

 (and perhaps our lives) in the attempt to descend, we decided, though 

 regretfully, to halt; and kindling our C/iuquirafftia-wood, we began to 

 melt some snow in our coffee-pot. At ten o'clock the thermometer, 

 which indicated 1'7° at five feet above the snow, was immersed in boil- 



■ 



ing water, where the mercury rose to 77*5°. Our observations finished, 

 we began to descend at a giant's pace, to regain our encampment, 

 which we reached, in the midst of a thick fog, at about one in the 

 afternoon. The thunder rolled without intermission, and vivid light- 

 ning-flashes, sharply defined, as we only see them in pictures, played 

 incessantly around us till about three o'clock; an awful tempest of 

 hail, rain, snow, and wind, rushed down upon us and our imperfectly 

 sheltering rock, and never gave over till past midnight. We lay in a 

 bed of water; and when daylight came we could perceive nothing but 

 wide tracts of hail and snow, with such signs of a fresh tempest as 

 compelled us to relinquish the thought of making another trial for the 

 summit of Chimborazo, which we had however satisfied ourselves to be 

 within the bounds of practicability ; so we struck our tent, and hastened 

 back to Guaranda, where we arrived late in the afternoon, the thick fog 

 having all along intercepted the grand prospect which we longed to 

 behold. 



When we had calculated our observations, we made the unexpected 

 and gratifying discovery that we had stood on the summit of Chimbo- 

 razo, without beins aware of it. Prom calculations and researches 

 pursued in the Archipelago of Hawaii, and repeated upon the Cordil- 

 leras of the Equator, we had ascertained that the boiling- water point 

 indicates a difference of 29 metres (95-146 feet) for the tenth of a de- 



