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MEMOIR OF AUGUSTE BRAVAIS. 



In 1843 IVT, Bravais made no excursion ; it was for him a year of mourn- 

 ing. His eldest brother, M. Louis Bravais, his coadjutor in tlie memoii 

 on the symjuetrical arrangement of leaves, died at the commencement 

 of summer, after six months of suli'ering", borne with Cliristian resigna- 

 tion, in the midst of which he occu])ied himself, to his last day, with 

 researches in botany. This painful separation slackened but transiently 

 the labors of M. Auguste Bravais. He speedily returned to them with 

 his accustomed ardor, and the year following entered upon a new ex- 

 pedition, the last and i)erhaps the most remaricable of those which it 

 was given him to acconipbsh. 



The su[)[)osition is not improbable that two of our distinguished per- 

 petual secretaries, always pleased at meeting one another on neutral 

 ground, had, about that time, exchanged some words on the subject of 

 M. Bravais. M. Arago had, from the tribune of the Chamber of Depu- 

 ties, cited him as one of the officers who, by their knowledge, reflected 

 most honor on our marine, even comparing him, in his extemporization, 

 with the geometers of antiquity. M. Villemain, then minister of public 

 instruction, enlightened also by our learned colleague M. Pouillet, had 

 the merit of comprehending the expediency of an adventure which 

 would crown, by the ascent of Mont Blanc, the i)revious labors of M. 

 Bravais, and drew upon the budget of his department for the expenses 

 of this difficult enterprise. 



De Baussure was the lirst physicist who had made the ascent of Mont 

 Blanc; M. Bravais was the second. He shared this distinction with his 

 friend M. Ch. Martins, and with Dr. Pileur, his collaborator in editing 

 the Fatria, 



It was with no little interest that learned Europe had heard that M. 

 De Saussure, already celebrated for his travels in the Alps, had suc- 

 ceeded in carrying his barometer to the summit of Mont Blanc, and had 

 fixed the height of the mountain at 2,450 toises. He had made at the 

 same time several experiments in physics, which have never ceased to 

 hold an honorable place in all treatises on meteorology. But physics 

 had made great progress in the space of fifty-seven years ; it had be- 

 come time to renew the experiments of De Saussure, and to add new 

 ones, of which no idea could exist in his time. Such was the path which 

 the enlightened liberality of M. Villemain now opened to the hardihood 

 and skill of the three modern physicists. 



Having left Paris, July 10, 1844, with a complete series of instruments 

 of better construction than had ever before been employed in a work of 

 this nature, the travelers stopped at Geneva in order to compare them 

 with those which are there daily employed, with a care and dexterity 

 worthy of the countr}' of De Saussure, and arrived at Chamouni, where, 

 in 17S7, this last-named savant had been obliged to wait four weeks for 

 weather propitious to his undertaking. M. Bravais and his companions 

 were scarcely more favored. A first and second attempt failed from 

 atmospheric accidents, which were not unattended with danger, but at 

 length they arrived, August 28, for the third time at a wide plateau of 

 snow, 880 metres below the summit of the mountain, where their instru- 

 ments had been permanently fixed for three weeks, under shelter of a 

 small tent. The night passed cold and calm, and next day, the obser- 

 vations of the morning being completed, the adventurers proceeded, at 

 ten o'clock, to climb to the top of Mont Blanc. This was reached, with- 

 out any extraordinary difficulties, at forty-five minutes after one ox-lock. 

 The wind was blowing with gTeat force from the northwest ; the ther- 

 mometer marked 7° below zero. The sun shone brightly, but vapors 

 veiled the more remote parts of the vast horizon, which extends from 



