EULOGY ON GAY-LUSSAC. 145 



regularity ; it would have been necessary, as Gay-Lussac himself 

 remarks, in order to deduce rigorous consequences, to combine them 

 with the corresponding measurements of the inclination, which could 

 not be effected.* Our friend, as M. Biot did, from the discussion 

 of the numbers collected in the first ascension, drew from his obser- 

 vations the conclusion that magnetic attraction is constant at all 

 accessible heights. This consequence was logical, at a period when 

 it was not generally known that, in a given place and under given cir- 

 cumstances, the duration of the oscillations of a magnetic needle is 

 influenced by its temperature, and that a decrement of the thermometer 

 of 37° must produce the most remarkable changes. We see that owing 

 to the imperfect state of the instruments, and of science in 1804, it was 

 impossible to arrive at an exact solution of the problem in question. 

 Moreover, it would be astonishing at the present time to hear that the 

 problem had been solved. 



No considerations of any nature would authorize throwing a veil 

 over the gaps of science. This reflection especially concerns the works 

 of men whose authority is incontestable and uncontested. 



Gay-Lussac, after having finished all his investigations with the calm- 

 ness and composure of a physicist seated in his laboratory, landed at 

 forty-five minutes after. three o^clock, between Rouen and Dieppe, forty 

 leagues from Paris, near the hamlet of St. Gourgon, whose inhab- 

 itants executed with great readiness all the maneuvers directed by 

 the aerial voyager in order that the car should avoid the shocks that 

 would have placed the instruments in danger. 



The dignity of this assembly and of the narrative should not, I 

 think, prevent my relating a singular anecdote, for which I am indebted 

 to my friend. Having reached a height of 7,000 meters Gay-Lussac 

 was desirous to rise still higher, and for this purpose rid himself of every 

 article not absolutely needed. Among these was a white wooden chair, 

 which fell by chance into a bush near a young girl guarding some 

 sheep. What was the astonishment of the shepherdess, as Floriau 

 might have said. The sky was pure, the balloon invisible. How 

 explain the cliair, if it came not from paradise ? The only argument 

 against this conjecture was the coarseness of the work ; the workmen, 

 said the skeptics, must be very unskillful above. The dispute was at 

 this point when the journals, publishing the particulars of Gay-Lussac's 

 voyage, put an end to it, and classed among natural effects what until 

 then had seeme^l to them a miracle. 



The ascensions of M. Biot and Gay-Lussac will live in the memory of 

 men as the first which have been made with marked success for the 

 solution of scientific questions. 



The very remarkable meteorological phenomena of a fall of the ther- 



* Gay-Lussac succeeded in observing the dip of the needle, only at a height of 

 4,000 metres. He found there, in round numbers, 20^. This result, supposing it to 

 be exactly reported, differs immensely from the dip which takes place upon the earth. 

 S5 10 



