150 AUTOBIOGRAPHY OF FEANCIS ARAGO. 



iii my bumble family there are no authentic documents preserved wliicli 

 could enable me to trace back the civil position of my ancestors. Eacli 

 one there is the child of his own deeds. I declare to you again that 1 

 am Fi-ench, and that ought to be sufficient for you." 



The vivacity of this last answer had not disposed M. Legendre in my 

 favor. I saw this very soon ; for, having j)ut a question to me which 

 required the use of double integrals, he stopped me, saying: "The 

 method which you are following was not given to you by the professor. 

 Whence did you get it?" "From one of your papers." "Why did 

 you choose it? Was it to bribe me?" "Xo; nothing w^as farther from 

 my thoughts. I only adopted it because it appeared to me preferable." 

 " If you are unable to explain to me the reasons for your preference, 

 I declare to you that you shall receive a bad mark, at least as to 

 character." 



I then entered upon the details which established, as I thought, that 

 the method of double integrals was in all points more clear and more 

 rational than that which Lacroix had exi)ounded to us in the amphi- 

 theater. From this moment Legendre appeared to me to be satisfied, 

 and to relent. 



Afterward, he asked me to determine the center of gravity of a spher- 

 ical sector. "The question is easy," I said to him. "Very well; since 

 you find it easy, I will complicate it; instead of supposing the density 

 constant, I will suppose that it varies from the center to the surface 

 according to a determined function." I got through this calculation 

 A'ery happily; and from this moment I had entirely gained the favor of 

 the examiner. Indeed, on my retiring, he addressed to me these words, 

 v.'hich, coming from hisn, appeared to my comrades as a very favorable 

 augury for my chance of promotion : " I see that you have employed your 

 time well; go on in the same way the second year, and we shall part 

 very good friends." 



In the mode of examination adopted at the Polytechnic School in 1804, 

 which is always cited as being better than the present organization, room 

 was allowed for the exercise of some unjustifiable caprices. Would it 

 be believed, for example, that the old M. Barruel examined two pupils 

 at a time in physics, and gave them, it is said, the same mark, which 

 was the mean between the actual merits of the two ? For my part, I 

 was associated with a comrade full of intelligence, but who had not 

 studied this branch of the course. We agreed that he should leave the 

 answering to me, and we found the arrangement advantageous to both. 



As I have been led to speak of the school as it was in 1804, I will say 

 that its faults were less those of organization than those of personal 

 management ; for many of the professors were much below their office, 

 a fact which gave rise to somewhat ridiculous scenes. The pupils, for 

 instance, having observed the insutticiency of M. Hassenfratz, made a 

 demonstration of the dimensions of the rainbow, full of errors of calcu- 

 lation, but in which the one compensated the other so that the final 



