In this philosophic repose he continued till the Revolu tion, without adding any thing to his mathematical discove ries, or even opening his Mecanique ./Inalytique, which had been published for two years.
The Revolution gave philosophers an opportunity of making a great and difficult innovation ; the establishment of a system of weights and measures founded on nature, and perfectly analogous to our scale of numbers. La Grange was one of the commissioners whom the Academy charged with that task. He was one of its keenest pro moters. He wished to see the decimal system in all its purity. He was provoked at the complaisance of Borda, who got quarters of the metre made. Ile thought the ob jection of little importance which was drawn against the system from the small number of divisors that its base afforded. He regretted that it was not a prime number, as 11, which would have given the same denominator to all the fractions. This idea perhaps will be regarded as one of those exaggerations, which are hazarded by men of the best understandings, in the heat of dispute. But he mentioned the number 11 merely to get rid of the number 12, which more intrepid innovators would have wished to substitute, in place of the number 10, that constitutes the base of the whole of our numeration.
When the Academy was suppressed, the commission charged with the establishment of the new system was re tained for a time. Three months had scarcely elapsed when, in order to purify that commission, the names of Lavoisier, Borda, La Place, Coulomb, Brisson, and Delam bre,vere struck out. La Grange was retained. In quali ty of president, he informed rne, in a long letter full of kindness, that I should recicve official information of my removal. As soon as he saw me on my return to Paris, he expressed to me his regret at the dismissal of so many associates. " I do not know," said he, " 4 why they have retained me." But unless the suppression had been total, it could scarcely have extended to him. The more losses the commission had sustained, of the more importance was it not to deprive it of the consideration attached to the name of La Grange. Besides, he was known to be whol ly devoted to the sciences ; he had no place either in the civil department or the administration. The moderation of his character had prevented him from expressing what he could not but think in secret ; but I shall never forget the conversation which I had with him at that period. It
was the day after the atrocious and absurd sentence, con trary to every thing like justice, had thrown all lovers of the sciences into mourning, by cutting off the most illustri ous philosopher in Europe. " It has cost them but a mo ment," said he," to cut off that head, and a hundred years perhaps will not be sufficient to produce another like it." Some months before we had had a similar conversation in the cabinet of Lavoisier, on account of the death of the unfortunate Bailly. We lamented together the dreadful consequences of the dangerous experiment which the French had attempted. All these chimerical projects of amelioration appeared to him very equivocal proofs of the greatness of the human mind. " If you wish to see it tru ly great," added he, " enter into the cabinet of Newton, employed in decomposing light, or in explaining the system of the world." Already for some time lie had regretted not having listened to the advice of his friends, who at the commence ment of our troubles had recommended him to seek an asylum, which it would have been so easy for him to find. As long as the revolution seemed only to threaten the pension which he -enjoyed in France, he had neglected that consideration, ouC.of curiosity to be upon the spot of one of those great convulsions which it is always more pru• dent to observe at a distance. " It was your own choice.," said he several times to himself, when he entrusted me with his regret. It was to no purpose that a special decree of the Constituent Assembly had ensured the payment of his pension. The decree was of no value, because the depreciation of the paper currency was sufficient to render it illusory. He had been named member of the Board of i Consultation, appointed to examine and reward useful n ventions_ He had been appointed one of the administra tors of the Mint. This commission offered him few ob jects to fix his attention, and could in no degree remove his apprehensions. It was again proposed to draw him to B. rlin, and to restore him to his former situation. He had agreed to the proposal. Herault de Sechelles, to whom he had applied for a passport, offered him, for the greater security, a mission to Prussia. Madame La Grange would not consent to quit her country. This repugnance, which at that time he considered as a misfortune, was to him a source of fortune and of new glory.