M. Borda was appointed major-general to the naval arinament' which sailed from Toulon under the Count D'Estaing, and he Was present with that distinguish ed commander at all the naval operations, by which he contributed to the final emancipation of America. In this.high situation, the wisdom, prudence, and in tegrity of Borda excited the admiration of hisifellow officers.
From the experience which he had now obtained of the naval service, Borda perceived many .defects . in the construction of vessels, which could easily be remedied.. He considered the want of uniformity in the construction of ships which were to act together as•a great defect, from which, arose a great discord ance in their movements, and in the execution of sig nals. Upon his return. to France, he communica ted this idea to the government, who immediately resolved:to carry it .into effect. .The best form for a ship of 74 guns was selected by Borda from a va riety.olcOnstructions,.and was •made the model for the formation of others ;. and- the same plan was fol lowed for vessels of different rates: • . • - ..In the -year 1781, Borda was appointed to the command.of the vessel Le Guerrier • and in-the year. he obtained the command the Solitaire, a ship .of 64•guns, for the purpose of escorting a body of troops to the island of Martinique, at a time when the reduction of all our West India islands was the fa vourite' object of. the allies, and when they had ac tually succeeded in the capture of the islands of, Nevis and St Christophers. Borda had the good for tune to convoy the troops under his orders to their final destinatm.i•; 'and- having joined the fleet the Count De Grasse, he was ordered to a cruising. ftvtion wkh the ce,mmand of several frigates. After tr- fil•n fkrt, thick fog came on, aad• to his little: - - , squadron in the middle of eight English ships of war. He tried, in vain, to extricate himself from a force so superior to his own; and when he found that escape was impossible, he refused to surrender till his own ship became a .complete wreck. Borda was treated with great .kindness and • distinction by the English, .who sent him back ' to France upon. his parole ; but the chagrin which lie:felt kiss Of his squadron, and the fatigues of three naval campaigns, having be gun to produce a serious.effeet on his health, he de termined to spend the remainder of his days in the quiet prosecution of science and philosophy.
• Diirthg his 'io);akealcingwith Pingre in 1771, Bor .da fnund, from'experience, that the valuable quadrant •invented by our countryman Hadley, was susceptible of great improvement. The celebrated Tobias Mayer .had already endeavoured to remove its imperfections. .He made the instrument a complete circle, and re peated the of the angle on different parts of its graduated cireumference.l• By _taking a' mean of these•measui-es, he Jesuit the various sources of. error, to which _Hadley's qua: drant was liable. M. Lefeire Ginean, the biogra pher of Borda, declares that the idea of Mayer was ne•er carried into effect, and thus 'endeavours to ascribe the whole. merit of the. invention to his own countryniam This statement; hoWeirer, is corhplete= ly false; ohe:ofidgayeriss circles was made for Ad ink-al • .by ,and Mayer had himself .used an 'instrument for' ineisdring=teriestrial angles -upon the' repeating.principle, which. is-described in the Commentaries Royal Society of Gottingen, for 1752, tom. ii. p. 325.
. Borda having examined; with•the utmost attention, the construction proposed'by Mayer,' soon perceived its defects, which he has pointed out in .scription •.et usage •die circle de .Rylexion; published in 1787: , .These defects • he had,•in great.meaSure, removed,. in a new circle of his own invention, which was first =dein 1777; and which has Since.been em ployed with great success; under the name of the Circle Borda. This instrument, however, 'excellent as it was; had still numerous imperfections; and:it was re served to our ingenious countryman,,Mr.Troughton, to bring to perfection one of , the happiest' inventions that was ever made. See ASTRONOMY, .p. 722; and Cluctg.
• When the french -government had -resolved to re form their weights and measures, Borda was appointed by the Academy one of the commissaries for fixing the basis of • the •new :system: .With this view he in vented a.most simple and ingenious method of mea suring, with extreme accuracy, the length of -the pendulum ; .he gave a new form to' the rods which were employed for hleasuring a base in,,trigononictri cal surveys ; he employed a most ingenious, method of measuring•the changes which they suffered from a difference of temperature ; and he ascertained the increments in 'length and 'bulk which platina, iron, and brass sustained when the temperature was raised from.1° to 180° of Fahrenheit. Borda was delight ed with this national work, and exerted himself with -the utmost zeal to bring it to a close. The parsi mony of the French government, however, interrupt.
• and he was often obliged to advance money to the different artists who were employed in r this great undertaking, but who had sought in vain • for.payment from the public treasury. The experi inents were at length completed. The conferences with the foreign commissaries were opened, and no thing remained but to enjoy the praise which had been so laboriously earned. Borda, however, was not destined to receive, during his life, that high re ward at which genius aspires. The severity of the winter enfeebled his constitution, and brought on a dropsy in the breast, of which he expired on the 20th of February 1799, in the 64th year of his age.
Though Boma devoted his chief attention to the physical sciences and the useful arts, he had a great predilection for poetry and belles lettres ; and the Odyssey of Homer was his favourite work. The re spect which Borda's talents always inspired, was supported by the excellence of his private character. His conversation was agreeable and instructive, and was animated by a vivacity of. temper which. rendei ed him a. pleasant 'member of society.' Borda was,• in 1797, one of the candidates for the office of a di rector'of the French republici but he did not possess those talents for intrigue, which would have ensured success in such a struggle. • Besides the works which we have already Mentioned, Borda.dreiv up, in conjunction with M. De lambre, the s trigonbmetriptes Decimates, which was published'alParis in 1801. 1 r °.` The account of his voyage to the Canary rfslei; drawn up by himself, and full of informaz tion, has not yet been published ; but we. have reason to believe this work, along With other. Mann scripts .and fragments written by-Borda, will soon be given to the world. ''(o)