ing his duty, or even of reading the letters of his friends and fo trifling an accident as the dropping of a tea-cup would flurry him as much as if a houfe had tumbled down.

The phyficians advifed his native air for his recovery; and in February, 1761, he fet out, with much reluctance (believing he should never return) for Bofworth, along with fome relations. The journey fatigued him to fuch a degree, that upon his arrival, he betook himfelf to his chamber, where he grew continually worfe and worse, to the day of his death, May the 14th, in the fifty-firft year of his age.

He left a fon and a daughter; the former an officer in the royal regiment of artillery, at prefent in America. The king, at the inftances of lord vifcount Ligonier, in confideration of Mr. Simpfon's great merits, was gracioufly pleafed to grant a penfion to his widow, together with handfome apartments adjoining to the academy: a favour never conferred on any before.

The life of the Abbé de la Caille, member of the Royal Academy of Sciences at Paris, &c.

NICHOLAS Louis de la Caille

was born at a little town called Rumigny, in the diocefe of Rheims, the first of March, in the year 1713. His father was Louis de la Caille, his mother Barbara Rubuy; both happier in qualities of mind than affluence of fortune. The father had ferved in the army, which he quitted, and in his

retirement ftudied mathematics, and amufed himfelf with mechanic exercifes, wherein he proved the happy author of feveral inventions of confiderable ufe to the public.

Nicholas, almoft in his infancy, took a fancy to mechanics, which proved of fignal fervice to him in his maturer years. He was sent young to school at Mantes-furSeine, where he discovered fuch early tokens of genius, as gave his parents fanguine hopes of his fu ture improvement.

In 1729, he went to Paris, and ftudied at the college de Lifieux, firft the claffics, and then philofophy and mathematics, under M. Robert. In a few years his father died, and with him all family expectations: however, he happily met with a patron in the duke of Bourbon, who heard of his merit, and had been beneficent to his father.

After he had finished his courfe of philofophy, he went to study divinity at the college de Navarre, propofing to embrace an ecclefiaftical life. Here he redoubled his ftudies, employing many hours of the day in reading books of religion, and, as many of the night in mathematical exercifes, or in contemplating the stars. This was

his conftant tenor of life for three years.

At length he was ordained a deacon, and officiated as fuch in the church of the college de Mazarin feveral years; but he never entered into prieft's orders, apprehending that his aftronomical ftudies, to which he became most affiduously devoted, might too much interfere with his religious duties. His reputation

putation in aftronomy foon procured him accefs to the late James Caffini, the king's first aftronomer, and to the prefent M. Maraldi, who both had apartments, and all manner of inftruments and accommodations in the royal obfervatory. With these he contracted a moft intimate familiarity and friendship; and in the year 1738, he affifted the latter in a furvey of the fea-coaft from Bayonne to Nantes.

In 1739, he was conjoined with M. de Thury, the fon of the before-mentioned M. Caffini, in verifying the meridian of the royal obfervatory, through the whole extent of the kingdom of France. In the month of November, of the fame year, whilft he was engaged day and night in the operations which this grand undertaking required, and at a great distance from Paris, he was, with folicitation, or even knowing any thing of the matter, elected into the vacant mathematical chair, which the celebrated M. Varignon had fo worthily filled. Here he began to teach, about the end of 1740, after his return from his laborious expedition, and caused his lectures in due time to be printed at his own expence.

out any

The hours that could be fpared from the duties of his profefforfhip, he employed in carefully computing the refults of the many menfurations and obfervations celeftial and terreftrial, relative to the business of the meridian. In the mean time, an obfervatory was ordered to be erected for his ufe in the college, and furnished with a fuitable apparatus of the beft inftruments.

In May, 1741, M. de la Caille

was admitted into the Royal Academy of Sciences, as an adjoint member, for aftronomy. Befides the many excellent papers of his, difperfed up and down in their memoirs, he publifhed elements of geometry, mechanics, optics, and aftronomy. Moreover, he carefully computed all the eclipfes of the fun and moon that had happened fince the Chriftian æra, which were printed in a book, publifhed by two Benedictines, intituled, L'Art de verifier les dates, &c. Paris, 1750, in 4to.

Befides, these, he compiled a volume of Aftronomical Ephemerides for the years 1745 to 1755; another for the years 1755 to 1765; a third for the years 1765 to 1775; an excellent work, intituled, Astronomic fundamenta novissimis solis & stellarum observationibus stabilita, and the most correct folar tables that ever appeared.

Having gone through a feven years feries of aftronomical obfervations in his own obfervatory, he formed a project of going to obferve the fouthern stars at the Cape of Good Hope. This was highly approved of by the academy, and by the prime minifter, comte d'Argenfon, and very readily agreed to by the states of Holland.

Upon this he drew up a plan of the method he propofed to purfue in his fouthern obfervations, fetting forth that, befides fettling the places of the fixed stars, he propofed to determine the parallax of the Moon, Mars, and Venus. But whereas this required correfpondent obfervations to be made in the northern parts of the world, he fent to thofe of his correfpondents who were expert

in practical aftronomy,* previons notice in print, what obfer vations he defigned to make at fuch and fuch times, for the faid purpose.

Then, without further lofs of time, he packed up his inftruments and made preparations for his voyage; which count d'Argenfon being informed of, fent him 4000 livres, though he had never folicited any fuch favour, and with it a written promife of whatever further fum he might have occafion for; this, however, was but a fmall addition to his purfe, for he expended in the purchafe of new and larger inftruments much more than he was before poffeffed of.

At length, on the twenty-firft of October, 1750, he fet out from Paris for the Cape, accompanied only by a young artificer, who, from the great affection he bore him, earneftly requested that he might be the companion of his voyage. He failed from Port l'Orient the twenty-first of November, on board the Glorieux, and had the happiness to find the captain a very civil man, and a good mathematician, which was no fmall fatisfaction to him; and he proved an excellent help-mate in obferving the latitudes, longitudes, &c. during the whole voyage. They arrived at the Cape the 19th of April, 1751.

Having waited on the gover

nor, M. Tulbagh, who received him with great civility, and during his ftay there conferred inceffant favours upon him, he forthwith got his inftruments on fhore, and with the affiftance of fome Dutch artificers, fet about building an aftronomical obfervatory, in which his apparatus of inftruments was properly difpofed, as foon as it was in fit condition to receive them.

The fky at the Cape is generally pure and ferene, unless when a fouth-eaft wind blows. But this is often the cafe, and when it is, is attended with fome strange as well as terrible effects. The ftars look bigger, and feem to caper; the moon has an undulating tremor ; and the planets have a fort of beard, like comets.

Two hundred and twenty-eight nights did our aftronomer furvey the fouthern heavens; during which fpace, which is almoft incredible, he observed more than ten thoufand ftars: and whereas the ancients filled the heavens with monfters and old wives tales, the abbé de la Caille chofe rather to adorn them with the inftruments and machines which the modern philofophy has made ufe of in the conqueft of nature. (See the planifphere in his Cælum Australe Stelliferum.)

With no lefs fuccefs did he attend to the parallax of the Moon, Mars, Venus, and Sun.

from his own obfervations during his voyages.

His fame being now established upon fo firm a bafis, the moft celebrated academies of Europe claimed him as their own, and he was elected unanimoufly a member of the Royal Society of London, of the Inftitute of Bologna, of the Imperial Academy of Petersburgh, and of the Royal Academies of Berlin, Stockholm, and Gottingen.

In the year 1760, M. de la Caille was attacked with a fevere fit of the gout, which, however, did not interrupt the course of his ftudies, for he then planned out a new and immenfe work, no lefs than a history of aftronomy through all ages, with a comparifon of the ancient and modern obfervations, and the conftruction and ufe of the inftruments employed in making them. In order to pursue the talk he had impofed upon himself in a fuitable retirement, he obtained a grant of apartments in the royal palace of Vincennes; and whilft his aftronomical apparatus was erecting there, he began printing his catalogue of the fouthern ftars *, and the third volume of his Ephemeridest.

The state of his health, formerly confirmed by his labours, was towards the end of the winter of

1763 greatly reduced. His blood grew inflamed, he had pains of the head, obstructions of the kidnies,

lofs of appetite, with an oppletion of the whole habit. His mind re. mained unaffected, and he refolutely perfifted in his ftudies as ufual. In the month of March medicines were administered to him, which rather aggravated than alleviated his fymptoms: and he was now fenfible that the fame disorder which in Africa ten years before yielded to a few fimple remedies, did, in his native country, bid defiance to the best phyficians; this induced him to fettle his affairs: his manuscripts he committed to the care and difcretion of his esteemed friend M. Maraldi. It was at laft determined that a vein fhould be opened, but this brought on an obftinate lethargy, in which he died the twenty-third day of March, being then forty-nine years old.

He was naturally of a robust ha bit, with a very comely, open countenance, fignificant of the complexion of his mind; humane, friendly, and modeft to an extreme.