M. MAUPERTUIS,

OF THE

ROYAL ACADEMY OF SCIENCES,

AT

PARIS.

MADE BY ORDER OF THE FRENCH KING, TO DETERMINE THE FIGURE OF THE EARTH AT

THE POLAR CIRCLE.

MAU

AUPERTUIS, one of the most eminent mathematicians of his age, was born in 1698, and in his youth followed the profeffion of arms; but this not fuiting his tafte, he devoted himself to science, and soon became so distinguifhed, that he was admitted into the French Academy when only twenty-five years of age. Soon after he became a Fellow of the Royal Society of London.

In 1736, he was placed at the head of the academecians at Paris, and in this fituation he had the honour to be appointed to fettle a dispute among aftronomers, which gave rife to the following pages. To understand the nature of the difficult undertaking in which he was now engaged, it fhould be premised, that fome of the moft eminent mathematicians maintained the earth to be

ཀུ་

an oblate, and the other a prolate fpheroid. Thus the sentiments of scientific men being divided, on a fubject so important in aftronomy and navigation, the French king warmly patronised a scheme to terminate the controverfy; and accordingly a certain number of academicians were appointed to measure the first degree of the meridian at the equator, and others beneath the polar circle. The former were accompanied by Don George Juan and Don Antonio de Ulloa, whofe voyage to South America we have already laid before our readers. The latter party was conducted by Maupertuis; and the fame alacrity, the fame zeal, to do honour and fervice to their country, and to mankind, animated those who were to brave the meridian fun, and those who were to freeze beneath the polar circle.

After fuccessfully accomplishing this business, the late Frederic invited Maupertuis to Berlin, and appointed him prefident and director of the academy at that place. This prince being at war with the emperor, Maupertuis, probably out of gratitude to his benefactor, attended him into the field, expofed himself with refolution, and was taken prisoner; but foon liberated.

After this he revifited his native country; but from a ftrange inquietude of fpirit, and a temper too irritable for that of a philofopher, he could neither be fatisfied to continue in France nor in Pruffia, where he was much honoured and careffed, for any length of time together. A growing ftate of ill health, however, made him turn his thoughts to France, where he remained about two years, and afterwards retiring to Swifferland, he died at Bafil in 1759, while on a vifit to Bernouli.

But

But to return. The company deftined for the north, fays Maupertius whofe lively narrative we follow, was compofed of four academicians, Clairault, Camus, Le Monnier, and myself. The Abbe Outhier and M. Celfius, the celebrated profeffor of aftronomy at Upfal, affifted at all our operations, and their abilities and advice were of fingular fervice to us.

No fooner was the veffel- that carried us arrived at Stockholm, than we refolved, without delay to fet out for the bottom of the Gulph of Bothnia, where we might determine which fide of the gulph was proper for our operations, better than we could do by trufting to our charts. Nothing could retard us, neither the frightful ftories they told us at Stockholm, nor the goodnefs of his Swedish majefty; who, notwithstanding the orders he had given in our behalf, told us, oftener than once, that it was not without a fenfible concern, he faw us pursue fo defperate an undertaking.

We arrived at Tornea time enough to fee the fun perform his courfe for feveral days together without fetting: a fight which strikes with wonder an inhabitant of the temperate zones, even though he knows it is what must neceffarily happen in that climate.

We had flattered ourselves with the hopes of performing our operations upon the coaft of the Gulph of Bothnia, where we fhould have the convenience of transporting ourselves and our inftruments to the different ftations by fea, and where the many advantageous points of view, from the iflands in all our charts, feemed to promise us fuccefs. But when we went with great impatience to view them, all our labour ferved only to

convince

convince us, that this defign was impracticable. The islands that line the coafts of the gulph, and the coafts themselves, which we had fancied to be fo many promontories, that might furnish us with diftant points of view from one to another, lay all of them fo low upon the surface of the water, that, at a small diftance, the convexity of the earth must arise between them and us. So that, after several short voyages, in pursuance of our firft defign of making ufe of thefe iflands, we were at laft obliged to give it up.

We now refolved to endeavour to perform our operations upon the tops of the mountains to the northward of Tornea, though it appeared next to impoffible. In the deferts of a country scarcely habitable, in that immense foreft which extends from Tornea to Cape Nord, we must go through operations that are not easy, even where no convenience is wanting. There were but two ways of penetrating into thefe deferts, both of which we must prove; one, the failing up a river full of cataracts; the other, crofting thick woods and deep marthes on foot: and, if we should be able to make our way into the country, we muft, after the most painful marches, be obliged to clamber up fteep rocks, and to clear the tops of mountains of the wood that would intercept our fight. In these deserts we should be forced to take up with the most wretched diet, be expofed to the flies, which, in this feafon, are so insufferable, as to drive the Laplanders and their rein-deer from their habitations, to feek thelter on the coafts of e ocean. We were, in fine, to attempt this ork without knowing, or being able to inform urfelves whether it was practicable; whether the want of one mountain might not, after all our

toils, interrupt the series of our triangles; or whether it would be poffible to find upon the river a base by which they might be connected. But if we should furmount all these obftacles, we should ftill have the labour of building obfervatories on the most northerly of the mountains; the trouble of carrying thither as numerous a collection of inftruments as is, perhaps, to be feen in Europe, and of making there the niceft aftronomical obfervations: but we were fo far from being deterred by these combined difficulties, that the profpect of conquering them filled us with pleafure.

We fet out from Tornea on Friday the 6th of July, 1736, with a company of Finland foldiers, and a good number of boats laden with inftruments and provifions. We began our journey by failing up the great river, which rifing in the inmoft parts of Lapland, purfues its courfe till it falls into the Gulph of Bothnia; having firft divided itself into two branches, that from the Ifle of Swertzar, where is built a town of the fame name, in the latitude of 65 deg. 51 min. From this day forward, our only habitation was the deferts, and our time was spent on the fummits of thofe mountains which we were to connect by our triangles.

After a voyage of twelve hours, we landed in the evening at Korpikyla, a hamlet by the river-fide, inhabited by Finlanders; and having for fome time travelled on foot across the foreft, arrived at the bottom of a steep mountain called Niwa, whofe fummit, which is a bare rock, we chofe for our firft ftation. Upon the river we had been tormented by great flies with green VOL. XII. B b

heads