Some years previously a gallant officer of the royal navy, Chevalier Jacques Raymond de Geron de Grenier, who was one of that group of distinguished men,—the Chazelles, the Bordas, the Fleuriens, the Du Martz de Gormpy, the Chaberts, the Verduns de la Crenne, who contributed so zealously to the progress of navigation and geography—had employed his leisure, during a stay in the Isle of France, in exploring the adjacent seas.
He had made a very profitable cruise in the corvette, the Heure du Berger, during which he rectified the position of Saint Brandon's rock, and of the Saya-de-Malha sandbank, examined separately Saint Michael, Rocque-pire, and Agalega in the Seychelles archipelago, and corrected the charts of Adu and Diego Garcia Islands. Convinced of the connexion of the currents with the monsoon, which he had thoroughly studied, he proposed a shortened route, always open, from the Isle of France to the Indies. It would be a saving of eight hundred leagues, and was well worth serious consideration.
The minister of Marine, who had seen Grenier's proposition well received by the Naval Academy, decided to entrust its examination to a ship's officer, who was accustomed to work of the kind.
He selected Yves-Joseph de Kerguelen. During two expeditions, undertaken in 1767 and 1768, for the encouragement and protection of the cod-fisheries on the coast of Iceland, this navigator had surveyed a great number of ports and roadsteads, collected astronomical observations, rectified the map of Iceland, and accumulated a mass of particulars concerning this little-known country. It was he, indeed, who gave the earliest authentic account of "geysers," those springs of warm water which occasionally reach to such great heights, and he also supplied curious details of the existence of fossil wood, which prove that at an early geological period, Iceland, now entirely devoid of trees, possessed enormous forests.
Kerguelen had at the same time published novel details of the manners and customs of the inhabitants.
"The women," he said, "have dresses, jackets, and aprons made of a cloth called 'wadmal' which is made in Iceland. They wear an ample robe above their jackets, rather like that of the Jesuits, but not so long as the petticoats, which they allow to be seen. These robes are of different colours, but generally black; they are called 'hempe.' They are trimmed with velvet or some other ornament. The head-dresses look like pyramids or sugar-loaves, two or three feet high. The women ornament the head with a large handkerchief of very coarse cloth, which stands upright, and they cover it with another finer one, which forms the shape of which I spoke." Lastly, Kerguelen had collected very interesting documents, relating to Denmark, the Laplanders, the Samoyedes, the Faroe Islands, the Orkney and Shetland Islands, which he had thoroughly explored.
Kerguelen, entrusted with the examination of the route proposed by Grenier, asked permission of the minister to employ his ship to explore all the southern lands discovered in 1739 by Bouvet de Lozier. The Abbé Terray, who had just succeeded the Duke of Praslin, gave him command of the ship Le Berryer, which brought 300 able-bodied seamen and provisions for fourteen months from Lorient, together with some ammunition for Mauritius. The Abbé Rochon was associated with Kerguelen, for making astronomical observations. Upon reaching Mauritius, on the 20th of August, 1771, Kerguelen exchanged the Berryer for the La Fortune, to which a small vessel, the Gros-ventre, with sixteen guns and a crew of a hundred men, was attached under command of M. de Saint Allouarn.
As soon as the two vessels were equipped, Kerguelen set sail and steered northward in search of the Mahé Islands. During a great storm, the sounding lines of the Fortune gave an ever-decreasing depth, first thirty, then twenty, and at last only fourteen fathoms. Anchor was then cast, and it held fast throughout the tempest.
"Daybreak at last relieved our anxieties," says Kerguelen; "we perceived neither land nor rock. The Gros-ventre was three leagues distant; her captain could not believe that I was at anchor, for the noise of the thunder, and the dazzling lightning, prevented his hearing or seeing my signals. This is the sole instance of a vessel anchoring in the night in the open sea upon an unknown coast. I set sail, and allowed the vessels to drift, taking constant soundings. I at first found fourteen, then twenty, then twenty-five, at last twenty-eight fathoms. Then I suddenly lost the bottom altogether, proving that we had passed above a submarine mountain. This new bank, which I called Fortune Bank, stretched, N.W. and S.E. It is situated in 7° 16' S. lat. and 55° 50' E. long."
The Fortune and the Gros-ventre then made for 50° S. lat., which was the route recommended by the Chevalier de Grenier. The two captains were aware that the winds constantly blew from the east, at this season of the year, and therefore went to the Maldives, and coasted along Ceylon from Point de Galle, to Trincomalée. Upon their return the monsoon had changed. The prevailing winds were W. and S.W. as Grenier had predicted. The route suggested by him had undeniable advantages, and these have been so amply confirmed by experience that no other is now followed.