The Indian corn, which is also their produce, cost me about three shillings and sixpence a bushel; and the fruits and roots were, in general, very cheap. They have not any plentiful supply of fish from the adjoining sea; but a very considerable fishery is carried on by their vessels upon the coast of Barbary; and the produce of it sells at a reasonable price. Upon the whole, I found Teneriffe to be a more eligible place than Madeira for ships bound on long voyages to touch at; though the wine of the latter, according to my taste, is as much superior to that of the former, as strong beer is to small. To compensate for this, the difference of prices is considerable; for the best Teneriffe wine was now sold for twelve pounds a pipe; whereas a pipe of the best Madeira would have cost considerably more than double that sum.[81] The Chevalier de Borda, commander of the French frigate now lying in Santa Cruz road, was employed, in conjunction with Mr. Varila, a Spanish gentleman, in making astronomical observations for ascertaining the going of two time-keepers which they had on board their ship. For this purpose, they had a tent pitched on the pier head, where they made their observations, and compared their watches, every day at noon, with the clock on shore, by signals. These signals the Chevalier very obligingly communicated to us; so that we could compare our watch at the same time. But our stay was too short to profit much by his kindness. The three days’ comparisons which we made, assured us that the watch had not materially, if at all, altered her rate of going; and gave us the same longitude, within a very few seconds, that was obtained by finding the time from observations of the sun’s altitude from the horizon of the sea. The watch, from a mean of these observations, on the 1st, 2d, and 3d of August, made the longitude 16° 31ʹ west; and, in like manner, the latitude was found to be 28° 30ʹ 11ʺ north. Mr. Varila informed us, that the true longitude was 18° 35ʹ 30ʺ, from Paris, which is only 16° 16ʹ 30ʺ from Greenwich; less than what our watch gave by 14ʹ 30ʺ. But, far from looking upon this as an error in the watch, I rather think it a confirmation of its having gone well; and that the longitude by it may be nearer the truth than any other. It is farther confirmed by the lunar observations that we made in the road, which gave 16° 37ʹ 10ʺ. Those made before we arrived, and reduced to the road by the watch, gave 16° 33ʹ 30ʺ. And those made after we left it, and reduced back in the same manner, gave 16° 28ʹ. The mean of the three is 16° 30ʹ 40ʺ.