We visited also a convent of nuns, dedicated to _Santa Clara_, and the ladies did us the honour to express a particular pleasure in seeing us there: they had heard that there were great philosophers among us, and not at all knowing what were the objects of philosophical knowledge, they asked us several questions that were absurd and extravagant in the highest degree; one was, when it would thunder; and another, whether a spring of fresh water was to be found any where within the walls of their convent, of which it seems they were in great want. It will naturally be supposed that our answers to such questions were neither satisfactory to the ladies, nor, in their estimation, honourable to us; yet their disappointment did not in the least lessen their civility, and they talked, without ceasing, during the whole of our visit, which lasted about half an hour. The hills of this country are very high; the highest, Pico Ruivo, rises 5068 feet, near an English mile, perpendicularly from its base, which is much higher than any land that has been measured in Great Britain. The sides of these hills are covered with vines to a certain height, above which there are woods of chesnut and pine of immense extent, and above them forests of wild timber of various kinds not known in Europe; particularly two, called by the Portuguese _Mirmulano_ and _Paobranco_, the leaves of both which, particularly the _Paobranco_, are so beautiful, that these trees would be a great ornament to the gardens of Europe. The number of inhabitants in this island is supposed to be about 80,000, and the custom-house duties produce a revenue to the King of Portugal of 20,000 pounds a-year, clear of all expenses, which might easily be doubled by the product of the island, exclusive of the vines, if advantage was taken of the excellence of the climate, and the amazing fertility of the soil; but this object is utterly neglected by the Portuguese. In the trade of the inhabitants of Madeira with Lisbon the balance is against them, so that all the Portuguese money naturally going thither, the currency of the island is Spanish; there are, indeed, a few Portuguese pieces of copper, but they are so scarce that we did not see one of them: the Spanish coin is of three denominations; Pistereens, worth about a shilling; Bitts, worth about sixpence; and Half-bitts, three-pence. The tides at this place flow at the full and change of the moon, north and south; the spring tides rise seven feet perpendicular, and the neap tides four. By Dr. Heberden’s observation, the variation of the compass here is now 15° 30ʹ West, and decreasing; but I have some doubt whether he is not mistaken with respect to its decrease: we found that the North point of the dipping needle belonging to the Royal Society dipped 77° 18ʺ.