A Portuguese captain told me, that about half a league from the road in the direction of S.E., in a line between it and the south side of Pico, lies a sunken rock, over which is twenty-two feet water, and on which the sea breaks in hard gales from the south. He also assured me, that of all the shoals that are laid down in our charts and pilot-books about these isles, not one has any existence but the one between the islands of St Michael and St Mary, called Hormingan. This account may be believed, without relying entirely upon it. He further informed me, that it is forty-five leagues from Fayal to the island of Flores; and that there runs a strong tide between Fayal and Pico, the flood setting to the N.E. and the ebb to the S.W., but that, out at sea, the direction is E. and W. Mr Wales having observed the times of high and low water by the shore, concluded that it must be high water at the full and change, about twelve o'clock, and the water riseth about four or five feet.
The distance between Fayal and Flores was confirmed by Mr Rebiers, lieutenant of the French frigate, who told me, that after being by estimation two leagues due south of Flores, they made forty-four leagues on a S.E. by E. course by compass, to St Catherine's Point on Fayal.
I found the latitude of the ship at anchor 38° 31' 55" N. in the bay
By a mean of seventeen sets of lunar 28 24 30 W. observations, and reduced to the bay by the watch, the longitude was made
By a mean of six sets after leaving it, 28 53 22 and reduced back by the watch ----------------- Longitude by observation 28 38 56 ----------------- Ditto, by the watch 28 55 45
Error of the watch on our arrival at 16 26-1/2 Portsmouth ----------------- True longitude by the watch 28 39 18-1/2 _________________
I found the variation of the compass, by several azimuths, taken by different compasses on board the ship, to agree very well with the like observations made by Mr Wales on shore; and yet the variation thus found is greater by 5° than we found it to be at sea, for the azimuths taken on board the evening before we came into the bay, gave no more than 16° 18' W. variation, and the evening after we came out 17° 33' W.
I shall now give some account of the variation, as observed in our run from the island of Fernando De Noronha to Fayal. The least variation we found was 37' W. which was the day after we left Fernando De Noronha, and in the latitude of 33' S., longitude 32° 16' W. The next day, being nearly in the same longitude, and in the latitude of 1° 25' N., it was 1° 23' W.; and we did not find it increase till we got into the latitude of 5° N., longitude 31° W. After this our compasses gave different variation, viz. from 3° 57' to 5° 11' W. till we arrived in the latitude of 26° 44' N., longitude 41° W., when we found 6° W. It then increased gradually, so that in the latitude of 35° N., longitude 40° W., it was 10° 24' W.; in the latitude of 38° 12' N., longitude 32° 1/2 W. it was 14° 47'; and in sight of Fayal 16° 18' W., as mentioned above.