(2

(On the 16th of January (1833), when the Beagle was ten miles off the N. W. end of St. Jago, some very fine dust was found adhering to the under side of the horizontal wind-vane at the mast-head; it appeared to have been filtered by the gauze from the air, as the ship lay inclined to the wind. The wind had been for 24 hours previously ENE, & hence, from the position of the ship, the dust had probably come came from the coast of Africa. The atmosphere was so hazy that the visible horizon was often only one mile distant.

During our stay of three weeks at St. Jago (to Feb 8th) the wind was generally N.E., [3 words illeg] as is almost always the case during this time of the year; with the atmosphere air was often hazy, & it was found that very fine dust often fall was [illeg] almost constantly falling, so that the astronomical instruments were found injured roughened & a little injured. The dust & likewise four of the packets collected by Lieut James collected off on the Beagle, is excessively fine grained, of a reddish-brown colour; it does not effervesce with acids; it easily fuses under the blowpipe into a black or gray bead.

(A) Some The dust collected by Lieut James*, which together with a written communication, I owe to the kindness of Mr Lyell, fell on his vessel the successive days, 6th 7th 8, 9 & 10th of March, whilst with the wind from SE to ESE, whist sailing from (Lat 21˚ 10 N Long 22˚ 14' W to (Lat 17˚ 43' N Long 25˚ 54' W.) & being at a distance from 330 to 380 miles from the land. The dust which fell on the [illeg] first day, on 7th, was preceded by a thick haze & it is is much coarser than that which fell on the succeeding days. It contains numerous irregular, transparent, white variously coloured particles of about the 1/1000th of an inch square, with some few a little

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The dust is generally of excessive fineness, it is of a reddi & hence adhere to the sails; it is of a reddish brown colour, & fuses under the blowpipe into

(A)

In 1838, from the 7th to the 10th of March, whilst Lieut. James in H.M.S. Spey was sailing, at the distance of from 330 to 380 miles from the continent, between (Lat. 21° 10' N., Long. 22° 14' W and (Lat. 17° 43' N. long. 25° 54' W) considerable quantities of dust fell on his vessel, four packets of which, together with some a written communication, I owe to the kindness of Mr. Lyell.