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[Archival note:]

CD's M.S my first Paper "Perfect copy"

(Geol. Soc. Jl ii, 1846, pp 26-30)

P.J.G. 14/iv/67

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An account of the fine dust which often falls on vessels, off the N. W coast of Africa in the Atlantic ocean. by Charles Darwin M.A. F.R.S.

Many scattered accounts have appeared on the dust which has fallen in considerable quantities on vessels off the N W. coast on theof African side of the Atlantic ocean, it has appeared to me desirable to collect these accounts together, more especially since Professor Ehrenberg's remarkable discovery that the dust consists in considerable part chiefly of Infusoria. I have found eleven fifteen distinct statements of dust having fallen; & several of these, refer to a period of more than one day. (A) The area, in which the phenomenon has been chiefly observed, is in the neighbourhood of the Cape Verd Archipelago. The farthest point southward which I have met with recorded, is by Mr.  Burnett*(1) in Lat 4°. 20' N: Northward, according to Lieut Arlett,* (2) the water is discoloured, owing in part to the falling of dust, for a long distance both northward & southward of Cape Noon in Lat: 28°. 45' N.; so that Hence the phenomenon has been observed over a space of at least 1600 miles in of latitude. This dust has several times fallen on vessels when between 300 & 600 & even 800 miles from the coast of Africa: it fell in May 1840 on the Princess Louise*(3) when (in Lat 14°. 21' N & Long 35°. 24' W.) when 1030 miles from Cape Verd, the nearest point of the continent. In this case the dust probably came from a somewhat greater distance; for it is well known that the country changes & therefore half-way between Cayenne in S. America, & the dry country north of the Senegal in Africa.)

(A)

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(A) and some to considerably longer time. Other less distinct accounts are recorded have been also appeared. At the end of this paper, I will give the particular cases, & will now in here only refer to the more striking cases ones & make a few general remarks.

The phænomenon has been most frequently observed in the neighbourhood of the Cape Verd Archipelago. The most southern point of at which I have met with only account is by Capt. Hayward *(1), on whose vessel most it fell whilst sailing from lat. 10° N. to 2° 56' N.; being at which time this latter the distance from the nearest part of the Cape Verd Islands was being between 450 and 850 miles.

Respecting the northern limit of the phænomenon falling dust the water for a great distance on both sides of C. Noon in Lat 28˚ 45', is discoloured distant according to Lieut Arlett * [2 words illeg] cause [illeg] degree that the track of the ship is visible for a long time  [2 words illeg] quantities of fine blown from Hence owing in part, according to Lieut. Arlett, *(2) to the quantities of falling dust.