333 
' of Dust and Ashes: 
there should be an exception, when the distance is only 
about 360 miles from Cape Can tin. 
There appear to be two particular spots in the Atlantic 
where dust is frequently met with by vessels passing 
through those latitudes. These are the vicinity of the 
Cape de Verde group, and the ocean about 4° to 8° 
to north of the equator. 
On the 28th June, 1832, a vessel passing a few miles 
to the eastward of Ilka do Sal (Salt Island) was covered 
witli greyish brown ashes , which had a slightly sulphuric 
smell: the wind was then E.N.E.* 
Numerous similar cases have been mentioned to me, 
but the particulars are not distinct enough for reference, 
of sliips so covered with dust passing to the west of the 
group. J hus the ship Kingston passing through the 
group in June, 1822, experienced a shower of brownish 
dust, like triturated pumice, and smelling of sulphur.f 
Similar dust fell upon a British packet, bound to Brazil, 
in 1812, when 1000 miles from the nearest land. 
In the proceedings of the Geological Society (No. 65, 
vol. iv., p. 146) there is an abstract of a communication 
which I made to that Society on the subject of a similar 
show r er of dust which I myself witnessed near the same 
group in 1839. The particulars there are muoh cur¬ 
tailed : they are now introduced from my journal. 
On the 2nd February the ship Roxburgh Castle was in 
lat. 21° 14' N., long. 25° 6' W. The w r ind, which had 
blown nearly constant from the N.E. since we left 
Plymouth, on the 22nd January became at this place 
E. and S. E. All the 2nd and 3rd the air was obscured by 
a thick haze, increasing on the 4th to a more cloudy 
character. The temperature was only 72°; but the 
* Communicated to me by R. Johnson, Esq., late of Bahia, one of 
the passengers. 
t Communicated by the Commander, Capt. Emerson, of Clifton. 
