538 
APPENDIX. 
of the crew on board, and anchored of£ the Battery, in North river, in five 
days. The complement of her officers and crewwas suppUedhere; and 
on the 24th of August, 1831, the Potomac sailed with five hundred and 
two souls on board, all in apparent good health, except one oificer, whose 
.case will be noticed in the proper place. The average age of the crew, as 
near as could be estimated, was thirty-one years. During our passage to 
Rio de Janeiro we did not fall in with the northeast tradewinds ; variable 
winds and calms prevailed until we reached the third degree of north lati- 
tude when we met the southeast trades, which carried us to Rio. After pas- 
sing the Cape de Verd Islands, the Potomac's course for eight days was 
parallel with the coast of Africa, distant four hundred miles. Here we 
met with the most violent rains, with constant thick, heavy weather ; the 
sick-list increased ; several cases of fever occurred. On the 6th of Octo- 
ber crossed the equator, at which time the thermometer* stood at 79°, 
with twenty-two on the sick-list ; fresh tradewind and cloudy weather. 
Many of the younger part of the crew, who had not been previously at sea, 
suffered much from the change of diet and confinement to the ship during 
the passage, and were troubled with indigestion and catarrhs ; several 
obstinate cases of sea-sickness continued until our arrival at Rio. There 
were ten cases of fever, and twelve were admitted with slight injuries. 
The average of the thermometer, during the passage of fifty-one days, at 
noon, was 76°. 
During our stay of twenty days in the harbour of Rio de Janeiro, the 
crew were daily supplied with fresh provisions, and were permitted to 
use the tropical fruits, which are very abundant at this season, without 
restraint. The thermometer, at noon, averaged 76°, and the barometer 
stood at 29.70, and the daily proportion on the sick-report was seven- 
teen. Several cases of diarrhcea and derangement of the bowels occurred. 
"At Rio, malignant diseases seldom prevail ; the natives are of a bilious, 
lymphatic temperament, and are subject to elephantiasis, sarcocele, and 
frambossis. 
Ships-of-war that remain a long period in the harbour of Rio, usually 
have large sick-lists ; diarrhcsas commonly prevail ; they are very insidious 
in their approach, and frequently terminate in ulceration and a severe form 
of dysentery. Ships' crews should be protected from the rain^ — they 
should never be permitted to remain below decks with wet clothes on, and 
be careful to avoid the unripe fruits that are daily brought off for sale in 
the bomb-boats, and bathe frequently during the dry season. 
Sailed on the 5th of November for the Cape of Good Plope, where we 
arrived on the 6th of December, after a passage of thirty-one days. The 
passage was boisterous, with much rain and thick foggy weather. Our 
easting was made between 32° and 34° of south latitude, where we met 
with westerly winds, and the thermometer ranging at 60°. During the 
passage there were forty admitted with dysentery and diarrhoea ; most of 
them occurring immediately after leaving port, and continu.ed to swell the 
sick-list during the passage ; they however yielded to medical treatment 
and farinaceous diet. The average number sick during the passage was 
twenty-one. 
* Fahrenheit's is always given. 
