1823.] On the Temperature of the Coast of Africa. 361 



From Sierra Leone and the rivers in its immediate vicinity, as 

 far as Cape Appollonia, the tornado season sets in about the 

 middle of April, and continues to the middle of June, when it is 

 succeeded by the rains ; at this time these violent convulsions in 

 the atmosphere are frequent; rarely two days pass without one 

 being experienced ; and even in the early parts of the month of 

 April, they are sometimes felt. The load of vapour from which 

 the atmosphere is unburdened by them, renders the air pure and 

 wholesome, and the rain which falls in torrents for the space of 

 an hour dries up so immediately that they may be deemed as 

 contributing much to the salubrity of the climate ; even to ship- 

 ping, except at anchor in the rivers, if due precautions are taken, 

 they are attended with no danger, as the gust of wind always 

 comes from the land, north of Cape Palmas, and in a parallel 

 with it, east of that Cape, and with quite sufficient warning even 

 for a merchant ship, with but few men, to make the necessary 

 preparations. 



About the middle of June, the rainy season commences, and 

 continues to the beginning, and sometimes even to the latter end 

 of November : from the little cessation of rain which takes place 

 during this period, the ground soon becomes drenched, and 

 from it a miasma arises which engenders those pestilential 

 remittent fevers so destructive of human life in this part of the 

 world. 



As the rains begin to subside, they are succeeded by thick hazy 

 weather, arising from a rapid evaporation of the moisture still 

 remaining in the ground. 



About the latter end of December, and during the whole of 

 January, a wind occasionally blows, possessing properties, and 

 attended by circumstances, peculiar to itself; it is known by 

 the name of the Harmatan, and blows from the eastward with 

 considerable strength. It is always attended by thick hazy 

 weather, notwithstanding which it is so dry and parching, that 

 all wood-work warps and shrinks, and, if united by glue, becomes 

 detached. Paper and books appear as if they had been placed 

 close by a fire. On the human frame its effects are considerably 

 felt ; the lips and nostrils become sore and inflamed, and the 



distant thunder. After a time, it rises a little above the horizon, to which its lower edge 

 is parallel, and extremely black, and there remains stationary for a short time ; when it 

 is again put in motion, the most frightful flashes of forked lightning, accompanied by the 

 heaviest possible claps of thunder, now issue from it in rapid succession ; when it has 

 reached a little beyond the zenith, a sudden chill is felt in the temperature, and then fol- 

 lows a more violent squall, or gust of wind, and rain, than the most fertile imagination 

 can picture ; but which seldom lasts longer than half an hour. I always made a practice 

 of taking in every sail, and putting the ship before the wind : and I am of opinion that 

 in some of the most violent, even without sail set, if that precaution was not taken, any 

 ship would be thrown on her beam ends. On shore, all animated nature seems extinct; 

 nothing is seen, nothing is heard; every creature, whether man, bird, or beast, having 

 sought refuge and shelter from the approaching storm ; but no sooner is it over than the 

 air, which was before close and sultry, becomes so delightfully pure and invigorating as 

 to reanimate the whole animal creation. 



