Page:Travels to Discover the Source of the Nile - In the Years 1768, 1769, 1770, 1771, 1772, and 1773 volume 3.djvu/694

 670 TRAVELS TO DISCOVER

made to receive it, the moft violent thunder poffible to be conceived inftantly follows, with rain; after fome hours, the fky again clears, with a wind at north, and it is always dis- agreeably cold when the thermometer is below 6f.

The fecond thing remarkable is the variation of the thermometer ; when the fun is in the fouthern tropic, 36* diftant from the zenith of Gondar, it is feldom lower than 72 ; but it falls to 6o° and 59 when the fun is immediately vertical ; fo happily does the approach of rain compenfate the heat of a too-fcorching fun.

The third is, that remarkable ftop in the extent of the rains northward, when the fun, that has conducted the va- pours from the Line, and mould feem, now more than ever, to be in pofleflion of them, is here over-ruled fuddenly, till, on its return to the zenith of Gerri, again it refumes the ab- folute command over the rain, and reconducts it to the Line to furnifh diftant deluges to the Southward.

I cannot omit obferving here the particular difpofition of this peninfula of Africa; fuppofinga meridian line, drawn through the Cape of Good Hope, till it meets the Mediter- ranean where it bounds Egypt, and that this meridian has a portion of latitude that will comprehend all Abyflinia, Nubia, and Egypt below it, this fection of the continent, from fouth to north, contains 64 divided equally by the equator, fo that, from the Line to the fouthmoft point of Africa, is 32 ; and northward, to the edge of the Mediter- ranean, is 3 2 alfo : now, if on each fide we fet off 2, thefe are the limits of the variable winds, and we have then 30 fouth, and 30 north, within which fpace, on both fides, the 3 trade-