Page:Africa by Élisée Reclus, Volume 4.djvu/27

ANGOLAN CT.TMATE. 11 it freezes, as in Europe, and even at an altitude of 3,500 feel on the eMtem slopes of the mountuins, Capello and Ivens hud to endure great extremes of temperature, from freezing-jwint at night to S2^ and even 80"* F. during the day. The most continuous meteorological observations have been taken at Loanda, capital of the colony, showing that at this place, although lying not more than GOO miles to the south of the equator, the great summer heats are less intense than at Lisbon. Thus the maximum temperature in February, the hottest month at Loanda, is greater than that of August, the hottest in Portugal. Travellers leaving Lisbon in summer for Angola are surprised at the relative coolness of these tropical regions. In fact the mean temperature of Loanda scarcely exceeds 73^ F., while the annual divergence between the tliermomctric extremes for each month is not usually more than twenty degrees. JJut between the greatest heat and the greatest cold the discrepancy rose in 1879 to nearly thirty-four degrees, the glass fulling from 88° F. in November to 55° F. in August. On the inland plateaux under the same latitude and at an elevation of 5,300 feet, the discrepancy is twice as great, ranging from freezing-p<nnt to 98^ F. At Mos- samedes, which of all the coast towns enjoys the most equable climate, the annual temperature oscillates from thirty-six to thirty-eight degrees, and this place presents the most favourable conditions for the acclimatisation of European residents. The relative coolness of the Angolan climate is due to the direction of the marine breezes, which generally blow from the temperate southern regions. In these latitudes the coast stream setting from the Antarctic zone has sufficient in- fluence to considerably lower the normal temperature of the surrounding waters and atmospheric layers ; hence the name of Cubo Frio, or " Cold Cape," given to the headland lying to the south of the Cunene. A neighbouring creek is also known as the Angra Fria, or " Cold Bay." Even north of the Cunene the coast- lands benefit by this cool marine current, although to a less degree, and its in- fluence is known to be felt as far north as the island of Sam-Thome. Off Loanda its mean velocity is about 1^ mile per hour, but it is at times completely arrested or even partly revei'sed by violent gales from the north-west. Generally speak- ing, the southern breezes prevail greatly over those from the north along this seaboard, where the trade-winds rarel}'^ maintain their normal direction from the south-east to the north-west, being deflected by the rarefied air from the hot regions of the interior, and thus transformed to south-westerly and even westerly monsoons. According to Ribeiro, the marine breezes stand to those of the conti- nent in the proportion of rather more than five to two. From the observations regularly taken at Malange, over 180 miles from the sea, it appears that in this inland district, notwithstanding its great distance from the alternating land and seacoast breezes {terral and rira^U't), a certain rhythm is still maintained between the easterly and westerly winds. According to Ilann, the former prevail especi- ally in the morning, the latter in the afternoon, the aerial current thus showing a tendency to set from the quarter of the heavens where the sun is found. Under the influence of the vapour-charged monsoons there is always a con-