450 PHYSICAL GEOGRAPHY. 



are supposed to derive their heat from tracts of unknown deserts in the intertropical 

 regions of that island-continent. " One might almost fancy," says Mrs. Meredith, " the 

 Ancient Mariner to have experienced one during his ghostly voyage, he so accurately 

 describes their aspect : 



' All in a hot and copper sky, 

 The bloody sun, at noon, 

 Right up above the mast did stand, 

 No bigger than the moon.' " 



The sirocco of that country always blows from the north-west. At Sydney, its oven-like 

 temperature is moderated by the mid-day sea-breeze ; but in the interior, it is severely 

 felt, and is often fatal to the vegetation. Every green thing droops and dies, dried up 

 like half-burnt paper. Large tracts of cultivated land, covered with luxuriant green 

 crops of wheat or barley, just going into ear, are scorched, shrivelled, and absolutely 

 blackened by the heat, and become fit for nothing but to be cut as litter ; and of course 

 the delicate plants and flowers of the gardens are not spared by the " burning breath of 

 the fervid Air-king." 



6. Mistral. Autun. Bise. These are local atmospheric currents prevalent in the south- 

 east of France. Pliny mentions the first, under the name of Circius, as remarkable for 

 its violence. The Mistral blows from the north-west, descending from the mountains of 

 Central France, and sweeping over the ancient provinces of Provence and Languedoc, 

 where it is supposed to contribute greatly to the salubrity of the air, by dispelling the 

 exhalations from the marshes and stagnant waters common in that region of extensive 

 levels. In the Gulf of Lyons it frequently occasions great damage to the shipping, and to 

 the inhabitants upon the coast, owing to the opposition offered to the course of the wind 

 by the Alps and the Pyrenees, causing it to rush through the opening between them with 

 an increased momentum. Hence the name of the gulf, not derived, as commonly imagined, 

 from the city of Lyons, but from the lion-like violence of its tempests. Malte Brun 

 quotes from William of Nangis, a monk of the middle ages, a remark to this effect: " It 

 is called the Lion's sea, because it is ever rough, tempestuous, and destructive." The 

 Autun blows in an opposite direction, from the east and south-east, hot and unwholesome, 

 producing morbid effects upon the human system, like the sirocco. It is experienced 

 through the country extending from the coast about Narbonne to the neighbourhood of 

 Toulouse, and frequently blows with great force in the more westerly parts of its track 

 in the vicinity of Castelnaudary. The vent de Bise, or black wind, is a cold piercing 

 current from the Alps and the mountains of Auvergne, which chiefly follows the course 

 of the Rhone, in the valley through which it runs, from north to south, rendering the 

 climate in winter very severe. The currents we are now noticing, confined within a 

 comparatively narrow range, are uniform in their direction ; and innumerable examples 

 might be cited of localities where the same uniformity is found, caused by the irregularities 

 of the surface, the position of mountains and valleys. In many cases, local winds are 

 merely branches of a great atmospheric current, diverted from the main stream into an 

 inverse course by the superficial inequalities. Thus, at Liverpool, the prevalent south-west 

 wind of England is scarcely ever felt, owing to the situation of the town, while the 

 predominating wind is the south-east, which is rarely experienced in the kingdom at 

 large. The movements of the atmosphere over the Red Sea are plainly determined by 

 its 'channel, for the wind never blows in any other direction than to one of its extremities. 

 Captain Parry always found the wind either east or west in Lancaster Sound, and during 

 the whole year, excepting about two months, it blows constantly up the valleys of the 

 Mississippi and the Ohio. Saussure mentions a valley at the foot of the Pyrenees, wholly 

 environed with mountains, except towards the north-west, and a few other very narrow 



