diminution of heat does not proceed constantly at this or any other regular rate.

If the general slope of the land is towards the morning and noonday sun, it will gain more heat than if receiving the feebler rays of the afternoon. On some southern slopes of the Alps vineyards and orchards are flourishing, while the northern slopes are covered with snow.

SEA INFLUENCES.-The nearness of any place to the sea tends to equalise the temperature, because the sea absorbs heat, and parts with it again much more slowly than the land. Hence the terms insular and continental climates.

If marine currents bring warm water to a shore, as the Gulf Stream does to the west of Europe, the temperature is considerably raised.

LAND INFLUENCES.-The vicinity (vicinus, near) of mountains or high plateaux, on the contrary, tends to render the climate extreme. A mountain chain may interrupt cold winds, and cause the plains on one side to be warmer than those on the other. Thus the Carpathians shelter Hungary from the northern blasts to which Poland is exposed. Or it may keep the warm moisture on one side, and leave the other dry, as in South America. The climate of a plateau is generally

extreme.

WINDS.-The direction of the prevailing winds, taken with the form of the land, has much to do with the climate. The west winds of Europe, blowing from the sea, are warm and moist; those of America coming over the land are hot in summer and cold in winter.

On the other hand, our east winds are dry and cold in spring.

HUMAN INFLUENCES.-Both warmth and dryness in the atmosphere are greatly promoted by the felling of natural forests and the drainage of the land, which are the first steps towards cultivation.

SUMMARY.-By the climate of a country is meant the prevailing amount of heat and moisture. Climate depends on the following causes :-(1.) Latitude: The surface of the earth near the equator receives more heat, because it presents a more direct face to the sun's rays. Moreover, the days and nights are more uniform in length there; and hence the earth is not allowed to cool, as it does during the long nights of higher latitudes. (2.) Altitude: The higher a place is the cooler it is likely to be. Three hundred feet of elevation is equal to one degree of latitude. (3.) Proximity to the sea tends to mitigate both heat and cold. Hence the difference between an insular and a continental climate. (4.) The character of the adjacent country: Mountains often become a screen from either hot or cold winds, thus rendering a climate less extreme. (5.) Winds affect climate, according to the quarter from which they generally come. In England, for example, our west winds are moist and warm, coming from the Atlantic. (6.) The clearing of trees and drainage tend to raise the temperature of a district.

QUESTIONS.

What is climate? Name the causes of climate in the order of their importance. Explain how latitude affects climate. What is the difference between the succession of a day and night at the tropics and near the poles? What places in the tropical region may enjoy a temperate or cool climate? How does the sea affect the adjacent lands? Give examples of places having insular and continental climates. Give any countries you know which are made colder by the presence of mountains, and any made warmer. What kind of winds are east winds in England and in New York? What operations of men affect climate? and explain, if you can, how?

The morse or walrus is an inhabitant of the icy seas. It is one of the seal family, though differing greatly from them in some respects. It has a wellproportioned head, with an intelligent face, and two large, long tusks; an unwieldy body, covered with a dark hairy skin, and four legs so short that it walks very awkwardly on land, though it moves quickly and easily in the water. It lives on seaweeds and shell-fish. It tears the sea-weed from

the rocks with its strong tusks, and by means of them it climbs on the smooth ice. The walrus has two great enemies in its icy home-the polar bear and the Esquimaux. The bears, when they are hungry, watch for the walruses, and often catch them when they are asleep on the ice.

Captain Beechy graphically describes the manœuvres of a polar bear when watching for a walrus : -"One sunshiny day, a walrus, of nine or ten feet in length, rose in a pool of water not very far from us; and, after looking around, drew his greasy carcase upon the ice, where he rolled about for a time, and at length laid himself down to sleep. A bear, which had probably been observing his movements, crawled upon the ice on the opposite side of the pool, and began to roll about also, but apparently more with design than amusement, as he progressively lessened the distance that intervened between him and his prey. The walrus, suspicious of his advances, drew himself up preparatory to a precipitate retreat into the water, in case of a nearer acquaintance with his playful but treacherous visitor; on which the bear was instantly motionless, as if in the act of sleep, but after a time began to lick his paws and clean himself, occasionally encroaching a little more upon his intended prey. But even this artifice did not succeed: the wary walrus was far too cunning to allow himself to be entrapped, and suddenly plunged into the pool, which the bear no sooner observed, than he threw off all disguise, rushed towards the spot, and followed him in an instant into the water, where, I fear, he was as 6

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much disappointed in his meal as we were of the pleasure of witnessing a very interesting encounter."

"The meat of the walrus is not despised by Europeans," says a writer, "and its heart is reckoned a delicacy. To the Esquimaux there is no greater treat than a kettle well filled with walrus blubber; and to the natives along Behring's Straits this quadruped is as valuable as is the palm to the sons of the desert. Their canoes are covered with its skin; their weapons and sledge-runners, and many useful articles, are formed from its tusks; their lamps are filled with its oil, and they themselves are fed with its fat and fibre. So thick is its skin, that a bayonet is almost the only weapon which can pierce it. Cut into shreds, it makes excellent cordage, being especially adapted for wheel ropes. The tusks bear a high commercial value, and are extensively employed by dentists in the manufacture of artificial teeth. The fat of a good-sized specimen yields thirty gallons of oil."