SCIENCE UP TO DATE.

Lyttelton Times, Volume CXVII, Issue 17287, 30 September 1916, Page 5

SCIENCE UP TO DATE.

CLIMATE AND MAN. (By JAMES COLLIER.) Bucklo was doubtless the last or most recent in modern times, aa,,tke old French writer, Bodin, may have been the first, to treat climate as the great outward determining agency in tho life of man. Tho speculations of tho English historian, thetagh published almost sixty years ago, are still fresh in memory, and they were largely influential in forming the opinions of men lately deceased or still living. It wae pointed out at the timo that G. P. Marsh, then United States Minister at Florence, had shown conversely to how largo an extent man and bis labours and achievements had affected his outward environment. So ancient a writer a 3 the old Greek physician, Hippocrates, had anticipated Bucklo as Montesquieu had anticipated Buckle, and Bodin Montesquieu. The whole subject lias since been thoroughly overhauled. Ratzel’s researches (already recapitulated in. this) science column) are admirable in their completeness, and still later writers have in various directions taken steps, strides or leaps in advance. Some of these may he new to many readers, and all of them are charged with practical activity. CLIMATIC CONTROL. Tho control created by climate, or the physical environment generally, is both direct or indirect. It is direct when tho climate induces physical or moral changes in man, and indirect when it brings about changes in the distribution of plants and animals on. which man depends for his food, clothing or habitation. They would be notably (and amazingly), direct if we believed with Buckle and 'Livingstone that man’s religion depends on the distance of his habitat from the equator. But no one now believes that it does. Tylor, Spencer and Grant Allen have proved that religion is self-identical tho world over. There has never been but one religion. Here it has taken this direction and assumed this particular form; elsewhere it has worked out in a slightly different manner. Climate has therefore only a secondary effect. HABITATION. A more primary and less dubitablo effect of climate is that it dictates the situation of man’s abode. It divides the world into a habitable and an uninhabitable portion. It is desert (namely, deserted), and then it is a snowy or a sandy desert. Even tho desert may bo habitable for a part of the year. The desert of snow in Greenland and the desert of sand in the Sahara are eternally deserted. Yet there are degrees even there. The desert of Sahara is being broached by the Algerian colonists at various points, as it was at many points by the ancient Romans. and tho wilds of north and north-west Canada are being brought under tho plough. Not only do the Eskimos livo within tho Arctic Circle, but tho Siberians dwell at Verkhoyansk which has in January the coldest climate on the globe; and the Italians govern their colony of Eritrea from Massowa, almost the hottest

place on earth. The limits of habitation are determined less by temperaturo than by rainfall. 'Water mam must have. It thero is too much, as in forests the forest must be cut down and supplanted by open tillable lands before settlement can advance. There is a regular gradation from the nomadic tribes of Africa or Greenland, through the farming population of the plains and valleys to the crowded industrial centres. THE TROPICS. There, under the equator, plants, insects and animals, if not exactly man, attain their highest development. There the soil is at its richest. Ih abundant food is provided fur man with a minimum of labour on his part, Man consequently remains comparatively undeveloped, indolent and untrustworthy, superstitious and P*® 51 ™' Yet. many able and energetic men lia been bred in the tropics. Still, effective growth has taken place only where Chinese, Japanese, or coolie labour has been imported, and the _ Spaniards, Dutch, British ami Americans have regulated, directed or enforced mdus--1 Despotic government's arc thus bred, marked social inequalties thus arise, and castes are thus differentiated. No democracy exists, and the tropics aio governed from the temperate zone. That zone may bo created in the immediate neighbourhood and still in the tropics by climbing a few thousand feet. Hence it is said ihat India is Governed (os at Simla) from a height of 7000 feet. But that government, it is believed by many, must some day end. British children cannot ho thero Somowhore in the tropics, most ethnologists hold, primitive man was born. Nots however, where tho spontaneous products of nature are most profusely lavished, but where man needed to expend at least a modicum of labour to obtain regular supplies of food. Such a site may well have been Mesopotamia, where indeed it is placed by the Hebrew records, in the portion where the Tigris and the Euphrates form a delta with the Persian Gulf. There, perhaps, wheat was first grown.

CONQUESTS AND MIGRATIONS. When a race has at length been enervated by long residence in a tropical country, it has often been overcome by moro hardy invaders from the highlands. Thus the Aryans climbed tho Himalayas and descended into India, the Manchurians conquered China, the Dorans and lonians Greece and Italy, the Incas Peru, and tho Toltecs and Aztecs Mexico. TROPICAL DWELLINGS.

Though ho spends the most of his time in the open, tho tropica! native needs but little protection against sun or rain or against the nignt's cold. Primitive huts are made of bamboo, palm and cocoanut leaves,' sugar-cane, and grass. Other slight structures are made of shins, while some are permanent roofed houses. Once built of thick stone and the light shut out, tropical cities are now built of wide streets and spacious boulevards. The rooms in opulent houses are largo and airy, and they are shaded by broad verandahs with screens. No chimneys are to be seen. The east end is the fashionablo quarter because tho prevailing winds are easterly. Midday work is unknown, and the afternoon siesta is general. TROPICAL CLOTHING AND FOOD. Tropical clothing is minutely regulated with the whites, but native clothing is almost non-existent. Khaki is coming into general use. The chief articles of food are tropical fruits—the delicious banana, the nutritious cocoanut, and tho lusoions breadfruit are staples. There is little meat or fish, and'some writers believe that the prevailing anaemia of tropical dwellers is to be ascribed to the lack' of such viands. Preserved fruit is sent from temperate countries. USEFUL ARTS. Agriculture has in general mado little progress) and yet rice is cultivated in Malaysia and India, wheat is growu in Polynesia, and many African negroes are farmers. But tropical soils .are not always fertile. The torrential rains wash out the salts, and some soils are poor in plant-foods. Some useful arts are cultivated. Cocoanut sheila are made into bowls

and other domestic utensils. Cocoannt fibres are plaited into thatch, baskets and mats: and their steins aro used in building houses and boats. Bark cloth is worn in. both Melanesia and Africa. Out of bamboo and rattan are made hunting and agricultural implements, houses, boats, rafts and carts, and also musical instruments. It is especially notable at the present timo that European countries, particularly Gonnany, are making machines for harvesting and exporting tropical products, such as splitting coconuts, extracting oil from palms, making caoutchouc from the sap of the rubber tree. EQUATORIAL FORESTS. The dense tropical forests are crowded with creepers and plants. There aro few animals. The superabundant vegetation is unfavourable to human occupation. Man develops rapidly, and he agos quickly. Population is scanty. Trees and undergrowth are effectual barriers. The waves of civilisation dash against it and fall back broken. The natives live along tho banks of rivers. In New Guinea they spend so much time in their boats that they lose the capacity of walking, and become almost amphibious. Along the Amazon and the Mosq*aito Coast the food supply is governed by tho rise and fall of the water. MILLS AND FACTORIES, So great is the valuo of tropical forest products that many whites have settled on their margin and along the rivers that run through them. In Brazil and along the Amazon coco:), sugar, coffee, tobacco, manioc and rice plantations abound; and sugar, rice and lumber factories and mills have been started. TROPICAL ROADS. In the equatorial belt tho climate controls travel and transportation. The heavy rains of the rainy season make travelling in many parts impracticable, or facilitate it if boats are used. Work on railways is then affected. The dense vegetation of the tropics' obstructs railway construction. Tho roadway gets constantly overgrown and has to be cleared at great cost. Ties and trestles rot. On the other hand, the vegetation arrests landslides. Fevers are a serious handicap, and so is tho sultry heat. Many peculiar features on the Uganda railway show the climatic control. THE SAVANNAS. A transition zone of moderate rainfall lies between tho forests and tho deserts. A belt of open grassy country, with but a brief season for growth, is suited for grazing purposes—in the Sudan, South America, the llanos of Venezuela, tho campos of Brazil and the downs of Australia. The people are pastoral, and population has grown denser than in the forest. In most of tlicso tracts they are nomadic. Droughts and famines aro frequent. Seasonal migration is regular. With irrigation these savannas become suited for agriculture and aro sown with wheat. THE DESERT’S. Tho country swept by the trade winds is a desert, and is blit scantily peopled. Thero travel and transportation are difficult. Deserts to the north and south of Central Africa bar it against contact.with civilisation. Goods and passengers go round. Trails are effaced by blowing sand. Rivers flow long distances without tributaries. Along their banks population settles, towns spring up, and tho entire valley becomes an oasis. In tho Nile and Deccan valleys the river systoms are centres ol a dense population. But in tho desert ptopei a nomadic life and a scattered population aro a consequence of the.aridity. Population crowds the oases, which are abandoned when they begin to diy UP The climate of tho deserts is dry and stimulating. Food is more difficult to procure, and life is harder. Therefore the desert produces men of a bolder iypo, moro energetic and independent. The tribes of tho Sahara are more robust than tho Soudanese. The dwellers in Boluchistan and tho Persian desert have often subjugated the richer Jowlanders. The Mohammedan religion, and tho Empire of the Khalffs too. their rise in the deserts of Arabia. Tho desert is monotheist. • R. Aberciombic publishes two maps—one showing the area of Mohaminedism, and tho area in Asia and Africa with lc-s than ten degrees of annual ranifall. They aro almost co-extensivo. Aval ceremonies, rain dances and vain sacn fices aro horn in droughty regions. Hut railways are changing all that. The life of man m the polar zone's shows the monotony of cold, as he tropica do tho monotony of heat and the temperate zones reveal tho cenUc* of tho world’s civilisation.