September io, 1914] 



NATURE 



47 



and moisture. I must leave it to men of science to 

 say whether this was the result of some electrical or 

 other force, or whether what was obser\'ed was due 

 simply to a wet cycle coinciding with the laying of the 

 rails and the erection of the wires. I am told that it 

 is probably a coincidence of this kind which accounts 

 for the fact that in the neighbourhood of the Assouan 

 dam there is at present a small annual rainfall, 

 whereas in past years the locality was rainless. 

 Reference has already been made to the effect of culti- 

 vation in the Kalahari Desert in increasing the storage 

 of moisture in the soil. But it is when we come to 

 tlie division between healthy and unhealthy climates 

 that the effect of science upon climate is most clearly 

 seen. The great researches of Ross, Manson, and 

 many other men of science, British and foreign alike, 

 who have traced malaria and yellow fever back to the 

 mosquito, and assured the prevention ajid gradual 

 extirpation of tropical diseases, bid fair to revolu- 

 tionise climatic control. Note, however, that in our 

 penitent desire to preserve the wild fauna of the earth 

 we are also establishing preserves for mosquitos, 

 trypanosomes and the tsetse fl}'. 



Nowhere have the triumphs of medical science been 

 more conspicuous than where engineers have per- 

 formed their greatest feats. De Lesseps decided that 

 Ismailia should be the headquarters of the Suez 

 Canal, but the prevalence of malaria made it neces- 

 sary to transfer the headquarters to Port Said. In 

 1886 there were 2300 cases of malaria at Ismailia; in 

 1900 almost exactly the same number. In 1901 Sir 

 Ronald Ross was called in to advise ; in 1906 there 

 were no fresh cases, and malaria has been stamped 

 out. Lesseps 's attempt to construct the Panama Canal 

 was defeated largely, if not mainly, by the frightful 

 death-rate among the labourers ; 50,000 lives are said 

 to have been lost, the result of malaria and yellow- 

 fever. When the Americans took up the enterprise 

 they started with sending in doctors and sanitary 

 experts, and the result of splendid medical skill and 

 sanitary administration was that malaria and yellow 

 fever were practically killed out. The Panama Canal 

 is a glorious creation of medical as well as of engineer- 

 ing science, and this change of climate has been 

 mainly due to reclamation of pools and swamps, and 

 to cutting down bush, for even the virtuous trees, 

 under some conditions, conduce to malaria. Man is 

 a geographical agency, and in no respect more than 

 in the effect of his handiwork on climate, for climate 

 determines products, human and others. Science is 

 deciding that animal pests shall be extirpated in the 

 tropics, and that there shall be no climates which 

 shall be barred to white men on the ground of danger 

 of infection from tropical diseases. 



If we turn to products, it is almost superfluous to 

 give illustrations of the changes wrought by man. 

 As the incoming white man has in many places sup- 

 planted the coloured aboriginal, so the plants and the 

 living creatures brought in by the white man have 

 in many cases, as you know well, ousted the flora and 

 fauna of the soil. Here is one well-known illustra- 

 tion of the immigration of plants. Charles Darwin, 

 on the voyage of the Beagle, visited the island of St. 

 Helena in the year 1836. He wrote " that the number 

 of plants now found on the island is 746, and that out 

 of these fifty-two alone are indigenous species." The 

 immigrants, he said, had been imported mainly from 

 England, but some from Australia, and, he continued, 

 " the many imported species must have destroyed some 

 of the native kinds, and it is only on the highest and 

 steepest ridges that the indigenous flora is now pre- 

 dominant." 



Set yourselves to write a geography of Australia 

 as Australia was when first made known to Europe, 



XO. 2341, VOL. 94] 



and compare it with a geography now. Suppose 

 Australia to have been fully discovered when Euro- 

 peans first reached it, but consider the surface then 

 and the surface now, and the living things upon the 

 surface then and now. Will not man have been found 

 to be a geographical agency? How much waste land, 

 how many fringes of desert have been reclaimed? 

 The wilderness has become pasture land, and pasture 

 land, in turn, is being converted into arable. The 

 Blue Mountains, which barred the way to the interior, 

 are now a health resort. Let us see what Sir Joseph 

 Banks wrote after his visit to Australia on Captain 

 Cook's first voyage in 1770. He has a chapter 

 headed " Some Account of that part of New Holland 

 now called New South Wales." New Holland he 

 thought *' in every respect the most barren countrj- I 

 have seen " ; " the fertile soil bears no kind of pro- 

 portion to that which seems by nature doomed to 

 everlasting barrenness." "In the whole length of 

 coast which we sailed along there was a very unusual 

 sameness to be observed in the face of the countr%\ 

 Barren it may justly be called, and in a ven,- high 

 degree, so far, at least, as we saw." It is true that 

 he only saw the land by the sea, but it was the richer 

 eastern side of Australia, the outer edge of New 

 South Wales and Queensland. What animals did he 

 find in Australia? He "saw an animal as large as a 

 greyhound, of a mouse colour, and very swift." " He 

 was not only like a greyhound in size and running, 

 but had a tail as long as any greyhound's. What to 

 liken him to I could not tell." Banks had a grey- 

 hound with him, which chased this animal. "We 

 i observed, much to our surprise, that, instead of going 

 I upon all fours, this animal went only on two legs, 

 i making vast bounds." He found out that the natives 

 ■ called it kangaroo, and it was "as large as a middling 

 lamb." He found " this immense tract of land," 

 ! which he said was considerably larger than all 

 Europe, " thinly inhabited, even to admiration, at 

 least that part of it that we saw." He noted the 

 Indians, as he called them, whom he thought "a 

 very pusillanimous people." They "seemed to have 

 no idea of traffic " ; they had "a wooden weapon made 

 like a short scimitar." Suppose a new Sir Joseph 

 Banks came down from the planet Mars to visit 

 Australia at this moment, what account would he give 

 of it in a geographical handbook for the children of 

 Mars? He would modify the views about barrenness, 

 if he saw the cornfields and flocks and herds; if he 

 visited Adelaide, he would change his opinion as to 

 scanty population, though not so, perhaps, if he went 

 to the back blocks. He would record that the popula- 

 tion was almost entirely white, apparently akin to a 

 certain race in the North Sea, from which, by tradi- 

 tion, they had come; that their worst enemies could 

 not call them pusillanimous ; that they had some ideas 

 of traffic, and used other weapons than a wooden 

 scimitar; and he would probably give the first place 

 in animal life not to the animal like a greyhound on 

 two legs, but to the middling lamb, or perhaps to the 

 ubiquitous rabbit. Australia is the same island con- 

 tinent that it always was ; there are the same indenta- 

 tions of coast, the same mountains and rivers, but 

 the face of the land is different. In past years there 

 was no town, and the country was wilderness; on the 

 surface of the wilderness many of the living things 

 were different; and from under the earth has come 

 water and mineral, the existence of which was not 

 suspected. A century hence it will be different again, 

 and I want to see sets of maps illustrating more 

 clearlv than is now the case the changes which suc- 

 cessive generations of men have made and are making 

 in the face of Australia and of the whole earth. 

 j More than half a centun.- ago Buckle, in his "His- 



