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THE TROPICAL AGRICULTURIST. 



[JlTNE T, 1883. 



if the region is one of great extent, the attempt to effect 

 such a change is a perfectly hopeless one. On the other 

 hand, the contrary process — that is to attempt to change 

 a climate which is too moist into one of less humidity — is 

 in general not attended with much difficulty. A judicious 

 system of clearing neai'ly always leads to the desired result. 

 It seems to be generally believed that trees produce the 

 following effects: — They increase the amoimt of rainfall. 

 This they probably effect thus: They lower the temperature, 

 and thus cause the moisture-laden ah first to become visible 

 as cloud, and secondly, to be precipitated as rain. They 

 intercept, and as it were, tap the vapoui- charged winds. 

 They supersede the state of tension and polarisation which 

 exists when a electrified cloud is above them by silently 

 dischargnig the electricity. The discharge of electricity, 

 as for example in the case of thunder-storms, is generally 

 accompanietl by rain. It is well known that a moderate 

 amount of rain falls upon the ocean far away from land, 

 and it may be thought by some that the absence of trees 

 cannot reduce the rainfall to an amount less than the fall 

 at sea, which may be considered the normal fall. That 

 from some cause or other a less amount of rain may fall 

 upon land than sea, is evident from the existence of the 

 rainless districts of North Africa, Mexico and Peru. In 

 order to attract rain it has been shown that the surface 

 must be covered with objects like trees, which produce a 

 diminution of temperature, which can intercept the current 

 of ah, and which are good conductors of electricity. The 

 luxuriance of vegetation does not tiepend on the amount 

 of rainfall, but upon a .sufficiency of moisture finding its 

 way to the roots of the plants. A heavy tropical rain of 

 say five inches in a single day produces no more good than 

 a gentle continuous rain of one inch during the same 

 period, as fom*-fifths of the former rain are carried away 

 by streams into the sea, and some valuable soil with it. 

 Uentle rain is aU utilised ; every drop sinl^s into the ground, 

 neither water nor soil is carried away. If the foregoing 

 explanations are correct it ^vill follow that the gentle 

 showers are attracted by trees, and that\dolent rains will 

 faU whether trees are present or not. But the ti'ees on 

 the slopes of mountains check the fury of the violent rain, 

 prevent the low lands from being flooded, and save the 

 soil from bemg washed away. 



A good deal might be done m affecting the chmate for 

 the better, if owners of estates would make up their minds 

 to plant a few hunched trees each year in a belt east and 

 west across the south-west or rainy winds on their boundary 

 lines; it would have a double effect of attracting the 

 vapour-laden clouds and producing moistme, and also check 

 the spread of large fii'es from one estate to another — letting 

 alone the great value such plant-ations would prove in a 

 few years, if suitable trees were planted for wagon wood 

 and railway sleepers, the demand for which I anticipate 

 will be great in futiu-e years. For any one who has the 

 capital to spare and can aft'ord to wait for a return, I don't 

 know of any investment which would pay better here than 

 tree-planting. Our Government might assist the movement 

 by giving prizes or premiums in each country for the 

 greatest number of hardwood trees planted when two years 

 old, taking good cultivation into consideration; also by 

 taking the present tax off plantations by striking plant- 

 ations out of the valuations for railway taxes. The great 

 di'awback to persons planting trees is, that it takes both 

 time and money, and there is a long time to wait for 

 any return. Now if a scheme could be elaborated for 

 Government to make loans at a low rate of interest to 

 persons for tree-planting in a similar manner to what is 

 done in England for draining land (such loan to be a fi-rst 

 charge on an estate), something might be done towards 

 forming extensive plantations, which would have a doul)le 

 economic effect, viz., improve the clunate and .save money 

 to the colony for the importation of railway sleepers, which 

 no doubt could be grown for le.s's price and of better quality 

 than those imported. Government might also, at the Botanic 

 Gardens, raise suitable trees in quantity from seed, and 

 supply them at cost price to parties requiring them. Few 

 people have the knowledge and time requisite for raising 

 the various kinds of young trees from seed — it is a business 

 in itself and requires great care and attention. In view of 

 cuture use the last few years I have given a good deal 

 of attention to the kind of trees best adapted to our 

 oast lands and the most economical way of planting out. 



Scarcely any of the Em-opean forest trees are suitable to 

 the coast lands. The oak makes a good shade tree, but 

 it is of slow growth. For forming plantations rapidly the 

 gums, or Eucali/jHi of AustraUa, rank first, and as there 

 are over 50 varieties now growing in the colony there is 

 plenty of choice. The blue gum and stringy bark, which 

 grow so well at Maritzbm-g and beyond, have the great 

 drawback of being destroyed by the white ants. Next to 

 the gums is the blackwood of Tasmania, Acacia Melanoxulon, 

 It is a straight-growing tree of rapid gi-owth; the wood 

 is very hard when seasoned, and is suitable for wagon 

 wood, furniture, and railway sleepers. The blackivood has 

 one very valuable property, it will grow well on waste 

 stony places if only a pit is made in the stone to start 

 it m, and it ratoons well, that is grows up again from the 

 roots into fine straight poles when cut down, thus render- 

 ing replanting unnecessary. The blackwood must not be 

 confounded with the black wattle; the wattles don't thrive 

 well on the coast, they die away after 5 or 6 years, and 

 are only fit for firewood. The Cctsuarina grows well, being 

 a tropical tree; it is straight and hai-d, but white ants 

 are rather fond of it; it is a fine tree for attracting 

 rain-clouds from its nimierous points. It has been found 

 good for that pm'pose in IMauritius, where I hear hundreds 

 of acres have been planted with it; it is there called Felon. 

 The silver oak or GrexiUm does well and gi-ows rapidly; 

 but I do not know if the timber is of much value. But 

 the tree of most value to us, if we could get it to gi'ow, 

 would be the pitch pine of the Southern States of America. 

 This pine grows in a similar latitude to Natal; forests of 

 it extend for himdreds of miles, from Savannah across 

 Georgia and Alabama to Mobile. The wood of this tree 

 is all that can be wished for building purposes; it is also 

 good for resisting white ants where gi'owing; for fuel it 

 bm-ns like a torch. There is a difficulty in raismg the 

 yomig plant from seed, but when once over the first year, 

 and planted out, they run up rapidly and are handsome 

 trees; the difficulty at fiist can be overcome by care and 

 attention. The pitch pine grows best in America in red 

 sandy soil similar to our Berea soil. I must not forget 

 the bamboo, one of the most valuable plants for our water- 

 courses and river banks. In a semi-tropical climate it is 

 invaluable, both for fuel, building coohe houses, fencing, &c. 

 If planted along the watercourses, it preserves the banks 

 from being washed away, and the water from being evapor- 

 ated; it is very ornamental, easily propagated by cuttings 

 like cane in the spring from last year's shoots; and it 

 is in great demand for building houses. In forming 

 plantations, I would plant these trees out in rows feet 

 apart, or about 500 trees to the acre (allowing for a few 

 misses) in rows both ways, so that a small one-horse plough 

 can be run thi'ough each way; and I would put row 

 of mealies between the trees for the first two years. This 

 would ensm-e proper cultivation of the trees, and the mealies 

 would pay for the cultivation. It is of httle use planting 

 trees in this climate unless you cultivate them well, and 

 keep them free from weeds. "What the Mormons have 

 done in Utah to improve the climate for agTiculture can 

 surely be done by English colonists in Victoria Country, 

 Natal. The Mormons went to Utah and found it a desert; 

 they have made it one of the gardens of the world. But 

 I am- afraid if we go on here as we have been doing this 

 last year, cutting down so much bush and planting no 

 trees, jve shall reverse that picture; so let us endeavour 

 to do something to remedy the e^nl before it is too late. 

 This paper has extended to much greater length than I 

 had intended it, but to treat the suljject of the loss of 

 rainfall and its remedy in its various aspects I could nut 

 well make it shorter; but I hope it may have the effect 

 of drawing your attention to the very important subject 

 of which it treats. 



Mr. Garland said that he had found in the first two 

 years he was in the comitry that he was able to get over 

 the Umgeni, he walked across the Great Umhlanga dry 

 shod, and all the water in the rivers was collected in 

 pools. In 1850 and 1851 the rainfall was so inconsiderable 

 that the Great Umhlanga was so empty that water to 

 drink could not be obtained, and he remembered trekking 

 up and down to find water for that purpose. That was 

 before any bush was stripped uff or ti-ees cut down, so 

 that there were times when thoughts occm-red. He did 

 not dispute the principle that the denudation of forests 



