JuLy 10, 1902] 
imported timber, and the evils, including physical degeneration 
of the race, and coal fogs in the big cities, which have been 
shown elsewhere to result from England’s neglect of its forests. 
The reference to De Wet in Prof. Perry’s communication is un- 
fortunate: a small quick-moving army would probably have 
caught him. And surely cheap coal and luxury is not the 
summum bonum. Rather let us have hamlets of strong forest 
workers than the luxurious town dwellers of to-day with their 
decayed muscle and cheap mechanical power! Compare a 
European engine-driver with the runner castes of India and 
Japan. The engine-driver shows us perhaps fine inherited 
muscle, but going to decay for want of use; the Eastern runners 
show the development of muscle by both use and inheritance. 
Which would have the best chance of catching De Wet a 
hundred years hence ? 
As far back as 1882 the discovery was made by Sir D. Brandis 
and myself that Eucalypts planted on tropical mountains will 
produce wood fuel at the rate of 20 tons (dry weight at 60 Ibs. 
per cubic foot) per acre per year in perpetuity. The eucalypt 
plantation reproduces itself when cut, without further expense, 
and its dry timber, heavier than coal (which, as met with com- 
mercially, weighs 50lbs. to 52 lbs. the cubic foot) has an equal 
or a higher thermal power, bulk for bulk, than coal. We ob- 
tained this result as the maximum yield of Zucalyptus globulus 
on the Nilgiris, Southern India. No doubt there are other 
instances where higher yields are produced now, and no doubt 
also when the coal supply is exhausted, selection and experiment 
will produce a forest vegetation that will produce more than 
20 tons per acre per year. The sugar beet and all the fruits 
and vegetables of civilisation show how the vegetable kingdom 
can be moulded to suit man’s wants. If a chance tree on a 
chance mountain in a chance soil can produce the equivalent of 
20 tons of coal per acre per year, it seems not unreasonable 
to suppose that by selection we can produce, say, double this, 
or 40 tons. To produce this in perpetuity we should probably 
have to find a tree with the moderate soil requirements of the 
Conifers. A powerful sun, a heavy rainfall, and a very rapid 
forced growth would be the essentials of such a production of 
wood fuel. 
Looking at a rainfall map of the world, one sees that these 
conditions are fulfilled over about 8009 million acres of its 
surface (which is between one-fourth and one-fifth of the total 
land surface of 35,200 million acres). I take latitudes below 
40° and rainfalls above 40 inches. One-half of this area under 
forest might thus yield the equivalent of 161,000 million tons of 
coal yearly. This is more than 288 times the world’s present 
consumption of coal, assuming that coal and eucalypt timber 
are of approximately equal heating power. On the basis of the 
actual forest yields of to-day we have half this, or 80,500 
million tons. In Germany, one-fourth of the total area is 
under forest, and this is held on the highest authority to be the 
suitable proportion for a thickly-peopled civilised country such 
as Germany. The forest should properly occupy a higher pro- 
portion in countries where large areas are pestilential and 
unsuited for human habitation. Putting this, however, aside, 
and taking the German standard of one-fourth forest, then on 
the basis of to-day’s maximum yields we should obtain a yearly 
output of 40,250 million tons. And if to convert the maximum 
forest yield to an average forest yield we again divide by two, 
we obtain 20,175 million tons. Lower than this [ do not think 
we can reasonably go for the class of forest under consideration. 
it ts a little more than thirty times the world’s present con- 
sumption of coal. The world’s yearly output of coal recently 
was 663 million tons, says Prof. Perry. 
Thus we see that the yield of firewood from the world’s 
tropical and extra-tropical forests, whenever they are fully 
stocked and scientifically worked, will yield the equivalent of 
from thirty times to 122 times the present consumption of coal, 
or even up to 243 times the present consumption of coal if 
we succeed by cultivation in doubling present timber yield 
figures. 
It may be objected that my figures are far in excess of those 
representing the yield of European forests and that they require 
confirmation, No doubt they are far in excess of European 
figures ; but so also is the intensity of the vegetative process in 
these latitudes, and so also is the stature of the Sequoias of 
California, and the Eucalypts of Australia and South Africa 
above the stature of the biggest spruces and silver-firs of 
Europe. The Nilgiri figures [have quoted above were formally 
recorded in two official reports printed and published by the 
NO. 1706, VOL. 66] 
NATURE 
247 
Madras Government in 1882.1 They have since been confirmed 
by the measurements of forest officers who have subsequently 
had charge of the Nilgiri plantations. Similar figures have 
been obtained by myself and other forest officers in South 
Africa. They have been exceeded in several plantations in 
Natal, while at Johannesburg they have not been confined to 
Eucalypts, but have been obtained from Acacéa decurrens, or 
black wattle, as well as from some other trees. 
Therefore, ‘‘ when our coal supply is exhausted, when all the 
races of the world have fought for the waterfalls and places of 
high tide,” there will still remain that which Englishmen of all 
the civilised races of the world do most neglect—the forest. 
. D. E. Hurcuins. 
Grootvadersbosch, Swellendam, Cape Colony, May 14. 
Cold Weather in'South Africa, 
WE have been getting exceptional weather here of late. 
General French was actually snowed up at Middelburg. A 
good general idea of the circumstances will be obtained from 
the telegrams abridged below from the Déamond Fields 
Advertiser of June 14. 
Middelburg (Cape), June 11.—For the first time for sixteen 
years the town is covered to a great depth with snow. King- 
williamstown, June 11.—A fierce thunderstorm occurred last 
night, accompanied by heavy rain. Port Elizabeth, June 11.— 
The train service between Graaff-Reinet and Rosmead is to-day 
stopped temporarily owing to heavy snowstorms—an unusual 
experience for South Africa. Cradock, June 12.—An ex- 
ceptionally heavy fall of snow occurred in the Midlands on 
Tuesday night and yesterday. Queenstown, June 12.—The 
rainfall reported during the first five months of the year is the 
lowest recorded for the same period for the past thirty years. 
The drought has, however, been broken. Rain started on June 
10, and during the night there was a heavy fall of snow. 
Kokstad, June 12.—There was a heavy snowstorm last 
night, accompanied by a heavy gale. The snow is several 
inches deep in the streets. Bloemfontein, June 12.—The 
weather is unprecedentedly cold. The hills round Thaba 
*Nchu are covered with snow. Last night snow fell in 
Bloemfontein. 
At Kimberley it has been intensely cold, with a low baro- 
meter, wind, rain and sleet, and afterwards heavy frost. With 
the one exception of July 12, 1886 (when Kimberley is said to 
have been under snow for the whole day), the maximum shade 
temperature registered is the lowest on record. For the eight 
days ending Sunday, June 15, the temperatures have been :— 
| 
| Observatory Screen. Stevenson Screen. 
| 
| 
Max, Min. Max. Min. 
June 8 72. fo) 34°"0 WSL 3370 
» 9 SOnG 39,0 59.8 3801 
33) LO | 46°2 380 459 37,8 
» I | 454 36°'9 44.9 36-1 
oe, He 48°°3 Bison |) 460: 31° 2 
pp ele 520i PISO NV S74 24°°2 
et 57.0 ZOn0 mal SS.0 26°°0 
x» 15 | 62°'0 29° 0 63°°2 28°'0 
The maximum temperatures registered on June 10 and 11 
are the lowest on record for any June. The maximum 
registered on July 12, 1886, was 35°°8: There was also a 
maximum temperature of 45° in July 1891. Both, however, 
were obtained under a Glaisher screen and are probably a little 
too low. Minimum temperatures lower than 25° have been 
registered perhaps three times; the lowest known is probably 
20° in July 1888. All these previous instances have been quite 
transitory, the temperatures in each case being much higher 
both the day before and the day after. There seems to be no 
record of a cold spell having the duration of the one in question. 
Kenilworth, Kimberley, June 16, J. R. Surron. 
1 “ Suggestions regarding Forest Administration in the Madras Presi- 
dency,’ by D. Brandis, C.I.E., Inspector-General to the Government of 
India (Madras, 1882). 
‘Report on Measurements of the Growth of Australian Trees on the 
Nilgiris,’ by D. E. Hutchins, Dep. Cons, Forests, Mysore (Government 
Press, Madras, 1883). 
