62 Transactions of the South African Philosophical Socrety. 
camphor -tree, the two pencil cedars, the catalpa, and various 
cypresses yielding durable fragrant and easily worked woods. 
One hundred miles nearly due north of Cape Town begins the 
rugged and lofty Cedarberg Range. I hope very soon to see the 
restoration of the once fine cedar forests going forward at the rate 
of an acre a day. Last summer fire was successfully excluded from 
the whole of the demarcated forest area. The Clanwilliam cedar 
(Callitris arborea) is noteworthy as being the only valuable in- 
digenous timber that lends itself easily to reproduction from broad- 
cast sowings im situ. Seed is obtainable at the same price as pine 
seed. This cedar is the only indigenous timber that is at the same 
time durable, easily worked, and not liable to shrink, crack, or warp 
on seasoning. It has at the same time a most delicious fragrance 
when cut, and is no doubt one of the valuable timbers of the world. 
Trees of large size were formerly obtainable. 
~The exact influence of forests on climate is a much controverted 
point. This may be taken as established: that the general action 
of forests is to moderate temperatures and to more evenly distribute 
subsoil moisture. Forests render days cooler and nights warmer. 
They dry up swamps and subsoil moisture, but keep the soil 
moderately moist at the surface by protecting it from sun and wind. 
They have a slight and varying influence on the direct rainfall. 
Their chief and most beneficent influence is as storers of moisture. 
This they do in three ways :— 
1. Their foliage stopping sun and wind checks evaporation. 
2. The forest soil-humus has wonderful water-absorbing powers. 
It holds about ten times as much water as a sandy soil. 
3. The forest subsoil is penetrated and opened up by the deep- 
reaching roots of forest trees. Roots of vigorous forest trees 
will penetrate pot-clay and burst asunder massive rock. — 
The effect of all this is to retain in our midst the water that would 
otherwise rush off to the sea. Who that has watched South African 
rivers in flood has not been impressed by the wealth of water, and 
indeed soil too, rushing purposelessly away to the ocean? The country . 
is mountainous and elevated, and a large part of its rainfall is thus 
practically lost. The actual rainfall is often enough if only we 
could keep it from running away into the sea. Our coast districts 
‘average aS much rain as the east of England, our dry Karoo has as 
much rain as central Spain, but our sun is hotter, our winds more 
powerful and drying. Hence the wonderful climatic utility of forest 
in South Africa ! 
Says that accurate observer Gilbert White of Selborne :—“‘ Trees 
perspire profusely, condense largely, and check evaporation so much 
