628 
president's address. 
The experience of increased rainfall over the station at Lintzel 
with increase of forest area points strongly towards interdepen- 
dence. 
Secondly, as to the influence of forests upon the climate of the 
surrounding country. 
Any effects that arise must either take place by diffusion or by 
means of local air currents, or from the fact of the forest acting 
as a windbreak. 
Deforestation allows of the uninterrupted sweep of winds over 
the country, the evaporating and parching effects being much 
more intense than those resulting from mere dryness of the air. 
This class of effect is, of course, worse in flat country and on the 
seashore. 
When moisture-laden winds pass over cool areas of forest the 
possibility of condensation is at least not reduced, whereas heated 
plains certainly do reduce it. The presence of large forests in 
Asiatic and European Russia has been shown to produce a 
sensible effect in lowering temperature. 
In general we may expect that an alternation of large forested 
and unf ores ted areas in regions which on account of their 
geographical situation have a dry and rigorous climate is more 
beneficial than large uninterrupted forest areas which would fail 
to set up that local circulation which is brought about by differ- 
ence of temperature and permits an exchange of the forest climate 
to the neighbourhood. 
The results of systematic observations in forest meteorology 
made in France, Germany, Sweden, Austria and elsewhere, and 
extensive observations on temperature and rainfall extending to 
Russia and India are given in the Report. 
It seems scarcely necessary to mention the sanitary effect of 
forests. As is well known, trees have been planted with success 
to absorb the moisture of swamps, and the exhalations of eucalypt 
trees are particularly beneficial in counteracting malaria. 
The idea that our forests may get exhausted is often jeered at, 
and figures have been brought forward to show what an enormous 
and practically inexhaustible suppi} T of timber exists; yet in other 
