344 KANSAS CITY REVIEW OF SCIENCE. 
tations growing on both sides of the filled-up gorge. The mountain thus becomes 
gradually covered with wood from the gorges. The further bush and tree are 
extending the longer snow and moisture are kept back, the waters rushing to- 
ward the gorge decrease, lose in violence, whereby the matter they carry with 
them is precipitated, and kept back more completely, and, in a corresponding 
degree, more nourishment conveyed to the plants. The impetuous mountain 
torrent, which during the short term of its yearly existence only causes mischief 
and devastation, is gradually tamed, but it flows during a longer period, for the 
snow retained by the trees no longer melts all at once. The further afforestation 
advances the further this development proceeds. Finally, the mountain is trans- 
formed into a quiet forest brook, which fertilizes the gorge by degrees almost 
entirely filled up, and never dries up. The mountain covered with forest makes 
the precipitation of moisture possible; springs break forth, whose waters seek the 
bed of the old tumbling and plunging torrent. 
In the plain, also, this beneficial change makes itself felt. The never failing 
brook drives mill and machinery ; it serves for the irrigation of meadows, fields, 
and gardens. On the lower slopes, since afforestation has been effected, vine- 
yards, orchards, or fertile, if rugged, fields have sprung up. ‘The afforested 
mountain protects from cold, excessive humidity, and exceeding aridity alike, 
but, especially, also from inundations. It tempers winter, cools summer, and pre- 
vents especially, many of the late night frosts which are so destructive to many of 
the most fertile plantations. 
It is principally mountain chains of medium height where such works are 
possible as we have here pointed out. But lines of hills of small elevation, or 
swellings of the ground as we meet them in large plains, exert a similar influence 
on climate and weather if they are covered by forests. A great many will, at 
the present day, smile incredulously when they read how in the Middle Ages 
vineyards existed in all parts of Northern Germany, and a not inconsiderable 
trade was carried on with their products. And yet the explanation is as easy and 
as simple as it can possibly be. At that time nearly the whole country was still 
covered by large tracts of forest, the winters were consequently somewhat milder, 
frosts ceasing earlier in spring. As matter of fact, wherever the vine is cultivat- 
ed in Germany at the present day, there we find the largest forests. Examples 
are not rare that as late as this century villages have suffered injury in the culti- 
vation of the vine, or entirely lost it, because forests in the neighborhood have 
been destroyed. There is no protection in Germany against this wholesale de- 
struction of forests. It is true there is a Ministry of Agriculture, and there are 
Boards of Health, but there is an absence of legislative enactments for the pres- 
ervation of forests. It has been repeatedly suggested that existing German 
forests should be preserved, and, where practicable, schemes of afforestation 
carried out; at present, however, without any visible effect. 
In France the state of the question is in a no more advanced condition. Af 
forestation proceeds but slowly, and yet France is acknowledged to possess the 
