4A TREES OF MASSACHUSET'IS. 
and shrubs that have found root-hold there, a soil is forming or 
is already formed. What happens here takes place on all moun- 
tain tops in New England. A sheltering tree allows the creative 
action to take place. 
2. Another use of forests is to serve as conductors of electricity 
between the clouds and its great reservoir the earth; thus giving 
activity to the vital powers of plants, and leading the clouds to 
discharge their contents upon the earth. A few tall trees on 
the summit of a hill are sufficient to produce this effect. A 
charged thunder cloud, which passes unbroken over a bare hill, 
will pour down its moisture, if its electricity is drawn off by 
these natural conductors. The dry sterility of some parts of 
Spain, anciently very fertile, is probably owing, in a great de- 
gree, to the improvident destruction of the forests, and the absurd 
laws which discourage their renewal. ‘The forests also coat the 
earth and keep it warm in winter, shutting in the central heat 
which would otherwise more rapidly radiate into space and be 
lost. If you go into the woods at the end of a severe winter, 
you may any where easily drive down a stake without impedi- 
ment from the frost; while, in the open field by their edge, you 
find a foot or more of earth frozen solid. Forests act not less 
favorably as a protection against the excessive heat of the sum- 
mer’s sun, which rapidly evaporates the moisture and parches 
up the surface. The first mahogany cutters in Honduras 
found the cold under the immense forests so great, that they 
were obliged, though within 16° of the equator, to kindle fires 
to keep themselves warm.* The rain, falling on the woods of 
a hill side, is retained by the deep and spongy mass formed 
by the roots and the accumulated deposit of leaves, instead of 
rushing down, as it otherwise would, in torrents, carrying with 
it great quantities of loose soil. Protected also from rapid evap- 
oration, it remains laid up as in a reservoir, trickling gradually 
out and forming perennial streams, watering and fertilizing the 
* «At Guiana, in South America, within 5° of the line, the inhabitants living 
amid immense forests, a century ago, were obliged to alleviate the severity of the 
cold by evening fires. Even the duration of the rainy season has been shortened 
by the clearing of the country, and the warmth is so increased, that a fire now 
would be deemed an annoyance.” — Ure’s Dictionary of Chemistry,—article, Climate. 
