Woadland, Lawn and Garden. 
INFLUENCE OF FORESTS ON AIR AND 
SOIL, AND THEIR CLIMATIC AND 
HYGIENIC IMPORTANCE. 

pe Se a 
“ag O ascertain by actual scientific observation and ‘neas- 
uremen‘ the influence of forests on the air and soil, 
and their climatic and hygienic importance, the Bavacian 
Government instituted at different elevations and in various 
parts of the kingdom seven forestial and meteorological 
stations, at each of which, three daily observations are 
made at two different points, one situated in the middle 
ot a large forest, and the other inthe middle of a large 
field. The results of these observations according to Dr. 
K.bermayer’s report (published by C. Krebs in Aschaffen- 
burgh, 1873), proves conclusively the marked influence 
of forests on the temperature of the soil. In the spring 
and summer months (March till August), the difference in 
the temperature of the soil of the forest and of the open 
field averages 7.24 °F, in the months of September, Octo- 
ber and February this difference falls to 2.75 “F, and du- 
ring winter months to °0. The observations further show, 
that although the adsolute moisture of forest air in the 
course of a year appears to be hardly greater than that 
of the open field, itis different as to the relative moist- 
ure, for, as the temperature of the air in forests is on the 
whole lower than that in the open field, the forest air must, 
with the same absolute moisture, have a greater relative 
moisture and be nearer its point of saturation; a determi- 
nate lowering of temperature will therefore produce in 
forests a separation of water more readily and in greater 
quantity, than in the open field. 
This difference of relative moisture is much more marked 
in high land than in low ‘and, corresponding to the increas- 
ing values of the difference of temperature between for- 
est and open air as we rise above the sea level; the 
reason is that the difference of temperature is greater in 
sunimer. This relative moisture of forest air in summer, 
exceeds that of the air in the open field by a greater amount 
than in the other seasons of the year. The forest thus 
makes the climate moister, and more so in summer, in the 
time of vegetation, than in other seasons. The difference 
of relative moisture between forest air and field air, was in 
spring, 5.70° in summer, 6.18°, in wutumn, 5.22° and in 
winter, 5.24°. 
The greater relative moisture in forest air affects 
the amount of evaporation. Observations were made of 
the quantities of water evaporated from free water surface 
in forests and in the open fields, and it appears that on an 
annual average, the evaporation is about 2.7 times smaller 
in forests than in open fields. On comparing seasons, it is 
nearly four times greater in summer thanin winter. but 
even in winter there was two and one-half times less water 
evaporated in the former than in the latter. The differ- 
ence in the amount of evaporation in the warmest and 
driest months (July and August) between forests and open 
air was on an average, 290.28 cubic inches of water for one 
square foot of water surface. 
The relative proportion of evaporation, however, does not 
essentially alter in the several moaths, as we find that in 
forests on an average two to three times less water is evapo- 
rated than in the open air. This great difference in the 
amount of evaporation probably arises in great part (be- 
sides the difference of temperature, saturation etc.) by the 
much weaker movement of the wind in forests., Of 
greater practical interest than the evaporation from a free 
water surface, is that from the ground. Asin many parts 
of Bavaria and Germany generaliy, the farmers and citi- 
zens of villages have an old privilege to gather from the 
forests dry leaves for littering and manuring purposes, not 
only forest and open field were compared with each other, 
but also the influence of such litter covering was examined. 
T_e forest alone deprived of its litter covering, diminishes 
the evaporation of ground water, as compared with that cf 
the open field, about 62°; with litter covering the evapora- 
tion was further diminished about 22°. In reference to the 
question ‘‘ What influence have forests on the quantity of 
rain in a country, and dothey favor the formation of rain 
or not?” Ebermayer’s observations lead him to affirm that 
in plains of the same general character, the influence of for- 
ests on the quantity of rain is very small, and that it has 
also no marked influence on the percentage of distribution 
of rain. With elevations above the sea level, the impor- 
tance of the forests as regards influence on the rain 
quantity increases. On mountains ithas a higher value than 
on plains. In the summer season the action of the forest on the 
rain quantity is much greater in the winter. If we compare 
the rain fall on one square foot of surface with the quantity 
of water evaporated from an equal free water surface in the 
forests and in the open field, it appears that everywhere the 
annual rain fall is greater than the evaporation. The higher 
the place is, the greater is the excess of rain and snow 
water over the quantity evaporated. In the interior of a 
forest the evaporation isso small, that a much larger 
quantity of water enters into the soil, than is dissipa ed by 
evaporation. In the open field most water penetrates the 
ground in the winter, next during spring and autumn, and 
least in summer. In summer the quantity of water which 
passed through the ground was atone foot depth, three 
and one-half times, at two feet depth, four and one-half 
times, at four f-et depth, seven and one-half times less than 
in winter. 
The forest-covered ground behaves towards water quite 
differently. in forest ground without litter covering, the 
quantity of water at one foot depth is greater in winter; 
countries. 
born to him, to dig a well, and to planta tree. 
sible for the untraveled Englishman to realize the misery 
FOREST AND STREAM. 
149 

then follows spring; and in autumn and in summer it is 
nearly equal. In litter covered forest ground the quantity 
penetrating the ground in all the four seasons was nearly 
equal. If we compare the forest ground with the open 
field, the quantity penetrating the former is, in winter less 
In spring the forest 
ground at four feet deep gave per three square feet surface 
about 133.42 cubic inches more water than the unwooded 
ground. In summer litter covered forest ground gave at 
six feet depth 1245.71 cubic inches more water per three 
square feet, than the ground in the open field, while in for- 
est ground without litter, at one foot depth twice as much 
than that penetrating the latter. 
water passed through as in the open field. In autumn, 
lastly, the penetrating quantities of water in the forest and 
in the open field were nearly epual. 
The action of the forest and of Jitter covering on the wa- 
ter contents of the ground and of the humidity of a region 
is thus most marked in the warmest season, and in hot 
The forest produces an equable distribution of 
the ground moisture in the several seasons of the year. 
In a hygienic point of view, it has been shown that 
in fever and malaria, contagion is generally carried and 
communicated by currents of air, but that forests often 
act as a protection against them. 
many localities in India which formerly were free of conta. 
gious diseases, these appeared after cutting down of the sur- 
rounding forests. 
Cuas, PLaAGert. 
Ss 
TREE-PLANTING. 
A 
things make a man to be truly a man—to have a son 
It is impos- 
of a treeless country. Europe has no natural deficiency 
of trees; hence, bridge-building took the place of the old 
Aryan tree-planting, as an act of piety to God, and of duty 
to the future, in the counsels of the early Christian teach- 
Both in East and West, trees 
were no doubt the first temples, and the planting of groves 
ers of the European nations. 
was the primitive form of church-building. Abraham we 
are told, planted a grove in Beersheba, to commemorate 
his solemn covenant; but among his descendants it became 
in time the mark of a pious ruler to ‘“‘cut down the groves,” 
as the seats of pagan worship: the mark of a careless ruler 
to leave them untouched; and the mark of an impious ru- 
Itis not hard to find 
ler to plant and dedicate new groves. 
reasons why the grove naturally became the first temple. 
Men were no doubt impressed by the hoary age of trees 
compared with the short life of man. A tree was often 
the center around which each succeeding generation de- 
posited its traditions—a visible bond uniting the departed 
with the living, and the living with the unborn. The cool, 
grateful shade of trees was a natural type of the gracious- 
ness the worshipers sought for from the power they wor- 
shipped—especially in Eastern lands, where shadow is so 
precious and so exceptional. The yearly new birth and 
death of their foilage was a national symbol of human 
life. The darkness and density of the grove, we must add, 
hid the obscenities and cruelties which belonged to the 
darker developments of heathen worship. 
Tree-planting has retained in Germany longer than else- 
where something of its occult character, binding together 
religion, uation, and family. In the Vosgessen, the old 
German farmers were not allowed to marry until they had 
done something for the future good of the tribe by plant- 
ing a stated number of walnut-trees. 
The asking of a distinguished guest to plant a tree, is a 
pleasant way of commemorating a visit. We do not 
know that it is much used here. In 1852 the oratorian poet, 
F. W. Faber, was visited at St. Mary’s, Sydenham, by 
Prince Massimo and Cardinal Wiseman, each of whom left 
behind him the record of his visit in a tree of his own 
planting. According to the German fancy, no tree planted 
as a memorial will grow and flourieh unless it has a motto 
given it at the time of its planting. 
In. different parts of our country we may come across 
trees—in Sherwood, indeed, across entire woods—planted 
to commemorate national events. But our English tree- 
plantings have long been mainly the work of individuals, 
and not of communities. A tree planted in Lord Rollo’s 
garden at Duncrub, to commemorate the Union of Eng- 
land and Scotland in 1707, a fir, eighty feet high, and eight- 
een feet in girth, was blown down in the gale of March, 
1866. The greatest day of commemorative tree-planting 
ever known in England was probably the first anniversary 
of the Restoration, May 29th, 1661. The letters from dif- 
ferent towns in the Mercwrius Publicus and the King’s Intel- 
ligencer of that year, contain accounts of such plantings. 
Many of these, however, were, like the Trees of Liberty, 
planted only to last as long as the festival. In one letter 
from Halesworth, in Suffolk, the ‘‘ own correspondent” 
of the period writes: ‘‘The number of trees that were 
planted in the town was so great that it perfectly rescm- 
bled an artificiai forest. The whole town lay under so ab- 
solute a disguise that the inhabitants knew not their own 
houses.”—(Mercurtus Publicus, June 6, No. 28.) The 
wholesale commemorative planting in the Sherwood dis- 
trict marks victories gained by our famous admirals. 
Lord Newark planted twenty-five acres, partly forest-tree 
and partly fir, and called it Howe’s Grove, in honor of Earl 
Howe’s great victory. A plantation of fifteen acres, ad- 
joining Thoresby Park, is called after Earl St. Vincent; 
and twelve acres on the north boundary of Budby Forest, 
celebrate Lord Duncan. In other parts of the Sherwood 
district great plantations bear the names of Nelson, St. Vin- 
cent, Howe, and Spencer—the last in honor of the noble- 
man who then presided at the admiralty, and to whose 
judicious arrangement of the fleet the English successes 
were in part attributed.—Chambers’ Journal. 

Louis XVI. A Crack Sporrsman.—From the ‘Journal de 
Louis XVI.,” lately published by M. Nicolardot, it appears 
that the unfortunate monarch was passionately fond of hunt- 
ing. Louis XVI., the meekest of mortals, was one of the 
crack Nimrods. In his diary he records having brought 
down 189,251 pieces, and 1,274 deer. When large game 
was in abeyance, he would shoot martinets, squirrels, or 
small game of any kind. Even swallows were not spared; 
he averaged seventy aday. Anentry of the diary on the 
28th July 1784, states, ‘‘killed 200 swallows,” 
It was observed that in 
ls eae eae 
PROVERB of Northwest India declares that three 

Aatural History. 
“BIRDS WALKING UNDER WATER.” 


LATE paragraph in this paper under the above head- 
ing, concludes by requesting further observations on 
the movements of birds under water. The writer assumes 
that it would be “‘physically impossible” fora bird to swim 
horizontally under water, ‘‘unless it could in some way as- 
similate its specific gravity to that of the water around it.” 
While it is perhaps not surprising that the ability of cer- 
tain birds to progress under water in all directions should 
not be generally known, owing to limited and infrequent 
opportunities of observation, their possession of this power 
is nevertheless established, and readily explained without 
recourse to the above-mentioned theory. It is well known 
to naturalists that cormorants, loons, grebes, and some al- 
lied species habitually pursue their prey under water, some- 
times at a depth of several fathoms. As their food consists 
in large part of fish, they must be able to move rapidly in 
any direction in order to secure it. I have only witnessed 
the act myself under the most favorable circumstances of 
observation, in the case of loons; but the mode of progres- 
sion is essentially similar, if not the same, in other instan- 
ces. From the stern of a steamer anchored in the quiet, 
transparent water of the harbor of San Pedro, Southern 
California, I once watched the movements of some loons 
which were playing about the vessel without showing any 
of the wildness these birds usually exhibit. They frequent- 
ly swam and dived within a few feet of me, and in several 
instances I could readily trace their course for some dis- 
tarce under water. It wasan interesting sight, and a novel 
one, to see such wary birds disporting heedlessly just be- 
low, gliding through the water with the ease and speed of a 
fish, bespangled and glittering like fishes, too, with the 
bubbles of air that clung to their sleek, glossy plumage. 
They appeared to swim in every direction with equal facil- 
ity, using both wings and legs. But it was not, in reality, 
so much swimming as flying; the birds actually flew through 
the water, moving the half-spread wings much as in ordi- 
nary aerial flight. They appeared to shape their course 
with strokes of the broad, webbed feet which projected, 
rudderlike, far behind, and to propel themselves largely by 
using the wings like fins; but as both members were in 
continual motion the amount of impulse derived from each 
source could not well be estimated. The birds sometimes 
reached a depth at which they were lost to view, reappear- 
ing nearly where they went down; and again, they accom- 
plished the long distances they are well known to swim un- 
der water in a horizontal direction, in both cases remaining 
submerged for the same surprising length of time. It is not 
in the least probable that they were prepared to swim in 
thisor that particular direction by a change in their spe- 
cific gravity; it will be evident that no such alteration 
would be required. 
As we all know, a bird dives by pushing itself down 
with the feet or wings, or both, exactly as it swims on the 
surface by pushing itself forward; in the former case over- 
coming, by muscular exertion, its tendency to float, as well 
as the simple resistance of the water toits progress. Now, 
to swim horizontally under water the bird need only incline 
the axis of the body obliquely downward ata certain slight 
angle, and then push straight forward. For in this posi- 
tion the bird opposes its broad flat back to the obliquely 
downward action of the water, which offers the required 
resistance to counteract the tendency to rise, as long as the 
bird continues to propel itself onward. It could not re- 
main under water motionless; were its course arrested it 
would immediately begin to rise obliquely backward. The 
adjustment of the body at an angle which balances the up- 
ward tendency with a resistance from above, is of course, 
instinctively effected, and the direction is altered at will 
by a change in the inclination of the body. Progress under 
water is the resultant of three forees—muscular energy, 
directed forward, specific gravity of the water acting verti- 
cally upward, and an induced resistance of the water 
pressing obliquely downward and backward. A certain 
rate of speed is required to bring this last force into action, 
much as ‘‘headway” is needed to make a vessel mind the 
helm; if the motion slacken short of such rate the bird 
would ‘‘make leeway”—that is, drift upward. The prin- 
ciples involved are essentially the same as those upon which 
a vessel sails up to the wind—the bird trims its boat-shaped 
body to the water, just as the sails of « vessel are trimmed 
to the wind. . 
There is, however, no question that some birds possess 
the power of altering their specific gravity decidedly—per- 
haps to the extent of making themselves a little heavier 
than the same bulk of water. Some of their performances 
cannot, probably, be otherwise explained. When a grebe, 
for instance, as is frequently witnessed, sinks back into the 
water without perceptible move of its flippers, and with 
scarcely a ripple, until only the head remains visible, the 
bird has not dived in the ordinary sense of that term. It 
has neither pulled nor pushed itself under, but just let it- 
self down—sunk; and itis not evident how this could be 
effected without some increase in specific gravity. On one 
occasion I happened to see how a great change may he ef> 
fected. It is simply a matter of along breath. It is well known 
that birds breathe air not only into their lungs, but also thence 
into a system of inter-communicating cells in various parts 
of the body, the amount thus inhaled and exhaled being, in 
some cases at least, sufficient to effect the change in ques- 
tion. Holding a wounded grebe in my hands I saw and 
felt it swell with a long, labored inspiration that_seemed to 
