SEPTEMBER, 1897. MONTHLY WEATHER REVIEW. 396
North Carollna ................................................. South Carolina Qeorgla ........................................................ Alabama.. ........................................................ Luuislana.. ......................................................
...................................................
~~
the numbers entered in the tables, like Table 1, under the re-
spective columns, are collected in Table 2. This indicates the total cloudiness recorded. Then the total sums of the
three several observations under the two general heads are
transferred from Table 2 to the chart, where near the name of
a station appears two numbers. The left-hand number is the
total cloudiness recorded in the above notation for the whole
sky; the right-hand is the total cloudiness for the sky near
the suii. The maximum number, if complete cloudiness pre-
vailed every day a t the three observations, would be 394 for
the general state of the sky, and 288 for the sky near the sun.
The totals can, therefore, be readily reduced to percentages, on dividing them by this maximum number.
TABLE 2.
35.8 1.3 S.7 98.1
18.4 16.0 15.9 14.9 %. 5 91.5
Statlons. Observers.
Phea ple ......I J.
~
8.
~
Cnim
~
. .......... Castlt%erry.. ... 8. Castleberry.. .... Bay Mlnelte .... M. J. Wllklns ....... Latham ......... M. McGowan.. ..... Moblle .......... W. M. Dudley ......
Wt nia. Cape d n r y . .... Norfolk ......... N w t h Carolina. Wllleyton ....... Oatesvllle ...... Winton ........ Tarboro ......... Weldon ......... Rocky Mount .. S ringhope ..... &laon .......... Loulsburg ..... Aubnrn ......... 8elma.. ......... Ralel h ......... PIttsLro ....... Moncure ........ Fayettevllle .... Lanrlnbnrg ..... Rockln ham.. . Wadedoro ..... Monroe ......... South C’a‘ardha. Cheraw ........ Lancaster. ...... Santuck ........ Little Monntaln. Prosperlt ...... Cross H d ...... Saluda .......... Greenwood. ... Trenton.. ....... w”,”Ez,. ........... ........... Mount Cannel.. Oewgia. Leverett ........ Elberton ........ Camak ......... Cmwfordvllle .. Athens .......... Covindon ...... Talbotton ...... We& Point ...... Columbus. ...... Alabama. Smith Itstion.. . Fort Yltchell ... Auburn ......... Loachapoka .... Tallassee ....... Union Sprlngs .. Matthews ....... Montgomery.. .. Elghland Home. Fort De sit .... Green& ......
B. A. Blnndon... ... J. J. Orny .;... .....
E. 0. Wllllams ..... J. T. Walton ....... 8.8. Danlel.. ....... E. V. Zoeller ....... T.A. Clark.. ....... Gaaton Battle.. ... Q. W. Bunn ........ W. 8. Hprlss ...... T. B. Wilder ........ Tro Poole ......... Dr. 5. J.Noble .... C. F.von Aerrmann A. E. Merritt ....... W. H.Thompaon ... Frank Glover ..... L. D. McKennon.. .. J. M.Stansill......, W. K. Boggan ..... T. A. Ashuruft ......
J. H. Powe ......... J. C. Foster.. ....... E. W. Jeter... ...... J. M. Sease. ....... J. Perry Cook ...... E.T. YcSwaln ..... E. L. Mathls ....... M. Y. Colhoun ..... C.A. Long ......... A. C. Kennedy ..... J. W. Thomas ...... J. D. Cede ..........
W. C. Powell ...... H. A. Roebuck ..... J. A. Chapman ..... J. P. Moody ........ C. D. Cox .......... J. 8. Carroll ........ W. T. Uennls ....... T. J. Jennlnga ...... J. W. Long .........
A. H. Fraser.. ...... John Cantey ....... JamesT. Anderson. W. W. David ....... J. T. Jarman ....... P. L. Cowan ....... W. D. Dlllard ...... F. P. Chaffee ....... 8. Jordan.. ......... C. E. Rein .......... B. R. Dev ..........
General state of the sky, a. m.
Citronelle ...... Louieiana. Poydras ......... New Orleans ... Houmti ......... Palnconrtville.. Franklln ........ Centerville. ....
-
8%W
-
71 68
67 62
45 E4 46 87 83 87 80 42 57 62
56 45 48 a5 41 27 61
I 68 61
63 86
30 47 8 I’ G9’
42 I
n 15 24 45 31, 87
90 I4 8
I 26
21 I9 I I
18 I9 8 8 1 1’ I9 I 33 15 29 !xi 88
48 28 I 33 45 21
Dr. J. O. Michael...
P. F. Rellmplo ...... R. E. Kerkam ...... Mrs.E.M. Haggerty. J. E. Le Blanc.,.. . J.M.Bonney ....... T. P. Boutte.. ......
-
9 8
-
72
M
66 61 I 54 46 81 I 39 43 44
67 114 50
45 44 36 41 29 51
67 48 69
34 8 43 32 29 BL1 88 8
81
I4 yo
46 &T
88 38 11
11
81 27 18
21’ 23 29 16
10 8 8 8‘
!a 23 82 15 23
Po
46 41 90 88
4ll 28
m
-
Dm
__
67 69
M 61 I 64
41 80 61
41 41 4a I 6Ll
44 I e 81
40 29
I
61 60 46
81
aa 40 31
29 67 37 38
81 18 11
43 M I 88 9 11
90 Po 18 I6 21 30 14 14 9 8 0 90 19
45 15 23 19 81
45 40 11
48 M
%z2
m
-
-
gum
-
810 172
188
181
115 162
137 98 169
117 134 134
169 1W 160 129 140 96 122 WII 168
186
Po1 1% 176 104 90
IN 93
84 2od
117 a1
92
42 61 188 88 59 91
35 8
83 82
67 66 70 85
48 49 I !M I 81 83
110 4 P 62 M
13Q 108
59 114
148 66
-
Sky near the snn, a. m.
-
8.W
-
35 48
43 49 26 88 27 .!xi 41
81 !H 44 44 40 32 I 88 Po 18 42
81)
45 86
48
89 88
39 80 17
4T a4 19
13 12
1H
Y 1-7 19
11 11 6
17 18 m
Po 19 16
14 4 6 1sd 19 I9 Po 7 17 81 11
14 13 11
24 31
14
in
-
8:m
40
-
40
47 48 Y 39 90 I
41
PI 23
I 44 44
116 8
I
ur 17
88
36 41 38
86
n 88
90 32 17 38 29 23
Po 11 15 88 17 22 14 8 10
18 18 14 13 19 81 18
14 3 7 0
17 19
n 7 14 17 7
I3 21 11 88
33 B
ai
-
B.W
-
40 43
40 42 I 89
88 19 49 88 I I 40 47 0 I 86 19 09 19
I
37 99 31
a0 I
I 88
81
17 85 98
88
SI 10
11 88 17 21 13 8 9
17 19 15
11 18 23 18
13 3 6 B 16 I7 PI 0’
12 16 18
13 I 8 M 81
I
116 131
188 1%
5v 110
85 a la R w 75 1y8
183 10
Bd 104 76 85
118
114 I S 98
108
sa 68 Bo 9Y 51 118 u4 BB
as 89 44
61 62
I n 96
I I 49 81
67
63 40 41
10
I9 I I
65
74 m 43 ffl 31
40 66
31 Ll8
98 61
m
m
-
lone day mlsslng. *Two days mlsslng. * Four days misslng.
An inspection of Table 3, pfrcentage of cloudiness, shows
that the conditions in the iiiterzor of Georgia aid Alnhnnin ‘~uely
better than in North Carolinn, South Carolina, or Louisiana.
TABLE 3.-Pmcmtage of cloudineaa bg &tea.
Name of the state. Qeneral Near the
I sky. I sun.
Judging from this table i t would be much safer-to locate
in central Georgia or Alabama, upon the southern end of the Appalachian Mountains, .where the track cro88e8 the elevated areas, than nearer the coast line in either direction, northeast-
ward toward the Atlantic coast, or southwestward toward the
Gulf Coast.
TABLE 4 .-A m g e elouditasss for Il~8 s e m l month of the year, a8 duiuced - f w m long aerids of obaemzlwns (scab 0-10).
Cape Henry Va... Norfolk. Vi.. ..... Ralelgb N C ...... Charlotie. N. C....
New Orleans. La..
To exhibit the average cloiidiness for these districts, as com-
piled from data extending over many years, Table 4 is added. It indicates that there is a minimum of cloudiness for May
in the South Atlantic and Gulf States, and therefore this season of the year is generally favorable for eclipse work.
An examination of the several days of the interval, May
15 to June 16, 1897, shows that days of cloudiness occurred from May 2’9 to June 9, the remaining days being generally
clear. An inspection of the daily weather maps for the same
period shows that from May 15 to May 29, areas of high pres-
sure persistently covered the South Atlantic States, giving
fine, clear weather; from May 30 to June 15, the high areas
were located in the northwestern districts of the United States, that is, in the Missouri Valley, causing low pressures
and lowering skies in the Southern States. Rain areas tended
to prevail in the Mississippi Valley, and also on the North
Atlantic coast, in which districts the conditions would have
been much less favorable for seeing the eclipse than in Georgia and Alabama. It is intended to repeat these observations dur-
ing the years 1898 and 1899, after which we shall be as well
informed as possible regarding the selection of the eclipse stations for the year 1900.
-0-
FORESTS AND RAINFALL.’
By Prof. H. A. H A l E l r (dated September 15,18R7).
Can i t be poseible that the cutting away of forests affects
the amount of precipitation in any locality 1 To many, no
doubt this question will seem easy of answer, but we find the results of study by no means reassuring, and recent investi-
gations have led to almost diametrically opposite conclusions,
depending, somewhat a t least, upoii the feeling of the writer. When we reflect that our rain storms are of very wide extent,
oftentimes over 1,OOO miles in diameter, and may take their
origin and bring their moistlire from distances of 1,OOO miles
or more, the thought that man, by his puny efforts, may
change their actioii, or modify it in any manner, seems ridic-
ulous in the extreme.
It has been well established that foresta have a most im-
Presented at the annual meeting of the American Foreatry Associa- tion at Nashville, Tenn., September 22, 1897.
396 MONTHLY WEATHER REVIEW. SEPTEMBER, 1897
portant bearing upon the conservation of rainfall ; that the
forest floor permits a seepage of water to the source of springs
and thus maintains their steady flow ; that they hold back the precipitation that falls, especially in the form of snow,
thus preventing or ameliorating the effects of dangerous
freshets. There is not the slightest doubt of their great im- portance to the welfare of man, but all these facts do not
.affect the question of their influence upon precipitation.
The following paper is prepared from the standpoint of a
meteorologist, and is an attempt to present facts.
Formerly, the historical argunient was a favorite one, I quote one of t.hese: “ It is a familiar fact that there are many regions
in Asia and southern Europe, once exceedingly fertile and
densely populated, that are now utterly sterile and desolate.
The country bordering 011 the Euphrates and portions of Tur-
key, Greece, Egypt, Italy, and Spain are now incapable of
cultivation from lack of rain due to deforestation.” The
most fertile of all provinces in Bucharia was that of Sogd.
Haid Malta Brun in 1836, “ For eight days we may travel and
not be out of one delicious garden.” I n 1879 another writer
says of this same region : “ Within thirty years this was one
of the most fertile spots of central Asia, a couiitry which, when well wooded and watered, was a terrestrial paradise.
But within the last twenty-five years a mania of clearing has
seized upon the people, and all the great forests have been
cut awayand the little that remained was ravaged by fire during a civil war. The consequences followed quickly and
this country has been transformed into a kind of nrid desert.
The water courses are dried up and the irrigating canals are
eplpty.” It has also been said that in the older eettled por- tions of New England and the Middle States there are arid hills and worn-out fields, due to the falling off of precipita-
tion from the cutting away of the forest growth. Such quo- tations and statemeiits might be made to fill a large volume.
Without more precise data as to rainfall it would be hazard-
ous to conclude that we have here a case of cause and effect.
It is certain that the fertility of these regions in ancient
times was due to stupendous irrigating devices and canals,
and when these were neglected, through wars and other un-
toward circumstances, the fertility necessarily ceased. It is
certain that there are ruins of enormous irrigating ditches and canals in Babylonia, where history indicates that there
was once a teeming population and great fertility, but where
now only a sandy desert greets the eye.
Some have said that where our densest forests are found there we have the greatest precipitation. There is no way
whereby we can see that such forests would have started un-
less favored by rainfall, so that the presence of the forest
rather indicated the earlier occurrence of practically the
smnie rainfall as a t present. Meteorologists are agreed that there has been practically no change in the climate of the
world since the earliest mention of ‘such climates. Plants
found in mummy cases in Egypt that were plucked thousands
of years ago show the same size as those now found in that land.
The “early and the latter rains ” are experienced in Palestine
to-day just as they were four thousand years ago. Jordan “overflows all its banks ” to-day, in February, precisely as it did in Joshua’s day. When we come down to recent times
and to the records of rainfall meaeured in New England for more than one hundred years or, a t least, before and since
the forests were cut, we find a constancy in the rainfall which shows its entire independence of man’s efforts. Right here
it should be noted that totally barren lands of any extent,
in New England for example, are to be found only in imagi-
nation. Eveu where the forest has been cut away mercilessly there springs up a growth of sprouts which covers the ground
and answers almost the same purpose in causing rainfall (if
there is any effect of that kind) as the forest. Even where land is entirely cleared of a forest we have a t times the green
pasture, and at others still heavier crops which leave the
ground anything but a sandy waste.
But the strongest argument adduced in the past to show
the influence of forest on rainfall has existed in a comparison between rain-gauge measures in the forest and the open field.
Such records have been made for more than thirty years in
France and Germany and surely we must have here, if any-
where, a sufficient proof of a forest’s influence.
Admitting that we have perfect instruments and careful
observers, there still remains a most serious doubt as tu the
immediate environment of each gauge and as to the possi-
bility of a direct comparison. It is probable that no two
gauges 2,000 feet apart can be placed so as to catch the same amount of rain, though to all appearances the exposure is
faultless in each case. This is plainly seen on the roof of a
building. For example, before the ofice of the Weather
Bureau was removed to its present location in Washington,
eighteen rain gauges were placed on the roof and one upon
the sod not 500 feet away. There was only one of the gauges
that gave the same rainfall in all storms as the one on the
sod. Some of the others gave more in some storms and some
less, but all of them in the total rainfall of eight months
gave less than the one which compared exactly with the sod gauge. In an early publication of rainfall records in this
country (not by the Weather Bureau, however,) two stations
are given, Marengo and Riley, in Illinois, not more than 3
miles apart, hut yet differing by 19 inches in the total annual
precipitation for several gears. I have no doubt that in the
latter instance one or both gauges were badly exposed ; but
enough has been said to show the extreme caution needed in
studying such records and the absolute necessity that exists in
obtaining a comparison between gauges that are not affected harmfully by their surroundings.
One of the best of all researches in this line has been con-
ducted a t Nancy, in France. Within a dist.ance of 5 or 6 miles
there have been four stations established. A t Nancy in the
open and a t Belle-Fontaine in the forest ; and, 500 feet higher
vertically, Aniance (open) and Cinq-Tranche& (forest). The latter stations are in a more hilly region and can not be com-
pared together, as can the former. At the lower stations we
have comparative observations for twenty-five years. I have summed these in three groups, containingeight, eight, and nine
years in each group. Fimt group, Nancy (open), had 31.16
inches, while Belle-Fontaine (forest) had 32.46 inches ; second
group, 33.39 inches and 34.07 inches ; third group, 30.05 inches
a d 2989 inches. We see that while the first eight years showed a very slight excess in the forest rainfall over that in
the open field, in the last nine years (including 1894, last
published) the open station showed a little more rain than the forest station. These observations were made with par-
ticular care, for the purpose of exactly determining the in0u-
ence, and may be relied on if the environments of the gauges
were comparable. At Amance (open) and Cinq-TrancheBs
(forest) the observations have not been quite so regular, thoiigh we have twenty-five full years of records at th6se two
stations, but not the same years as a t the other stations.
Amance shows 26.70 inches and Cinq-Tranche& (forest) 33.39
inches, or an apparent preponderance of 6.7 inches a year i n the
forest. This would. make more than 80 per cent greater in the
forest than in the open. It should be borne in mind, how-
ever, that these last two stations are on an eminence, and are
not striotly comparable, and this result can not vitiate that at
the two other stations, which shows no effect.
I n Germany we have a rather remarkable record of a slightly
different character. Lintzel is a station on the Luneburg
heath, which began to be planted with trees in 1887, a t the rate
of 1,OOO to 1,500 acres a year, and in a few years over 8,000 acres were covered. In the midst of this forest is the meteoro-
logic station in an open field of some 75 acres. Before plant-
SEPTEMBER, 1897. MONTHLY WEATHER REVIEW. 397
ing the forest 97 per cent of the surface was field, meadow, o
heath, and afterward 80 per cent was forest and 20 per cen
was roads, open field, and heath. Around this station, prettj evenly distributed, and within 60 miles, there are thirteer rainfall stations, which have been carefully established anc
presumably are comparable with the Lintzel station in thc
midst of the growing forest. There is no means of knowinl
whether any of these stations have been changed or not, bu
for our purpose we may consider the material homogenour
and treat it accordingly. Records from 1882 to 1896 (fifteer
years) are available. Charta were prepared for each yea] showing the ratio between the Lintzel record and that ai
each station of the thirteen. There is no space for theet
charts, but, in place of them, I give here the mean of 'all tht
thirteen station ratios for each year: 1882, 81; 1883, 83 1884,101 ; 1885,103 ; 1886,82 ; 1887,98; 1888,93 ; 1889,122 1890,97 ; 1891,100; 1892,90 ; 1893,96 ; 1894,142 ; 1896,128 1896,136.
These figures are extremely significant, and may be furthei
elucidated as follows : The smaller ratios show a less rainfal
a t Lintzel, or, these figures are the percentage of rainfall a1
Lintzel as compared with surrounding stations. It is impos. sible to determine whether these trees have reached the cul.
mination of their effect or not. I n 1896 most of them would
be seventeen years old, and the ground would probably be
fairly covered. It is a great pity that the environment Waf changed or some accident happened a t Lintzel so as to vitiatt
the three last' years. (An inquiry was sent to Germany re.
garding the error, but 110 response has yet been received.)
Tho record does not seem to show any appreciable effect upon
the precipitation; in 1884 the ratio was 101, while in 1893 nine years later, it was 96. It is probable that no definib
and unassailable result can ever be obtained either by the
method adopted in France or this later one in Germany
The rainfall ie so variable within a distance of even a mile
or two, and i t is so difficult, if not impossible, to obtain simi.
lar environments a t all the stations, that no decisive resull
can be obtained. It will be seen readily that the niultiplica-
tion of stations will do 110 good, and, above all, that the ob-
servation of rainfall under trees in a forest is absolutely uselese for any such discussion or study as this.
It seems probable that if two or three lines of statione could be established a mile or two apart on four sides of an
enormous forest, each line to have a dozen stations or so:
about 3,000 feet apart, four of the stations to be outaide of
the forest and the others each in a large, cleared space of at
least 2 acres extent in the forest, something decisive might
beobtained. It should be noted, however, that from the
evidence already accumulated there would be very little to he
gained by a further study of the question. It is certain that the effect, if there be one, is almost inappreciable. The favoring conditions over the foreet are balanced by those
not favoring and the integrated effect is practically the same
in the two cases. Prof. H. F. Blanford, of India, determined from a most
careful series of records, from which all known errors had
been eliminated, that the forest had a tendency to give 2 per cent more rain than contiguous open fields, That is, if an
open place had 50 inches of rain in a year a near by forest would have only 51 inches, which is practically inappreciable.
It would be an interesting study to select all those cases i n
experiments in forest and near by fields in which the wind
was blowing either from the forest to the field, or vice vema.
It is evident that if there is any effect on rainfall by the
forest, it would be vitiated if not exactly reversed by such
winds.
There is a class of visual observations which seem to show
an effect upon rainfall by the forest. Probably many have
seen heavy clouds passing over a plain, but which only pre-
REV^
~
cipitated as they passed over a forest. Also in a hilly region it is a frequent phenomenon that fog and low lying c l o d
hover near a forest, and not over an open plain. One also notes very often in passing into a forest on a damp day that
the trees drip moisture, possibly condensed from moisture
evaporated from the damp earth underneath. Obmrvations of
this nature, however, can not ordinarily be checked by instru-
mental means, but show in a general way that the foreat
tends to conserve vapor and moisture whichin the cam of the open field would be diffused into the atmoaphere. .
-- REPORT ON THE OPEFLATION OF THE MOUNT TAMAL-
PAIS STATION FOR SEPTEMBER, 1897.
BY W. E. HAYYON, Forecast O ~C h l .
The station is on a comparatively narrow neck of land
(about 8 miles wide) between the ocean and the Bay of San Francisco, and across the Golden Gate (entrance to Sen Fran-
cisco harbor) from San Francisco and about 13 miles dintant
therefrom. It is on a very abrupt peak, 2,692 feet high, at
the eastern end of a short range of mountaim running east and west across the peninsula. From the peak the surface
declines very abruptly almost to sea level on the north, east,
and south faces.
It is an ideal place for an observatory, in that nothing ob-
scures the outlook and because the point is above all disturb-
ing influences of local conditions and topography. A t San
Francisco wind directions and velocities are greatly influenced by the surrounding hills. Moreover, the intense heat of sum-
mer in the interior valleys of the State causes a most remark-
able indraft from the sea on snmmer afternoons and nights,
which more than half the time in such seasons is laden with
fog, and the latter either surrounds the observer or obscuree the sky a t the hours of observation. On fourteen out of the tweaty-
three p. m. observations which have been repeated to me from
the city a westerly wind exceeding 20 miles per hour has been
reported. On but four of these occasions has the wind at
this station reached that velocity, and three of these were
during a severe northwest gale, which occasioned a most un-
usual cold wave in the Pacific Coast Region. More then half
the time a t the hours of observation the valleys and sea below have been obscured by fog, but only on three occasions haa
the fog enveloped the peak. While the sky has been reported
obscured a t fifteen of the observations repeated from San Francisco, on only five occasions has that been the cam here.
It is believed that the conditions observed here am of
especial value to the forecaster. Rain has been recorded at
some of the stations in northern California on fifteen weather
maps. On fourteen of these occasions it has been preceded
from twelve to forty-eight hours on the mountain by high winds and gales, amounting to 360 miles or more per day, the
Force of the wind being in a measure proportional to the ex-
tant and severity of the storm. The one exception was a
trace of rain a t San Francisco, which was merely a mist pre-
:ipitated from a low cloud or fog entirely below the summit
If the mountain. With one exception there has been no
instaiice when the wind has reached a movement of 400 miles
per day that rain has not followed within thirty-six hours.
rhe exception was when t i gale on the 13th continued on the
14th and rain occurred on the night of the 13th and 14th. Another indication of rain which is especially observable
here is the unusual visibility of the air.
From this peak cumulo-stratus and cumulo-nimbus clouds,
which precede and accompany local showers in the valley,
:an be seen and their courses followed for 100 miles or more
it times when the smoke and dust of lower elevations would
ibscure them at much shorter distances. The dust and
imoke of forest fires usually ends quite abruptly a t about
1,600 or 2,000 feet elevation.