a00 MONTHLY WEATHER REVIEW. MAY, 19cS
1903-
1801.
--
3.3 3.3 6.9 6.3 3.3 6.9
1.8
1.1 1.7
3.3
3.0 a.8
40.9
a8.1 12.8
+0.34 -0.24
METEOROLOGICAL REGISTRATIONS IN SAMOA. 1902-1906. 11. RBINFBLL.'
1w4- 1805.
-_
1.6 3.5 3.8 1.8 2.9 3.9
0.8 2.0 0.7
3.1
1.4 1.5
a6.9
17.5 8.4
+0.23 -0.29
general dected the catch of the gage; occasional comparisoiii were made with raingages placed near by and the results were
in satisfactory agreement.
MONTHLY RAINFALL.
The separate montlis.
The following table, Table 1, gives for each month the durs-
tion, intensity, and quantity of rain, and summary of rainfalls.
Although the rainy season in Samoa is not so pronounced aa in some other countries, yet it is very distinct. This is especi-
ally true of the northern coast of Upolu where the trade win&,
during the clry season, come from a more southerly direction
and the north coast thus becomes the lee shore. During the rainy season the winds blow from a more northerly direction
and the north coast is then the weather shore. On the south
coast the influence of the wind is just contrary to the above,and
the two seasons are therefore inore equal. In order to contrast
the two seasons the months have been grouped under them so
that now the tables begin with November, the first month of the
wet season. The observations recorded embrace 4 wet and 4
dry seasons.
190$. 1906.
--
2.5
2.1 4.8 1.9
2
a.3 2.4 1.8 3.1 1.0 3.1
29.0
15.4 13.6
4-0.16 (-0.06)
By OTTO TETENS, Ph. I). Datad Rerne, Ssltzerland, March 9, 1'909.
INBTRUMENT.
The self-registering raingage was one designed by Professor
Hellman and constructed by Fuess. The receiving area is 200
square centimeters. There are two chambers, the upper one
of small diameter empties its contents by means of a syphon,
aa Boon as 10 millimeters of rain water have been collectecl,
into the lower and larger vessel. The larger vessel serves as a reservoir and the quantity collected therein is measured daily by means of a glass graduate. The upper chamber also con-
tains a float to which is attached a pen registering the height of the water (from 0-10 millimeters) on a drum which revolves
once in about 26 hours. Owing to the small diameter of the upper vessel, the scale of rainfall is highly magnified showing
0.1 millimeter. This instrument was erected at Apia in 5s
favorable an exposure as was possible. The surrounding cocoa-
nut palms, viewed from the raingage, did not exceed an altitude
of 45 degrees. It is difficult to say whether the palms have in
I For I. Winds, aee Monthly Weather Review, March, 1909, 37:93-5.
~
~. .
lax.
4.3
j.? ..... ..... .....
..... ..... ..... .....
..... .....
.....
..... .....
..... .....
84
161 140 60
107
37 80 84 69 44 41
89
83 131
19 ....
la8 ....
S4 137
15 ....
84 ....
78 .... na .... 13 .... 115 .... 66 .... 61 ....
a4 23 .... ....
ao
ao 14
222
118 106
+0.14
(-0.W
- __-
....
.... ....
....
.... ....
.... ....
~o n t b . Intensit Centimeters per 1 ,d r a i n minutes.
_.
wel reown.
November . December.. . January.. .. February.. Mamh.. ..... A d .. ......
Drg maon. May. ........ June ........ July.. ....... Augmt.. .... September.. October.. ...
Year.
Wet Beanon.. ~r y ~~o n ..
10 6 7 14 8 8
6 9 6 6 11 9
8.6
8.6 8.9
loa 113
174 148 94 168
m
74
1 .a ~
407
49 51 106
52
797
8s la6 127 46 64 69
34
a8
rw
aa4
69 84 43
26
479
66 j 79 57 93 66
89 ..... 72 ......
Bo ..... 71 ..... 59 ..... 88 ..... 47 ..... 39 .....
54 j:::::
8 9 a3
8 a4
7 17 7 6 6 19
20 a9 8
18 8 7 16 9 9
151
90
61
..... .....
..... .....
..... .....
..... .....
.....
..... .....
io 11
7
8.5
8.3 6.7
8 5
a 7 6 8 3 6 6
7 4
7.8
7.8 5.8
8
7 .... ....
Character: Wet maeon..
Dryaeamn..
;I (+0.03)' +o. 10. +o. IO -0.04 I -0.10 I -0.13
TABLE l.-Obseroed rainfall data for Apia, Stpion, 190246.
Months.
Duratlon.
Sumber of raiu days. Number of rain houra. Number of rain mlnutes (: 1,Mo).
--
1m- I 1903- 1803. lwu.
-.I-_
1903- 1903.
...
95 66 165
159 99 11s
88
57
85
7s 136
1.287
731 666
(+O. 131 -0.18
118
-- _-
1903- 1903.
-
2.1
1.7 5.4
5.2
4.8
8.0
a. 9
1. 2 1. 6 1.7 3.8
35.1
22.1 13.0
a. 7
(+O. 23 -0.28
-
1003- 1004.
-
1% 127
120 199
83 66
65
iaa 98
65
1.46a
9M
aoa aoo
1001- 1905.
__
23 24 23 16 19
19
7 11 10 13 10 14
186
I21 65
to. 1s -0.26
.~ ~
p3
30
20
as a7
a7
19 1" 13
1s
16 ai
ayI
146 99
+O. 18
-0.13
- --
19
14 53
21
16 20
15 17 13 17 17
212
113 99
( +O. 08 -0.11
ao
- -
Wet seama.
November ............................................. Dwamber.. ............................................ January. ............................................. February. ............................................. Ymh. ................................................ April.. .................................................
Yay. .................................................. June ................................................... July.. .................................................. A m .. ............................................... Beptember ............................................. October. ...............................................
Yew.
. Dry sewn.
Dry 52Mon.. ....................................... Wet &aeon... ......................................
Character: Drymason ............................................. Wet maeon.. ...........................................
---
I
936 I 1,015 I ....
.... -0.21 .... I
Rainfdla.
Quantity. Centlmeters.
~
I Rainfella of more than one hour's duration. Total number of rainfalls.
--
I ~ISOB
I
17 , 31 17 I 27 14 14 1:::: 48 I....
14 ....
18
-
10 I::::
15 1: ... s I....
9 ... 10 I....
193 ....
I 1aa I....
71 i.- +0.32 I....
(-0.34);. ..
. I- __- - --
1902- 1903.
-. -
78 49 113 117 S2 117
70
103 45 75 73 116
1.038
556 489
-~
1903- 1904.
-
1804- 1905.
....
6 12 10 10 16 16
a 'I 4 10 6 8
106
69 a7
1902 1903. 1903-1 1w- 1904. , 1905.
2.3
68 64 27 60
18
11 10
15
847
86
a8
:a
ai
aw
30
9 38 71 18 a7
12
7 10 18
297
191 106
a6
8a
17
28
38 14 22 21
1 15 6 13 10 5
186
137 49
+o. 33 -0.42
-
11 11 21
26 23
a7
a
ia
8 11 I4
6
186 747 I.....( 152
383 ..... ! 93 119 364 ..... 80 i 47
!
(+0.061' +O.26 +O.%
-0.14 -0.18 i -0.23 +0.13 ..... j ~+0.19) +0.35 (-0.02) ..... I -0.24 -0.28
I
(i-0.26: t0.44
--Oma2 I -o.34 -
+0.22 +0.28 ..... -0.83 (-0.17) .....
HAY, 1909.
14 15 13 17 16
MONTHLY WEATHER REVIEW.
71 1.7 65 2.1 68 1.3 98 2.5
70 2.0
201
2.3 2.8 1.8 3.2 2.3 2.5
3.2
3.9 2.5
1.6
rrCharacter of seasons dejned.-The total amounts for the
year and the two seasons give some interesting facts. The
character of the one season in comparison to that of thepre- d i n g and following one is here espressecl by a figure which is
obtained by taking the difference of logarithms for the season
in question and for the geometric mean of the two contigu-
ous seaaons. This definition of character does not apply to
the &st and last seasons observed as these lack either a preced-
ing or succeeding season; therefore the characterof such a
aewn has been derived by comparison with one season only
and its weight is 4. In the tables the figures representing this
character are in ( ) . Duration of roin.-The duration of rain bas been expressed
separately by the number of rain clays, rain hours, and rain minutes, for which the mean characters are 0.15, 0.20 mcl
0.24, respectively, showing that through the rain ininutes the seasons receive their most potent character. Rain iiateasity.-The rain intensity does not characterize the
8easons even as well as do the number of rain clays, the resulting
mean character by intensity being only 0.11. As the depth or quantity is equal to the product of cluration and intensity,
the character by quantity equals the sum of the %haracters
by duration and intensity. For this reason the quantity of rain is the most important elenient in characterizing the seasons;
the mean seasonal character by rain quantity is 0.35. The mean seasonal character by the number of rainfalls is 0.18,
but by those of more than one hours duration, 0.27. The dif- ferent rain features for the two seasons as observed at Apia for
eight seasons, when arranged according to their mean  char-
acters rank as follows:
1. Rain quantity.. ................................. 0.35
2. Rainfalls of inore than one hours duration. ......... 0.27 3. Duration by rain minutes.. ...................... 0 .a
4. Duration by rain hours.. ......................... 0.m 5. Rainfalls ......................................... 0.1s
6. Duration by rain day*. ........................... 0.15 7. Intensity ......................................... 0.11
rlfeaia srwsoirul rhurnrtr~.
A longer period of observation will undoubtedly change the
above averages, as the data for the single years vary greatly. In
54 70 43 61
I35
75
80
115 65
1.8
this respect the values of the individual months show the
greatest variations, but the seasonal and even the yearly totals
are likewise remarkable. If we consider only the last-named, the ratio of the largest and smallest of the four totals is 1.3, 1.6, 1.6, for the rain clays, rain hours, and rain minutes, and 1.3 and
1.9 for intensity and quantity, while the number of rainfalls
shows the extreme ratio 1.7 and the rainfalls of more than one
hours duration, 1.6. Thus the four years of observation have sufficed to determine fairly well the average rain intensity and the annual number of rain days, whereas it will require a much longer series of observations to determine equally well the aver-
age quantity. However, i t is well known that precipitation is everywhere an irregular element.
Avercrge for four years.
The average inonthly values of the precipitation features for
the four years, 1902-06, are given in Table 2. The seBsonal ratio is obtained by dividing the average for the wet season by
the average for the dry season. The logarithm of the seasonal
ratio is equivaleiit to the mean seasonal character.  The m&uirnuni and niinimuin values of the various factors here pre-
sented fall in various inonths, being found in all the months
esceptiiig November and December. It will be interesting to learn, if, after a longer series of observations is available, the same characteristics for each month which appear in the 24
coluinns of Table 2 will be essentially changed. In this respect Table 1 of this chapter throws some light upon this speculation
as the data for each month are given. Some months show decided variations, and i t may be safely expected that these
fluctuations will recur in later years. In order to show these fluctuations more clearly the quantity and duration char-
acters for each month have been calculated and these are given
in Table 3. As the division of the year into 12 months is an accidental one from a ineterological point of view while the rainfall is the basis
of the seasonal division, the meteorological character for the
single month cannot be expected to be as steady as is the se&
sonal character. The unsteady character of the single months
appears in Table 3.
4.1 4.8 3.3
4.8 4.9
1.7
TABLE 2.-.4vemp rainfall data, Nolvea~ber, 1902, to Odder, lOOG, nt Apia, Sawwa.
10 7.: 12 6.C
8 6.8
11 7.4 10 6.7
6 4.4
12 0.39 io 13 8 13 10 10
3.8 4.9 3.0 5.7 4.5 5.2
Duration.
~ ~~
Percentages. Rainfalls. I n t e d t y .
Centimeters wr
-
i
71
tY
- M
Fi
3
5
.n
a __
4.9 5.5 6.4 8.1 5.5 0.0
5.0 5.7 4.4 5.5 4.0 4.3
5.4
5. s 4.9
I. 2
-
.-
R a 5 ii 5
4
II
s -
65
64
73
64
74
46 49 43 55 57 56
59
68
50
1. 4
sa
-
Ralnfalla of more than 1 hours duration.
-
3
2
1.0
II
a .I
.-
on. 1.0
1.8 2. 0 1.4 1.1
0.9 1.1 0.6 0.7 0.9 0.9
1.2
1.4 0. Y
1.7
-
Averam ralnfall. Number of rainfalls.
4 3 s .
--
76 2.5 86 2.8 .117 91 3.8 3.2
Months.
Number. -
d
t a
3
-
rnin
31 3:
41 44
P I
3E 32 34
rl(i
$
at
a5
36 32
1.1
-
-
14 ;z
4 1
-
13 13 14 10 I 17
10 19 16 14 14 18
16
17 14
1. a
-
__
G
Q 9
& -
m. 0.29 0.23 0.33 0.46 0.88 0.29
0.20 0.23 0.18 0.14 0.28
0.27
0.28
0.32 0.21
4 I
!I k -
10 11 17 18 20 18
8 9
7 11 8 10
12
15 9
1.8
-
.-
3.3 3. s 5.8 5.7 4.5 6.8
9.2 2.9 1.8 3.4 2.7 3.1
3.7
4. s 2.7
1.8
-
Wet aeaaon. November. ............ Demmber.. ............ January.. ............. February.. ............ Ysmh.. ............... April.. .................
Dru *awn.
Y4. .................. June.. ................. July. .................. Aw.ut.. ............... bptamber. ............ October.. ..............
Year.
Dry maon... ...... wet B8BM)n. ........
&mnd ratlo *. .......
118

24 143 ! 25 101  23 149 I 26
1
152 i 2s
168 29 130 j 26
I lol 1.5  1 5  1.5 I *i
= mean Wet c mean Dry.
aoa MONTHLY WEATHER REVIEW. MAY, 1909
+0.11 +0.05 -0.04 -0.15 +O.M -0.22
TABLE 3.-Variatwns in quantity and duration oj rainfall at Apia, Samoa, ezpresmd by the respective characters.
I
+O. 13 +0.01 0.11 (+0.05) -0.04 0.15
.......... +o .u aoo .......... -0.04 0.18
.......... -0.04 asI .......... +o .~ asI
-0.12 -0.15
+0.20
+0.17 -0.31 +0.36
-0.14 -0.06 -0.01 -0.16
+0.32 -0.m
-0.07 +0.01 +0.30 -0.33 4-0.13 +O.a
-1.25 +0.79 -0.38 4-0.24 +o.OB -0.37
+O.%
+0.04 -0.03
-0.2s
+0.27 +0.11 0.18 (-0.05) -0.13 0.16
.......... +0.17 0.10
.......... -0.01 0.30 +0.54 , .......... -0.33 I ..........
I
-0.W 0.36 +0.37 0.30
Wel Mason.
November. ............................ December.. ............................ January ................................ February. .............................
April ...................................
Dry aeamn. Yay. .................................. June. .................................. July. .................................. August. ............................... September.. ........................... October.. .............................
Mmh.. ...............................
(S0.34, -0.48 +O. 20 +0.41
+0.42
-0.40 +0.43 -0.32 -0.09 +O. 03
+o. 20
-0.48
+0.04 +O. 07 -0.19 +o.u
.......... .......... .......... ..........
-0.25
+o.m -0.24
~
+o.w
0.m
a3p
ala am
Wet 1 DW enson. mmn.
43 22 30 22 52 12
Bo 9 49 11 45 13
48 10 40 15 36 I6 3.2 20
98 16 32 PI
yeear.
_-
3.9 3.8 4.0 4.1 4.1 4.3
3.5 3.7 3.7 3.6 3.4 3.4
5.1 6.0 4.7 4.5 4.5 4.a
2.4 2.4 2.6 2.8 2.3 2.6
7.9 7.3 6.8 7.7
Duration.
I-
Quantlty.
1902- 1803.
Month. 1903- 1904. 1904-
1905.
I-- --
(+0:08; -0.2s
+O. 25 +O. 13 -0.27 +O. 32
-0.28 +o. 20 -0.27 +o. 05
-a 16
+o. 20
-
-0.02 -0.13 +o. 11 +O. 16 -0.27
+o. 38
-0. I4 -0.20
-0. a5 +o. 18 +O. 03
-0. v2
-
-0.23 +O. 15
+o. 19 -0. a8 +o. 04 $0.46
-0.63 +O. 46 -0.44
+o. 29 -0. OB -0.12
+o.os I ..........
-0.23 1. .........
+O. 13 .......... -0.25 .......... 4-0.15 .......... -0.m ..........
-0.43 +o. 32 -0.31
+o. 04
+a 06 -0.12 I
From the column Mean Departures of Table 3 it can be
seen that the five months, February to June, are the most in-
consistent ones both in quantity and duration of rainfall.
DAILY RAINFALL.
/. &anfin& % o f dai& to&/.
% %
6 6
5 5
4 4
3 3
2 lam. 3 6 9 Noon 3 6 9pm.l 2
T-LE 4.- Daily rainfall pmwd at Apia, Samoa. Mean hourly vnlites, 1903-1906.
~
Duration. ran minutes.
I
Quantity. Thousandths of a centimeter.
IntenFdty. Thousandths of a centlmeter per ran Dllnute.
Year. Wet Bason.
-I-
0-1 a. m ...... 1-2 a. m ...... 2-8 n m ...... 3-4 a.m...... 4-8 a.m...... &el a.m. ....
5 7 a.m..... 7-88. m ...... 8-9 a.m...... e l 0 a.m.....
10-11 a. m.... 11-12 a. m.. .. Noon. 0-1 n. m ......
33 28 32 84 30 29
28
n 28 26
aa 26
27 26 10 32 37 38
31 27
31 244
28
m
8.0 7.0 7.4 7.0 6.5 6. 0
6.6 7.2 6.8 7.3 6.5 7.8
7.5 6.7
s. a 7.6 7.6 9.4
7.4 7.6 8.0 9.4 7.5 7.0
9.2 6.9 10.8 10.6 8.9 7.7
9.3 8.0 7.7 7.1
7.6
0.4 7.1
s. 8 6.6 9.2 8.9
6. a
6.9 7.1 3.9 8.4 4.1 4.7
3.9 6.3 5.9 7.3 6.5 8.0
6.6 6.3 8.5 8.7 6.1 10.0
2. Duration, % o f daily fohf.
% %
4 4
3 3
2 2
5 5
i-a 5. m ...... 2-3p.m ...... 3-4 p.m...... C1Ip.m ...... S-6 p.m......
5 7 D. m ...... 5.4 I 3.0 4.9 2.4
4.8 4.71 2.4 2.4 4.5 2.8
4.6 a.0 7-8 P.m ..... 8-9 p.m...... 0-10 p. m..... 10-11 p. m.... 11-12 p. m....
3. htensify, emper 1000 ran minutes.
Ct??. cm
10 IO
8 8
6 6
4 4
2 2. la.m.3 6 9 Noon 3 6 9 nm.1
In order to diminish the accidental fluctuations i t seemed
advisable to adjust the data of Table 4 by using the formula b=f (a+2 b+c), where a, b, c, are the originally recorded
falls of three successive hourly intervals, and b is the resulting
adjusted value for the second hour. After computing these the values for quantity and duration have been converted into
per cents of the daily totals, and thus the curves of fig. 1 have
been constructed.
It appears from fig. 1 that the duration presents the least daily fluctuations, they amounting to a little more than 1 per
cent. The durations for the two seasons agree very well, both
showing the typical maximum between 3 and 6 p. m. This is
also the time of maximum quantity. Evidently this maximum is caused by the daily temperature maximum which generally
throws the atmosphere into very unstable equilibrium. This
statement applies to Apia during the dry season only. In the wet season the northerly winds coming from the high seas favor
precipitation. The atmospheric radiation during the night
cools the upper strata whereas the lower strata are kept warm
wet season, dry season. --------..
64.
FIG. 1.-Rainfall curves for Apia, Samoa.
by the sea water. Thus a nocturnal unstable equilibrium is to be expected, especially during the rainy season, and owing to this fact the nocturnal rain maximum from 3 to 5 a. m. of the
wet season, as shown by the three diagrams, is not surprising.
Analyzing the results we obtain the following formulas ex- pressing the departures from the mean average:
MAY, 1909. MONTHLY WEATHER REVIEW. a03
....
~ ~
Grade of raln.
---
O... .................................................
1. w?liay: Wet season, 4 .3 sin ( 85+h)+0.7 sin (324+2h) Dry season, 4 .2 sin (195+h)+0.2 sin (395+2h) (1)
(3
Quantlty measured.
Unity=O. 1 mm. Unlty=O. 01 inch.
ti and leas ?4 and lesa
2. DwatGn: Wet seasonl=O.l sin (222+h)+0.5 sin (310+2h) (3)
~
Dry season, 4 .1 sin (116+h)+O.4 sin (35S0+2h) (4)
3 .................................................... 4 .................................................... 5 .................................................... 0 .................................................... 7 .................................................... 8 ....................................................
3. Intensity: Wet season,4.7 sin ( 82-h)+0.6 sin (358+2h) Dry season, =1.8 sin (195-h)+0.7 sin (166+2h) (5)
(6)
from 6 to 17 from 18 to 56 from 67 to 177 from 178 to 562 from 663 to 1778 from 1779 to 5623
These analytic formulas verify the previous statements. I n
Quantity and Intensity the first terms angular values agree
m y well, placing the daily maximum according to the thermal
hfluence. The second terms angular values are equal in aantity and Duration causing two maxima from 3b-4h, two
minima from gh- loh. These double daily periods of rain may be explained by the fluctuations in atmospheric pressure. The
lrwv phenomena are exactly opposite in phase. According to
formulas 1 and 2 the variation of Quantity is about 0.07 milli-
meters during the wet season and 0.01 during the dry season.
It must now be seen if these aniounts may be explained by the daily tropical fluctuations of the barometer. We have the
equations:
*-. .
dQ==c,. dt+Apdv, pv=RT, AR=c,- c,, where
dQ=the quantity of heat given to a certain quantity of air, c,=the specific weight (=0.238) of air at a constant
c,= the specific weight of air at a constant volume, 11.
A= the reciprocal thermal equivalent (1/427),
p-pressure (-760 mm.) u=volume.
R=constant of the gas (=29.3).
t=centigrade temperature of the gas.
T= absolute temperature (= 300 A).
pressure, p.
From the above equations we easily derive the following
ones :
pdv+vd.p= Rdt, dQ=C,dt+ARTdt- Atdp,
dQ=c,dt-ART.- - dP
P
The adiabatic condition gives dQ=O, from which we derive
ARTdp
CPP
By substituting the above given values of the different quanti-
ties in this equation the result is dt=0.114 dp,
therefore the mean daily fluctuations of the air pressure aniount-
ing to more than 1 millimeter cause temperature fluctuations of more than 0.1C. Saturated air a t about 25C. condenses
more than 0.1 gram water per cubic meter for a decrease of
0.1C. in temperature, or more than 100 granls per 1,000 cubic
meters. This quantity is equivalent to a precipitation of 0.1 millimeter over an area of 1 square meter. Although the air
is not always near the point of saturation, yet the quantity
ascribable to the daily barometric fluctuations is sufficient to
explain the above-mentioned daily amplitude of 0.07 milli-
meter. Since the rainfall is usually observed but twice a clay in the
Tropics, 6 a. m. and 6 p. m., it is of interest to figure the daily
and nightly percentage.
Percentage of day and night preeipulrtion, Apia, Samoa.
The result is as follows:
Period. I Night. I Day.
-_~
Year .......................................... Wet neamon. .................................. 48.5 Dry Beamon. ..................................
GRADES OF RAIN.
In reference to the rain quantity f d e n during certain inter-
vals of time, for example hours or days, a new gradation of
rain has been introduced. As the soil, plants, tanks, etc., are
unable to absorb more than a certain quantity of rain, the excess is obliged to overflow and thereby become useless.
From a practical point of view the usual additive scale seems
to overestimate the amount of rain falling at one time; and so
in order to find a niore adequate gradation a logarithmic scale
seemed the most satisfactory. The rain being subject to the physical sensibilities of mankind Webers law becomes appli-
cable which also requires a logarithmic gradation. Considering 0.1 millimeter as unity and 101 as the ratio of
quantities corresponding to two succeeding grades, the values
for whole grades are ...... .loo, lo*, lo, 102, lo, etc.
The limits of two succeeding grades are. . lot, 101, 101, etc. which equal.. ....................... .1.78, 5.63, 17.78, etc.
When i t is desired to convert these quantities into inches,
considering 0.01 inch as unity, the above figures are multiplied by 0.3937.
Hence Table 6 is derived.
which equal.. ............. 1 , 3.16, 10, 31.6, 100, etc.
fi 1 and a from 3 to 7 from 8to 22 from a3 to 70 from 71 to 221 from from 232 701 to to 8313 700
I n Samoa the rain falls in large quantities, and therefore it
niight be permissible in the original work to class falls of 0.1
millimeter and less in the 0-grade of rain; but in order that this method of classifying rainfalls may find application in dis-
cussions of clryer climates this Summary has classed precipita-
tions of 0.05 millimeter and less in grade 0, and 0.1 millimeter in grade 1.
Hourly rmh grades. 
This method of expressing rainfalls by grades makes it possible to publish on one page the hourly records of a self-
registering rain-gage for 12 months. As an example the wet and dry seasons of November, 1902 to October, 1903, are given
in Table 7.
Froni these 12 months of single hourly rain grades tables
S, 9, 10, and 11 are derived. Table 8 shows for each month the
number of hours characterized by each (grade. It appears that Lgrades 3-6 are the most frequent during the wet seuon,
whereas the average (grade for the rain hours is not very dif-
ferent for the two seasons.
Webers Law. Fechners Law, or the Psychephysical Law, may be for- mulated thus-The difference between any two stimuli is experienced as of equal magnitude, in case the mathematical relation of these stimuli remains unaltered Or, otherwise espressed: In order that the intensity of a
smsat.ion may increase in mathematical progression, the stimulus muat iiirrem in geometrical prograssion. It is also e r p m d by Fechner in the form: The sensation increases aa the logarithm of the stimulus. For example, If we can distinguish 16 os. and 17 oz., we shall we able to d& tin uish 32 oz. and 31 oz., but not 32 oz. and 33 oz., the addition being in eacf case, for example, 1/16 of the preceding stirnulus.--E~~l~cb diu Britaranica, 1888-91. Ninth edition. Vd. 24. p . 469. Art. Webers l%~.~
MONTHLY WEATHER REVIEW.
TABLE 7.-HoicrIy grades of rain ad Apia, Sanioa, 1302-1903.
MAY, 1909
WET SEASON. DRY REASON.
1902.
Nuv. 1
tl
11
16
21
26
Dec. 1
6
11
16
21
26
31 1m.
Jan. 1
6
11
16
21
26
31
a.m. 6 a.m. M.p.m. 6 p.m.
.................. .3..21 ..20.. 2..452 2 .... 2 ...... ..3.4. .... 3. 20 .......... ..................... 3..
43301. . .4. .............. ..2.. ...................
.......... 3. .. I ... ...... ...................... 13
........................
........................
9
............ ......I ...... .. .53. .................. ....................... a .1.20. ..... 3 5331.. ...... ........................
........................ ........................ ........................ ........................ ........................
...... ..35.. .15... ..... 4 ... 244 4231.5 1.41.. ,3243. 3.533. 33. ......... .4. . .2 ...... ..3331 .13443 5%. .. ..... 3 1..4.. 50..40 ......
............ 2 .... 5 43.1..
.... 30 1 .................
........................
........................ ........................
... 0.. .................. .13.. . 3.. ..... ,433 .... 1 . .... 1. .................. ........................ ........................
. .32. ................ .3. ..2.2. ...... 33.41. ...... .. .01. .................. ........................ ........................
........................ .............. l... ......
... .12 .%E31 222121 . .4543
033354 .......... .l ...... .................. .30...
........................ .......................
........................ ........................ ........................
........................ .................. .Ubi13
..... 1 3 ........ 3.. ...... ........................ ........................
........................ ........................ ........................ ...... .44421 O... ........
..... 2 533355 544444 3.22..
........................
........................ ........................ ............ ...... .42W 233. ........
........ ,331 ,3442. ...... .......... 22 10.. .... o... .. ,432 .4. ............... ...... a... ..... 3 . 2455
645432 ..110. ............
.... 53 .45424 43. .31 .O .. .. .... 3. 343 ... 333444 545641 148833 332100 10 .......... ........... 3 2 ........... ........ .23 ............
401134 44431. .... 5 31 .... 1. .13. . ,401. ............ ............... .?3. ......
..................... .42 ........................
...20. .oalZl
431.1. ......
...... ...... 30343.
...... ...... ...... ......
.................. .22321 1. .o .. ...... .. .01. ......... .20 ,23301 0 ..... ..333.
............ ..m. ..................
.................. .................. .................. .................. ................ 33.
190%
Feh. 1
6
11
16
31
26
Mar. 1
6
11
lli
21
26
31
April 1
0
11
I6
21
26
30
a.m. 6 a.m M. p.m. 6 p.m.
34. ..................... ........ .a. ........ .31
................ 1. ...... ... 233 3110.. ............
I .. .I . ...... .3?. ........ ............ .O .... ..41.3 0.. .31 ,144.. . .51.. .. .?. . 12.0.. ... .44 353855 432. .. ...... ..I223 454566 654145
........................
555686 554043 14.3443 0.23.0 13513. ... 525 555544 41.3115 551455 334.21 .35445 U343.2 3243.1 .3.. .. ,5431. . ,4331 1. .....................
..... 3 ..................
3. ...................... ....................... 3
........................
........................
........................ ... 4.. .... 45 ..... 1 ...... ........................ ........................ ........................
2 .. ... 4434.2 ... .o. ...... 4. .......... .w. ...... .............. .?2. ......
........................ ........................ ........................ ............ .I .......... ........................
.......... 52 434554 3.. ... .1.... .................. ......... 3.. ,32333 12241. 52313. 2.14.. 13 .... 442432 133243 31 ...... 4... .....
........................ ........................ ........................ ........................ .. ,313 . ..?.. ............
................ 3 .M... ,11433 4.121. ..32.0 2122..
.... 33 31.. .............. .......... 44 Y ..?.. ...... ........................
........................ ................... 24 .. 1
............ 4.. ... ,3345. ... .41 ....... ...05 440335 2..2.. ..................
.................. .o. ... ........................
........................ ........................ ........................ ........................
........................ .................. 135..4 40..33 343143 1.. .l. ......
.................. 321 ...
.................. ,451.. .. ,544 0. ................ ....................... 9
1. .... 313. ......... .14.5 551.. ... .O.. . .W.. .I .. ..
........................
....................... ........................ .................. 3 ..... ........................ ........................
........................ ...... ,2521. ......... .36 3?1..2 ......... 255 38.. .. .. .?53 ,33331 .... .3 . ,9.?.
.. .11. . ,3424 4158.. .22.. .
.33433 31.. ........ 30. .35 333. .. 2 E .O I... .... .353 .... 34 .. l... ..3444 5543.1 ... .2. ....... .3310 ,5321 444l.3 333345 544455 2.111.
........................ ................ 30 ...... ................... 2 ..... ........................ ......................
1903.
lay I
6
11
16
21
26
31
une 1
6
11
111
21
2s
uly 1
1
11
16
21
26
31
a.m. ti a.m. M. p.m. 8 p.m.
........................ ........................ ........................ ........................ ................ 1. ......
13 ................ 3 .....
...... .I .. ... .53,. .. .ll.
............ .11.. .......
........................
........................
........................ ........................ ........... 3 2 ..... 513402 341 ..... ..I33 O... .2 3210.4 1...1. ... 2.. ..... 3 1 .... 4
44 ... 4 131 ... 1. .?.. ...... ...a. 2.4 ...... 4.. 2 .... 2
..ao.. ............ 1 ..... ...... ,14100 21..34 54443. 1. ......................
.. ,020 .................. ........................ .............. .33. ,45444 434.33 E l .. ............. ........................
........................ ........................ ........................ ........................ ........................ ........................
........................ ........................ ........ 2 ... ...... 231.. . .... 1. ... .34 221 .... ..454  as.... ..................
........................ ........................ .................. 352... ... 1.. ..... 1 I?..!!. 33 .... ... 123 2 .................
........................ ............. ..52. 1 ..... ........................ ........................ .6?1.2 1 .... 0 .1.34. ......
.. .?S. ..... 1 ............ .90.. ... .99. 2. .451 ...... ........................ ........................ ........................
........................ ....... .341. .1.2.. ...... ......................... .................... .LO1 3 ........... .%3.5 223432
41533. 444333 445645 334553 244.3. ............ 34 ....
............. .lo.. ...... .... 11 01.22. .... 53 43 ....
......... 411 ........... 2
............ .3 .......... ............. .33. ....... .................. 3.. .la .23... 4 ......... 36 2.383.
... 1.. ,24432 34..*4 1.. ...
........................
.............. l... ...... .51.23 10283. .U.. ........ ........................ ........................
........................ ........................ ........................ ........................ ........................
........................ .................. ,120..
.... 0. .................. 02.423 2. ....... 33. .O. ... ........................ ........................ ........................ ........................ ........................ ........................
........................ ........................ ...... .2. ...............
.1.... 4 ................. ........................
........................
1903.
Lug. 1
6
11
16
21
26
31
ept. 1
6
11
16
31
26
ICt. 1
6
11
16
31
211
31
a.m. 6 a.m.M.p.m. 6 p.m.
...... 0 2 m 1 0 ...........
........................ ........................
........................ . ,2221 1 .................
........................ ........................ ........................ ............... .O. 42.431
34444. . 1.3. .............
.0...1 333353 .0.132 .... 0. 12.. .. .110.. ........... 4 .................. .2. .a1
. ,1311 .................. .I5445 350..2 2.. .........
................ 3. ...... ........................ ........................ ........................ ........................
........................ ............ .3 .......... .3...1 .. l... ............ ........................ ........................
...... 1..3.. ........... a 3 .... 1 ...................
2 ................ 3 ...... ...... 1.2100 3.. ... .Ha. a4 ......................
............ 2.4154 4 .... 1
51.. .l ..................
........................
........................
........................ ........................
.................. .3 ....
............... 1.. ...... ..................... 0.a
........................
......... 311 ... .05 Wl3.5 .l..lI ...... 0343.. ...... ........................ ........................ ........................ ........................
... 344 3 ............... a 2. ......................
........... 4 10. ......... ...... 33. ...............
........................
........................ ................ 2. ...... ........................ ........................ ........................
........ 3.. ............ .................. .3 .... 3.1..4 53.634 334554 5652.. ..0.1. ........... 1 2 1 ... 0 aol... ... 3.3 0 ..... 2 .....
........................ ........................ ......... 1.. .0...3 ......
.. I ... 32133. .42.1. m... ........................
1.1441 .................. ................ .I ,23244
441.. ................... ................ 1. ...... ........................
.... .O .. .24. . ,313. ,34663 344333 3421.. ..5554 220...
I ................. 22.44 13044l .43556 422312 3(321. ...0 3 . ...... ..30.2 ..... 1
5531..
. . 321
...... ......
...... ...... ...... l ..... .1..4.
53431.
......
...... ...... ...... ...... ..11..
.32l..
...... ...... ...... ...... ...... ...... .44.. .
... 0.3
..... 6
......
...... ...... ...... .. .3..
......
... 61.
...... ...... ...... ...... ...... ..... 2
... 13.
52 ....
......
......
...... ...... ...... ...... ......
4.. . .z ...... ...... ...... ...... ...... 430. .a
10 .... .I..).
... 21.
......
...... ...... ...... ...... ......
MAY, 1909. NONTHLY WEATHER REVIEW. 206
30to
59
-
17
TABLE %-The number qf hours each rain grade muwed at Apia, Swwa,
November, 1902, to Odober, 1903. A comparison shows that the number of ~ainfalls aa computed
by the grade hours, amount to about 4/10 of the number
obtained in the usual way, by counting by minutes. In all four
1 columns of Table 9 the rainfalls are divided into three groups,
viz, those lasting from 1-3, from 4-12, and more than 12
successive grade hours. The group 4-12h. gives the highest seasonal ratio in each of the four columns.
Table 10 gives the daily arithmetical totals of the hourly grades as given in Table 7, and this is summarized in Table 11
which shows the number of days characterizedbyvariouspups
of daily grade totals. The group embracing totals from 30 to
59 in Table 11 gives the largest seasonal ratio. The monthly averages and totals given in the last three columns of that table also bring out distinctly the difference between the two
Bot0
99
-_
2 0 1 0 5 0 2 4 3 0 4 1
1 0 0 1 0 0
4 1
2 3 8
5 6 3
0 1 1 0
8 ! 5 14 17
14
10 4 6
1;
253 13 145 10 10 482
pa 189
8 2 M 416 21 16
13
ow lQ4 17 12a 0 17b 10
h,! 1 18 11
Wdasawn.
Demmber ..... January. ..... February. .... March ......... April .........
ory 88a.son. Yay. ......... June .......... July. ......... August ........ Beptember .... Ootober .......
Year.
Wet season.... Drymaaon ....
Beasonal ratio.
17 8 8 10 7 10 15 7 10 5
16 6
13 7 18 0
14 12 13 11 11 0
153 100
09 40 85 54
Oe8 I O.g
277
1:
1
331 7 2 .m
1.6 I 1.5
16
18 13
1.4
1-3
146 57 111 93
73 124
85 112 76 63
7s :
h h 4-12
--
107
88
a00 251 142 240
109 lo2 46 112 64
Wet a w n . November December.. January. .... RIXUW....
... ..
18 45 2S 34 17 15 4 . -
7 i i 13 7 8 2 0 4 6 6 6 7 6 7 0 7 1 3 8 1 3 3 3 . . 14 1 7 1 3 4 ---
. 8 7 li . . 15 b 17 1 8 15 1 1 56 i i e s i s a i a i , 3 i 5 7 3 i i 4 3 8 8 6 .6 i l 8 a a i ,: 8 1 3 .. . i
2 8 2 1 8 li .j * - 6 1 9 1 2 3 15 2 . 4 4
uuwon.
May. June. ........ J* ......... A&.. ...... Bepternber 00~ber
.......... 1 7 .1 0 2 17 22 12 20 18 3 34 1 2 27 18 i i L
7 .8 l i i 2 6 0 i 6 3 i i :3 4 :: i i 6 15 4
i 2i 5 10 12 i :i . .a 0 5 18 .i i .a i G i 
.... 22 7 . i i 2 24 13 1 9 i :5 5 .a o 3 7 i 5 1 1 -
........ 3 . Za 11 ii 9 i . 35 52 ii i i 32 .. 5 . .1 2 i 1 6 7 3 2 .. .3 2
i 3 6 5 2 7 ai, i i e 3 0 1 i : i 6
................. 0 1 95 2.7 Mmber.. ................. 0 e6 2.2
Nawmber.
January. ................... FubNsry. .................. 10 159 3.1 Much. ..................... 0 99 2.6
Msy ........................ 0 88 2.2
July. ....................... 1 . 67 2.1
A m . 0 85 2.1 &pbmber. ................. a m 2.5 ootober.. ................... 4 186 2.6
I
wd E8lWOn.
4 I le6 2.6
A d . a iu1 2.8 ...................... Dry sea8on.
Jnne 3 112 2.6 ........................
....................
Year. 7473 I 112 237 I 283 I 272 240 I
W &m m .................. 3613 I 57 117 I 151 I 188 145 Dry mwn. ................
a880 I s I
120 i 13a 1 io6 95
b-ndratlo .............. 0.94 1.04 0.07 1.14 1.57 1.53
- -
Table 9 gives a summary of the time characterized by hourly
rain grades. Two or more rainfalls, in the usual meaning of that term and of the previous statistics based on rain minutes,
are now represented by one grade number unless their inter-
val covers the full hour and then a period appears in Table 7
of hourly grades.
TABLE g.-Frequency and i&nsityofrainf& of variOua dwatwna in grade
Ralnfslls (=Suoceaalve hours with ran).
hours. Apia, Samoa, 1902-1903.
seasons.
TABLE ll.-Nu& of dags having various totd k l g rain grades. Apia, Samoa, 1902-1903.
Number of daw with
I
10 to 29 >QQ
8 5 8 6 6
10
8 0 4 4 5 6
78
42 36
1. 2
0
0 0
0 0 0
0 0 0 0 0
0
0
0
0
.....
Intensity.
grade:
8Wrage hourly Sum of hourly .srades for falls
1aatlJl.S
Sum of houn
h h h 1-3 4-12 >12
---
hr8. h 8 . hrs. 58 37 0 29 36 0 52 75 40 44 78 35 33 62 14 57 77 14
4 3 4 5 0 63 38 21 39 18 0 37 48 0
40 26 13
276 j 215 ti5
L99;l.M 1.58
Number of raln- falb lasting
-
h
> 11
-
.... .... 3. a 3.0 2. 1 3.7
.... 3.0
4.2 3.3
3.5
3.5 3.7
D. 95
.... ....
.
h
>I3
-
0
0
128 138 38 52
0
8a 0 0
55 101
594
356 238 C!.l
1.50
-
h 1-3
-
2.5 2.0 2.1 2.1 2.2 2. 2
2.0 2.1 1.9 1.7 1.9 2.0
8.1
2.2 2.0
-10
--
h
cia
-
2. 0
2. 4 2.7 3.2 2.7 3.1
2.4 2. 7 2. 6 2.3 2.6 3.0
3.8
2.9 2.6
i. i a
Number of
hlg grades.
Wd mwn.
November.. . 38 Decemb er.... 19 January. .... 26
February.... 30 Marah ........ 21 Apd ......... 30
---
h 4-12
Daily rain grades.
According to a long established custom eye observations of rainfall are usually made but once during 24 hours, it therefore
seems advisable and of general interest to compare the daily quantities of rain with those of the hourly grades referred to in this summary. Table 12 gives the daily grades for the h t
two seasons observed.
From Table 12 the statistics presented in Table 13 have been
derived, showiiig that the two seasons are best characterized by the daily grade 6, grade 7 an&-8 happen too seldom and the
grades below 6 in the wet season do not predominate over the
same in the dry season. The monthly totals of the daily grades
give the seasonal ratio 1.3 which is only one-half of that given by grade 6, but still it is sufficient to characterize the two seasons in regard to the benefits derived from the rainfall.
7 5 12 11 8 13
Lhn mwn. May ......... Jnne ......... 7 1 July ......... 23 3 0
August ....... I 27 8 0 Bsptember 25 5 1 Ootoaa... :::) 41 1 7 , 2
Wet mason.. 56 5 31 4
TABLE lO.-Dadg withmelicd tOB& of hourly rain grodes d Apia. Samoa, 1902-1903.
~~
Day. 1 1 2 3 4 5 6 7 8 9 10 11 13 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 20 30 31
-- --
28-5
206 MONTHLY WEATHER REVIEW. . MAY, 1909
TABLE 12.-DaiZy rain grades, Apia, Samoa, 1 ~1 9 0 3 .
D a y ./ 1 2 3 4 5 6 7 8 0 10 11 12 13 14 15 16 17 IS 19 20 21 22 23 24 25 26 27 28 29 30 31
1  4
4 5 4 3  5
4 1 2
6 3
1 1g tion from year to year. Only the daily grades for the rain days do not show remarkable features, the individual monthly
D9 average of the wet season varying between 3.5 and 5.0, and for the dry season between 2.4 and 4.4. The averwe values for the Dry Modon.
Y a y .. ............ June ............... July. .............. Aug& ............. m m b e r ......... October ............
YW.
Wet mason ......... Dry mason .........
Seasonal ratlo ......
16 13 18 14 13 11
153
68 85
0.80
0 1 1 1 1 3 0 . 0 2
6 3 3 ; 1 2
1.00 1.17 0.47
1902-
1 m . 1m- 1804.
--
3.6 4.2 4.7 4.6 4.1
3.8
4.6 4.6 4.1 4.0 8.6 4.0 4.1 .......... 4.5 3.6 4.4 4.5 .......... 4.3 3.7 .......... 1. a
..........
I I
2.11 3.2 2 .2 , 3.2
2.41 .......... 2.3 ..........
2.9 i ..........
3.5 I ..........
2.7 2.5
3.3 3.1 9.8
3.2
4.3 3.6
4.6 4.6 3.8
6.0
4.3
4.5 4.7 4.6 4.8 4.7
2.6
9.2 .......... 2.9
.......... .1 .9
................. ..................
Dry msson... ...........................................
CkwaCleT:
Drymason ..................................................
Wet leason.. ................................................
2.1 1 2.0
I
2
0
2 6
3 .
5
f i l l a w n .
Yay. ....... June ........ July. ....... A@.. .... September.. Octokr.. ...
b 5 7
i
0 2 3
5 2
i
i
1
2 3
.. 6 -
4
4 - 3 2
4 4
TABLE 13.-Frequsncy of vati0lc-s daily rain pades. Apia, Samoa, 1902-1903. The same ratio, when computed from the hourly grades, is 1.5, whereas the ratio from rain quantities measured in the
customary additive manner is 1.8. It can safely be ex-
pected that a similar proportion will exist in other rain statis- I 4 - s tics. I Number of days havlng daily grade 
__
7
-
0 0
3 4
0
1
0
I 0
0 1 3
13
8 5
1.60
-
--__
4 i 5 1 6 I We4 amm.
November. ........ Deoember .......... 0 0 1 0 0
0 0 0 0
0 0
1
1
0
m
1 5
5 2
3
I 4 2
8
2 3
41
21 20
1.05
January ............ 8 . 0 0 : 2
February. ......... 0
Yamh ............. I til 0 April.. ............. 2
57 two seasons are 4.3 and 3.7 and characterize the seasonal dif-
ii ference very slightly. 3 3 3 2
3
29
15 14
I. 07
__
62 55 89 WIND DIRECTIONS AND RAlN.
877 For the year 1906 the wind registrations are quite complete,
491 and the statistics given in Table 15 have been obtained.
353 These percentages when divided by one hundred give the
1-29 respective probabilities. Thus i t appears that the tradewinds,
... during both seasons, afford a smaller rain probability than the
52 I 37
20 I 26
26
~
11
1.00  8.36
I .......
TABLE 14.-The m a n daity rain rrgradea for each wwnth of the period, Notwith, 19K?,-Decetnbsr, 1906, Apia, Sanwa.
For the rain days. For all days.
Month.
1902-
1903.
~
-
Wet m o n . N w s m k .. ............................................... ( 2.7
Dmnmber ................................................. ..I 1.6 Jsnuuy ..................................................... 3.4
February.. .................................................. 3.4 March ....................................................... 2.0
Aprll ........................................................ 3.3
Yay. ....................................................... 1.8
June ........................................................ 2.4 July. .......................................................  1.4
August ...................................................... ! 2.0
September.. ................................................ 1.9
i Dru ueaaon.
October ..................................................... 1 2.9
- . I.---)---- 3.3 2.9 4.2
4.3 3.1 4.2
2.2
1.5 1.8 2.2 2.4 5.0
2.6
3.3
3.3 2.5 2.5 2.4
0.5 1.1
1.0 1.6 1.4 1.6
2.0
2.8
1.3
+O. 24
-0.32
--
a. 4 3.9
3.2 3.8 4. I 3.6
3.9
4.1
3.6
4.2 .......... 3.1 4.2 .......... 3.8 I .......... I ::: 3.6 I .......... 3.6 3.5 .......... 3.4 , ..........
3 4 3.4 4:4 I 3.8
4 .1 1 ! 4.2 2.4 I .......... I 2.4 3.9 .......... 4.1
4.0
I .......... I 4.3
3.8 ..........I 3.1
4.6
::: 1
3.7
(+0.05)! +o.m -0.08 i -0.07 .......... ..........
MAY, 1909. MONTHLY WEATHER REVIEW. 207
1906.
Beyrdless of wind direc-)
U O ~. rain hours, per cant of all hours.
Group of wmds.
-. --
............
. .
............
average of all winds. During the dry season a much higher rain
probability is presented by the south to west-northwest winds,
evidently because atmospheric disturhances are accompanied by
these winds.
TABLE 15.-Wind diretiion and rafn.
Wet months. Dry months.
-~
14.7 10.9
~~
NWto ENEto S to
NE. SSE WNW
~~
I
SSE 1
WNW
wLnQ.percent of all wlndn.. 14.0 58.6 25.8
per cent Of 16.8 53.2 3.2 nln hours. .............. \
hours of h e special wind 17.0 13.3 13.3 Rain hours per cent of all
group .................... I
The northwest to northeast winds change remarkably from
one season to the other. During the wet season they are the
rain-bringing winds as they come from the high seas; but dur-
ing the dry season they are dry ancl therefore seem in fact to
be trade winds which are shifted by the sea breeze ancl come
from the north. -
8.3 89.8 2. a
4.4 6.8 S7.5
11.9 10.8 21.6
WEATHEB NOTES FROM PUERTO PLATA, DOMINICAN REPUBLIC.
By R.J. TOTTEN, U. S. Consul. Dated Puerto Plata. D. R.. August 14.1909.
The Tacajo Cacao ancl Sugar Company, whose banana
plantation lies at Sosua in the province of Puerto Plata, has
published'from time to time a series of weather notes. From these notes the following suniniary for the fiscal year, July 1,
1908-June 30, 1909, has been conipilecl.
The total rainfall for this period was 110 inches, distributed
88 follows:
TABLE l.-Mo?ilhZy rainfall at Pwrto Plnla, D. R., 1008-9.
I 1908. I1 1909.
1 I P I C h .9 .
July. ............................. ........................ 2O.W Augwt ............................ ...................... Beptember. ....................... ............................ I ;::: October ........................... ............................. 1.35 November ........................ ............................ 8.05 December ......................... ............................. 7.W
~ ~
The average monthly rainfall was 9.16 inches. The heaviest
rainfall registered in any one dag was 9.10 inches on Septeni-
ber 10, 1908. The highest temperature recorded during this period was
94" F., on July 12, 1908, the lowest was 62O, on January 19,
1909. The maximum and niinimum temperatures recorded in
each month follow:
TABLE 2.-Monlhly temperotrire exlretties at Piierto Plata, D. R., 190s-9. - . . . - . .
-- Max* I
1 W . i Mar. Min. ' 1 1909.
--I1
I OF. OF. 1 1 OF. OF _. ..
J&. ...................... I 94 77 1 1 January. .................
~
sl si Au@. .................... 80 February. ................. 80 70 Bentember ................. i ii I 73 ;I Mmh ...................... I s6 71
0 e -d ~~~. ................... i 7s 11 A ril ....................... 88 . 74
................. ' E I
76 d y . ...................... 87
~
74 November. Demmber .................. 84 72 1 1 June ....................... 87 ! 70
I I .- _- ... - .-.
The average mean temperature for the year was 79' F. The prevailing winds are east-northeast and are commonly
known as "Local Trades." Average velocity of wind 6 miles
per hour. The highest recorded barometer reading was 30.45 inches,
the lowest was 28.25 inches.
CHANGES IN THE MONTHLY WEATHER REVIEW.
In the issues of the MONTHLY WEATHER REVIEW for February
and March, 1909, we published in full all the pertinent parts
of orders issued by the Chief of the U. S. Weather Bureau,
outlining changes which he planned to make in the character
of the REVIEW beginning with the issue for July, 1909. At the beginning of the announcement in the issue for February
the following statement was made:
It appears from the following that those readers particularly inter- ested iii clinmalolo&al statietres should request that the REVIEW be con- tinued to their addresses; those who are more interested in theoretical and technical discussions of data should request that the Mount Weather Bulletin be sent thein in place of the MONTHLY WFATHER REVIEW.
It appears that there are many who have not read these no-
tices and outlines of prospective changes, and the Weather Bureau is still frequently requested to renew or add to its
subscription list recipients who apparently do not realize the
character of the new publications. Our readers are therefore informed that beginning with the issue for July, 1909, the MONTHLY WEATHER REVIEW will be re-
stricted to statistical tables of general climatological data for
the whole of the United BtateR. The relatively small amount of accompanying test will summarize the weather conditions
of the month in the different districts. It is thus evident that
hereafter the REVIEW will be of value only to those advanced students of climates, engineers, etc., who need detailed data
for their own discussion.
Few papers of general interest to teachers, except as related to climatology, will be published in the MONTHLY WEATHEB RE-
VIEW, and it is not probable that the publication will be of
Value to those public schools and high schools that have been
receiving it heretofore. These circles of readers must now turn to the editors of already existing journals to supply their
needs along those lines formerly met, perhaps, by articles in
the MONTHLY WEATHER REVIEW.
We may .here also take the opportunity to remark that the
scope of the articles appearing in the Mount Weather Bulletin
will be limited to technical treatments of subjects of advanaed
research. This will make most of the articles of that publi- cation also beyond the comprehension of the average pupil
of the above grades of schools, and make the Bulletin only
appropriate for the libraries of colleges and universities.-
C. A.
TORNADOES IN MISSOURI.
On April 29 a very destructive tornado passed through
Golden, Barry County, killing nineteen or twenty persons and
injuring about eighteen others. Property amounting to nearly $20,000 was destroyed within the village and probably as
much more along the route of the storm northeastward to Viola, Stone County, where two or three persons were killed
ancl nine seriously hurt. A number of citizens saw the ap-
proaching storm aid describe it as resembling the smoke of a
railway engine. It was not accompanied by rain or hail.
Nearly all the trees blown clown by the tornado fell in the
direction whence it came, the trees to the southwest being badly
battered and bruised as usual. Chickens were picked of their feathers and some were torn to pieces. It is reported that the
large amount of atmospheric electricity present increased the
difficulties of telephoning to Golden.
Another tornado visited Alton, Oregon County, on this same date, destroying most of the buildings of the town and killing
six persons.-C. A., j r .
TORNADO AT ANNISTON, ALA.
- .-
By W. F . CLARK, Asslatant Observer. Dated Annlaton. Ala., M a y 8,1900.
On April 13,1909, a t about 3 a. in., a small tornado traversed
Calhoun County, Ala., from southwest to northeast, passing