TABLE 8.-Monthly mean of the minima of temperature in Manila: 1885-1902.

[° C.]

YEAR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. age.

Aver

In Table 9 we begin to treat particularly of the oscillation of the air in Manila corresponding to each month and year for a period of eighteen years, 1885-1902.

TABLE 9.--Mean monthly oscillation of temperature in Manila: 1885–1902.

[° C.]

Aver

YEAR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

age.

1897.

8.9

8.1

1898.

1899.

1900.

1901.

1902.

10.2 10.4 9.8 9.9
8.1 9.3 8.1 9.2 8.5 6.9 6.8 5.4 7.9
7.7 9.0 8.8 9.6 8.1 8.6 5.0 6.2 6.7 7.7 7.1 9.0
9.6 9.6 10.4 10.7 9.6 7.7 8.0 6.3 6.4 8.3 7.9 8.1
10.6 8.6 10.7 12.0 10.2 8.7 8.5 6.7 7.1 7.6 7.7 9.1
8.6 9.9 11.4 11.4 9.7 8.3 6.4 6.3 6.9 9.6 9.8 10.1

7.2 6.4 7.2 7.0 7.8

7.3

8.4

In Tables 10 and 11 we give the mean of maximum oscillation, and in Tables 12 and 13 the mean of minimum oscillation, corresponding to each month and year, 1883-1902.

TABLE 10.-Maximum monthly and annual variation of temperature in Manila:

1883-1898.
[° C.]

YEAR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

Annual maximum.

TABLE 11.-Maximum monthly and annual variation of temperature in Manila:

1899-1902.
[°C.]

Annual

YEAR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. maxi

mum.

1899

1900

1901

1902

Average

12.8 13.4 15.0 14.6 12.3 12.8 9.8 10.3 11.2 12.0 12.5 12.3
15.4 13.3 15.1 15.5 12.5 11.8 12.1 12.8 10.2 11.9 14.3 15.7
14.4 13.2 16.2 16.6 16.0 14.0 12.6 9.2 12.5 12.7 11.6 15.2
12.9 16.2 17.0 17.0 14.1 13.6 12.0 10.1 13.5 14.2 13.9 15.4
13.7 14.0 15.5 15.9 13.7 13.0 11.6 10.6 11.8 12.7 13.1 14.6

15.0

15.7

16.6

17.0

16.1

These tables are intended to show the absolute variation of temperature during each month by comparing the absolute maximum and the absolute minimum for the month, and the highest range for each year by comparing the absolute extremes during the year.

TABLE 12.-Minimum monthly and annual variation of temperature in Manila:

1883-1898.
[°C]

YEAR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

Annual mini

mum.

6.2 6.9
6.6 6.3
7.9 7.7 5.0
8.1 7.2 7.1
8.8 4.3 5.8 2.6 1.5 5.4 1.1 2.6 2.9 4.7
6.6 7.4 5.6 2.3 2.6 2.9 3.2 5.6 2.1 3.7
6.3 7.1 7.3 5.3 4.0 4.0 2.7 3.5 3.2 5.1
6.2 6.7 2.2 1.6 2.4 2.8 3.4 2.9 2.2 5.0
5.6 6.5 5.3 3.1 3.6 3.6 2.0 5.5 3.1
5.5 6.5 5.9 6.7 2.7 2.9 4.5 4.1 2.5 4.7 4.4 5.0
5.8 8.0 7.6 6.9 2.9 2.9 4.2 2.7 3.8 2.7 6.0 7.2
3.9 1.9 2.7
2.4 3.5 3.8
3.3 2.2 5.6 8.2 1.8 5.5

4.4 6.5 6.7 4.3 2.8 3.9 1.6 3.0 2.1 1.8 1.8 4.6
4.8 4.5 6.2 5.9 3.2
5.2 6.8 5.2 4.4 6.4
5.9!

1.6

3.1 2.6 2.8 2.4 5.2 3.4 3.4

2.4

2.9 2.5 2.9 5.1

5.6 2.7 3.5 4.8 4.0

TABLE 13.-Minimum monthly and annual variation of temperature in Manila:

1899-1902.
[°C.]

Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

Annual mini

mum.

Table 14 presents an exhaustive account of the slightest changes of temperature in Manila.

TABLE 14.-Differences between the hourly means of temperature in Manila compared between themselves, and between the same hourly means and the monthly means.

[° C.]

An

HOUR.

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

nual.

18. m.

0-1 a. m.

2 a. m.

1-2 8. m Sa.m..

2-3 a. m.

4 a. m..

3-4 a. m.

5 a. m....

4-5 a. m.

68. m..

5-6 a. m..

7 a. m..

-1.93

-0.32

-2.20

-0.27

-2.51

- 0.31 -2.80

-2.0-2.2-2.4-2.5 -2.2 -2.0 -1.6 -1.5 -1.4-1.8-1.7 -1.8
-0.3-0.5 -0.5 -0.5 -0.4 ).30.2-0.2-0.1-0.8 -0.2-0.3
-2.4 −2.6 −2.8-2.9-2.5 -2.2 -1.8-1.7 -1.6 -2.0 -1.9-2.0
-0.4-0.4 -0.4-0.4 -0.3 -0.2-0.2-0.2-0.2-0.2-0.2-0.2
-2.7 -8.0-8.2 -3.4 -2.9 -2.5 −2.0 -1.9 -1.7 -2.3 -2.2-2.3
-0.3-0.4-0.4 -0.5 -0.4 -0.3 -0.2-0.2-0.1-0.3 -0.3 -0.3
-3.1 -8.4 -3.6 -3.9 -3.2 -2.7 -2.2 -2.1 -1.9-2.5 -2.5 -2.5
-0.4 0.4-0.4 -0.5 -0.3 -0.2-0.2-0.2-0.2-0.2-0.3 -0.2
-3.4-3.9-4.0 -4.3 -3.5 −2.9 −2.4 -2.2 -2.0 -2.6 -2.6 -2.8 -3.05
-0.3-0.5 -0.4-0.4 -0.2-0.2 0.2-0.1-0.10.1-0.1-0.3
-3.6-4.1-4.2 -4.5 -3.4-2.8-2.4-2.8-2.1 -2.7 -2.8-3.0
-0.2-0.2-0.2-0.2-0.1-0.1 0.0 -0.10.10.10.2-0.2
-3.4-3.7-3.8-2.7 -1.6 -1.6 -1.4 -1.4-1.2 -1.8-2.1 -2.5 -2.28
0.2 0.4 0.9 1.8 1.8 1.2 1.0 0.9 0.9 0.9 0.7 0.5
-1.7-1.5 -0.9 -0.1

-0.29

-0.25

-8.16

-0.11

0.93

-0.49

0.5 0.5 0.6 0.5 0.1 0.1 0.0 -0.1 -0.1
4.0 4.4 4.4 4.4 3.2 2.8 2.4 2.1 2.1
0.2 0.2 0.2 0.1-0.3 -0.3 -0.2-0.3 -0.3 -0.3 -0.2 -0.1
3.6 4.1 4.0 4.0 2.6 2.4 1.9 1.6 1.6 2.2 2.8 2.7
-0.4 -0.3 -0.4-0.4 -0.6 -0.4 -0.5 -0.5 -0.5 -0.4 -0.4-0.4
2.7 3.8 3.2 3.1 1.9 1.7 1.8 1.2 1.1 1.5 1.5 1.9
-0.9 -0.8 -0.8 -0.9 -0.7 -0.7 -0.6 -0.4 -0.5 -0.7 -0.8 -0.8
1.5 1.9 1.8 1.7 1.0 0.9 0.7 0.6 0.5 0.7 0.7 0.8
-1.2 -1.4 -1.4 -1.4 -0.9 -0.8 -0.6-0.6 -0.6 -0.3 -0.8 -1.1
0.4 0.7 0.7 0.6 0.3 0.2 0.1 0.1 0.1 0.1 0.0 0.1
-1.1-1.2-1.1-1.1 -- 0.7 0.7 0.6 0.5 0.4 0.6 0.7-0.7
-0.2-0.0 -0.1-0.1 -0.2 -0.3 -0.2-0.3 -0.2-0.2-0.4 -0.3
0.6-0.7 0.80.7-0.5-0.5 -0.3 0.4 0.3 0.3 0.4 0.4
-0.6 −0.6 -0.7 -0.7 -0.7 -0.7 -0.6 -0.6 -0.6 -0.7 -0.7 -0.8
0.40.6-0.6-0.6-0.5 -0.4-0.4 - 0.3-0.4 0.5-1.1 -0.5
1.0-1.0-1.1-1.2 -1.1-1.1 -1.0 -0.8 -0.8] 1.0 1.0-1.0
0.4-0.4 0.4 0.5 0.4 0.4 0.4 0.2-0.2-0.3 -0.3
1.8 -1.8 -1.5 -1.5 -1.5 -1.4-1.2 -1.1-1.0 --1.8-1.3-1.3
-0.8 0.8 0.4 0.3 0.4 0.3 0.2 0.3-0.2 0.3 0.3 0.3
∙1.7 -1.7 -1.9-2.0 -1.8-1.7 -1.4-1.8-1.3 1.5 -1.5 -1.5
-0.4-0.4 0.4 0.5 0.3 0.3 0.2 0.2 0.3 0.20.2-0.2

- 0.49 -0.67

-0.46

-1.61

-0.2

-0.34

-1.31

-0.30

-1.61

-0.30

Concluding this branch of the subject Table 15 presents a summary of the most important data about the air temperature in Manila for periods of twenty and twenty-two years.

TABLE 15.-Summary of the most important features of temperature in Manila.

1 These two values are the maximum and minimum during the period 1881-1902.

Plate I will illustrate the general movement of temperature during the year in Manila.

WATER VAPOR.

The other climatic element, as before stated, is the amount of aqueous vapor contained in the air. This is the cause of clouds and cloudiness, or rather, it is made visible by the clouds. It is also the real cause of the rain, and its amount constitutes the hygrometric condition of the atmosphere. We shall then treat here first, of clouds and cloudiness; second, of rainfall; third, of relative humidity; and finally refer briefly to the tension of the aqueous vapor in the air.

CLOUDS.

Cloudiness has a very close relation to temperature, and thus to climate, because of the direct influence it has upon thermic oscillation, upon the amount of radiation of heat, and also upon the hygrometric condition of the air; therefore it is closely related to that temperature which modern authors have called sensible temperature.1

The average cloudiness for each month in Manila as deduced from hourly observations for many years is as follows, the scale being 0 to 10, or from 0, clear sky, to 10, entirely covered:

Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec.

4.6 3.8 3.8 8.5 5.1 6.8 7.5 7.5

The mean cloudiness for the year is 5.6.

7.4 6.1 5.8 5.6

We shall furthermore consider cloudiness in the different parts of the day so as to present the distribution of clouds throughout the

"Handbook of Climatology" by Dr. Julius Hann, New York, 1903.