AW;i c-~:r~!n~~~ e I - - — I - CENSUS OF THE PHILIPPINE ISLANDS I -- BULLETIN 2 THE CLIMATE OF THE PHILIPPINES j DEPARTMENT OF COMMERCE AND LABOR - BUREAU OF THE CENSUS 1904 -;:: I {4 i W i Ti:4 /82J Em::.1^::: ~ ~ ~ ~: i Y ": rf. I I I I it:;. - F CENSUS OF THE PHILIPPINE ISLANDS: 1903 DIRECTOR GEN. J. P. SANGER, U. S. A. ASSISTANT DIRECTORS HENRY GANNETT, VICTOR H. OLMSTED BULLETIN 2 THE CLIMATE OF THE PHILIPPINES BY REV. JOSE ALGUE, S. J. Director of the Philippine Weather Bureau I P DEPARTMENT OF COMMERCE AND LABOR BUREAU OF THE CENSUS: 1904 momwomomm J \: 4 -a 0Xta aJiW) fiuIt tuil samuaoqroD W/, TABLE OF CONTENTS. Page. Introductory note........................................................ 5,6 Preliminary notes --------------- ----- 7-11 Latitude............................................................. 8 Altitude.................... 8 Altitude............. C --- — --—... --- —-. ----, --- —--- 8 Distribution of land and sea -... -- -. ---.. 8 Size, configuration, and orientation of the islands....................... 9 The proximity of mountain ranges.................................... 9 Composition of the soil..................................... 9,10 Vegetation........................................................... 10 The general ocean currents.......................................... 10 Special currents in the straits and channels............................ 10, 11 Temperature.. ---. --- —-. --- —. --- —. --- —-.. 11-24 Thermic conditions in Manila....................................... 18 Water vapor............-.......................... 24-48 Clouds.......................... -......... 24-26 Rainfall............................................................. 28-42 Relative humidity. 42-48 Monthly maxima and minima of relative humidity, 1883-1902..... 46-48 Movements of the atmosphere.................... 48-103 Surface winds........................................................ 48-66 Annual frequency........... 53 Prevalence of winds in Manila during two seasons.................. 53 Hourly, annual, semiannual frequency. 54,55 Normal average of the wind in different months of the year......... 55-58 Maximum and minimum daily velocity at Manila......... 58-60 Monthly distribution of the maximum and minimum annual velocities. 60,61 Hourly variation of velocity in Manila............................. 61,62 Winds which often acquire a greater force in Manila................ 62,63 Maximum hourly velocity in Manila...............................' 64 Monthlyannualand semiannnal average of frequency atspecified points. 64-66 Conclusions-........................... 66 Higher currents of air.................................................. 66-72 Direction of the clouds:............ 66-70 General circulation of the atmosphere at different latitudes in the northern hemisphere........................................... 70-.2 Extraordinary air currents........................................... 72-103 Depressions in low latitudes................................... 73 Depressions in higher latitudes.........................-........ 73,74 Effect oi these depressions........................................ 74 Baguios, or cyclones............................ 74-96 Number observed and their distribution........................ 74-76 Annual mean................................................. 76,77 Minimum distance of baguios from Manila..................... 77 Months in which occur those baguios most terrible and dangerous for Manila................................................. 77,78 Classification by direction..................................... 78 Relative frequency........................................... 81 Monthly distribution......................................... 81,82 Classification of paths of baguios....................... 82-96 Thunderstorms.........-......................................... 9-103 Monthly distribution of thunderstorms......................... 96-99 Relative intensity of thunderstorms in Manila............... 99 (3) 4 Movements of the atmosphere-Continued. Extraordinary air currents-Continued. Thunderstorms-Continued. Page. Monthly and yearly totals corresponding to the three groups of our classification ------------- ------ -- - 99, 100 Diurnal distribution of different classes of thunderstorms ---- 100 Orientation of the thunderstorms - --- -------- 100-102 Location of the different classes of thunderstorms ------- 102,103 General remarks —. -------- ----- —............-.......... -. 103 MAPS AND DIAGRAMS. Mean annual temperature- ------ - Colored map, opposite - 8 Mean annual rainfall ----------- Colored map, opposite - 28 Plate I. Annual variation of temperature at Manila, 1880-1902.-.. Diagram. 25 II. Annual variation of the efficacy of the sun's rays at Manila Diagram. 27 III. Annual variation of rain at Manila, 1865-1902 Diagram. 31 IV. Rain at Manila from 1865-1902, annual rainfall in millimeters.-. -............................... Diagram. 33 V. Annual variation of rain in various places of the Philippine archipelago, of the Antilles, and of the United States - - Diagram. 41 VI. Annual variation of the relative humidity at Manila, 1880 -1902.-... —..-.................. Diagram. 43 VII. Thermnic oscillation, hygrometric state, and nebulosity at Manila -........................ Diagram. 45 VIII. Annual variation of the tension of aqueous vapor at Manila, 1883-1902 Diagram. 47 IX. Annual progression of the winds at Manila. ---- -- Diagram. 49 X. Semiannual progression of the winds at Manila --- - Diagram. 50 XI. Annual variation of the daily velocity of the wind at Manila, 1885-1898 -- -- - ------—. Diagramn. 57 XII. General movements of the atmosphere at Manila.... Diagram. 67 XIII. General circulation of the atmosphere at different latitudes.- ------------ -—.. ------ - Diagram. 71 XIV. Monthly distribution of the baguios or cyclones in the Far East, 1880-1898 ---- ---------- --- Diagram. 75 XV. Cyclones of the Marianas or Magallanes --------—. Map. 83 XVI. Cyclones which recurve far from the meridian of Manila- - Map. 84 XVII. Cyclones which recurve near the meridian of Manila before or after crossing it -.- - -..... —... --- ——. Map. 85 XVIII. Cyclones of Formosa. ----M — ------— a --- —------ Map. 86 XIX. Cyclones which recurve in the interior of Luzon, or in the China sea not far from the island i — --------- --- Map. 87 XX. Cyclones of China, Tonkin, and Cochin China ------- Map. 88 XXI. Cyclones of China, Tonkin, and Cochin China, varied a little from Plate XX..... ---......-......-M —. Map. 89 XXII. Cyclones which cross to the south of Manila ---.. Mapl). 90 XXIII. Cyclones of the Visayas and Mindanao —. ---. —.- Map. 91 XXIV. Cyclones which recurve in the China sea between the 10th and 20th parallels north latitude, crossing first to the south and then to the north of Manila.. —.-. — - Map. 92 XXV. Cyclones formed in the China sea ----- ----- Map. 93 XXVI. Cyclones formed in the Jolo sea or the interisland waters south of Luzon ---—. ------—. ---..- Map. 94 XXVII. Monthly distribution of the thunderstorms observed at Manila, 1888-1897. --- —--—. ---. —....-. --- —- Diagram. 97 CENSUS OF THE PHILIPPINES: 1903. To those engaged in agriculture or commerce in the Philippines, the climatology of the islands has always been of great interest and importance. While the temperature, as indicated by the thermometer at the sea level, is practically the same throughout the entire area of the archipelago, the topographical features of the different islands, and the longitudinal direction of the mountains and hills with reference to the prevailing winds, have a marked effect on the amount of rainfall as well as on the duration of the rainy season. Therefore, while in provinces like Rizal, Batangas, Tayabas, and Bulacan there is a rainy season and a dry season, whose limits can be fairly well defined, there are other provinces, like Albay, Samar, and Surigao, where it usually rains at short intervals throughout the entire year, and where, as a consequence, the climate is more especially adapted to the cultivation of certain important crops than in other provinces. The prevalence of typhoons, or as they are called in the Philippines, "baguios," during the summer months, frequently with disastrous results to the shipping, has always been the cause of much apprehension to the owners of vessels and to shippers, but with the establishment of the meteorological department of the Manila observatory in 1865, and the systematic study of these storms, which was commenced by Father Faura, S. J., at that time, and carried on in later years by Father Algue, S. J., the laws governing their origin and movement have been so fully established that their progress, duration, and intensity can now be predicted with great accuracy, and timely notice of their approach be given wherever there is a telegraph station. For a history of the development of this very important public service, the reader is referred to the account in Volume IV of the report of the Taft Philippine Commission to the President, January 31, 1900. It is sufficient to say here that all important ports in the Philippine Islands now have weather observers who are in telegraphic communication with the central weather bureau in Manila, to which daily reports of the state of the thermometer, barometer, and the direction and force of the wind are telegraphed. The cable communication recently established with Guam, not far from which typhoons originating in the Pacific are supposed to form, will add greatly to the accuracy of the predictions and will admit of (5) far earlier and more timely notice of tlie phenomena which precede and attend their formation and movement. While the establishment of the Weather Bureau in Manila was primarily for the benefit of the Philippine Islands, it has proved of infinite service to shipping in all parts of the Orient from Singapore to Yokohama, froin which, and from intermediate points, telegrams from the masters of vessels are often received asking information as to the condition of the weather and the probability of encountering a typhoon in the passage they have to make. In addition to this, the approach of all storms is telegraphed from Manila to Hongkong, Macao, Saigon, Shanghai, and Tokyo, so that the apprehension in regard to typhoons, born largely of ignorance as to their probable consequences, has given place to a greater feeling of security, the natural result of knowing the direction which the vortex or center of such storms will probably take, the violence of the wind, and the probable effect of the storm at any given point within the area of depression. Any seaworthy vessel with a reliable master and one of Father Algue's barocyclonometers on board is in very little danger when threatened by a typhoon, no matter what its violence may be. The following interesting and scientific account of the climate and storms of the Philippines was prepared for the Philippine Census Report by Rev. Jose Algue, S. J., the Director of the Weather Bureau, Manila, whose tireless efforts in behalf of the Manila observatory and more especially the meteorological department, which now constitutes the Philippine Weather Bureau, and whose scientific investigations and improvements in the instruments used in observing and recording atmospheric changes and in indicating the probable path of the storms, whereby the storm center can be avoided, have made him the highest living meteorological authority in the Orient, and placed him among the foremost of the world's scientists. Portions of this paper have been published previously in the Report of the Philippine Commission for 1900. J. P. SANGER, J)irector. WASHINGTON, Ml(ay 11, 1903. THE CLIMATE OF THE PHILIPPINES. By Rev. JosE ALGU1, S. J. PRELIMINARY NOTES. The climate of a country is the complex of the average atmospheric conditions which have an influence upon organic life; therefore, an adequate study of the different elements which go to make up these atmospheric conditions would give a true idea of the climate.1 The more important elements which form the climate may be reduced to three, viz, heat or temperature; water vapor in its different forms, such as humidity, evaporation, clouds, and precipitation; and finally, the movement or circulation of the atmosphere, which includes the direction and force of the wind, cyclonic and noncyclonic storms, together with local and general storms. Atmospheric pressure is not, properly speaking, a climatological element, but, as it serves as an indication of the general variations of the climatological elements, strictly so called, a few words will be said occasionally on it, in so far as it has any relation to the above-mentioned elements. The Philippine archipelago is situated in the Torrid zone or within the Tropics. The climate is, therefore, generally speaking, tropical, although there are points in the islands where it can not strictly be so termed. The exceptions are due to the fact that there are so many causes which influence the climatological conditions of the archipelago, that the different islands, and even different parts of the same island, have meteorological values so unlike that they possess climates entirely distinct. Not only does the latitude affectthe climate, as the name " climate " itself seems to indicate,2 but also the altitude, the relative distribution of land and sea, the size and configuration of the island, the proximity of mountain ranges, the composition of the soil, the vegetation, the ocean currents-especially those in the straits 1 That the study of the climatological conditions be adequate, it is not sufficient to know simply the mean annual values of the elements, but it is necessary, also, to know the mean values for months and days in the various regions, together with the extreme values, and the maximum and mean oscillation. Over and above these data it is necessary to be cognizant of the circumstances which influence these values. 2 In its original and stricter etymological meaning the word climate (Greek K2ijla, slope or inclination) was applied to one of a series of regions or zones of the earth running parallel to the ejuator, from which the earth's surface was supposed to slope to the poles, hence the Latin rendering of KMUa, inclinatCio cceli. (7) I 8 and the channels-in fine, all those causes which can in any way modify the climatological elements already mentioned. Before speaking of these elements we propose to say a few words concerning the effects of each of the above causes in the different regions of the archipelago. Latitude.-Of all the causes mentioned above which have influence on the climatological elements perhaps the relative latitude has the least influence of all. For example, Zamboanga, in Mindanao, and Aparri, in Luzon, are separated from one another by more than eleven degrees of latitude, but although Zamboanga is much nearer to the equator than Aparri, it enjoys a climate quite as mild as that of Aparri, which is at the extreme north of Luzon. The same may be said of Jolo, Davao, Dapitan, and other towns of Mindanao in comparison with those of the north of Luzon. Altitude.-Altitude has a great influence on temperature, humidity, and direction of the winds in the islands. This may be observed by comparing the climate of the relatively high Baguio with that of the plain of Pampanga. Many other examples of the influence which altitude has qn the climate might be cited, such as the towns surrounding Lake Lanao, the altitude of which is 2,200 feet above the level of the sea, compared with the climate of the lowlands around Iligan bay; the climate of the highlands of Abra, Lepanto, and Bontoc, with that of the Cagayan valley; the climate of the rising land all along the ridge which runs from the river Pansipit to its western slope, with the plain of Balayan, although this rising ground is only 300 feet above the level of the sea. Distribution of land and sea. -The archipelago is situated between the Pacific ocean and the China sea, at a distance of some 500 miles from the Asiatic continent and about 1,000 miles from Australia. On one side of the archipelago is the lower limit of an immense area of high pressure wfich is caused by the cooling off of the air in the interior of the continent, and on the other is the western limit of the enormous area of high pressure situated in the Pacific. The first area of high pressure slowly changes its position during the course of the year from east to west and from west to east between the parallels 30~ and 40~ north. During the winter months the center of the Siberian high pressure area lends force to the polar wind currents, as well as to the northeast monsoon. The permanent center of the Pacific high pressure area, on the other hand, has some influence on the predominance of the east and the southeast winds, especially at the period when the monsoon dies away. It is also very probable that the distribution of land and sea in this part of the Far East is the principal cause of the nonexistence of the southwest monsoon in the archipelago, although it blows in the Indian ocean. We have had occasion to speak of this fact in other publications, where we have proved the nonexistence of this monsoon in the Philippines. ,~~~~~~~~~~~~~~~~~~~~~~ MEAN ANNUAL TEMPERATURE. r PHILIPPINE ISLAND& ME R~~~~~~~FEGIONS OF HIGH TEMPERATURE! DOIL INTERMEIQATrE DOX MILD lt' OF DO. COOL BECAUSE OF ALTITUDE..E~~~~~~~~~~~~~~~~1.= p ai, * V k Ja t=JU @LgJ 1 I I i I -1 'I i A I t. jgg~~~~~~~~~ -lb~~~~~~~~~~', 9 Size, configuration, and orientation of the islands.-The climatological conditions of the eastern coasts of the larger islands of the archipelago, such as Luzon, Mindanao, Panay, Mindoro, Samar, and Leyte, are quite different from those of the interior and western coast of these islands. This is especially the case if the islands extend from east to west, as with Mindanao, Panay, and Mindoro. If, on the other hand, the islands are not very broad and are prolonged in the direction north-south,.as are the islands Cebu and Paragua, then the difference is not so great, while if the islands are narrow, like Tablas, Dinagat, Ticao, and Burias, there is scarcely any difference between the climate of the interior and that of the eastern and western coasts, no matter what be the general direction of their prolongation. The climate of the smaller islands does not suffer any modification on account of the land, but is generally that of the region they occupy; thus, for example, Capul, Viri, Laguan, and Siargao have the general climatological conditions of the east of the archipelago, and the islands of Corregidor, Lubang, and Calamian, those of the western coast of the archipelago. The proximity of mountain ranges. —Mountain ranges influence the climate of a country by protecting the lower plains from the strong winds. Thus the Sungay range protects the fertile lands of Cavite from the destructive effects of the south and southwest winds. Manila is shielded from the strong southeast winds by the Tayabas hills, and the mountains Maquiling and Banajao. Again it is owing to the Zambales hills that the climate of the eastern slope and the plains of Pangasinan, Tarlac, and Pampanga is so different from that of the province of Zambales. tlTAL7F4t The well-known province of Benguet owes its salubrious climate and its abundant rainfall in July and August in great part to the fact that there is no high land on the east and south. The prevailing winds during the months of March, April, May, and June, on the table-land of Baguio, are from the west and the west-southwest. These winds bring with them the aqueous vapor with which they are saturated, and thus cause a moderate rainfall during May and June, which diminishes the temperature much more than could be expected from the height alone. Thus the same cause which helps to cool the lowlying plains in the western part of the archipelago during the months of June, July, and August, also contributes to the tempering of the heat in Baguio during the months of March, April, May, and June.' Composition of the soil. —The geological constitution of the soil is one of the circumstances which has the least influence on the climate, still it has some influence, for, as the radiation and even the calorific capacity is quite distinct in different soils, it follows that these two "See "Climate of Baguio, Benguet," pages 64-7,; 0 ~ ~~~~~~~~~~~~~~~~~~~~~~~e e 00 fff;0 A, fff o: 000ffAnd:::.0::0::f~f:0:::;0:\;:L:::000:.|ff:0:X:00: Heeer.:f 10 factors modify to some degree the general conditions of the climate. Thus, all other conditions being the same, the temperature of sandy soil will be different from that of clayey soil, which in turn will be distinct from the temperature of rocky or of soft soil. For this reason there is a considerable contrast between the temperature of Cavite and that of Marilao in the Bulacan plain, and between that of Manila and of Bifiang in the province of La Laguna, both of which places are situated at but a small height above the level of the sea. Vegetation.-In saying that the vegetation of a country has some influence on the climate, we mean it to be taken in the sense of amount of vegetation or the amount of land covered by vegetation. Vegetation in general has a very direct influence on the condensation of aqueous vapor as well as on the radiation of heat, and consequently can modify in a very notable degree the climatological conditions. The two principal elements which it modifies are the rainfall and the temperature; thus, for example, these two elements have somewhat different values in Atimonan, Daet, and Albay, owing doubtless to the conditions of vegetation in these regions. The general ocean currents. -If we look at a map of the isotherms of the world it will be seen that in many places they are irregular, and depart greatly from the east and west course which we would naturally expect them to follow. The reason for this variation is to be found in the course of the great ocean currents which cause the interchange of ocean waters between the equator and the poles, and thus cool or warm the surrounding land. There are two general currents which affect the zone of the archipelago. The one which extends from latitude 5" N. to 100 N. has great influence on the temperature of the archipelago of Jolo and the whole of the south coast of Mindanao. The other current, which in some respects is like the Gulf Stream, but much greater, comes fron the east in the Pacific and extends from close to latitude 100 N. as far as the northern extremity of the Tropics, that is, as far as 23~ N. This immense current inclines to the north on reaching the archipelago and then curves to the south of Japan and flows on from there to the east. As this current brings cool water, it tempers the heat of the eastern coasts, especially during the hot months, when the influence of the north monsoon has become a mininum-nthat is to say during the months of March, April, and May, during which months it is very probable that this current also contributes to the prevalence of the winds from the second quadrant. kSpeci'a ceurrents in the straits and channels. —Besides the general ocean currents, of which we have spoken above, there are also smaller currents in the straits and channels between islands, which are in part caused by the general currents. These small currents have much influence on the climate, as is shown by the climate of Zamboanga and the islaedA,@f3 issilan, which is modified by the currents of the Basilan e.e ' e,. 11 channel. Again, the climates of Aparri and the Batanes are influenced by the currents in the Balingtan and the Bashi channels, alnd the peninsula of Sorsogon and the north coast of Samar by the currents in the San Bernardino strait. Accordingly, as these causes, either individually or in various combinations, affect the different regions of the archipelago, the climates of these regions have different characteristics. These it is the aim of this paper to group and classify. TEMPERATURE.1 The temperature probably constitutes the principal element of a climate, which is considerably modified by the thermic oscillations, especially by the annual oscillation. This annual thermic chan.ge varies within the archipelago fron 70 C. on the Batanes tiad Babuyanes islands to 2-3~ C. in the southernmost parts of the Philippine group. It must be well understood that we speak of the variations of the mean monthly temperature, not of the extreme, which occur during the year. This oscillation does not, however, increase uniformly from theJolo group to the Batanes, but is distributed somewhat irregularly between these limits of the Philippine archipelago, as the following table shows: TABLE 1.-Annual thermic oscillation in the Philippine archipelago. Annual PLACE, oscillation Lattude (~ C ) (north). o t Santo Domingo, or Basco (Batanes islands)...................................... 7.0 20 28 Aparri (Cagayan, Luzon).....................5.......................... 6.5 18 22 San Isidro (Nueva Ecija, Luzon)................................................ 2 15 22 Tarlac (Tarlac, Luzon).......................................................... 5. 2 15 31 Surigao (Mindanao)..........................................4.6 9 9 47 Arayat (Pampanga, Luzon)................................................... 4.6 15 8 Baguio (Benguet, Luzon)....................................................... 4.5 16 35 Atimonan (Tayabas, Luzon)................................................... 4.3 14 2 Dagupan (Pangasinan, Luzon)......................................3 16 4 San Fernando (La Union, Luzon)................................................ 2 16 37 iloilo (Panay)...................................................................8 10 42 Legaspi (Albay, Luzon).......................................... 3...............5 13 9 M anila...........................................................................5 14 35 Iba (Zambales, Luzon)........................................................... 3.4 15 21 Capiz ( anay)......................................2..................9....... 11 36 Orm oc (Leyte)................................................................... 2.8 11 0 Cebu (island of Cebu)........................................................... 2.7 10 18 Davao (Mindanao) 2.2 7 1 Tagbiaran (Bohol).9 38 Tagbilaran (Bohol).............................................................. 2.1 9 38 From this table we learn: (1) That, generally speaking, the thermic oscillation increases with latitude; (2) that in equal latitudes the oscillation is less on the coast than in the interior. The variation on the peninsula of Surigao is remarkable, and probably due to the influence of the currents of the Pacific and of the Strait of Surigao. The difference between temperatures of the warmest and coolest To reduce degrees of centigrade to degrees of Fahrenheit, if above freezing poigt, multiply number of degrees by 9, divide product by 5, and add 32 to qU Oti&'eA., 'tus 100~ X 9-4-5=180~, and 180~4- 32=212~. J U; 12 months is an important climatic element, namely, the mean annual range of temperature. In order to give an idea of the distribution of temperature in the archipelago we have arranged the stations of the Philippine weather service into as many groups as there are different isotherms which affect them.:It is, however, not enough to consider merely the isotherms corresponding to the various stations to ascertain the mean annual range of temperature of each station. We must also take into account the mean daily variation of temperature found by comparing the means of the highest and lowest temperatures, which latter are called by some the ' nonperiodic amplitude of temperature."' In forming the following table only those stations have been taken into account whose elevation above sea level is less than 80 meters. TABLJ,: 2.-JMaximum 'idilrnal range of temperature att specijied stations, with location of isotherm, by months. JANUARY. Station. Iso- Maximum Ith- diurnal therm range ( C.). (0 C.). Station. Isotherm ( C.). Maximum diurnal range ( C.). Catbalogan................... Balingasag................... Isabela de Basilan............ Zamboanga................. Tagbilaran.................. Jolo.......................... Romblon.................... Tuguegarao.................. Daguplan.................... Bifi ng....................... Dapitan...................... Atinonan.................... Davao..................... Bacolod...................... Iloilo........................ Loon......................... Borongan................... Matasin....................... Cebu......................... Cavite........................ Surigao....................... Cuyo......................... Tarlac........................ Arayat....................... Balang...................... Cottabato.................... Marilao.............. Porac....................... Bolinao...................... M anila....................... Legaspi...................... Baler....................... Daet.......................... Capiz......................... Masinloc................. Magalang.................... Bayombong................ San Fernando (La Union).... Aparri.................... Candon................. Santo Domingo, or Basco.... Vigan.....................:_*~~~I 27 27 27 27 27 27 27 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 25 25 25 25 25 25 25 25 25 25 25 24 24 24 24 23 23 23 23 23 17.1 16.0 14.3 12.2 11.9 10.7 8.4 22. 6 17.0 16.0 14.1 12.5 12.0 11.7 11. 1 11. 0 10. 5 10.1 9.0 8.8 7.5 6.5 19. 1 18.0 17.4 15.9 15.7 15.3 14.1 14.0 11.3 10.8 10.0 9.1 14.3........... 16.5 14.4 14.1 11.0............ Isabela de Basilan............ Davao....................... Zamboanga.................. Loon....................... Dapitan...................... Capiz......................... (1uyo........................ Biilang....................... Arayat....................... Dagupan..................... Cottabato.................... Balanga................ Iba........................... Iloilo......................... Tagbilaran................... Bacolod...................... Caraga.................... Cavite................. M aasin.................... Jolo.......................... Surigao.................. Ceb.......................... Romblon................... Tuguegarao................ Tarlac........................ Marilno................ San Jose de Buenavista...... Manila...................... Porac........................ Tuburan.............. Bolinao....................... Atimonan.................... Corregidor................. Legaspi....................... Magalang.................... Bayombong.................. Olongapo........-.-.-.Catbalogan................. Calbayog.................... Aparri........................ Masinloc............... —... San Fernando (La Union).... Candon................... Borongan............... Daet.......................... Santo Domingo, or Basco..... 27 27 27 27 27 27 27 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 25 25 25 25 25 25 25 25 25 25 26 25 25 24 24 24 24 24 24 24 24 24 22 15.3 13.0 12.3 11.6 11.5 11.0 8.9 19.2 18.9 18.4 17.6 17.2 16.9 12.0 11.8 11.6 11.0 10.7 10.7 9.6 9.0 8.8 8.4 21.3 19.5 18.1 17.0 16.0 15.8 14.4 13.6 12.0 12.0 9.0........... 17.9 17.0 15.9 14.9 14.6 13.8 13.2 12.0 9.4 12.0 * * * nn "I an llHandbook of Climatology," page 13. 91~- I 0 * 13 TABLE 2.-Maximum diurnal range of temperature at specified stations, with location of isotherm, by months-Continued. MARCH. APRTL. Iso- Maximum- Maximum Station, therm drnal Station. therm dliual.. range (). range C.). (o C.). (~ C.). Dagupan....... Isabela de Basilanl..... Bolinao................ Iloilo........................ Dapitan...................... Tarlac..................... Arayat....................... Iba...................... Cottabato..................... Bacolod...................... Davao....................... Loon......................... San Fernando (La Union)... Cavite.................. Capiz................... Romblon............... Cebu......................... Cuyo.................. Magalang................... Tuguegarao................. Marilao....................... San Jose de Buenavista...... Balanga.............. Porac......................... Manila................... Calbayog................... Catbalogan................... Tuburan................... Atimonan.................... Indan....................... Tagbilaran................... Masinloc..................... Zamboanga................... Corregidor.................... Daet................. Jolo.......................... Candon..................... Vigan........................ Bayombong................. San Isidro................... Bifiang....................... Olongapo..................... Orm oc........................ Aparri........................ Borongan................... M aasin....................... Legaspi....................... Caraga........................ Surigao....................... Santo Domingo, or Basco.... 28 28 28 28 28 27 27 27 27 27 27 27 27 27 27 27 27 27 27 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 25 25 25 25 25 25 25 25 25 25 25 17.2 16.9 14.5 13.2 11.5 22.5 21.8 18.0 16.3 15.9 15.6 13.6 13.2 12.5 11.0 9.8 9.4 7.4 21.5 19.2 18.1 17.8 17.8 17.3 16.4 16.2 15.2 13.9 13. 12.5 12.5 12.0 11.2 11.0 10.2 10.2 22. 3 18.5 17.6 17.3 15.2 12.5 12.0 11.6 10.9 10.3 9.6 Arayat.................... Dagupan............... Cavite................... Tarlac...................... Tuguegarao............... Iba......................... Balanga..................... Bifiang................... Vigan..................... Dapitan................... Capiz........................ Bolinao.................. Iloilo........................ Marilao.................. Manila................ Porac........................ Catbalogan................. Bacolod..................... San Jose de Buenavista..... Davao...................... Tuburan.................... Corregidor.................. Tagbilaran................... Atimonan.................... San Fernando (La Union)... Loon.................. Romblon..................... Cebu.................... Candon...................... Magalang................... San Isidro.................. Olongapo.................. Calbayog.................... Isabela de Basilan.......... Aparri....................... Masinloc.............. Daet................... Zamboanga............... Gubat........................ Bayombong............... Ormoc....................... Borongan.................... Maasin....................... Santo Domingo, or Basco..... Caraga...................... Legaspi....................... Jolo................... Surigao................ 30 30 30 29 29 29 29 29 29 29 29 29 29 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 27 27 27 27 27 27 27 27 27 27 26 26 26 26 26 26 26 26 19.8 16.6 12.0 21.0 19.6 18.0 16.2 15.2 15.0 14.0 13. 9 13.6 13.1 18.1 17.3 16.6 16.1 14.9 14.8 14.3 14.1 13.5 13. 4 13.0 12.0 11.9 10.7 9.7 8.8........... 22.8 17.8 16.0 14.8 14.1 13.6 11.1 11.0 8.4 125. 12.6 12.3 10.9 10.4 10.1 9.8 8.9 14 TABLE 2.-Maximum diurnal range of temperature at specified stations, with location of isotherm, by months-Continued. MAY. JUNE. I Maximum Iso Maximum diurnal diurnal Station. therm dStation. therm rduma (0 ngo (O C.)._ rang(e I' ( C. (~ C.). (~O C.). San Isidro................. Arayat.................... Vigan................... Dagupan................... Iba......................... Iloilo...................... San Fernando (La Union).. Cavite.................. Tarlac.................... Tuguegarao................. Marilao............... Porac................ Bifiang................... Manila.................. Balanga................ Cottabato................... Bolinao................... Dapitan.................... Atimonan.................. San Jose de Buenavista...... Capiz......................... Romblon..................... Candon..................... Olongapo..................... Aparri...................... Tuburan.................... Isabela de Basilan........... Bacolod...................... Davao.................. Masinloc................ Tagbilaran................. Loon......................... Daet.......................... Cebu........................ Legaspi....................... Cuyo....................... Magalang................ Ormoc................... Calbayog................... Corregidor.................... Maasin....................... Caraga....................... Zamboanga.................. Santo Domingo, or Basco..... Gubat........................ Surigao.......-.........-. Bayombong.................. Borongan.................... 30 30 30 30 30 30 30 30 29 29 29 29 29 29 29 29 29 29 29 29 29 29 29 28 28 28 28 28 28 28 28 28 28 28 28 28 28 27 27 27 27 27 27 27 27 27 27 26 21.6 20.1 16.3 15.8 15.5 14.3 13.3 10.9 21.4 21.2 17.2 17.0 16.2 16.9 15.4 14.3 13.8 13.2 13.0 12.7 12.2 10.9 9.7 16.8 14.8 13.6 13.3 13.2 12.7 12.1 11.8 10.6 10.5 10.0 9.8 8.9........... 17.4 16.8 13.7 13.4 11.0 10.3 10.1 8.8 8.7 11.5 Tuguegarao.................. Tarlac........................ Arayat..................... Capiz......................... Dagupan................. Marilao...................... Vigan.................. Atimonanl............. Daet...................... Legaspi....................... Cavite....................... Biflang...................... San Isidro.................... Aparri................ Porac......................... Indan....................... Iba........- -...........-. Calbayog.................. Balanga...................... Tuburan................. Bolinao..................... Romblon.................... Palanoc............... Candon.................. Olongapo.................... Dapitan...................... Manila................ Cottabato.................... San Fernando (La Union)... Iloilo..................... Corregidor.................... Davao................. Santo Domingo, or Basco..... Gubat........................ Masinloc..................... Zamboanga............ Surigao...................... Cebu....................... Catbalogan................... Loon.................... Tagbilaran................. Bacolod...................... San Jose de Buenavista...... Isabela de Basilan.......... Borongan.................. Caraga...................... Cuyo........... — ----- Bayombong.................. Magalang.............. Maasin................. 30 30 30 30 30 30 30 30 30 30 30 30 29 29 29 29 29 29 29 29 29 29 29 29 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 27 27 27 27 27 27 27 27 26 19.8 18.1 17.9 16.2 15.3 14.9 13.5 13.4 13.0 12.7 11.3 11.2 19.8 35.8 15.4 14.5 14.4 13.4 11.7 11.7 11.4 10.4 9.8 8.8 15.7 14.2 13.8 13.2 12.7 11.8 11.5 10.6 10.4 10.3 10.1 10.0 9.6 9.4 9.4 9.3 9.1 12.1 12.0 11.5 11.5 10.6 8.6 4.......6. 14.6 15 TABLE 2.-Maximum diurnal range of temperature at specified stations, with location of isotherm, by months-Continued. JULY.. IsoStation. therm (O C.). Nueva Caceres.............. 29 Dagupan..............-...... 29 Atimonan................... 29 Capiz...............29 Iba.................... 29 San Fernando (La Union)... 29 Manila................... 28 Tuburan................. 28 Legaspi................... 28 Aparri................. —28 Arayat................. 28 Surigao...................... 28 M aasin....................... 28 Candon.................... 28 Vigan................. 28 Dumaguete.............. 28 Daet....................... 28 Tagbilaran....... -........ 27 Dapitan.....2............. 27 Bacolod..................... 27 Ormoc..-......... ------ 27 Ccbu.............2....... 27 Caraga..................... 27 Jolo.......2................ 27 Corregidor.................. 27 Magalang.................. 27 Bayombong................ 27 Zamboanga.................. 27 Iloilo......................... 26 Davao..2............... 26 AUGUST. SEPTEMBER. Maximum IS Maximum diurnal Station. thern diurnal range (o 0.) (rane. _ O C.. C.). (" C.). 13.7 13.6 12.9 12.8 9.5 8.0 14.2 13.5 11.6 11.6 11.1 10.2 10.0 9.2 8.5 7.9 14.3 12.8 12.0 10.8 10.4 9.6 9.5 9.0........... 1........... 10.8 Tuburan..................... Capiz....................... Nueva Caceres.............. San Fernando (La Union)... San Isidro.................... Atimonan................... Dapital................. Tagbilaran................. Caraga.................. Legaspi................... Surigao............... Cebu............. San Jose de BHuenavista..... M anila....................... Dagupan..................... Tarlac........................ Aparri................... Iloilo................... Bacolod...................... M aasin....................... Davao........... ---..-.... Magalang................ Jolo...................-... Zamboanga................... Arayat....................... Ormoc....-....-...-...... --- Dumaguete................ Candon-..................... Vigan.................... Bayombong.................. Cottabato.........-...... 29 29 28 28 28 28 28 28 28 28 28 28 28 27 27 27 27 27 27 27 27 27 26 26 26 26 26 26 26 2.6 25 12.2 11.4 14.4 14,2 13.9 12.9 12.6 11.9 11.8 11.7 10.3 8.3 7.8 14.3 13.6 13.5 12.6 12.1 11.0 9.4 9.0........... 12.3 11.5 11.4 11.4 11.2 10.6 9.5......... 21.7 Dagupan..................... 29 San Fernando (La Union)...i 29 Manila...................... 28 Aparri...................... 28 Atimonan.................... 28 Taghilaran.................. 28 Tarlac................28 Tuburan..................... 28 SNueva Caceres.............. 28 Legaspi...................... 28 San Isidro.................. 28 Arayat....................... 28 8urigao....................... 28 Maasin....................... 28 Capiz.................... 28 Daet.2.................... 28 Dumag etc................... 27 Caraga..................... 27 Dapitan..................... 27 Jolo................... 27 Ormoc........................ 27 Davao..................... 27 Cebu.............I 27 Candon....................... 27 Iba...............27......27 Vigan...................... 27 Zamboanga............ 27 Bacolod...................... 26 Bayombong.................. 26 lo0lo.............. 25 Cottabato..................... 23 11.7 9.5 14. 6 13.4 12.8 12.3 12.0 11.8 11.5 11. 5 10.5 10.1 10.0 9.7 9.6 13. 7 11.4 11.0 10.4 10.3 9.5 9.0 7.3 7.1 6.4 9.6 12.1 17.7 Corregidor.................. Dagupan.................... Arayat...................... Tagbilaran................. San Josde1e Buenavista...... Atimonan.................... Iba.......................... Daet.......................... Sa lsidro.................... M anila...................... Tarlnc...................... Vigan.................. Dapitan.................. lo ilo......................... Legaspi.................... Caraga....................... Tuburan................... Davao........................ Zamboanga.................. Bacolod...................... San Fernando (La Union)... Jolo......................... Maasin..................... Cebu......................... Capiz........................ Surigao....................... Candon........................ Ormoc........................ Aparri........................ Bayombong................ 29 28 28 28 28 28 28 28 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 27 26 26 26 13.3 15.0 14.4 11.3 11.0 10.7 10.3........... 15.3 15.3 14.8 14.4 13.6 11.7 11.5 11.0 10.9 10.8 10.7 10.6 10.3 9.9 9.6 9.4 9.4 8.9 7.9 12.1 11.6........... 23621 —No. 2-04-2 16 TABJLE 2.-Maximwrum dirntal range of temperature at speciJied stations, with location of isotherm, by months —Continued. NOVEMBER. DECEMBER. Maximum I Maximum Station. therm a grnl Station. therm ldiural (0 p ) lis c\,ranger (o C C.). (.) (0C) D)apitan...................... 28 14.8 Dapitan...................... 28 12.6 Taghilaran.................. 28 12.1 Da tipan.................... 27 15.2 Dagupal,..................... 27 15.5 Bolinao....... -....:-. 27 13.5 Aiayat....................... 27 15. 1 Atimona.................... 27 12.3 Cottabato..................... 27 13.3 Tagbilaran................ --- 27 12.2 Corregidor................ 27 12.8 Zaniboanga................. 27 11.5 Bolinto...................... 27 12.6 Caraga...................... - 27 - 10.2 Iba.......................... 27 12.2 Romblon.................... 27. 7 Atinioniani................... 27 11. 9 Cebu......................... 27 8.6 Zaimboanga................... 27 11.0 Jolo.......................... 27 Iloilo......................... 27 10.3 Arayat....................... 26 16.2 Cn1piz..................... 27 10 lb og............................ 26 - 13.8 Cnraga....................... 27[ 10.2 Tuburan.....1............... 2 13.0 Cebl....................... 27 10.1 Bacolod..................... 26 12.7 Di vao...................... 27 ' 9.9 Capiz...................... 11.8 Joilo......... 27 9.7 D ao.............. 26 11.0 o o.................. 27 8.0 Iloilo......................... 10.9 Manila..................... 26 16.9 Maasin......... '26 9.4 Fin Isidro.................... 26 15.8 Surigao....................:' 7.6 'T]rlhc.....e................... 26 ' 15.0 Manila....................... Vigtin.....26.................. 2 14.2 Tarlac...................... 25 17.0 (aibayog...............2... 26 13.9 Cottabato.................... 25 16.0 San Fermando(Lat Union).... 26 12.6 Ormoc....................... 25 14.8 Tuguegarim................. 26 12.3 Tuguegarao................. 25 13.6 San Jlose de 3Buenavista...... 26 ' 12.2 Legaspi................ 25 11.1 Bacolod...................... 26 11.9 CatldaO n................... 25 10.4 Legaspi..................... '26 11.2 Da t.......................... 25 10.0 Tnluburan.................... '26 11.2 Magalt ng.................... 25 Maasin..................... 26.10.2 2Aparri...............7.........: ' 24 - 12.7 Candon...................... 26 10.2 Corregidor................... 24 - 10.8 urigao.6...................... 26 9.2 Santo Domingo, or Basco.... 24 10. 6 Dact.................. 2 -7.9 Bayombong...24........... Magalang.................... 26..... Aparri........................ 25 13. 9 Ormoc.........7....... 25. 12.7 Bayombong............... 25... Some of the conclusions suggested by the preceding tables are these:. 1. Taking into account the general theranic aspect of the archipelago, the, period of greatest heat comprises the nonltlhs of April, May, and' June, during which the isotherm 30' pas5ses through several islands of the group. 2. Given equal elevations above sea level, the temperature is generally milder onl the coasts thati in the interior of the islands, especdially if they are of considerable dimensions. 3. The annual oscillation of temnperature, as exhibited by the tables, shows also that only north of the parallel of 180 north latitude there. is a pronounced difference between the extreme seasons of the year, viz, winter and suimmer. In the greater part of the archipelago lying south of +18~ this difference almost disappears. There are, however, three different thermic conditions met with in these regions. At some points the temlperature is rather high throughout the year, the annual variation being but small; at others the temperature is always sufficiently temper:te, varying only little during the ye'ar. Other places finally combine the characteristics of the two preceding classes, being 17 hot during one part of the year and temperate during the other; they have thus two seasons. There are consequently regions in the archipelago which we may call hot, others which we may designate as intermediate, and finally such as may be termed cool, or better, mnild, throughout the year. The first class comprises all places at which the mean temlperature of the hottest months reaches 30~ or 31~ C., without any great annual oscillation. The second class is formed by the parts of the archipelago whose mean temperature during the warmest months does not exceed 2?~ C., and which likewise do not show great annual thermic variation. The third class is made up of those regions in which the mean temperature of April, May, and June is not higher tharn 27~ C. The following list gives the regions belonging respectively to each of the three classes; I. Regions of higit temperature. The great valley of the Cagayan river, from Lalloc to the northern part of the province of Nueva Vizcaya. The coast along the provinces Ilocos Norte, llocos Sur, and La Union. The coast along the province of Zambales. The plains of Pangasinan. The eastern part of Tarlac and the western part of Nueva Ecija to the south of the Caraballo Sur mountains. The lowlands in the provinces of Pampanga and IBulacan. The bay of Bacoor (as far as the harbor of Cavite) and the south shore of the Laguna dc Bay. The northern coast line along Tayabas and Ambos (amatrines, also the southeast extremity of Luzon (except Sorsogon). The northern part of the island of Patlay and the Strait of Iloilo. II. Reg/dons of intermediate temperature. The peninsula of Bolinao. The portion of the province of Pampanga which borders on Zambales and Bataan. The highlands of the province of Bulacan. rThe province of Rizal. The northern and eastern parts of Bataan. Manila and its surroundings tpward the east. The island of Corregidor. The bay of Sorsogon. The west coast of Samar. The I lomblon gbroup of islands. The west coast of Negro1;. The west coast of Panay. 18 The island of Cebu. The west coast of Bohol. The peninsula of Zamboanga. III. Reguions of mild temperature. The east coast of the province of Sorsogon. The islands of the Strait of San Bernardino. A great part of the eastern Visayas-i. e., Samar (especially the east coast), Leyte, and the adjacent islands. The peninsula of Surigao. The east coast of Mindanao. The archipelago of Jolo. THIERMIC CONDITIONS IN MANILA. We shall now discuss particularly the most important features of the temperature in Manila, inasmuch as they can be applied to many other regions of the arch-ipelago, as, for instance, to the interior of Luzon south of Caraballo Sulr, or the provinces of Nueva Ecija, Pangasinan, Pamlpanga, Bulacan, Rizal, Cavite, Batangas, and to the other islands of the archipelago where the annual thermic oscillation ranges between 2.5~ and 40. Table 3 gives the mIean temperature for each month and year corresponding to a period of 20 years, together with the resultant mean normal monthly and annual temperatures. TABLE 3.-Mean monthly mtd antnuall temnqeratUres: 188-1902?. [~ (1.] YEAR. Jan. Febh. Mar. Apr. May. J1une. July. Aug. Sept. Oct. Nov. Dec. AverI'~ ' ' ~~~age. 1883................ 25. 27. 28.2 28.7 27.1 26.7 27.4 26.5 26.5 26.0 24.1 26.6 1884.......... 23.6 24.7 26.4 27.8 28.2 27.0 26.3 26.5 26.6 26.6 25.9 24.3 26.2 18K)................ 24. 24 6.1 27.3 28.5 28.3 27.3 27.1 27.6 27.3 26.4 25.2 26.7 1................. 2 25.2 28.3 28.5 27.5 27.0 '27. 27.1 26.6 26.0 24.9 26.6 1887................ 2 25.2 5.3 26.7 27.7 27.7 27.6 27.1 27.3 26.3 26.4 26.1 25.4 26.6 1888................ 24.9 25. 2 28.7 29.2 27. 26.1 2 27.6 26.3 26. 26.0 32 26.9 1889................ 25.8 26.4 27.5 29.4 30.3 28.7 27. 7. 5 27.1 26.5 24.9 27.4 1890................ 25.6 25.9 27.3 27.9 27.9 27.3 27. 3 27.4 26.5 26.1 25.4 25.2 26.6 1891............... 5.0 26.7 28.6 29.8 27.6 26.8 26.6 26.8 27.4 26.3 25.5 26.8 1892................ 25 6.0 27.1 28.0 28.8 28.1 27.3 27.0 26.7 27.1 25.8 25.0 26.9 1893................ 24.1 25.4 26.5 28.3 27.8 M27.7 27.3 7 26.6 26.5 25.7 25.4 ' 26.6 1894................ 21.7 25.0 26.6 28.2 28.0 27. 7 27.2 27.3 26.8 26.9 25.6 25.0 26.6 1895................ 21.7 25.1 26.7 28.3 28.0 27.8 27.5 27.1 26.9 27.5 25.8 25.1 26.7 1896................ 24.6 25.8 27.2 28.4 27.6 28.0 27.3 26. 4 27.2 27. 26.4 2.3 26.8 1897................ 25. 7 2 29.0 29.4 29.5 27.5 27.1 27.2 27.3 26.8 25.5 27.4 1898................ 25.5 26.2 26. 3 27.9 28.2 27.6 26. 7.3 27.2 26.9 26.1 25.7 26.8 1899............... 25.3 25.0 25.7 27.9 28.1 27.5 0 27.0 27.3 25.8 25.7 26.6 1900................ 27.5 28.9 29.8 28.3 27.7 27.4 27.5 27.2 26. 5 25.5 27.3 1901...............5. 25. 2 26.6 28.4 28.9 28.3 27.6 26.8 27.7 27.0 26.4 25.0 26.9 1902................ 4 24.0 26.7 28.1 28.8 28.2 27.2 27.0 26.7 26.8 26.1 25.8 26.7 Average..... 25.0 25.4 26.8 28.3 28.6 27.9 27.1 27.1 27.0 26.9 26.1 25.2 26.8 {-21~0-{ _I 19 Table 4 gives a comparison of the normal temperature for the year in Manila with the temperature peculiar to each month. TABLE 4.-The normal monthly means compared 'with the mean (annual temperature and with the extreme monthly means: 1883-1902. [o C.] MONTH. Norml onthly Normal mn monthly minus mean. me'n. EXTREME DEPARTURES ()F MONTHLY MEANS FROM NORMAL MONTHLY MEAN. January................................ February............................................ M arch............................................... April........................................... M ayu...................................... July...................................... A ugust........ —...........-..-..-...-.....-........ September.....-................. — --......... October............................................. November -..............-..................... December...................-..-......... Year............................... 25.0 25.4 26.8 28. 3 28. 6 27. 9 27.1 27.1 27.0 26.9 26.1 25. 2. 0 t- 1.5 +1.1 + 0. 3 +- 0. 3 +0.2 -+. 1 - 0. 7 -- L-4; Positive. 0.8 (1889) 1.0 (1889) 0.19 (1883,18. 1.1 (1889) 1.7 (1S89) 1.6 (1897) 0.6 (1900) 0.6 (1893) 0.7 (1901) 0.6 (1895) 0.7 (1897) 0. 8 (1888) Negative. 1.4 (1884) 1.4 (1902).) L.1 (1899) 1.0 (1885) 1.0 (1896) 0.9 (1884) 1.0 (1888) 0.7 (1896) 0.7 (1887) 0. 8 (18(9)) 0.7 (1890) 1.1 (1883)................ I I 26. 8~.... The extreme departures of the annual means from the normal annual mean were: Positive 0.6~ in 1889 and 1897, and negative (.6~' in 1884. In Table 5 there will be found the mollthly and annual lmaxima of temperature for a period of twenty years, and also the average monthly and annual temperatures during this period. TABLE 5. —Monthly and (tnnual malxima of air temperature i,, Manila: 1883,-1902. [~ C] YEAR. Jan. I Feb. I Mar. 1883............ 1884.............. 1885............ 1886......... 1887.......... 1888............. 1889............. 1890.............. 1891.............. 1892....... 1893............. 1894............. 1895............. 1896............. 1897.............. 1898.............. 1899.............. 1900.............. 1901....... 1902.............. 33.2 30.5 30.6 31.8 32.1 32.0 33.0 32.3 31.4 32.3 31.7 31.7 33.0 32.3 33.9 32.1 31.7 32.2 32.0 32.1 34.1 31.4 32.1 32.9 32.8 33.8 33.8 32.8 32.5 35.4 34.4 32.4 33.7 32.9 33.2 32. 5 31.8 32.3 31.8 31.9 32.9 34.8 32.5 33.9 33.2 33.7 35. 34.8 33.7 34.0 35.5 34.1 35.4 35.0 34.6 33.6 32.2 34.6 35.6 34.7 34.3 Apr. May..835.8 34.1:5.2 34.0 35.7 35.5 34.9 35.0 31i.0 35.8 36. 7 37.2 37.8 35.6 35.7 35.4 37.7 35.2 36.9 36.1 35.7 35.6 35.4 36.2 35.4 36.2 35.0 35.4 37.2 34.9 35.4 34.8 34.6 37.1 36.2 36.5 37.3 35.7 36.1.35.536.1 33.9 33.4 i35. 6 34.4 35.0 34.4 35.0 34.7 33.8 36.0 35.4 34.9 36.1 35.3 35. 6 33. 8 35. 2 36. 2 ~)35. 9 33.6 31.8 33.1 33. 2 33.2 33.0 33.5 33.1 32.8 33.4 33.8 34.9 33.9 34.4 34. 1 32. 7 31.5 35.0 33.9 33.3 32.2 31.8 33.3 33. 8 33.4 33.9 3:3. 3 31.1 31.9 13.7 33. 7 33. 4 32.1 31.7 32. 4 35.2 31.7, 2.2 33.0 Jlune..1 uly. Aug. Sept. 3.23. 32.10 33. 3 32.9 32.4:34. 2 34.2 33.2 32.3 32.1 32.2 13. 2 34.0 33.3 33.1 34.3 34.3 32. 8 345. 2:34. 4 Oct. 32.3:31.9 33.3 33.4 32.7 3:3.7 33.1 32.2 34.9 33. 3 31.7 3:3. 9 34. 1 34.4 32.9 33.2 33. 4:.3. 7 34.1 33.8 Nov. I )ec. 32.5 32.9 32. 1:12. 32.4 33.1 32.2 32. 2 33. 2 31.7 32.9 32.7 33.3 32.8 32.1 33.4 32. 7 31.7 31.1 32.3:31.7 32. 7 33. 3: 31.4 32. 1 31. 6 31.1 31.2 32.2 32. 3 33.2 31.9 31.7 31.6 31.4 31.8:33.1 Annual maximum. 35.8 35.2 ':5.7 35.5 36.0 36.7 37.8 35.7 37.7 36.9 36. 1 35.6 36.2 36t.2 37.2 35.4 35.0 37.1 37.3 36.1 Average.... 32.1 I35.0 33.5 33. 3 1:33.3 32.2 i 32.1 11 36.3 20 In Table 6 we give similar values for the extreme minima of temperature. TAnBL: 6. —Monthly and annual minima of air temperature in Manila: 1883-1902. [~ C.] YEAR. JtlIl. Feb. I Mar. Apr. 1883............. 1H84.......... 18.5............ 1886.......... l S^7............... 1888.............. 1889............. 1H0............. 1891.............. 1892.............. 1.893........... 1894............. 1895.............. 189.;............ 1897.............. s198.............. 189Y.............. 19X)(............. l 1.............. 1902............. Average.... 18.3 18.0 18.; 16.7 17.2 17.7 18.2 17.8 17.8 19. 2 17.2 17.2 18.3 17.3 17. (9 17.1 19.4 16.8 17.6 19.2 17.9 19.2 17.9 18.3 17.6 17.2 16. 1 20.0 2(. o 0 18.2 17. 2 18.(6 17. 8 17.9 18. 2 18. 3 18.7 18. 4 18.4 19.0 18.6 ( 15. 7 20.1 19.9 17.4 18.9 19. 9 19. 3 19.4 20. 5 18. 3 20. 7 18. 9 18.4 18. 2 18.2 ]/s. 3 i19.9 19.8 17.2 19. 5 117. 17.7 22.8 21.0 20. (i 20.7 21.1 21.4 21.1 21.9 21. 0 20. 7 20.7 2(). 4 18.9 21.0 19.8 22.7 21.0 20.2 21.; 19.9 18. 7 1.Y.7' May. June. July. 22.0 22.8 22.8 23.1 22.8 21.6 22.2 23.1 22.9 22. 8 22.8 22.4 22.3 21.9 22.8 22.8 22.8 22.3 23.3 22.8 22.8 22.9 22.2 22.4 22.6 22.2 21.1 21.7 22.9 22. 5 22.5 21.7 22.8 22.3 22.8 22. 9 22.9 21.6 21.6; 22. 9 23.4 22.8 23. 9 23.4 22. 4 23. 0 22.9 22.9 2. 3 22.2 21.7 "23. 7 23. 4 22.9 21.3 22.2 22.4 22.0 22. 3 21.9 22.7 22.6 22.4 22.8 22.2 22.2 21. 9 22. 2 23.2 22.2 23.3 22.7 22. 1 23.1 22.8 22. 6 20. ( 22. 3 22.5 22.1 22.4 22.5 22.1 22.8 21.9 22.9 22.9 22.2 23. 1 22.8 22. 5 22.2 21.8 21.7 22. 5 21.4 23. 3 23. 1 22.5 23.1 22. 6 22. 7 20.9 22.2 21.8 22.4 21.9 20. 6 21.7 22.9 20.4 21.2 21.7 21.1 21. (i 20. 6 21. 8 22.2 22. 7 21. 4 21.8 21.4 19.6f 21.0 19.0 21.0 20.7 21.2 21. 1 21.4 18.3 21.1 19.2 20. 8 18.9 18X.8 21.2 21.7 21.7 19.( 19.1 21.4 is. 8 Aug. Sept. t. t. Nov. )ec. 16. 7 17.5 18.4 19.2 18.3 17.7 19.4 17.8 19. 3 15.7 19.2 19.3 18.3 18.7 20.1 19.4 19.3 17.7 16. 6 17.7 18.3 Annual miniInum. 16.7 17.5 17.4 16.7 17.2 16.1 18.2 17.8 17.2 15.7 17.2 17.2 18.2 17.3 17.9 17.1 17.2 16.8 16.6 15.7 17.1 18.0 1 8.1 20.8 22.3 22.4 21.4 20.3 It is also very useful to know not only the al)solute extremes of temlperature, btlut also the meall of the extreme tmperatture of each nlonth and ye ar. In1 TalIle 7 we grive the mean of thernic maxima for each month and year duringl a period of eighteen years, and in Table,. the correspoI)onding mllinima. TABLE1 7. ---Monthl!! me()n17 of the maxima of f(ir temp)erature in Manila: 18&5-1902. [~ (:.] YEAR. 188............... 1886................ 18 7................ 1889............... 1889................ 1891................ 1891............... 1892............... 1893............. 18945................ 18956................ 1896............... 1898............... 1S9............... 1899................ 1900............. 1901............... 192................ Jin. 28.8 29.5 30.2 29.6 30.8 30.5 29.0 29.5 29.1 29.7 29.8 29.9 30.9 29.8 29.5 30.1 30.5 29. i1 Feb. 29.4 29. 5 30.3 31.0 31.6:31.1 30.0) 31.4 31.0 29.9 30.5 31.6 31.6 30. 9 29.7 30. 9 29.5 28. 7 Malr. 31.2 31. 6 31.8 33.2 33.2 32.9 32.1 32.4 31.8 31.7 32.1 33.0 32. (6 30. 6 30.2 32.6 31.9 32.1 Apr. ay. Jl. Jily. AugJ. Se-l pt. ' Oct. Nov. Dec. AverIage. I12 3.3 3.4 3. 0 30.2 31. 31. 6 29. 32.3 33. 3 32.4 34.4 35.1 33.1 33.9 33.5 33.9 34.0 33.5 33.8 34.0 32.5 32.7 34.1 34.3 33.4 33.1 32.4 34.3 35.8 32.9(3 35. 0 33. 9 32.1 33.0 32.0 31.3 34.1 32. 5 32.2 34..6 33.7 33.2 32.8 31.7 31.8 31.4 33.2 31.7 31.2 32.9 32.5 31.9 32. 2 31.8 33.4 31.2 32.1 32.2 32..2 31.8 30. 3 31.2 30.1 29.0 31.7 30.7 29.8 30.9 30.9 30.8 31.6 30.9 31.2 30.4 29.4 32.1 31.7 30.6 30.2 31.3 31.4 30.1 31.0 31.4 29.6 31.4 30.8 30.9 30. 8 29(.1 30. 5 29.7 30.0o 30.6 3 30.0 29.7 31.3 30.5 29.2 31.7 31.7 29.6 29.6 29.8 29.7 30.3 29. 9 30.6 31.4 30.9 30.6 30.9 29.7 31.6 30.7 30.5 31.0 31.1 29. 8 32.1 30.9 30.2 30.9 32.2 31.0 31.0 30.6 31.1 31.1 30.4 31.5 30.4 30.1 29.9 30.9 30.2 29.6 30.4 29.7 29.6 29.8 30. 4 31.5 31.0 29.4 29.6 30.6 30.2 30.8 29.8 28.7 30.7 30. 6 28.4 29.6 29.5 29.2 29. 3 29.0 30.0 30.5 29. 6 29.9 30.5 29. (6 29.5 30.6 31.0 30.9 30.9 31.4 32.0 31.1 31.0 31 3 30.9 31.0 ' 31.3 31.2 31; 8 30. 7 30.7 31.6 31.2 31.0 31.2 Average -..... 29. 30.5 32.1 34.6fi 33.3 32.1 30.7 30.5 30.5 31.0 30.2 129.7 21 TABLE 8. —Monthly mean of the mininmt of (/ir temtp)(rature in Manila: 1885-1902. [oC.] YEAPR. Jaln. Feb. Mar. I Apr. I May. Jlune. JJuly. Aug. Sept. Oct. Nov. Dec. 1885................ 1887.......... 1 87................ 1888........... 1889...................... 1890....... —........ 1891................ 1892................ 1893............... 1894...-.. —. —.. --- 1895.............. 1896... —......-. --- 1897.. ----......-.1898..............1900....-.......-.-. 1901................ 1902.. -- -—. --- 20.5 21.1 20.8 20.6 21.4 21.5 20.7 21.6 19.5 20.1 20.2 19.8 20.7 21.7 21.8 20.5 19.9 21.0 20.0 20.3 20.5 19.5 21.6 21.2 19.9 21.3 20.1 20.6 20.2 20.6 21.2 21.6 20.7 21.3 20.9 18.8 21.4 21.4 22.5 22.4 22.1 22. 2 21.4 22. 5 21.5 21.9 21.8 22.0 22.8 22.5 21.4 22.2 21.2 20.7 23. 0 24.0 23. 2 23.0.23.8 23.5 23.3 22.8 23.2 23.0 23.2 22.7 24.1 23.3 23.1 24.4 22.3 22.3 23.2 24.2 i24.6 23. 8 24.2 24.9 23.9 24.6 24.1 24.1 I23.8 24.4 24.3 25.2 24.0 24.1 25.0 23.5 23. 5 24.6 24.1 23.8 24.3 24.7 23. 7 23.9 24.0 23.7 24. 0 24.3 24.5 25. 3 24.3 23. 5 24.6 23. 5 23. 5 24.1 23.8 24.3 23.7 24.1 23.8 23.7 24.0 24.0 23.8 23.7 24.1 24.0 23. 6 24.4 24.1 23.2 23. 2 24.0 23.8 23.7 23.7 24.0 23. 6 23.8 23.3 24.2 24.0 23. 8 23.8 24. 1 21.3 23.8 24.3 23. 3 23.4 24.0 24.1 23.6 23.9 24.0 23.8 23. 9 23.7 23. 4 24.7 24.0 24.0 21. 1 23. 5 24.2 24.2 23.8 22.8 23.6 23.5 22.9 23.4 23.8 23.1 23.2 23. 23.2 23.3 23.3 23.9 24.0 23.7 23. 22.8 22.8 21.9 23.1 22.1 22.9 22. (i6 23.4 21.7 22.8 22.4 22.0 21.9 22. 2 23.2 23. 2 22.7 22. 5 21.0 21.4 21.7 21.8 21. 9 22.0 20. 8 22.2 21. 6 22.0 21.5 20.9 20.7 22.3 22.0 21.5 21.5 20.4 20.5, Average. 22.8 22.9 22. 8 22. 8 23. 3 22.7 22. 8 22.9 22.6 22.7 22.6 22.7 23.4 23.1 22. 9 23.1 21.9 22.8 Average —.. 20. 7 20.6 21.9 24.2 24.1 23.:9 23.8 23.9 23.3 22.5 21.5 In Table 9 we begin to treat particularlV of the oscillation of the air in Manila corresponding to each month and year for a period of eighteen years, 1885-1902. In TTables 10 and 11 we give the mean of nmaximum oscillation and the mnean of minimum oscillation corresponding to eachll nonth and year of the eighteen-year period, respectively. TABLE ().-eaen mnontldy oscillation of air temperature in Manlila: 1,85-1902. [~ (.] YEAR. 1885....... 1885................. 1886....... 1887............. 1888................ 1889................ 1890.............. 1891.............. 1892............... 1893............... 189................ 1895................ 1896................ 1897................ 1898................ 1899............... 1900... 1901................ 1902................ Average..... Ja.il. 1)111. 8.3 8.4 9. 4 9.0 9.4 9.0 8. 3 7.9 9.6 9. 6 9.6 10.1 10.2 8.1 7.7 9. 6 10.6 8.6 9.1 Flebi). Mar. 9.1 t9.8 9.2 10).2 9.8 9. 3 11.5 110.8 10.0 11.16 9.9 10.7 10.1 10.7 10.1 9.93 10.9 10.3 9.3 9.8 10.3 10.3 11.0 11.0 10.4 9.8 *9.3 3 8.1 9.0 8.8 9'.6 10. 4 8.6 10.7 9.9 11.4 9.9 10.2, 9.3 9.3 9.2 11.4 11.3 9.6 / 10.6 1 10.7 1 10. 7 11.0 10.3 11. 1 9.9 9.2 9.6 10.7 12.0 11.4 I May. 9.2 8.5 8.6 10.1 10.9 9.0 10.4 9.8 8.0 9. 2 7.6 7.0 8.9 8.5 8.1 9.6 10.2 93.7 Junle..iuy. Alg. Sept. 8.2 7.6 8. 0 7.1 8.5 8.0 7.3 8.9 8.8 7.9 7.9 7.3 8.1 6.9 8.6 7.7 8.7 8.3 6.2 7.4 t 5.8 5. 3' 7.6 6.9 6.1 6.9 6,9 7.0 7.9 6.8 7.2 6. 8 5.0 8.0 8. 5 6.4 6.3 6C. 2 7.5.7.7 6. 4 7.0 7.8 5.8 8.1 6. C; 6.9 7.0 5.3 5'. 4 5.2 6.2 6. 3 6.7 6.3 6.6 7.3 6(. 4 5.6 7.8 7.7 5. 8 5.7 6. I 6.3 5. 6 5.9 6. 5 7.2 7. 9 6.7 6.4 7.1 6.9 O(ct. 8.0 7.2 7.6 7.6 7.3 6.7 8.9 7.3 7.0 7. 6 7.1 i 7. 0 6. 9 7.7 i. 3 | 7. I; 9. 6 Nov. 7..3 7.3 7.0 8.3 6.8 C). % 7.9 7.6 7.3 7.1 7.8 8.5 9. 3 7.8 6.2 7.1 7.9 7.7 9.8 7.7 1De). 8.4 7.0 8.93 8.7 6.4 8.8 7.3 7.6 7.3 7.5 9.1. 9.8 7.3 7.9 9.0 8.1 9.1 10.1 8.2 A verage. 8.1 8.0 8.1 8.6 8.7 8.4 8.2 8.4 8.3 8.3 8.6 8.5 8.4 7.6 7.8 8.6 9.0 9.0 10.4 9.11 8.0 C6.i 7.7 8.3 22 TABLE 10.-Maximum monthly and annual variation of air temperature in Manila: 1883-1898. [~ C.] Annual YEAR. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. maximum. 1883.............. 12.9 12.9 13.2 13.0 10.9 10.0 9.8 94 9.4 10.0 11.0 10.7 13.2 1884.............. 11.3 11.1 11.9 11.8 10.8 9.0 8.6 8.8 9.3 93 9.9 10.3 11.9 1885............. 11.2 13.5 14.3 12.7 11.6 11.0 8.9 9.6 9.4 9.8 10.2 11.1 14.3 1886............ 11.9 12.0 12.1 12.3 11.1 10.2 10.9 10.0 9.3 11.2 11.8 11.1 12.3 1887............. 13.4 13.7 12.6 12.5 11.6 11.1 9.3 11.0 8.4 11.1 10.5 12.1 13.7 1888.............. 11.5 13.9 13.4 13.2 13.0 9.4 9.2 8.4 10.9 11.0 10.7 11.3 13.9 1889............. 13.4 12.5 14.0 14.3 13.0 12.2 10.2 10.6 10.6 95 10.8 10.6 14.3 1890............ 12.8 12.7 13.4 12.8 11.4 11.5 10.2 10.7 9.3 10 7 11.5 12.0 13.4 1891............. 12.0 14.5 13.6 14.1 12.5 9.7 8.9 7.7 8.8 11.0 10.8 10.6 14.5 1892........... 12.3 15.0 13.3 13.4 13.2 12.0 10.0 11.5 9.6 10.6 11.4 12.7 15.0 1893............. 12.7 14.3 13.8 13.0 11.4 11.4 9.8 9.8 8.6 9.7 11.5 10.5 14.3 1894............. 13.9 13.2 13.5 16.4 12.1 11.0 11.4 10.0 9.7 10.9 10.4 10.3 16.4 1895............. 14.7 12.9 14.6 13.3 11.4 11.2 10.1 9.4 9.7 11.2 122 12.8 14.7 1896.............. 14.0 14.3 14.9 13.7 11.2 10.3 10.0 8.9 9.9 11.0 11.3 13.8 14.9 1897.............. 13.4 12.9 13.4 11.6 12.1 12.1 9.8 9.7 9.3 9.9 10.9 10.9 13.4 1898.............. 13.0 12.9 12.0 12.2 11.6 10.4 9.5 8.9 11.4 9.3 9.6 11.2 13.0 Average... 12.8 13.3 13.4 13.1 11.8 10.8 9.8 | 9.7 9.6 10.4 10.9 11.4 14.0 TABLE 11.-Mlaximum range of temperature for each month and year in Manila: 1899-1902. ___ ____________[oc.] Annual YEAR. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. maximum. 1899.............. 12.3 13.4 15.0 14.6 12.3 12.8 9.8 10.3 11.2 12.0 12.5 12.3 15.0 1900.............. 15.4 13.3 15.1 15.5 12.5 11.8 12.1 12.8 10.2 11.9 14.3 15.7 15.7 1901.............. 14.4 13.2 16.2 16.6 16.0 14.0 12.6 9.2 12.5 12.7 11.6 15.2 16.6 1902.............. 12.9 16.2 17.0 17.0 14.1 13.6 12.0 10.1 13.5 14.2 13.9 15.4 17.0 Average... 13.7 14.0 15.5 15. 9 13.7 13.0 11.6 10.6 11.8 12.7 13.1 14.6 16.1 Table 11 is intended to show the absolute variation of temperature during each month, by comparing the absolute maximum and the absolute minimum of 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 air temperature in Manila: 1883-1898. Annual YEAR. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. minimum. 1883.............. 4.4 6.5 6.7 4.3 2.8 3.9 1.6 3.0 2.1 1.8 1.8 4.6 1.6 1884..... 4.8 4.5 6.2 5.9 3.2 3.1 2.6 2.8 2.4 5.2 3.4 3.4 2.4 1885............. 5.2 6.8 5.2 4.4 6.4 3.5 3.4 4.1 2.6 5.9 4.1 6.0 2.6 1886............. 5.9 6.2 6.9 5.8 5.5 5.0 3.6 2.8 2.4 1.9 4.0 3.0 1.9 1887.... 4.5 6.6 6.3 4.2 6.5 4.7 3.1 4.0 2.9 2.5 2.7 4.1 2.5 1888............. 4.9 8.3 7.9 7.7 5.0 2.9 2.5 2.9 5.1 2.6 5.0 2.1 2.1 1889... 5.1 7.2 8.1 7.2 7.1 5.6 2.7 3.5 4.3 4.0 2.8 1.2 1.2 1890.............. 6.2 7.1 8.8 4.3 5.8 2.6 1.5 5.4 1.1 2.6 2.9 4.7 1.1 1891.............. 2.5 6.0 6.6 7.4 5.6 2.3 2.6 2.9 3.2 5.6 2.1 3.7 2.1 1892.............. 2.0 6.2 6.3 7.1 7.3 5.3 4.0 4.0 2.7 3.5 3.2 5.1 2.0 1893.............. 5.4 6.8 6.2 6.7 2.2. 1.6 2.4 2.8 3.4 2.9 2.2 5.0 1.6 1894.............. 5.4 6. b 5.6 6.5 5.3 3.1 3.6 3.6 2.0 5.5 3.1 6.0 2.0 1895............. 5.5 6.5 5.9 6.7 2.7 2.9 4.5 4.1 2.5 4.7 4.4 5.0. 2.5 1896.............. 5.8 8.0 7.6 6.9 2.9 2.9 4.2 2.7 3.8 2.7 6.0 7.2 2.7 1897.............. 6.2 7.2 4.7 7.9 4.8 4.3 3.9 1.9 2.7 2.4 3.5 3.8 1.9 1898.............. 3.7 2.9 2.2 5.4 3.2 3.5 3.3 2.2 5.6 3.2 1.8 5.5 1.8 Average... 4.8 6.5 6.6.3 6.2 4.7.6 3. 3.36 3.3 4.3 2.0 I I i II w I 23 TABLE 13.-Mizimum range of tentperature for each month and year in Manila: 1899-1902. [o c.] Annual YEAR. Jan, Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. mini1899........... 3 40 4. 2 39 1.5 0.4 0.1 0.2 0.0 2.7 0.0 1900............. 5.6 0 5.0 7.0 6.2 0.6 3.2 1.6 0.4 0.8 l.6 1.2 0.4 1901........ 5.3 4.2 2.9 4.7 3.6 4.0 2.3 3.7 1.6 2.2 2.8 0.5 0.5 1902........... 4.8 5.1 5.8 2.9 5.4 2.7 1.5 1.1 2.2 6.3 5.1 3.3 1.1 Average... 4.7 4.4 4.4 4.7 4.4 2.0 2.1 1.7 1.1 2.4 2.4 1.9 0.5 Table 14 presents an exhaustive account of the slightest changes of temperature in Manila. TABLE 14.-Differences between the hourly means of air temperature in Manila compared between themselves, and betiveen the same hourly means and the monthly means. [~C.] _: _ = HOUR. 1 a. m........... 0-1 a. m...... 2a. m........... 1-2 a. m..... 3a. m........... 2-3 a. m...... 4a.m........... 3-4 a....... 5a. m............ 4-5 a. m...... 6a............. 5-6 a. M...... 7 a. m............ 6-7 a. m..... 8 a. m............ 7-8 a. m...... 9a. m............ 8-9 a. n...... 10 a........... 9-10 a. m..... 11 a. m....... 10-11 a. m.... 12 noon.......... 11-12 a. m.... 1 p. m........... 12-1 p. m..... 2p. m............ 1-2 p....... 3p. m............ 2-3 p....... 4 p. m........... 3-4 p. m...... p. m........... 4-5 p....... 6 p. m............ 5-6 p. m...... 7 p. m........... 6-7 p. m..... 8 p. m.......... 7-8 p. m...... 9 p. m............ 8-9 p. m...... 10 p. m........... 9-10 p. m..... 11 p. m........... 10-11 p. m.... 12 midnight...... 11-12 p. m.... Jan. Feb. -2.0 -2.2 -0.3 -0.5 -2.4 -2.6 -0.4 -0.4 -2.7 -8.0 -0.3 -0.4 — 8. 1 -8.4 -0.4 -0.4 -8.4 -8.9 — 0.3 — 0.5 -3.6 -4.1 -0.2 -0.2 -8.4 -8.7 0.2 0.4 -1.7 -1.5 1.7 2.2 0.6 0.8 2.3 2.3 1.6 1.6 1.0 0.8 2.2 2.8 0.6 0.7 2.8 2.8 0.6 0.5 3.8 8.7 0.5 0.9 8.81 4.2 0.6' 0.5 4.0 4.4 0.21 0.2 3.6, 4.1 -0.4 -0.3 2.71 3.8 — 0.9 -0.8 1.51 1.9 — 1.2 -1.4 0.4 0.7 - 1.1 -1.2 — 0.2 -0.0 -0.6 - 0.7 — 0.6 -0.6 -0.4 -0.6 — 1.0 -1.0 — 0.4 -0.4 -1.8 -1.8 — 0.3 -0.3 — 1.7 -1.7 -0.4 -0.4 l Mar. I Apr. -2.4 -0.5 -2.8 -0.4 -3.2 — 0.4 -3.6 -0.4 -4.0 -0.4 -4.2 -0.2 -8.8 0.9 -0.9 2.4 1.1 2.0 1.6 0.5 2.1 0.5 2.8 0.7 8.6 0.8 4.2 0.6 4.4 0.2 4.0 -0.4 8.2 — 0.8 1.8 -1.4 0.7 -1.1 -0.1 -0.8 -0.7 - 0.6 -1.1 -0.4 -1.6 - 0.4 -1.9 -0.4 -2. -- O. I -_2. - 0.4 -3.4 -- 0 a.i --- 0. 5 — 4.8 — 0.4 — 4. A -0.1 2. C 1.1 1.2 1.6 0.6 2.2 0.6 2.9 0.7 8.8 0.9 4.8 0.6 4.4 0.1 4.0 -0.4 - 0.1 -0.3 1.7 -1.4 0. 6 -1.1 -0.1 -0.7 -0.7 -0.6 -1.2 -0.5 -1.5 -0.3 -2.0 -0.5 May. -2.2 -0.4 - o.4l -2.5 — 0.3 — 2.9 — 0.4 — 8.2 -8.6 — 0.2 0.4 -o0.1 -1.6 1.8 0.41 2.0 1.4 1.0 1.8 0.4 2.4 0.6 2.9 3l.4 0.6 18.6 0.1 8.2 -0.3 2.6 -0.6 1.9 — 0.7 1.0 -0.9 0.83 — 0.7 -0.2 -0.5 -0.7 -1.1 — 0.4 -1.6 -0.4 -1.8 -0.3 June. JVly. Aug. S lt. (ct. Nov. -2.0 -1.6 -1.6 -1.4 -1.8 -1.7 - 0.3 - 0.2 - 0.1 - -. — 0.3 — 0.2 -2.2 -1.8 -1.7 -I.6 -2.0 -1.9 — 0.2 -0.2 -0.2 - 0.2 -2 -0.2 — 2.6 — 2.0 -1.9 -1.7 -2.8 -2.2 — 0.3 -— 0.2 -0.2 — 0.1 -0.3 -0.3 -2.7 -2.2 -2.1 — 1.9 — 2.51 -2.5 — 0.2 — 0.2 - -0.2 — 0.2 -- -0.3 -2.9 — 2.4 -2.2 — 2.0 -2.16 — 2.6 — 0.2 -0.2 -0.1 - — 0.1 -0.1 -0.1 — 2.S -2.4 -2.8 — 2.1 -2.7 -2.8 — 0.1 -0.0 - 0.1 -0.1 — 0.1 - 0.2 -—.. —1.4 -1.4 -1.2 -1.8 -2.1 1.2 1.0 0.9 0.9 0. 0.7 0.2 0.0 0.1 0.0 -0.8 -0.7 1.81 1.4 1.3 1.2 1. 1.4 1.8 1.0 0.9 1.0 1.0 0.7 1.1 1.0 1.0 1.0 1.31 1.4 2.0 1.7 1. 1. 1.8 1.7 07 0.70 0.6 0.7 0.8 1.0 2.4 2.1 2.0 2.0 2. 2.8 0.4 0.4 0.6 0.3 0.5 0.6 2.7 2.4 2.2 2.3 2.71 2.6 3 0. 3 0.2 0.3 0.4 0.3 8.0 2.6 2.5 2.5 2.9 0.3 0.2 0.3 0.2 0.2 0.3 83.1 2.6 2.4 2.4 2.9 2.9 0.1 0.0 — 0.1 -0.1 0.0 0.0 2.8 2.4 2.1 2.1 6 2.7 -0.3 -0.2 -0.3 — 0.3 -0.3 -0.2 2.4 1.9 1.6 1.6 2.21 2.8 -0.4 -0.5 -0.56 -0.5 — 0.4 -0.4 1.7 1.8 1.2 1 1. 5 1.5 -0.7 -0.6 -0.4 -0.5 7 -0. 8 091 0.7 0.6 0.5 0.7 0 -0.8 -0.6 -0.6 -0.6 -— 0.31 -0.8 02 0.1 0.1 0.1 0.11 0.0 - 0.7 -0.6 - 0.5 - 0.4 - 0.6- 0.7 -0.8 -0.2 -0.8 -0.2 -0.28 -0.4 - 0.5 -0.3 - 0.4 -0.3 -0.3- 0.4 — 0.7 0.6 -0.6 -0.6 -0. 7 -0.7 -0.4 - 0.4.4 -0.3 - 0.4 -0.5 -1.1 -1.1 -1.0 -0.8 — 0.8 -1.0 - 1.0 -0.4 — 0.4 — 0.2-0.2 -0.3 -0.3 -1.4 -1.2 -1.1 -1.0 -1.8-1.8 -0.3 -0.2 — 3 - 0.2 -0.3 -0.8 -1.7- - -1.4 - 1..3 -1.6 — 1. - o0.3-0.2 -0.2 -0.3: -0.2 -0.2 1 _ _ _ ~..........-77 Dlec. -1.8 — 0.3 -2.0 -- 0.2 -2.8 - 0.3 -2.5 -0.2 -2.8 -0.3 — 8.0 -0.2 -2.6 0.5 -1.1 1.4 0.6 1.7 1.6 1.0 2.4 0.8 2.7 0.3 8.1 0.4 8.2 0.1 8.1 -0. 1 2.7 -0.4 1.9 -0.8 0.8 -1. 1 0.1 -0.7 -0.8 -0.4 — 0.8 -0.5 o. 5 -10.2 --- 0.2 -1.81 -0.3 -1.6 -0.2 Annual. -1.98 -0.32 — 2.20 - 0.27 -2.61 -- 0.31 -2.80 -0.29 -8.05 - 0.25 -8.16 - 0.11 - 2.28 0.93 -0.49 1.74 0.96 1.46 1.68 0.72 2.22 0.64 2.65 0.43 8.11 0.46 3.29 0.18 8.18 -0.11 2.75 -0.43 2.03 -0.72 1.06 -0.97 0.28 - 0.78 -0.21 -0.49 -0.07 - 0.46 -1.61 -0.34 -1.81 -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 20 and 22 years. 24 TABLE 15.-Summary of the most imnportant fectures of air temperature in Manila. [o c.] * g ~1 ^ aMEAN I 00 O o' MONTHLY Vg W ^ HOURS OF MOURSOF AND AN>.. MINIM.UM AND UAL rx ABSOLUTE EXTREMES (22 YEARS). ~4> &1 -C?1 Lj *M A TTTM'TT'M' NUAL EX- rMAXIMUM. TEMES MONTH. O G, (O Y ES) (20 YEARS). o 0. Max. Min. Cd _ ~! < M U I. VXw 1 Max. Min. ~ Maximum. Minimum. (p.m.) (a.m.) Jan.... 25.1 — 1.8 7.6 3 6 32.1 17.9 14.2 33.9 (14,1897) 15.6 (27,1881) Feb.... 25.6 -1.3 8.5 3 6 32.9 18.0 14.9 35.4 (24,1892) 15.7 (27,1902) Mar... 26.9 0.0 8.6 3 6 34.3 18.5 15.8 35.6 (28,1901) 17,2 ( 2,1899) Apr... 28.4 +1.5 8.9 3 6 35.5 20.8 14.7 37.2 (30,1889) 18.7 ( 9,1902) May..28.8 +1.9 7.0 2 5 36.1 22.7 13.4 37. 8 (23,1889) 21.3 (4,1901) Jue... 28.0 +1. 1 6.0 2 5 35.0 22.6 12.4 36.8 (1,1881) 21.1 (30,1881) July.... 27.2 +0.3 5.0 { 2 }33.5 22.4 11.1 35.2 (10,1881) 21.0 (11,1881) Aug.... 27.2 +0.3 4.8 1 6 33.0 22.3 10.7 35.2 22'188 } 20.6 (27,1896) Sept.... 27.1 +0.2 4.6 1 6 33.3 22.4 10.9 35.2 (29,1901.) 20.9 (22,1902) Oct... 27.0 +0. 1 5.6 { 1 6 33.3 21.4 11.9 34.9 (24,1891) 19.6 (24,1902) Nov... 26.2 -0.7 5.26 7 5 { 1 6 32.2 20.3 11.9 34.2 (15,1882) 17.3 (29,1880) Dec.... 25.2 -1.7 6.2 2 6 32.1 18.3 13.8 33.4 ( 3,1900) 15.7 (31,1892) Year. 26.9 ~...... 6.5... 3.6 2-0. 6 1:3.0 37.8 May 23,1889 1 15.6 Jan. 27,1881 1 These two vailues are the maximrum and minimum i 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 amlount constitutes the hygrometric condition of the atmlosphere. 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 therinic oscillation, upon the amount of radiation of heat, and also upon thehygronietric 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 3.5 5.1 6.8 7.5 7.5 7.4 6.1 5.8 5.6 The mean cloudiness for the year is 5.6. We shall furthermore consider cloudiness in the different parts of the day so as to present the distribution'of clouds throughout'the See "Handbook of Climatology" by Dr. Julius Hann, New York, 1903. PLATE I. _,.,. l i..,.. - --- l - i 1! ANNUAL VARIATION OF THE TEMPERATURE AT MANILA 1880- 1902 1 aInn. rah Mnr. Anr,. u.inu.l, lu A,,n. Rnt. Ot_ Nn,. nDne..Inn. C,...................., 29.0 _ __ _ - 29.0 28.0 28.0 28l0 __ - __ _- _ _ 2.0 N~~~~~~~~~~~ I,..1.. ~ ~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~~~~ ~ ~.... 26 day in Manila. By dividing the day into four parts-early morning, forenoon, afternoon, and night-Table 14 shows the average cloudiness for each as the result of hourly observations made for many years. This table is based upon the classification of clear, covered, and variable, meaning cloudiness from 0 to 2, from 8 to 10, and from 3 to 8, respectively. TABLE 16.-Monthly variation of cloudiness, by divisions of the day. EARLY MO()RNING. | FORENOON. AFTERNOON. NIGHT. MONTH. Jaulllary..... February.... March..... April...... May......... June...... July......... August..... September... October..... November... December... a,.,i:, i: _I.',. a 7 3 1.. _7 7 _. 7 17. 4. 3 14. 8 12. 3.. 11.7 7.3I 12.0 5.7 7.7 17.6 4.9 11.3 14.8 12.3 6.0 12.7 13. 8 5.0 9.3 10.2 6.5 11.5 8.0 7.4 12.8 16.1 6.3 7.8 14.7 7.1 9.2 10.0 8.4 12.6 9.5 7.7 13.8 17.8 4.9 8.3 17.8 4.0 8.2 11.3 4.7 14.0 7.8 6.2 16.0 17.3 4.7 8.0 6.9 8.8 15.3 4.1 9.6 17.3 2.0 14.5 14.5 6.6 11.3 13.1 3,9 10.8 15.3 2.3 11.8 15.9 0.7 15.5 13.8 2.9 12.4 14.7 2.8 13.2 15.0 1.5 13.7 15.8 0.6 20.0 10.4 2.2 17.4 11.4 2.1 15.9 13.0 1.4 15.3 14.3 0.3 18.8 11.9 1.1 18.0 11.9 2.2 16.3 11.5 1.2 14.8 14.0 0.4 18.2 11.4 2.0 18.0 10.0 6.5 12.7 11.8 6.0 13.3 11.7 2.3 17.0 11.7 6.1 12.6 12.3 7.6 10.4 12.0 5.1 10.5 14.4 3.1 13.2 13.7 10.0 11.5 8.5 9.2 9.5 12.3 4.0 11.8 15.2 2.5 14.0 14.5 13.0 8.1 9.9 Year... 99.2 121.0 144.9 62.8 128.1 174.3 | 42.1 163.8 159.3 1 107.4 129.2 118.6 Table 16 contains some interesting facts of importance in climatology, which may be thus summarized: 1. Tlle number of clear forenoons and clear early mornings reach a maximum in April, decreasing rapidly from April to August, and increasing from August to April, in almost regular progression. 2. The number of overcast afternoons is greatest from May to Novemlber because of the electric storlns which usually develop in the afternoons during these months. 3. The clearest months of the year are March and April, due to the easterly prevailing currents, followed by February, January, and December. 4. Generally fromI May until October clear early mornings are more numerous than clear nights, and clear afternoons are fewer than clear nights and clear forenoons. 5. The minimum of clear days occurs in September and the maximum in April. Other:particulars about clouds and cloudiness in the Philippines imay be seen in the volume published by the Manila observatory "Las nubes en el archipi'lago Filipino," Manila, 1897. Sunshine has a very close connection with the degree of cloudiness. Plate II shows the average numrber of hours of sunshine in Manila for each month, and its distribution almost agrees with that of the average clear and variable days, for each month, which is as follows: Jan. Feb. Mar. Apr. May. |June. July. Aug. Sept. Oct. Nov. Dec. Average clear and vari- able days............. 23.9 23.8 23.9 25.1 19.9 17.3 14.9 14.0 13.1 17.1 18.6 22.6 ~~~~~~~~~. _.,. _-.t,. _. 1...._ PLATE 11. ANNUAL VARIATION OF THE EFFIOAOY OF THE SUN'S RAYS AT MANILA Hours Jan. Febr. Mar. Apr. May June July Aug. Sept. Oct. Nou. Dec. Hours. T I T I. I AI 260 _ _ _ _ _ _ lt _ _ __ _ _ _ __ _ _ _ __ _ _ _A_ 260 250 _ _ _ _ _ __ _ 250 220 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 220 210 __ __ JL __ _ __ _ __ _ _ __ __ __ __ __ __ __ __ _ __ __ __ _ _ _ 210 200_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _200 190 | _ _______-1___ ____ _ _-_ _ 190 180 t______ _ ____ _+ _ _ ___ 180 170 _ _ _ _1 _ _ _ _ _ 1t _ _ _ _ _ _ t _ _ L70 _ _ _ _ _ 1150 40 1 40 28 RAINFALL. Rainfall, which is closely related to cloudiness, should be first considered by distribution over the archipelago, based upon observations made during the years 1902 and 1903 at the stations of the Philippine weather bureau,,'and then considered particuiarly with relation to certain features of rainfall in Manila, where water precipitation has been accurately recorded since the year 1865. TABLE 17.-Monthly and annual rainfall, in millimeters, at different stations of the archipelago from September, 1902, to Atugust, 1903. STATION. September. October. November; December. January. February. Masinloc......129....8...... 1,239.8 52.8 218.4 0. 0.0; 0.0 Borongan..................... 79.2 399.0 355.8 390.1 623.1: 399.3 araga....................... 26.7 18.4 4214 586.4 354.8 707.4 Baler................... 248.7' 304.6 406.4 382.0 273.3 117.9 Baguio........................ 602.77 212.1 75.9 24.1 5.1 0.0 Capiz.................. 140.1. 336.2 70.9 114.3 90.3 117.1 Olongapo..................... 869.0 30.5 143.5 2.8 0.01 1.3 Tagbilararft.........:: -.... 472, 3 114.2 255.1 207.1: 164.3 91.4 Vigan....... 843.3 0.0 0.0 3.8: 0.0 0.0 Atimonan...................... 317.4 591.i 235.9 63.2 165.9 90.4 Dagupan...................... 379.2 83.1A 37.3 2.0 4.3 2.8 Bolinao............... I 402.8 9.4 38.1 2.5 0.0 7.6 Legaspi.................. 230.4 336.5 173.2 289.0 128.4 130.0 Iloilo......:..... 511.9 219.5 {(24dav's } 126.7 5.5 5 olo,1ll....."............ (24 days) ~ 7 ~ Balanga....................... 772.0 132.6 116.9 15.1 12.9 30.2 San Fernando (La Union).... 439.4 1.88 5.8 5.1 0.3 0.0 Surigao.................. 46.7 174.0 292.1 190.0 243.6 100.8 Candon....................... 923 {(l8days 50.8 0.0 0.0 0.0 Porac........................ 539.2 100.1 100.6 42.2 26.2 0.0 Aparri........................ 594.4 118.9 161.0 198.1. 65.5 85.6 Dapitan..................... 132.8 364.0 291.3 183.4 140.2 60.5 Ormoc........................ 266.2 236.2 114.3 81.8' 238.2 55.4 Marilao....................... 396.5 144.8 89.9 89.0. 7.6 2.5 Corregidor.................... 868.2 29.7 34.0 10.9 7.6 6.4 Cottabato..................... 249.2 159.5 81.3 109.2 { (20 day) 85.9 Tarlac............31...... 373.8 141.6 55.6 17.0 9.4 24.4 Jolo.......................... 101.1 148.0 120.4 173.6 3.0 23.1 San Isidro..................... days23.3 } 37.8 143.3 51.9 21.4 0.0 Manila........................ 523.8 69.6 71.1 57.6 25.3 8.9 Davao...................... 50.7 118.4 62.7 112.0 22.1 159.7 Cuyo.................... 276.9 83.8 14.6 66.8 0.0 0 0.0 SanJosedeBuenavista....... 338.1 72.1 22.0 10.2. 18.7 0.0 Cavite........................ 529.9 103.5 77.8 36.3 17.6 4.9 Isabela de Basilan........... 140.5 65.3 472 53. 1 15.7 7.1 Tuburan...................... 71.9 170.0 191.5 52.7 96.0 18.3 Nneva Caceres................. 127.2 225.0 63.0 51.0 18.1 19.9 Maasin..1..........4............ 2..2 108.9 87.8 115.0 52. 1 Cebul.......5............... 52.3 106.7 120.4 58.4. 72.5 24.0 Arayat........................ (29y2. 25.1 6.6 20.1 20.8 1.5 Zamboanga................... 91.9 39.4 18.7 (27 1. 15.0 8.3 Santo Domingo, or Basco......................2./........ 337.9 270.1 27.2 Tguegarao......................1.. 13.7 7. 4 Bifiang....................................................................... 5.1 4.8 Iba........................ 1,200.6 49.3 87.6 7.6 0.0 0.0 Daet.......................... (17. 179.6 243.8 181.6 134.1 115.6 Romblon.......................................... 167.2 90.4 137.4 51.0 Calbayog........................................... 96.7 137.7 92.2 29.2 Palanoc............................................................................................. Bacolod....3.............3. 02.1 406.1 10.8............ 51.3 13.0 Loon............................................................ 27.5 d5ays) 0. 8.4 I Dn(22 days) Catbalogar.......... 87.6 79.8 153.7 77.5 Ballngasa., ' )."-'.-. 2... 436.9 80.6 79.7 35.6 19.8 117.1 t I~tI I: PH~L1P~NE SLAND.j j.U ND.E N HESH ceo'~~~~~~~~~~~~~~~~~~~~~~~~~t 1 iiiiii^i^iii1|1lii11lii~i1||11|l 'tp 1 1 I llllll l^ '. '. | " i|~ili l::~ all al ~ ~~~~~~~~ iii^":"'~~ ~~~ o*9d * 0 1. tXr | *0~~~~~~~0f '0 li"'-' ff ^ *'~~~ g ~ m m rr 1~'i- ''1 ~t olI;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I ssr~~~~~f~~i~~~~~iila-~~',irr 'lii, l'l C 44 7 29 TABLE 17. — Monthly and annual rainfall, in millimeters, at different stations of the archipelago from September, 1902, to August, 1903-Continued... STATION. March.,April...[ Masinloc..............:.. Borongan.................... Caraga......-................ Baler.......................... Baguio....................... Capiz......................... Olongapo..................... Tagbilaran.................... Vigan......................... Atimonan................... Dagupan............... Bolinao..................... Legaspi...................... Iloilo......................... Balanga....................... San Fernando (La U iol.).... Surigao....................... Candon..................... Porac........................ Aparri........................ Dapitan..................... Ormoc....................... Marilao...................... Corregidor................... Cottabato..................... Tarlac........................ Jolo........................ San Isidro..................... Manila....................... Davao..................... Cuyo.......................... San Jose de Buenavista....... Cavite........................ Isabela de Basilan........... Tuburan...................... Nueva Caceres............... Maasin........................ Cebu..................... Arayat........................ Zamboanga................... Santo Domingo, or Ban (..... Tuguegarao................... Bifiang....................... Iba. bDae........................... Dnet......................... Romblon.................. Calbayog................... Palanoc....................... Bacolod...................... Loon...................... Catbalogan................. Balingasag.................... ~ 0.0 109.5 233.4 53.3 16.5 7.4 0.0 35.8 16.3 24.6 5. 1 96.9 3.,g 0.0 0.0 135.9 0.0 0.0 6.9 f 36.8 t(22days) 0. 5 0.0 J 68.1 {(24days) 0.0 32.5 0.0 0.0 18.7 0.0 0.0 2.9 0.0 22.3 4.0 32.1 30.9 0.0 0.0 51.8 0.0 0.0 0.0 29.2 1.3 47.8 6.3 9.7 19.5 3.3 24.6 135.4 117.4 239.0 97.0 16.3 0.0 17.7 11.4 -15.5 54.9 5.3 116.9 4.8 6.1 12.2 118.1 33.3 48.8 30.0 58.4 } 40.6 37.3 0.0 72.9 46.7 105.0 1.3 13.1 181.8 1.8 87.9 5.0 22.5 0.0 9.8 10,7 7.9 15.5 7.0 141.0 48.3 5.8 8.4 40.1 29.0 82.0 - 2.8 42.2 ( 10.7 (22days) 7.6. My. 176.8 325.6 301.5 389.9 131.8 127.0 49.0 161.5 45.0 61.5 214.4 100. 6 81.4 165.6 168.2 53.6 238.0 5.3 40.6 79.5 71.9 47.5 27.6 18.8 212.8 81.3 65.7 - 38.1 15.1 127.6 88.1 56.6 18.4 108.5 81.3. 66.8 77.3 34.5 8.1 41.5 201.1 119.4 15.0 72.6 20.1 114.6 167.1.......... 91.3 16.9 114.3 (14 days).......... f 3411 {(20days) 295. 1 108.2 290.8 168.4 590.8 128.8 183:1 177. 0 77.9 271.5 122.4 99.0 244. 3 96.3 115.8 102.9 147.0 163.3. 11.7;139.7 101.9 160.8 110.7 157.7 146.3 214.4 116.0 100.2 111.2 139.8 215.9 56.2 307.6 118.5 175.5 109.6 200.9 30.0 66.1 163.7 118.4 30.7 225.3 60.5. 101.3 140.5 113.0 178.1 88.3 43.2.......... June. July,. I A 903.9 265.4 225.3 249.4 760.8 936.5 t618. 2 395.3 456.9 320.8 664.2 726.2 194.0 427.0 418.1 511.5 135.1 586.7 424.4 49.0 156.5 381.0 461.0 345.2 250.0 428.7 292.0 386.4 267.2 224.3 442.8 343. 7 195.9 131.1 166.0 217.2 69.9 133.9 142.5 65.8 340.6 98.6 280.2.......... 102.6 70.1 168.4 119.1 334.6 202.7 298.4 r. {(..... igust. Annual. 905.5 3,862.9 75.2 3,452.7 64.3 3, 15.2 1902),,3,165.2 5. 3 3,008.4 767.9 2,862.3 241.8 2,788.7 474. 7 2,317.8 188. ' 2,286.0 54.2 } 2,207.9 1902); 7.9 232.7 2,197.3 351.3 2,066.3 599.7 2,019.7 80.3 1,955.0 186.2 1,925.0 139.7 1908.1 724.2 1,869.7 4.3 1,781.5 344.4 1,780.9 272.5 1,757.9 324.1 1,717.8 95.0 1,700.6 99.6 1,699.5 281.8 1,69'9. 3 241. 6 1, 673.1 187.2 1,633.8 155.7 1, 480. 5 157.6 1,436.4 134.9 1,354.4 180.9 1,332.3 121.0 1,310.2 179.3 1,293.9 93. 7 1,258.9 54.2 1,10'2.6 201.9 1,100.5 60.6 1,049.1 69.5 1,047.0 64.4 976.2 74.2 916.6 199.4 761.7 48.6 413.4 910. 7 910.7.......... 80.2.......... 125.2......... 49.'5 i1,474. 2................ 97.8.......... 88.1.......... 200.2................. 101.6........ 210.......... The preceding table shows that the distribution of rainfall over the archipelago differs widely, according to locality. As far as the distribution of precipitation is concerned, the archipelago may be divided into two zones: Zones of rainy and dry season: Western coast of Luzon from Santiago. Point to Cape Bojeador, including Manila bay. Interior of Luzon from Laguna de Bay to South Cagayan valley, and in the highlands above 3,000 feet. Western coast of Mindoro. 30 Zones of rainy and dry season-Continued. Western coast of Panay. Calamianes group. Islands on the North Jolo sea. Palawan or Paragua Island. In these zones the rain is very abundant (from 2,000 to 4,000 mm.) in: Zambales. Highland of Luzon above 4,000 feet. Ilocos Norte and Ilocos Sur. La Union province. The Lingayen gulf. While the rain is moderate (below 2,000 mm.) in: The Manila bay. The interior of Luzon below 4,000 feet. The western coast of Panay. The western coast of Mindoro. The North Jolo sea. Paragua Island. West coast of Luzon south of Corregidor Island. Zones of more even distribution of rain: Southeast end of Luzon. Eastern coast of Luzon. Eastern Visayas (Samar, Leyte, Cebu, Bohol, and adjacent islands). Eastern Mindoro. Northern and eastern Panay. Jolo archipelago. Mindanao, Dinagat, and Camiguin. Batanes and Babuyanes islands. Northern Luzon. In these zones the rain is very abundant in: Eastern Luzon, from Atimonan to Cape Engaino. Eastern Mindanao. Northern Panay. Extreme southeast of Luzon. Eastern Samar. Eastern Leyte, south of Tacloban. Bohol. The rain is moderate in: North Mindanao. West, south, and the interior of Mindanao. Jolo archipelago. Cebu. Western coast of Samar. Western coast of Leyte. Tables 23, 24, and 25, given below, may explain also this division. ' -.1 X: /! '. ' -a * PLATE III. i,, 11,1i iii11,, i i,111u... 1,1:.. i,/,,~,.,,~ i i i i i, i!, I ANNUAL VARIATION OF'RAIN AT MANILA 1865 -1902 Jan. F, br. Mar. Apr. May June July Aug. S. Oep t. Oct.. Deo. Jan. mm. I I 1 1 I L mm, 400 __ _ _ _ _ ___ _ _ 400 B60 350 300 = =_ = ==_ 300 260 ___ Hv _250 200 __200 160 _4 t _ _0 _-l7 \_4:_ = =-. 100 __ _/ ', / J __ __ __ __ __ ]\ 100 80,50 - 2 23621 —No. 2-04-3 9, 32 On Plate III we give an illustration of the variation of rain in Manila compared with the variation in Albay and Tamontaca, where the rainfall is more evenly distributed and very abundant, as in Albay, and moderate, as in Tamontaca (Mindanao). In Table 18 will be found the amount of rainfall in Manila for each month since the year 1865, or in a period of 38 years. Attention is called to the fact that, except during the years 1874, 1885, and 1892, the driest of the whole period, and the years 1867, 1869, and 1899, the wettest, the total quantity of the others is not very far from the general mean, 1,938 mm. The same may be deduced from Table 19, in which we give the days of rainfall in Manila for the period mentioned. In Table 20 is presented the amount of rain for the dry and wet seasons. The result may be taken as a type for the regions similarly affected and mentioned above. Table 21 gives the extreme values concerning the rainfall in Manila. Other features about the rainfall in Manila will be shown in Tables 22, 23, and 24. A graphic representation of the total rainfall in Manila for each year since 1865 will be found on Plate IV. TABLE 18.- Quantity of water collected by the pluviometers of Manila observatory: 1865-1902. [Millimeters.] YEAR. IJan. Feb. Mar. Apr. 186........ 11.0 38.0 0.0 0. 1866......... 44.0 00. 60.0 20. 0 1867........ 21.5 18. 2 12.8 21. 1868......... 0.. 0 0.01 0.0. 1869........ 35.5 11.11 0.0 40.8 1870........ 82.6 24.6] 3. 4 21. 1871..... 9.6 6.7 11.2 0.C 1872...... 15.3 10.0 28.2 39. 1873.........20.0 12.81 14.0 100). 1874.........13.9 5.0! 2.2 17.7 1875........ 99.2 28. 3 24. 2 2.3 1876........ 8.4 3.6 9. 4 29. 1877........ 2. 2 1 0.2 0.2 0 1878......... 1 7.5 10.8 5. 1879....... 55.2 39. 6 11.3 119. 1880........ 42.3 11.6 15.6 136.4 1881..... 0.01 9.2 7.1 1882......... 9.5 2 30. 7 40. 1883........ 195. 2 15.4l 23.01 7,5.! 1884......... 0.5 0.4..5 0. 1885........ 2.0 o. Oi 3.0 22. 0 186......... 3.0i 16.5 0.0 31. 1 1887........ 13.4 4.8! 100.2 27.' 1888.........16. 0. O 18.8 114. 1889.........98.1 10.81.8 3. 1890........ 14.1 15.6 t 16.4 77. 1891......... 18.7 18 4.1 4. C 1891. 18.7 1,8 4.1 4. 1 1892..... 17.1 27.1 13. 1893....... 14.2 5.7il 18.0 20. s 1894...... 10.0 3.31 61.9 22 1 1895........ 26.7 1.6i 11.4 5. 1896........ 1.0 7.6i 10.6 4. 1897..... — 12.3 0.01 22.4 25. (; 1898......... 54.2 10.31 65. 6 35. 1899....... 42.4 3.01 29.9 70.4 1900........ 3.2 3.51 15.4 2. 1901........ 0.1 9.7 16.1 12.2 1902........ 27.2 1.0 7. 6 7 Average. 29. 0 9.8 18.1 28.4 0i "i' May. 1 90.1( 106.4 1693. 75.A 129.' 194.1 12.( 89.4 59. ( 37.21 O.C 185.7 200.4 76.1 103. 21.( 174.'1 131. ( 123. 7 '96. 4 1.1 107.1 256. i 28. ' 0.( 69.( 97. 76.. 184.1 108. 1 246. 8 168.8 36. 167.1 65.' 49.1 71.( 51.4 101. June. July. Aug. Sept. Oct. Nov. Dec. Total. 266.2 249.01 219.0 687.9 266.4 95.0 19.5 1,942.6 355.0 134.0 302.7 362.5 403.9 137.5 131.0 2,057.0 206. 357.8 340.2 1,469.7 280.1 69.0 13. 2,978.8 393.7 286.0 286.5 462.0 162.4 267.3 2.3 1,943.9 276.9 368.8 407.8 446.. 6589.7 200.8 42.0 2,548.8 199.2 390.1 423.3 ' 3.' 133.8 210.8 46.1 2,002.7 375.7 269.6 248.9 351. 3 189.1 141.4 7.9 1,624.0 168.6 206. 6 798.8 257.4 198.0 133.4 32.0 1,977.5 354.3 261.7 388.3 146.1 317.8 37.9 1.0 1,713.8 110.3 284.4 422.0 115.6 138.2 4 15.5 1,207.0 49.4 330.22 400.7 486. 9 134.2 98.6 32. 9 1,686.9 222.1 470.1 339.6 520.3 58.2 61.5 61.5 1,990.2 233.9 602.0 1,095.6 93.6 239.4 50.1 6.8 2,525.0 207.2 239.1 220.5 399.6 99.6 122.4 89.6 1,479.5 96.5 143.4 290.7 316.4 147.3 397.8 5.0 1,726.9 205.5 809.8 499.8 349. 172.8 105.7 36.4 2,406.5 433.0 tl48f6.7 440.7 255.7 155.5 61.9 91. 21 2,122.3 235.1 573.6 306.3 327.5 320.3 177.4 104.91 2,286. 0 212.9 754.6 256.5 353.4 162.0 72.5 3.2 2,247.7 297.8 721.0 327.5 194.2 47. 149.1 61.7 1,901.6 16i9.5 313.9 170.7 50.8 111.6 57.5 3.5 906.5 219.9 225.9 248.4 233.1 363.5 63.5 89.3 1,601.6 135.7 378.7 142.8 738. 0210. 141.9 117.2 2,267.7 265. 4 680.6 355.2 138.1 200.2 53.4 36.91 1,807.1 167.7 292.9 339.0 117.5 198.8 152.6 346.9, 1,732.6 255. 5 498.8 130.8 536. 224.9 209.9 45.4 2,095.0 5.5 642. 7 276. 477. 8139.5 306. 6 59.2 2,583.7 114. 2 231.0 151.0 377.2 77.7 100.71 52.9 1,282.6 24.8 234.2 276.8 475. 1 83.81 94.2 9.3 1,441.4 281.3 209.9 189.5 399.2 24.6 59. 9' 108.6 1,678.4 539.5 178.6 349.4 463.8 78.3 167.61 15.4 2.084.7 156.6 221.8 650.2 424.6 109.2 29.8 0.2 1,785.3 96. 0 245. 7 263.6 213. 121.7 73. 9 142.8 1,303.5 329.6 288.1 414.3 325.1 245.2 277. 61 14.1 2,226.7 217.31,190.9 340.1 385. 79.8 227.1 143.1 2,794.3 415.0 186.9 770.9 928.0i 175.9 148.8i 66.7 2,125.7 1.t2. 228.6 341.5 151.6 457.3 310.8' 97.0 1,8.51.7 311.3 289.2 300.2 523. 31 69.6 71.1' 1 61,716.7 247.6 381. 0 361. 2 374. 71 191. 8 136.5 558.| 1 1,938,3 1I.~ 2o86 PLATE IV. RAIN AT MANILA FROM 1865 -1902 ANNUAL RAINFALL IN MILLIMETERS 8000 _ 50 2900 50 _ 2800 50 2700 _ 50 _ 2600 00 60 2500 _ 50 _ 2400 _ 50 2300 - - I I I I I I -_ - I I__ _ _ _ I I_ _ _-I I '"50 I II _ _ ____________ 3000 I_ _- ______ _ __ ____-___ __ __ 50 1 I ' - - _ _ -- _ _ _ _-_ _ _ _ - _ _ _ -- _ _.- -._ 2900 1 1_-. _ _ -- - _ -. _ _ - _ _ -_ _ -_ _ - - __ I I I I5 0 2800 50 oAnn 50 2400 50 2300 50 2200 20( 50 2000 50 1 9n 1700 50 1600 50 1500 60 1400 50 1300 50 1200 hn 50 _ 1600. 50 1500 _ 50 _1400 1100 50 1000 50 900 50 1200 50 _ _ - 1100 50 1- - 1000 50 900 0 ~ X 1 -, r M O T l ma, a..... 0 asI o MO al I, 0 s,, 8,, _! _ _ _w _ _ _ _! _? _ _! _2 _! _0 _ _ _!:! _- _! _! _ _ _2 _ _ _ _ _2 _ _ _ _ _ 34 TABLE 19.-Days of rain in Manila: 1866-1902. YEAR. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. Total. 1866................ 5 0 1 1 9 15 16 18 22 23 10 14 134 1867............... 6 2 4 2 10 9 14 23 26 15 10 4 125 1868............... 4 0 0 0 5 19 20 17 20 15 8 1 109 1869............... 1 2 0 2 11 14 19 16 15 20 8 8 116 1870............... 11 7 1 5 it 14 19 21 20 13 15 4 141 1871............... 4 3 1 0 4 18 15 16 18 13 11 5 108 1872............... 7 10 3 4 9 17 13 19 17 18 15 5 137 1873............... 8 4 2 9 2 16 20 23 15 17 5 3 124 1874............... 4 3 1 4 5 13 16 21 10 13 7 4.1 101 1875............. 8 7 4 1 0 6 21 23 26 21 15 7 139 1876............... 5 2 3 5 17 19 27 25 22 10 8 11 154 1877............... 6 1 2 0 10 19 24 26 13 20 141 5 140 1878............. 4. 3 3 4 8 15 23 16 21 13 17 14 141 1879............... 1 5 3 9 6 13 12 18 18 14 19 3 130 1880.............. 7 2 6 7 19 23 18 20 15 8 11 142 1881............... 6 0 5 1 4 13 30 17 18 12 14 8 128 1882............... 2 5 6 4 7 15 26 15 22 19 10 13 144 13............... 5 3 9 10 19 19 18 27 16 10 1 142 1884............... 1 1 1. 0 10 21 27 22 20 15 12 12 142 188............... 1 I 0 1 4 1 11 17 17 11 14 10 2 89 1886............... 2 0 ' 10 18 20 19 21 21 16 12 145 1887............... 5 3 7 3 20 19 22 19 29 12 13 14 166 1888........... 1 0 4 2 8 19 29 19 14 15 13 6 130 1889............... 9 1 2 2 0 13 20 25 22 18 13 13 138 1890.............. 7 5 2 7 13 16 17 13 25 21 7 7 140 1891............... 7 2 3 1 I 18 23 26 15 9 12 13 134 1892............... 6 2 5 6 9 17 25 20 22 11 14 9 146 1893............... 3 2 5 16 14 17 22 26 15 11 8 142 1894............... 4 2 2 2 14 18 21 22 20 15 14 8 142 1895.............. 5 2 4 2 19 14 22 22 23 13 10 8 144 1896............... 2 2 3 2 17 12 19 28 22 15l 4 2 128 1897.............. 3 0 2 5 10 11 18 23 24 22 10 17 145 1898.............. 9 5 13 11 13 22 26 22 22 24 22 9 198 1899.............. 9 2 10 9 14 20 25 25 16 15 15 11 171 1900.............. 2 3 2 5 16 23 26 21 17 15 11 144 1901.............. 1 2 3 11 18 21 29 17 17 21 9 152 1902............... 3 2 6 13 19 24 26 22 9 8 8 149 ~Average. 5 3 3 4 9 16 21 21 20 16 12 8 138 i:~~~;~ 35 TABLE 20.-Rainfall and days of rain in the dry and rainy season in Manila: 1865-1902. DRY SEASON. RAINY SEASON. YEAR. Amount of rain. Days of rain. Amount of rain. Days of rain. YE R. milli- Per cent. Number. Per cent. met Per cent. Tumber. Per cent. meters. meters. 1865................ 1866............... 1867................. 1868................. 1809. 1~9.............. 1870................. 1871................ 1872................. lb73............... 1874................. 1875...............1876................ 1877................ 1878................. 879................ 1880............... 1881............ 1882................ 1883................. 1884................. 1885......:......... 1886................. 1887................. 1888................. 1889................. 1890................ 1891................. 1892................. 1893................ 1894................. 1895................. 1896................. 1897................. 1898................. 1899................. 1900................. 1901............... 1902................. Average...... 254.1 498.9 325. 0 353.3 459.4 582.6 189.4 348.1 245.6 136.5 285.5 379.9 260.5 313.5 732.6 369. 0 350. 7 523.2 508.3 313.6 90.0 310.8 661.6 167.6 616.7 448.3 492.1 331.5 346.7 373.9 475.1 222.9 313.3 624.4 581.2 289.0 517.5 223.1 13 24 11 18 18 29 12 18 14 11 17 19 10 21 42 15 17 23 23 16 10 19 29 9 36 21 19 26 24 22 '23 12 24 28 21 14 28 13 40 38 18 32 54 28 53 33 28 42 51 38 53 55 47 38 47 43 37 19 46 65 84 40 48 43 51 48 46 50 32 47 82 70 41 50 49 30 30 17 28 38 26 39 27 28 30 33 27 38 42 33 30 33 30 26 21 32 39 26 29 34 32 35 34 32 36 25 82 41 41 29 33 33 1,688.5 1,558.1 2,653.8 1,590.6 2,089.4 1,420.1 1,434.6 1,629. 4 1,468.2 1,070.5 1,401.4 1,610.3 2,264.5 1,166.0 994.3 2,037.5 1,771.6 1,762.8 1,739.4 1,588.0 816.5 1,290.8 1,606.1 1,639.5 1,115.9 1,646.7 2,091.6 951.1 1,094.7 1,304.5 1,609.6 1,562.4 990.2 1,602.3 2,213.1 1,836.7 1,334.2 1,493. 6 87 76 89 82 82 71 88 82 86 89 " 83 81 90 79 58 85 83 77 77 84 90 81 71 91 64 79 81 74 76 78 77 88 76 72 79 86 72 87....... W 94 87 91 84 87 80 84 91 73 97 103 102 88 7o.95 90 97 99 105 70 98 101 96 99 92 91 95 94 96 94 96 98 116 101 103 102 100.......... 70 70 83 72 62 74 61 73 72 70 67 73 62 58 67 70 67 70 74 79 68 61 74 71 66 68 65 66 68 65 75 68 59 59 71 67 67 68 382.0 20 4 32 1,556. 801 94 1W. 36 TABLE 21.-Extremes of rain in Manila: 1865-1902. [Millimeters.] EXTREMES OF RAINFALL. EXTREMES OF DAYS OF RAIN. MONTH. Nor- Absolute Absolute Differ- Nor- Absolute Absolute Differmreal. maximum. minimum. ence. mal. maximum, minimum. ence. 1869i 1884 January...... 29.0 195.2 (1883) 0.1 (1901)1 195.1 5 I1 (1870) 1 1885 10 1888 1901 1866 1868 1868 1868 1881 1881 1888 1888 1897 1897 11865 )1865 11868 11868 March......... 18.6 100.2 (1887).0 1869 100.2 3 13 ( 8) 186 13.13 J u 186869 11886 | 1886 1865 [1865 April......... 28.4 136.4 (1880) 0.0 18|i 136.4 4 11 (1898) 0 1868 11 11871 11871 ] 1884 (1884 May........... 101.6 256.9 (1887) 0.0 1889 256. 9 20(1887) 18 ti 20 June........... 247.6 655.5 (1891) 24.8 (1893) 630.7 16 22 (1898)' 6 (1875) 16 July......... 1.0 1,190.9 (1899) 134.0 (1866) 1,0;. 9 21 30 (1881) 12 (1879) 18 August........ 361.2 1,095.6 (1877) 130.8 (1890) 961.8 21 29 (1901)1 13 (1890) 16 September..... 374.7 1,469.7 (1867) 50.8 (1885) 1,418.9 20 29 (1887) 10 (1874) 19 October........ 191.8 589.7 (1869) 39.5 (1891) 550.2 6 2 (1898) 9 02 } 15 November..... 136.5 397.8 (1879) 29.8 (1896) 368.0 12 22 (1898) 4 (1896) 18 )December.....1 346.9 (1889) 0.2 (1896) 346.7 8 17 (1897) 1{1868 16 TABLE 22.- imu aily raifall1883 5-90. TAB LE 2 2.- Maxlimunt daily rairlftll in, 7Manila: 1565-1902. 186.............. 186............ 1867.............. 1868.............. 14iS9............ 187(.............. 1871.............. 1872............... 1873............... 1874.............. 1876............... 1877............... 1877.............. 1878............... 18379............... 1880............... 1881........... 1882............... 188,3........... 1884............. 15............... 18863.............. 1887............... 1889............. 1889.............. 1890............ 1891............... 1893...... 1894............... 1894............... 189............. 1896............... 1897. 1898............... 1899............... 1900 1901............... 1902.............. l9V2 - ''' -! JANIUARY. FEBRITARY. M | 1. Ite. Mil. Date. 6....... 380...... 12.0) 12 0.0 0 13.0 22} 14.0 27 3.0 25 0.0 0 35.5 6 1 8.1 20:o. 0 25 13.0 9 4.4 9 2.5 15 8.0 24 1 4.0) 12 9.2 9 1 4.5 23 11.7 8 4.3 14 27.1 4 14.1 18 12.i6 10i:.11 12 1.9 30 0.2 26 0.8 131 4.6 7 15.31 11 31.9 2 20.3 5 i 11.1 24 1.6t 13 )0.0 0 5.9 1 5.0 1 186. 1 1 ' 9.7 11 0.5 29 0.4 16 2..0 9i o. 0 1.5 16 14.0 11 5.2 16 2.8 12 16.0 241 0.0 0 51.0 29 10.8 19 5.0 251 10.5 7 / 9.5 14 11.1 8 39.1 21 17.0 29 7.1 8 1 2.5 11 6.8 1 2.5 5 19.7 3 1.4 7 0.6 1 5.6 13 7.1 22 0.0 0 21.2 2 4.2 24 22.4 1 5 1.5f 1 2.0 18 2.0 8 0.1 30 4.8 5 14.9 20 0.6 14 _. _~~~~~~~~~~~~.! MAR Mm. 0.0 I 60.0 i 7.2 0.0 0.0 3.4 tCI[. )ate. APRIT,. | Mm. )Date. I — --- I — MAY. MI1i. Date. I- -I --- JUNE. Min. IDate. tI l 11.2 17.5 10.0 2.2 8.1 7.3 0.1 5.8 5.6 7.5 3.8 5. 5 3.0 0.0 24.2 10.8 3.0 15.4 3.3 12.2 13.3,52.5 9.6 8.0 22.2 24.4 7.5 9.4 12.5 7.5 0 18 30 0 1 0 4 9 27 31 13 31 28 i I 2 9 22 21 14 29 9 17 6 29 1 12 10 23 1 9 8 2 16 11 15 13 31 10 0.0 20.0 19.0 0.0 30.0 13.2 0.0 16.2 43.8 12.2 2.3 12.9 } 0.0 4.3 30.0 42.0 7.1. 19.8 24.0 0.0 18.0 29.4 10.8 14.0 2.5 18.8 4.0 i 5.9 1 13.0 21.7 1 4.0 4.2 -10.7 25.7 2.0 9.0 3.0 I 0 21 11 0 26 23 0 2 13 28 3 141 0 5 f 16 i.24 25 25 1.0 25 0 22 29 3 20 23 5 29 4 14 30 29 27 30 13 30 27 28 15 28.0 55.0 39.0 36.0 30.8 101.8 3.6 32.0 51.0 12.0 0.0 30.1 53.6 45. 0 51.5 11.1 166.8 56.0 29.5 21.2 1.2 32.5 45.6 7. 5 0.0 12.4 56.2 64.0 62.5 28.0 71.3 36.4 11.5 49.9 12.2 30.0 27.0 12.7 I 9 30 17 8 12 22 22 29 27 0 21 28 20 31 22 24 5 26 25 4 13 25 18 0 25 29 21 16 25 13 17 28 31 16 22 16 19 69.0 92.0 63.0 80.5 102.8 42.4 80.1 32.2 74.3 31.1 17.7 28.8 111.4 44.2 30.4 39.4 139.3 67.3 88.0 41.0 62.8 45.4 26.2 50.4 49.4 34.1 252. 7 18.1 6.1 93.6 143.4 58.3 33.0 80.1 105.2 107.0 38.1 116.3 24 26 18 23 11 24 13 25 22 24 9 21 29 1 3 29 29 3 15 29 16 21 17 30 15 15 11 21 28 24 6 16 16 28 27 13 17 L 37 TABLE 22.- Aaximumn daily rainfall in Manila: 1865-1902-Continued. JulT YEAR. --- Mil. 1865.....44..... 44.5 1866b....... —......21.5 1867...1...-...... 145.0 1868..............50.0 1869....1........ 101.8 1870.............. 71.0 1871.............. 15.0 1872............... 7.3 1873............ 48.7 1874............... 63.8 1875............... 9.8 1876............... 101. 1877............... 91.2 1878...............128.8 1879...............59.2 1880............... 290.1 1881............... 96.0 1882............... 176.8 1883.............. 156.9 1884.............. 179.5 1'885.............. 71.3 1886............... 38.0 1887............ 115.7 1888.............. 109.2 1889............... 95. 1890.............. 189.1 1891............... 139.4 1892............... 89.6 1893............... 53.8 1894.............. 67.0 1895........3....... 34.5 1896............... 46.1 1897........6.... 66.6 1898............... 30.0 1899............... 253.5 1900..7.......... 54.7 1901............... 36.1 1902............... 80.7 I _- - - - - -- 1 - -- - - - I-, --- -, --- - - --- - 111 1- " I 1 - - 1. -- -. -, —,- -- --, I I - -.1.. I.,Y. AUGUST. Date.l Mm. Date. 21 12 17 19 9 23 22 8 3 12 17 13 30 31 30 7 28 29 21 24.1 12 21 23 15 16 26 30 17 18 26 23 26 18 19:10 12 10 36.0 79.0 59.0 40.0 107.6 72.6 76.0 226.5 69.6 i 124.8 69. 1 95.5 192.7 84.0! 49.3 111.6 57.8 41.0 45.9 41.6 107.4 63.0 37. 6 89.6 45.9 58.5 43.8 t2.2 80.7 58.5 78.6 68.1 96.8 46. 7 37.1 28 2 30 2 21 3 2 31 30 22 8 15 17 27 4 20 8 2 1 i { 1 8 11 25 17 16 6 25 22 28 28 5 25 6 28 8 19 14 SE PT EMBER. Mill. Date. 114.0. 336.0 24 82.0 9 128.0 26 46.9 913 56.7 29 42.0 3 23.8 17 37.2 28 60. 4 28 117.8 13 32.2 15 74.2 23 162. 3 20 213.1 15 61.3 16 50. 5 22 5.0 5 50.9 12 11.4 5 4,8.8 18 164.8 19 47.0 17 40.2 10 83. 0 29 1158 15 60.2 7 77.0 6 67.7 28 115.6 2 72.2 75.4 1 87.2 16 180.8 20 76. 9 8 37. 6 123.2 22 O(CTOBER. Mmy). DI)ate. 94.0 61.0 172.0:12.5 94.8 29.7 88. 1 27.1 13.2 60.0 231. 3 48. 0 20, 8 165.2 34.5 11.2 2,24. 0 76.0 118.6 31.5 76.0 29.0 15.5 17.8 28.8 35. 9 21.:1 13.2 18.2 54.4 25.5 35.4 103. 9 26.8 3 19 7 16 1 27 16 13 2 27 17 14 30 8 12 20 10 12 19 11 '9 16 11) 9 7 7 1 19 6 NO)VEMBER. iIOCEMBER. Mni. It te.Mmi. Date. 37.5 9 8.5 16 55.0 30 65. 5 14 24.0 16 5.0 7 139.1 22 2.0 21 17 86.0 '21 10.0 17 24 40.0 5 25.2 9 80.I 3 5.0 8 52.7 5i '20.0 10 18.5 1 |50 12 15.6 '0 13.2 3 25.2 4 32.6 18 19.1, 32.2 3 21.0 23 '26. 23 102.6 20 2.6 15 68.8 8 8..5 2 15. 3 3 I 37.3 12 67.2 26. 2 19 14.7 18 3.2 12 98.7 18 17.7 2 18.9 7 i3. 3 16. 9 5 34.7 1 ) 61.2 26 i351 5 11.0 Ib 21. 1 63.3 3 90.0 1 15:3.8 11 20.3 22 1811.6 16. 8 4 2 1 11 14.4 3 34.6 20 ' 1 21 14.2 21 61.9 2 39.6 6 i 5.1 24 20.3 21 0. (I 1 19.0 21 20.8 31.,o 23.2 929.3 11 55.7 7 29. 0 12 57.3 8 26.0 28 ) i I ~~ - -~ -~ — -— ~~ ~- --— ~ - ~ -- ~~ ~ ~~ ~~~~ ~ ~~ -~- -— ~ ---~~-~~- — ~~ ---- — ~ — ~-~~~-~~~-~- ~~-~~~~~~-~- -~ — ~ — - - ~-~ ---~ —~ --- —- -~~ --- —----- TABILE 213.-(4n(mses atul c'cumslances of the roost Obtll(d((ft rainfaids n-hicwh hiv'e oc curred ivithin oflCl honr or pfirUt thelrei: Cf1885-1902. YEAR. Amount lDate. Hour. of rain (mm.). Cause of rain. Observations. 1892...... 1891...... 1887...-. 1899...... 1891...... 1890...... 1891.... May 21 liJune 15 Sept. 18 July 19 Sept. 15 lJuly 16 Nov. 16 1902...... une 1 1889...... Aug. 6 1889..... June:30 1898...... Sept. 14 1888..... Aug. 27 1888....... Sept. 17 1897....... Aug. 28 1894...... Mar. 9 1896...... Sept. 6 1888...... July 23 1886..... Aug. 26 1891...... May 29 5-6 p.m. 7-8 i. in. 6-7 p. m. 1-2 a. m. 5-6 p. in. 5-6 p.m. 3-4 p. m. 4-5 p.m. 2-3 p.m. 2-3 p.m. 1-2 a. m. 2-3 a.m. 7-8 p. m. 3-4 p.m. 0-1 p.u. 1-2 a.m. 4-5 a. m. 5-6 p.m. 7-8 p.m. 52.5 51.3 f). 3 49.8 48.5 47.2 47.2 47.0 417.0 46.0 45.8 44.0 42.8 42.0 42.0 Influence of distant pre.ssure. Intense thunderstornms...... Thunderstorm influenced by distant hurricane. Influence of distant hurriDistant hurricane in the north, Influence of a hurricane which crossed near the south of Manila. Thunderstorm inifluenced by a hurricane toward the east. Thtunderstorm..................... 10do....................... Distant pressure................... do........................ Thunderstorm................ Intense local thunderstorm.. Thunderstorm.............r. o.........................do.............................do.............................do........................ 60. 0 Intense local thunderstorm.. These 60 min. were registered by the pluviograph (Cassella in 30 I minutes. In 8 minutes 50 min. were collected. The pluviograph registered 40 minm. in: 30 imites. We foumnd 20 mnm. registered lin 15 minutes. 20 mmi. were registered in 12 m i n u tes. InI 7 minutes 50 mm. were registered. In 20 minutes 3(0 mim. were registered. In 17 miinutes 2f5 mnm. were registered in the phlviograph. 45 mm. of water fell in:35 minutte. 40 mm. registered in I6 minutes. '20 mm. collected in 15 minutes. 15 mm. registered in 15 minutes. I20 mm. registered in 10 minutes. 38 TABLE 24. —Maximum rainfall in each month, observed in Manila during the period 1885-1902. JANUARY. FEBRUARY. MARCH. YEAR......... Mm. Date. Hour. Mm. Date. Hour. Mm. Date. Hour. 1885.................. 1.0 9 3 p'm. 0.0 0 0 3.0 17 4-5 p.m. 1886.................. 1.5 16 0-1 p.m. 5.5 11 8-9 p.m. 0.0 0 0 18,7................. 0 6. 2-3 p.m. 2.8 12 0-1 p.m. 12.4 31 0-1 a.m. 18&-:;................ 11.5 24 2-3 p.m. 0.0 0 0 10.8 29 2-3 p.m. 1889................ 36.0 29 2-3 p.m. 10.7 19 2-3 p.m. 2.5 10 2-3 p.m. 18m.).................. 1.2 13 0-1 p. i. 3.0 7 8-9 p.m. 15.4 12 10-11 p.m. 1;.91...............9..5 14 2-3 p. 1.1 8 1-2 p.m. 3.3 10 0-1 ani. 1892.............. 8.4 21 3-4 a. 8.2 29 6-7 p.m. 8.5 23 5-6 p.m. 1893........... 3.0 8 10-11 p.m. 2.5 12 11-12 noon 8.0 10 3-4 p.m. 189..............0.9 4 1-2 p.m. 0.8 20 0-1 p.m. 45.8 9 0-1 p.m. 1895............... 14.5 3 5-6 p.m. 1.4 7 6-7 a.m. 9.6 8 3-4 p.m. 189.................. 0.4 2 6- a. 5.6 13 3-4 p.m. 2.1 2 0-1 a.m. 1 2-3 am. 1897................ 5.1 2.2 1-2 pl.. 0.0 0 0 9.5 16 5-6 p.m. 1898.................. 17.4 2 11-12 2.2 10 4-5 p.m. 6.1 15 3-4 p. m 189.................. 7.6 15 3-4 am. 1.5 12 10-11 a.. 5.8 30 2-3 p.m./ 1900................. 1.5 18 4-5 p.m. 1.2 9 7-8 p.m. 9.4 13 4-5 p.m. 1901.................. 0.1 30 6-7 am.. 4.1 5 3-4 p.m. 10.5 31 1-2 p.m. 1902.................. 9.3 20 3-4 p.m. 0.6 14 0-1 p.m. 7.5 10 1-2 p.m. APRIL. MAY. 188................. 1788.................. 1887.................. 188.................. 1889............. 1890................. 1891................ 1892.................. 1893................ 1894.................. 1895.................. 1896.................. 1897.................. 1898.................. 1899.................. 1900.................. 1901.................. 1902.................. JUNE. Mmi. Date.i Hour. 16. 0 J13.3,0. 8 1 t.0 2.5 14.6 4. 0 5.0 16.3 2.0 3.0 10.7 16.0 2.0 5.2 1.7 I Date. 2 3 20 23 15 29 27 30 13 22 27 28 15 Hour. 8-9 p.m. 4-5 p.m. 2 —3 p.. 7-8 p. n. 3-14. n. 3-4 a. i. 4-5 I. n. 4-5 a. n. 9-10 p.m. 11-12 noon 5-6 p. m. 2-3 p.m. 10-11 p.m. 1-2 p.m. 6-7 p.m. 9-10 p.m. 3-4 p.nm. 10-11 a.m. Mm. 1.0 16.5 36.5 4.0 0.0 10. 3 60. (0 13.8 21.3 25.5 133.6 II.5 25.0 9.2 30.0 15.8 10.9 Date. 4 2 22 21 0 6 29 21 16 10 13 17 28 10 16 22 16 31 Hour. 4-5 p.m. 2-3 p.m. 9-10 p.m. 7-8 p.m. 0 2-3 I.m. 7-8 Ip.m. 5-(6 p.m. 9-:0 a.m. 9-10 p.m. 9-10 a. m. 5-6 a. m. 2-3 p.m. 9-10 p. m. 1-2 p. m.I 2-3 a.m. 4-5 p. m. 7-8 p.m. 11 I 34.0 24.0 25.0 27.1 47. 2 27.1 55. 0 11.8 5.0 25. 4 31.8 16. 0 33.0 38.2 37.5 37.4 12.5 48.5 29 16 21 17;0, 15 15 11 18 i 28 28 26 6 16 10 28 27 13 1 5-6 a.m. 3-4 p.m. 8-9 p.m. 7-8 p.m. 2-3 p.m. 3-4 p.m. 7-8 a.m. 11-12 2-3 p.m. 1-2 p.m. 1-2 p.m. 0-1 a.m. 5-6 p.m. 4-5 p.m. 4-5 a.m. 4-5 p.m. 8-9 p.m. 5-6 a.m. 4-5 p.m. ~I~-~-^.l..i-._~X ~i(~tlll -_ l~lI.1_1 —.~I_.I. - -Ll1.1-_~ —__1~__~_ -~I~I^X-.::I -. ---- 1 1~I JULY. AU(GUST. YEAR. 1885.................. 1884............. 1887.................. 1881................. 1889.................. 1890.................. 1891.................. 1892.................. 1893.................. 1894.................. 1895........... 1896................. 1897................ 1899.................. 1900................. 1901................. 1902................. Min. 27.2 30.8 31.5 42.8 32. 7 10.0 26.2 40.0 27. 8 24.8 12.5 21.0 23.0 51. 3 26.5 29.0 39.0 I Date, 24 15 30 16 27 30 9 18 18 23 26 17 19 12 10 Hour. n.Mm 3-1 p.m. 2.5.0 0-1 a.m. 42.0 8 —9 Ip).in. 20.0 4-5 am. 47.0 6-7 a.m. -48.0 A5-6 p.. 20.5 9-10 a.ni. 22.0 0-1 a.i.. 20.3 9-10 p.m. 32.0 6-7 p.mII 29.2 7 8-9 p.m. 23.4 11-12 noon.32.8 4-5 p.im. 46.0 -4 p.m. 40.0 1-2 am.. 38. 0 5- p.m.in. 39.6 0-1 p.m i. 17, 2 2-3 p.m. 16.0 a Midnight. Date, 30 26 17 27 6 25 8 21 5 3 28 28 8 19 12 15 18 lHour. 8-9 p.m. 5-6 p.m. 7-8 p.m. 2-3 a m. 1-2 p.m. 7-8 p.m.m, 7-8 p.m. 5-6 p.m. 10-11 pIm. 8-9 p.m. 5-6 p.m. 7-8 p.m. 3-4 p.m. a11-12 8-9 p.m. 9-10 p. m. 0-1 p.m. 5-6 p.m. II a 1 -- I --- SEPTEMBER. I Mm. 9.0 23.3 52. 5 47.0 38.4 50.3 26.5 40.0 25.8 30.3 4-14.0 24.5 47.2 27.4 32.3 24.7 30.5 Date. 17 18 18 17 10 10 15 13 18 15 11 6 2 14 20 7 15 21 Hour. 7-8 p.m. 8-9 a. m. 6-7 p.m. 7-8 p.m. 2-3 a.m. a10-12 5-6 p.m. 7-8 a.m. 1-2 a.m. 7-8 p.m. 6-7 p.m. 1-2 a.m. 7-8 p.m. 1-2 a.m. 3-4 a.m. 7-8 p.m. 10-11 p.m. 3-4 p.m. I 39 TABLE 24.-Maximum rainfall in each month, observed in Manila during the period 1885-190;2 —Continued. OCTOBER. NOVEMBER. DECEMBER. YEAR. --- - -- -- - - - - -- Mm. Date. Hour. Mm. Date. Hour. Mm. Date. Hour. 1885.................. 24.0 6 6-7 p.m. 6.0 17 cll-12 3.0 3 4-5 p.m. 1886............... 31.5 10 4-5 p.m. 11.3 5 1-2 a.m. 7.0 19 1-2 p.m. 1887.......... —.... —. 17.0 5 1-2 p.m. 21.9 26 8-9 a.m. 25.6 5 2-3 p.m. 1888................. 27.0 9 9-10 p. 4.8 16 5-6 p.m. 13.3 5 5-6 p.m. 1889................. 14.5 18 4-5 p.m. 12.8 4 2-3 a.m. 22.0 9 3-4 p.m. 1890.................. 17.5 14 0-1 p. m. 24.0 11 10-11 a. m. 10.0 19 0-1 p.m. 1891 -.....-....... 15.5 9 5-6 p.m. 49.8 16 3-4 p.m. 10.8 3 0-1 a.m. 1892.................. 15.6 7 0-1 a.m. 12.6 4 1-2 p.m. 10.5 26 (11-12 1893.................. 22.4 11 all-12 11.0 22 3-4 p.m. 2.0 22 6-7 a.m. 1894.................. 21.6 22 1-2 p.m. 10.0 3 5-6 p.m. 16.2 2 4-5 a.m. 1895.................. 21.2 7 7-8 p.m. 17.0 6 1-2 p.m. 4.0 24 5-6 a.m. 1896.................. 10.0 12 all-12...... 21 2-3 p.m. 0.1 15 0-1 p.m. 1897............... 9.7 7 6-7 p.m. 17.7 21 2-3 p.m. 8.5 31 6(-7 a.m. 1898................. 21.8 6 all-12 35.5 22 1-2 p.m. 2.4 23 7-8 a.m. 1899............. 10. 1 9- p.. 14.3 14 5 —9- p.m. 16.5 19 3-4 p.m. 1300................. 19.5 5 3-4 p.m. 22.0 9 7-8 p.m. 8.7 11 2-3 p.m. 1901.................. 22.0 14 7-8 p.m. 21.0 13 0-1 p.m. 18.0 12 6-7 p.m. 1902................. 21.0 6 1-2 a.m. 24.0 8 10-11 p.m. 11.4 28 11-12 noon a Midnight. The following Tables, 25, 26, and 27, substantiate what has been said about the distribution of rainfall over the archipelago. They are the result of the observations made in different localities since the establishment of weather service in the islands. Finally, Table 28 compares the total amount of rainfall in Manila with that of several points in the Far East and in the United States, illustrating the result on Plate V. TABLE 25.-Monthly averages of rainfall and days of rain at different places in Luzon. JANUARY. FEBRUARY. MARCH. APRIL. STATION. Amount No. of Amount No. of Amount No. of Amount No. of (mm.), days. (mm.). days. (mm.). days. (mm.), days. Vigan (10 years)...... 0.0 0.2. 0 0.0 4.3 0.2 3.5 0.7 Bolinao (12 years)..... 1.2 0.3 1.5 0.4 11.3 0.8 10.1 1.4 Santiago (12 years).... 6.5 2.0 0.2 0.1 5.7 0.8 4.6 0.8 Daet (2 years)......... 252.3 21.5 177.9 11.5 226.7 1. 0 81.4 9.5 Atimonan (3 years).... 116.7 16. 7 81.3 10.3 73.3 7. 7 75.0 6.7 Albay (6 years)........ 233.5 21.3 168.2 15.2 229.0 16.3 155.4 13.7 Aparri (9 years)....... 230.9 11.7 98.8 6.1 48.7 5.7 27.9 3.2 Tuguegarao (2 years).. 3.4 2.0 1.1 1.0 11.2 4.0 23.2 8.5 San Isidro (10 years) 15.9 1.5 6.5 1.1 18.9 1.8 23.3 2.5 Tayabas (7 years) 124.0 10.4 48.9 7.7 60.2 8.1 23.8 6. 5 MAY. JUNE. JULY. AUGUST. STATION. Amount No. of Amount N. of Amount No. of Amount No. of (mm.). days. (mm.). days. (mm.). days. (mm.), days. Vigan (10 years)...... 89.2 2.9 217.4 10.0 535.6 13.8 289.4 13.9 Bolinao (12 years).... 122.6 6.9 382.5 14.1 558.2 17.0 525.4 18.1 Santiago (12 years)... 99.4 5.3 186.9 8.2 368.2 14.5 239.9 12.8 Daet (2 years)....... 189.5 12.5 139.7 11.5 211.4 15.0 382.2 17.5 Atimonan (3 years).. 163.3 10.3 169.1 13.3 258.4 18.3 178.7 15. 0 Albay (6 years)....... 188.3 15. 0 207.6 17.8 266.2 19.7 242. 1 21.5 Aparri (9 years)....... 66.9 5.4 58.3 5.3 129.4 7.5 174.1 10. 5 Tuguegarao (2 years). 27.1 5.0 52.6 14.0 154.6 16.5 68.0 10.0 San Isidro (10 years) 210.1 12.0 192.7 13.8 339.4 19.8 282.9 19.8 Tayabas (7 years) 100.7 9.9 88.6 13.0 96.6 12.7 73.9 12.6 40 TABLE 25.-Monthly averages of rainfall and days of rain at different places in Luzon-Continued. SEPTEMBER. OCTOBER. NOVEMBER. DECEMBER. TOTAL. STATION. Amount No. of Amount No of Amount No. of Amount No. of Amount No. of (mm.). days. (mm.). days. (mm.). days. (mm.). days. (mm.). days. Vigan (10 years)...... 486.1 15.8 176.4 5.0 65.5 1.9 0.3 0.1 1,867.7 64.5 Bollnao (12 years).... 584.0 17.5 192.1 7.5 34.4 2.6 8.1 1.0 2,431.4 87.6 Santiago (12 years)... 321.5 14.4 120. 8 9.5 101.6 7.5 57.5 5.1 1,512.8 80.5 Daet (2 years)........ 269.3 14.0 313.9 21.0 205.6 19.0 436.9 24.0 2,886.8 195.0 Atimonan (3 years)... 166.8 12.0 408.7 22.0 530.7 22.3 428.5 21.0 2,650. 5 175.6 Albay (6 years)....... 299.9 19.2 212.5 15.5 301.1 18.5 457.0 24.8 2,960.8 218.5 Aparri (9 years)...... 212.0 12.3 285.8 11.4 241.0 14.6 264.5 16.3 1,868.3 110.0 Tuguegarao (2 years). 76.1 14.0 143.8 15. 5 50.2 8.5 89. 1 14.5 700.4 108.5 San Isidro (10 years).. 361.5 20.7 168.0 11.3 102.0 7.0 51.6 4.6 1,772.8 115.9 Tayabas (7 years)..... 116.5 15.0 239.0 15.0 283.2 14.1 195.4 18.7 1,450.8 142.7 TABLE 26. —Monthly averages of rainfall and days of rain at different places in the Visayas and Mindanao. JANUARY. FEBRUARY. MARCH. APRIL. STATION. Amount No. of Amount No. of Amount 'No. of Amount No. of (mm.). (lays. (mm.). (lays. (mm.). days. (mm.). days. Mamburao (2 years)... 3.2 2.5 2.3 3.0 9.4 4.0 299 50 Zamboanga (2 years).. 41.2 11.2 27.0 7.0 58.5 9.0 21.8 5.0 Jolo (5 years).......... 103.1 5.5 45.6 2.5 44.2 3.7 88.3 4.5 Ilollo (4 years)........ 23.5 3.3 24.1 3.8 29.3 5.3 34.5 6.8 Cebu(5 years)......... 91.6 11.0 52.1 11.2 64.0 10.8 21.2 6.6 Tamontaca (2 years).. 61.4 6.0 50.3 5.0 128.0 9.0 828 8.0 Davao(2years)........ 283.5 17.5 124.8 10.0 71.0 14.5 161.7 130 Tandag (2 years)...... 682.5 27.5 403.6 22.0 624.4 23.0 356.3 23.5 MAY. JUNE. JULY. AUGUST. STATION. Amount Amount No. of Amount No. of Amount No. of Amount No. of (mm.). days. (mm.). days. (mm.). days. (mm.). days. Mamburao (2years)... 271.8 13.0 595.0 22.0 327.0 26.5 9971 24. Zamboanga (2 years).. 86.6 10.0 162.4 12.5 94 1 12.5 39.1 9.0 Jolo (5 years).......... 243.3 13.0 144.8 10.3 145.9 11.7 117.8 9.0 Iloilo (4 years)........ 222.9 11.5 174.2 17.8 367.8 18.3 288.8 22.0 Cebu (5years)......... 102.6 10.2 191.4 16.8 160.8 16.0 165.8 15.8 Tamnontaca (2 years).. 191.2 11.3 312.3 13.0 224.8 16.5 200.6 12.0 Tandag (2 years)...... 217.4 15.0 164.3 15.5 217.1 14.5 123.7 12.5 SEPTEMBER. OCTOBER. NOVEMBER. DECEMBER. TOTAL. STATION. AmountNo. of Amount No. of Amount No. of Amount No. of Amount No. of (mm.). days. (mm.). days. (mm.). days. (mm.). day. (mm.). dy Mamburao (2 years). 485.4 20.5 323.3 17.0 48.2 4.5 23.7 5.0 3,116.3 147.5 Zamboanga (2 years).. 73.6 10.0 95.6 13.0 746 110 111.6 110 8861 121.0 Jo (5 year)......... 149.5 9.0 163.9 13.0 127.8 8.7 160.2 10.3 1,534.4 101.2 nollo (4 years)........ 272.0 20.0 220.1 16.7 126. 0 13.8 63.1 13.3 1,796.3 152.6 Cebu(5yeare)........ 165.2 14.4 169.4 15.0 116.3 14.2 171.7 19.0 1,472.1 161.0 Tamontaca(2years). 293.8 13.0 136.5 9.5 1512 105 767 75 1 9096 121.3 Davao(2years)....... 159.5 14.0 234.8 A90 666 150 2085 130 20404 1870 Tandag(2years)...... 187.5 10.0 198.3 12.5 284.1 19.0 966.0 28.0 4,425.2 223. 0 ,i 'I-s PLATE V. ANNUAL VARIATION OF RAIN IN VARIOUS PLACES OF THE PHILIPPINE ARHIBPELAGO, OF THE ANTILLES AND OF THE UNITED STATES OF AMERICA 42 TABLE 27.-Yearly averages of rainfall in several places of the archipelago during the two periods of the year, June to October and November to May, inclusive. NOVEMBER TO MAY. JUNE TO OCTOBER. STATION. Millimeter. Per cent. Millimeter. Per cent. Manila................................................ 379.5 20 1,537.1 80 Vigan................................ 247.7 11 2, 109.6 89 Boliao............................................... 155.4 7 2,209.4 93 Puntal Santiago....................................... 283.2 19 1,234.3 81 Daet................................................. 1,468.6 53 1,285.9 47 Atimonan........................................ 1,468.8 55 1,181.7 45 Albay............................................... 1,732.4 59 1,228.2 41 Aparri................................ 1,049.2 54 905.2 46 Tuguegarao........................................... 205.2 29 494.9 71 San Isidro..................................... 461.2 25 1,390.0 75 Tayabas.............................................. 1,002.0 61 640.8 39 La Carlota..................................... 805.4 31 1,785.9 69 Jolo......................................... 716.6 47 823.9 53 Iloilo.................................................. 494.4 29 1,229.5 71 Cebu............................................... 5,50.5 41 788.8 59 Davao................................................. 963.8 49 995.3 51 Tandag............................................... 3,218.3 75 1,080.9 25 Mati, sowtltl-aest o1 Mindanao......................... 905.8 66 467.5 34 Yap, Western (Carolinas.............................. 734. 9 39 1,160.1 61 San Luis de Apra, Guam.............................. 303.3 24 951.9 76 TABLE 28.- Yearly average of rain, at secral po'ints of the Far East and the United States. Yearly Years of STATION. average observa(mm.). tion. Manila (luozon).................................................................. 1,938.3 38 Bolinno ( l,uxzoi)................................................................ 69 Bolffiiio It~l1?.I)l).2,326.5 9 Punta Santiag) (Luzon).1,517.5 9 San Isidro (Luzon)............................................................. 1,796.0 9 Albay (Iuzt)................................................................ 2,816.9 7 La (arlota!(Negros)............................................................. 2,591.3 9 Iloilo (Pallay)..................................1....... 1, 774.2 4 Cebu............................................................................ 1,198.4 3 Jolo..........................................................8....... 1,505. 8 3 Tandag (Mindanao)........................................................... 4,425.2 2 Iongkong...................................................................... 2,205.9 0 Zikawei, Shanghai........................................................... 1, 119.0 24 Tokyo, Ja1.n...................................................., 467.6 21 Yap, Wester Carol i............................................... 1,895.0 1 San ilis det Apra, (itlln..................................... 1,255.2 2 Honolulu......................................... 6.2 20 Sa Francisco.................................................................... 594.4 47 Chicago.......................................................................... 863.6 80 New York........................................................................ 1,135.4 61 Washington................................................................, 089.6 41 New Orleans...................................................531.6 26 Key West.................................................................. 970.3 49 Habana.................................................................... 1,314.2 30 San Juan, Porto Rico............................................................ 1, 510.0 14 RELATIVE HUMIDITY. The quantity of water vapor in the atmosphere has a direct influence on climate, because it checks to some extent the radiation, and conse quently may diminish the diurnal and annual ranges of temperature. Hence, the knowledge of the ratio between the observed vapor pressure and the vapor pressure at saturation under existing conditions of temperature is of importance in climatology. Table 29 presents the relative humidity for Manila only, showing the annual and monthly averages of relative humidity during a period r PLATE VI. ANNUAL VARIATION OF THE RELATIVE HUMIDITY AT MANILA 1880- 1902 aInn. Fhr. nr. Anr. Ma, June Julu Aun. eant. Opt. Nou. Dc. I.nn. 85.0 - -. -. - - -- -- 85 83.0 _ ___ _ _ \ _. __ 83,0 83. 0_ ____ 83, 0 82. 0 ___ ___ ___ ___ ___ / __ ___ ___ ___ "S ___ ___ 82. 0 81.0 __. __ _ 81.0 80.0 _ _ 80. 0 78.0 _ _ 178.0 77;0 _ 77.0 76.0 \ ___ ___ ^ ___ ___ __ --- --- --- --- 76.0 75.0 ~ L ____ ____ --- —--------- 75.0 74.0 __ _ _ I _ __ - 74.0 73.0 _ -. _ _ _ _ _ -. - 73.0 72.0 72. 0 71,0 - -~\~__ __ ___ __ -- -- - - 71.0 X/~~ 44 of twenty-one years; in Table 30 appears the comparison of monthly and annual averages; in Table 31 the absolute minima; in Table 32 the average monthly variations of relative humidity; and in Table 33 the annual averages of the tension of the aqueous vapor. Plate VI presents graphically the annual variation of the relative humidity at Manila; Plate VII that of aqueous vapor; Plate VIII compares temperature with humidity and cloudiness, confirming what has been pointed out concerning the influence of humidity and water vapor on the temperature, or on the thermic oscillation (range of temperature). TABLE 29. —Monthly and annual averages of relative humidity in Manila: 1883-1902. [Per cent.] Annual YEAR. Jan. Feb. Mar. Apr. May. June. July. Aug. Sept. Oct. Nov. Dec. average. 1883.............. 73.3 71.6 74.8 77.2 83.0 85.1 83.9 86.6 80.8 78.4 83.8 79.6 1884............ 77.1 75.7 70.1 68.4 75.1 81.6 86.1 83.8 83.4 79.9 77.4 79.0 78.1 1885............ 74.2 75.6 68.7 68.3 72.0 75.0 81.0 82.3 80.2 80.8 80.5 78.2 76.4 1886fi..........,,, 79.5 74.2 66.8 73.7 75.8 82.5 84.5 82.6 86.7 85.7 81.1 82.9' 79.7 1887............ 81.6 75.6 79.4 78.2 84.1 86.6 90.0 84.8 89.9 83.2 85.3 87.3 83.8 1888..... 83.6 73.6 71.0 72.0 72.2 82.9 90.8 85.5 82.8 83.7 82.9 80. 7 80.1 1889.............. 84.2 80.3 75.9 68.0 68.6 80.0 83.3 84.4 85.8 85.0 83.9 86.8 80.4 1890.............. 78.4 74.2 68.9 73.1 79.2 81.8 83.2 82.4 87.1 85 85. 8 790. 79.5 1891............. 76.0 70.2 70.0 67.0 69.4 84.2 85.8 86.9 86.6 79.4 81.9 79.7 78.1 1892............. 76.5 721 772.3 67.4 75.0 79.0 83.8 84.1 85.9 82.1 82.2 78.4 78.3 1893.......... 7. 72.4 70.7 71.3 80.1 78.5 84.0 85.2 86.7 82.4 79.0 77.8 78.7 1894.............. 75.0 71.9 70.6 66.9 77.9 81.3 83.0 83.9 85.7 83.0 79.8 80.3 78.3 1895............ 7. 73. 4 71.1 72.9 83.4 83.4 83.4 84.3 86.8 79.2 80.9 77.1 79.4 1896............ 8 72 73.8 72.7 71.4 66.6 84.1 83.3 84.5 88.8 85.7 83.1 81.9 79.2 79.6 1897.............. 75.6 1.4 69.3 68.2 77.2 76.0 83.5 85.1 85.4 3.1 83.6 83.0 78.5 1898............. 77. 77.6 78.9 77.6 79.7 84.1 86.2 83.1 83.6 84.9 85.7 78.7 81.4 1899............. 7. 7. 740 73.3 73.1 77.5 81.9 86.7 85.1 84.5 82.4 84.9 80.4 80.1 1900...... 7...... 776.9 74.2 68.7 73.5 80.6 83.9 86.7 86.3 83.3 82.3 81.5 79.6 1901............. 75.3 75.1 71.4 68.4 76.9 81.6 83.3 86.7 84.1 83.9 86.4 79.6 79.4 1902........... 77.6 72.3 70.1 68.7 75.9 80.9 83.9 86.8 85.8 82.0 80.6 80.6 78.8 Average.... 77.6 74.2 71.8 70.7 76.7 81.4 84.8 84.8 85.5 82.7 82.0 80.7 79.4 TABLE 30.-The normal monthly averages of relative humidity compared with the annual average and the extreme monthly averages: 1884-1901. [Per cent.] EXTREME DEPARTURES OF MONTHLY FROM MEAN Monthly MONTHLY AVERAGES. Normal minus MONTH. average. annual average. Maximum Maximum posi- M ative tive difference. negative tive d erence difference. January....................................... 77. 6 -1.8 6.6 1889) 3.8 (1896) February........................................... 74.2 -5.2 6. 1889) 4.0 (1891) February. --- —— ~ ----~ --- -~ —~ --- ~~~ — ~~~ --- ~~-~~~~ 74.2 -5.2 6.1 (1889) 4. 0 (1891) March...................................... 71.8 -7.6 7.6 1887) 5.0 (1886) April.7................................ 70.7 -8.7 7.5 1887) 3.9 (1896 May................................................ 76.7 -2.7 7.4 (1887,1896) 8.1 (1889 June................................................ 81.4 +2.0 5.2 (1887) 6.4 1885 July........................................... 84.8 +5.4 6.0 (1888) 3.8 (1885) August....................................... 84. 8 +5.4 4.0 (1896 2.5 1885 September.......................................... 85.5 +6.1 4.4 (1887.3 (1885 October...................................... 827 +3.3. 0 1886 3.5 1895 November....................................... 82.0 +2.6 4.4 (1901 4.6 (1884 December....................................... 80.7 +1.3 6.6 (1887 3.6 (1895) Year................................ 79.4........................................... --- PLATE VII. THERMIC OSCILLATION, HYGROMETRIO STATE AND NEBULOSITY AT MANILA Jan. Feb.,Mar. Apr May June July Aug. Sept. Oot. Nou. Dec. Z -, Ir - r - IT IF - - I -I I 0? 11 10 9 8 6 5 4 3 2 1 0 I I I I 90. _.. -.- -- 08 _ _;_, ' // _ -~ 88 04 - _/ - 70/. 74 1 - -- $ Thermic Oscillation. 72 - Hygrometric te t...... Neb1losity...-.. — 70, Vt!... 72..... 0 10 9 8 7 6 4 3 2 0 - _I I I. L - I I I - - - -. I I -.I -I - 46 The extreme departures of the annual mean from the normal annual mean were: Positive, 4.4 (1887); negative, 3.0 (1885). MJonthly maxima and mtinina of relative hlumidity: 1883-1902.During the whole period 1883-1902 the absolute monthly maximum of relative humidity was only four times below 95 per cent, namely, 93 per cent (March 6, 1884 and April 28, 1900), 94 per cent (March 6, 1885 and April 14, 1893), while it frequently reached 99 and 100 per cent (saturation). The minima of the same meteorological element corresponding to each month in the year are shown in the following table: TABLE 31.-Minima of relative humidity in Manila: 1884-1902....... = = - 7 -..... MONTH. Per eelt. January........................... 400 3,1897 1 40.0 {19,27,1901j February....................... 31.0 (12,1901) March........................ 1.5 (13,1897) April.............................3 0. 1888 May.......................... 3 1. 8,19021, MONTH. Per cent. Junle............................ 36.0 ( 1,1892) July....................-..... 51.0 (28,1900) August......................... 52.0 (16,1895) September...................... 51.0 (22,1888) October......................... 46.0 (22,1885) November...................... 39.0 (26,1884) December...................... 39.5 ( 2,1885) Hlence, the lowest relative humidity during the whole period was observed on February 12, 1901. TA BI:. 32. —.1 erlqe m(onthly/ variatioins of relative humidity in Manila: 1885-1902. 4 [I'er cent.] I- -1- - _. 1 ~- - - - - - I - "- 1. 11-1May.-. J n-. —Juy —. Aug. e t O. Nov.-I. --— Dec. -- ____...G__ _.. _.. _.__. _.. ___._. _ __ _ _ _ __ _ _~~~~~~~~~~~~~~~~~~~~~ Y EAR. Jan. I Feb. Mar. Alr. 1885.............. 18W6................ 1887............... 1&S8.............. 1889................ 1890............... 1891............... 1892................ 1893............... 1894............... 1895................ 18................ 1897............... 1898............... 1899................ 1900............... 1901................ 1902................ Average..... 32.0 28.7 32.4 26.2 31.2 35.7 31.0 30.8 33.3:34.0 31. 2 35.0 35.5 30.0 27.4 31.5 36.4 27.7 32.0 31.3 33.9 38.7 32.3 38.3 34.8 37.8 I36.6 34.8 37.1 i 36.5 33.2 32.2 32.4 30.0 28.8 30.5 33.4 34.9 33.1 38.5 38.1 41.9 36. 9 39.2 36. 7 31.8 36.4 36. 1 36.5 30.0 33.8 33.0 35.6 35.1 33.4 33.3 32.8 40.4 40.4 36.0 37.0 38.6 36.4 38.4 34.7 35.8 36.3 32.5 36.0 37.4 36.4 36.6 Mway. IJule. 33.7 34.2 31.5 30.1 31.7 29.0 41.1 28.4 38.9 34.8 34.2 31.1 36.8 26.5 38.2 35.5 31.6 33.6 33.9 30.4 26.8 28.9) 25.8 27.2 32.0 30.6 30. 25.2 31.2 31.2 35.2 28.6 33.0 29.2 32.3 28.6 33.2 30.2 July. 26.9 30.4 19.7 19.0 29.6 28.4 22. 2 26.3 28.7 28.9 26.4 26.9 25.4 17.6 28.5 28.5 2fi.0 1 Aug. 28.0 32.4 31.2 23.8 27.6 31.9 22.7 30.8 26.1 26.8 26.8 19.0 25.3 20.2 23.2 22.0 21.3 21.2 r Sept. 30.5 26.2 22.1 31.4 30.6 24.9 22.5 22.8 24.3 26.0 22.4 23. 1 23.9 29.9 25.6 21.7 23.7 22.2 31.1 28.9 29.5 30.1 27.6 28.0 33.5 28.6 27.9 29. 6 33.1 25.7 27.7 25.0 26.4 26. 6 25. 2 30.0 Oct. I Nov. I Dec. 28.9 31.0 27.5 31.1 26.2 29.7 29.7 26.5 26.4 30.3 31.1 28.7 27.2 22. 6 24.7 26.7 24.8 32.2 ll 24.8 28.0 26.9 32.7 23.7 34.0 28.4 29.6 27.5 32.0 30.6 29.3 24.8 27.1 31.9 27.1 29.1 30.3 Average. 30.7 30.6 29.2 31.8 31.8 32.8 30.2 32.0 30.6 31.6 30,9 29.0 30.0 27.5 28.5 29.0 29.3 29.3 30.3 31.8 33.9 35.8 36.2 25.8 25.6 25.2 28.6 28.1 28.811 PLATE VIII. ANNUAL VARIATION OF THE TENSION OF AQUEOUS VAPOR AT MANILA 1883 - 1902 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oc. Nou. Dec. Jan. mm. mm, 23.0 2.__ 23.0 22.0 - 1 - \ -- 22.0 21.0 -21.0 20.0 ___ \_ 20.0 Il.. I I I I I I I I I \I Il II 18.0 -.\ 2_ — 0.18.0 17.0 - - i --- 17.0 23621-No. 2-04-4 48 TABLE 33. —Monthly and annu.l averages of the tension of aqueous vapor in Manila: 1883-1902. [Millimeters.] YEAR. Jan. Feb. Mar. Ar.. May. June.uly. y.Aug. Sept. Oct. Nov. Dec. ver age. 1883...... 18.1 17.6 19.5 20.9 22.3 22.0 21.9 22.8 22.1 20.7 19.2 18.6 20.4 1884...........165 17.3 17.7 18.8 21.0 21.5 21.5 21.5 20.5 19.1 17.7 19.6 1885.........16.8 17.0 17.2 18.2 20.7 20.9 21. 21.9 21.9 21.6 20.3 18.7 19.7 1886................ 16.9 1.9 20.9 21.8 2.5 22.5 22.4 23.0 22.0 20.2 19.3 20.6 1887........ 18.0 20.4 21.3 23.0 23.5 23.8 22.6 22.7 21.1 21.3 20.9 21.5 1888.. 1.9.5..17.3 19.2 20.9 21.5 22.9 22.8 22.8 22.6121.9 212 20.1 21.1 1889........... 20.6 20.4 20.3 20 21.6 23.1 22.6 22.5 23.3 22.4 21.5 20.0 1.6 1890............... 19.0 18.2 18.3 20.3 22.1 21.9 22.1 22.0 22.2 21.4 19.3 18.7 20.5 1891............ 17.3 16.4 17.9 19.2 21.3 22.8 22.3 22.4 22.7 21.4 20.5 19.2 20.3 1892................ 18.2 17.9 18.9 18.7 21.8 22.0 22.5 22.1 22.3 21.6 20.2 18.4 20.4 1893................17.0 17.3 18.0 221 21.4 22.3 21.0 1 18.6 20.2 1894.............. 17.2 16.8 18.1 18.8 21.6 22.3 22.1 22.5 22.3 21.7 19.4 18.9 20.1 1895................ 17.8 17.2 18.4 20.6 23.3 23. 22.7 22. 22.7 2 21.4 19.8 18.1 20.6 1896............. 16.8 17.8 18.9 18.9 22.9 23.3 22.7 22.6 22.8 22.2 20.8 18.9 20.7 1897.............. 18.3 18.0 18.9 20.0 23.2 23.0 22. 22.6 22.8 22.2 21.8 20.0 21.1 1898................18.8 19.5 19.9 21.322 23.0 22.3 22 22.2 22.2 21.3 19.3 21.2 1899................ 18.6 17.4 17.9 20.2 21.7 22.1 22.9 22.4 22.6 21.7 2).8 19.6 20.7 1900........... 18.3 19.0 20.0 20.0 22.6 22.7 23.0 23.4 23.5 22.2 21.1 19.8 21.3 1901................ 17.8 17 18.3 9.4 22.5 23.1 22.6 27 231 22.1 21.9 18.7 20.8 1902.............. 18.6 6.0 18.1 19.1 22.1 22.8 22.3 22.9 22.3 21.3 20.1 19.7 20.4 Average.... 18.2 17.7 18. 19.9 22.1 22.5 22.5 22.5 22.5 21.6 20.5 19.2 20.7 MOVEMENT OF TIIE ATMOSPHERE. SURFACE1 WINDS. Another important climatic factor is the wind, because the movement of air increases evaporation and dries the soil, thus increasing the demand of organisms for water, and the evaporating capacity of a climate. Besides, the wind affects directly the sensible temperature or the physiological temperature which is not indicated by dry-bulb thermometers. Under this head are included surface currents, their frequency and direction and the average velocity of these currents; the average direction of higher currents, viz, direction of high clouds, intermediate clouds, and lower clouds; extraordinary currents, viz, general and cyclonic storms, electric storms, mostly local. The frequency and direction of the winds in Manila should be first considered, since they suggest the prevailing winds in the remainder of the archipelago. PLATE IX. ANNUAL PROGRESSION OF THE WINDS AT MANILA. 6 mm. 51% PLATE X. 8EMIAtUAL PBOLEBS8ION OF THE WIND8S AT MANILA. 5 mm.-1% (June to October) ( November to May) W8W I 51 TABLE 34.-Monthly, annual, and semiannual frequency of the winds in Manila. N. NNE. NE. ENE. E. ESE. MONTH. MONT. Num Num- Num- Num- Num- Num- er her of Per her of ber of ber of Per berof Per ber of cases, cent. cases. cent cases. cent. cases. cent. cases. cent. Cas. cent. January.......... 1,053 11.8 954 10.7 848 9.5 517 5.8 887 9.9 497 6.6 February......... 515 6.3 446 5.5 627 7. 7 527 6.5 1,197 14. 7 795 9.8 March............ 400 - 4.5 414 4.6 578 6.5 594 6.7 1,432 16.0 1,022 11.4 April............. 252 2.9 248 2.9 351 4.1 454 5.3 1,211 14.2 1,14'2 13.4 May.............. 398 4.5 391J 4.4 453 5.1 294 3.3 721 8.1 620 6.9 June............ 354 4.1 367 4.2 478 5.5 300 3.5 606 7.0 473 5.5 July.............. 348 3.9 281 3.1 309 3.5 240 2.7 369 4.1 268 3.0 August........... 297 3.4 243 2.8 385 4.4 197 2.3 334 3.8 251 2.9 September........ 330 3.8 291 3.4 307 3.6 203 2.4 343 4.0 239 2.8 October........... 562 6.3 664 7.4 615 6.9 322 3.6 516 5.8 330 3.7 November........ 984 11.4 899 10.4 &33 9.6 404 4.7- 5,51 6.4 290 3.4 December....... 1,314 14.9 1,168 13.2 902 10.2 369 4.2 593 6.7 314 3.6 Annual..... 6,807 6.5 6,366 6.1 6,686 6.4 4,421 4.2 8,760 8.4 6,241 6.0 November to May, inclusive....... 4,916 8.0 4,520 7.4 4,592 7.5 3,159 5.2 6,592 10.8 4, 680 7.7 June to October, inclusive....... 1,891 4.3 1,846 4.2 2,094 4.8 1,262 2.9 12,168 4.9 1,561 3.6 SE. SSE. S. SSW. SW. WSW. MONTH. Nuim Pe Num- Num- Nllm- r nu- Number of e ber of cent berof PceJ b ero f c en t be rof cen cent. cent. cent (cent. cent. cent. cases. ca es. cases. cases. Cases. cases. January.......... 341 3.8 124 1.4 114 1.3 158 1.8 358 4.0 457 5.1 February......... 591 7.3 184 2.3 103 1.3 141 1.7 328 4.0 483 5.9 March........... 741 8.3 284 3.2 125 1.4 154 1.7 385 4.2 506 6.7 April............ 996 11.7 334 3.9 142 1.7 188 2.2 430 5.0 471 5.5 May.............. 637 7.1 301 3.4 296 3.3 413 4.6 872 9.8 743 8.3 June........... 529 6.1 294 3.4 411 4.8 534 6.2 1,027 11.9 680 7.9 July............- 373 4.2 316 3.5 463 5.2 907 10.2 1,719 19.3 778 8.7 August.......... 224 2.6 221 2.5 461 5.3 892 10.2 1,712 19.6 1,008 11.5 September.... 257 3.0 269 3.1 466 5.4 833 9.7 1,700 19.7 910 10.6 October.......... 328 3.7 243 2.7 300 3.4 465 5.2 729 8.2 656 7.3 November........ 244 2.8 141 1.6 147 1.7 194 2.2 342 4.1 378 4.4 December........ 159 1.8 93 1.1 100 1.1 151 1.7 258 2.9 376 4.3 Annual.5... 6,420 5.2 2,804 2.7 3,128 3. 0 5,030 4.8 9,860 9.4 7,446 7.1 November to May, inclusive....... 3,709 6.1 1,461 2.4 1,027 1.7 1,399 2.3 2,973 4.9 3,414 5.6 June to October, inclusive...... 1,711 3.9 1,343 3.1 2,101 4.8 3,631 8.3 6,887 15.7 4, 032 9.2 W. WNW. NW. NNW. CAIM. ~~~___~_____ ____ -____. — ~ --- - - ~Total MONTH. obserMONT Num NPe m-r Num N - Per Num. Per Num- pr vatils. her of cent. er of Per her of ber of her of ces. cases. cases. cases. cases. cases. January.......... 410 4.6 161 1.8 151 1.7 185 2.1 1,713 19.2 8,928 February......... 431 5.3 184 2.3 99 1.2 88 1.1 1,397 17.2 8,13 March............ 451 6.1 149 1.7 90 1.0 308 1.2 1,495 16.6 8,928 April............. 471 5.56 182 2.1 84 1.0 69 0.8 1,519 17.8 8,544 May............ 534 6.0 169 1.9 96 1. 1 120 1.3 1,870 20.9 8, 928 June........... 409 4.7 180 2.1 142 1.6 90 1.0 1,766 20.4 8,640 July............... 445 5.0 211 2.4 173 1.9 119 1.3 1,609 18.0 8, 928 August......... 412 4.7 194 2.2 151 1.7 139 1.6 1,616 18.56 8,736 eptember.... 437 5.1 188 2.2 148 1.7 132 1. 1,563 18.1 8,616 October......... 421 4.1 47 200 2.2 142 1.6 171 1.9 2,264 25. 4 8,928 November....... 343 4.0 162 1.9 183 2. 1 237 2.7 2,308 26.7 8,640 December... 311 3.5 163 1.7 169 1.9 247 2.8 2,15 24.J 4 8,832 Annual..... 6,075 4.8 2,133 2.0 1,628 1.6 1,70 1.6 21,274 20.3 1.04,784 Novemberto May, 169 20.3 11 1, 9'28 nclusive. 2, 91 4.8 1,160 1.9 872 1.4 1,054 1.7 12,457 20.4 60,96 June to October, inclusive. 2,124 4.8 973 2.2 756 1.7 651, 1.5 8,817 20.1 43,848 52 In the following summary will be seen the maximum and minimum frequency or repetition of the winds in the different months of the year: FREQUENCY. FREQUENCY. MONTH. MONTH. Maximum. Minimum. Maximum. Minimum. January............ N. S. July......... SW. NNW. February........... E. NNW. August........... SW. NNW. March.......... E. NW. September......... SW. NNW. April.......... E. NNW. October............ SW. NW. May................ W. NW. November........ N. SSE. June................ SW. NNW. December....... N. SSE. and S. The prevailing wind in Manila, therefore, is from the southwest from May until October, inclusive; that is to say, for about six months. From November to January, inclusive, north winds prevail, and during the other three months, February, March, and April, the easterly winds prevail. The lowest frequency of the north and northwest winds occurs from February to October, and that of the south and south-southeast winds in the months of November, December, and January. Table 34 shows that in the months in which the north wind has the greatest per cent the north-northeast and northeast winds prevail mostly after that, and also that in the months in which the east winds are most prevalent the next frequency corresponds to the east-southeast and southeast, if we leave out the month of February, which gives the northeast wind a larger per cent thathahat from the southeast. Accordingly it can be said that from November to January, both inclusive, the north and northeast winds prevail, while in the months of February, March, and April the east and southeast winds prevail. As to the months in which the southwest winds prevail, it is to be seen that May and October are not far below the maximum frequency of east and north-northeast winds, from which it appears that May is the month of the veering of the winds from east to those of southwest, and that October is the month wherein they change from southwest to those of the north. Applying Lambert's complete form and substituting each of the 16 directions instead of the corresponding per cent the table gives us, we will have found the medium or resultant directions for each of the twelve months in the year, as follows: MONTH. Resultant. MONTH.Resultant. January........................ 410 07' E. July........................... S. 34~ 28' W. February....................N. 830 13' E. August.....5............... S.400 48' W. March............................ S. 84 18' E. September...................... S. 39 41' W. April.............5.... S. 630 31' E. October...................... 75032'E. May............................... S. 16~ 55 E. November........................ N. 27 45' E. June.. 0 41....................... 0 41 E. December...........N. 24013' E.. ~ ~~~~~~~ ~ ~ ~ ~ ~ ~~~~ ~~ ~~~~~ iN,. 24.,3 E.. - 53 Annual frequency.-From the annual sums or totals and the corresponding percentage which we have given in Table 34 the annual variation of the winds can be deduced, which is herewith graphically represented in the drawing or figure (1). These facts show that the prevailing winds during the year are those from the southwest, followed by those from the east. The frequency or prevalence of those from the other directions diminish in the following order: West-southwest, north, northeast, north-northeast, east-southeast, southeast, south-southwest, west, east-northeast, south, south-southeast, west-northwest, northwest, and north-northwest. Prevalence of winds in Manila duriny two seasons.-We have divided the year into two periods, from November to May, inclusive, and from June to October, inclusive, and we have added to Table 34 the corresponding facts which have helped us to give in the two following drawings, 2 A and 3 A, the annual variation of the wind direction in Manila. During the period from June to October those from the southwest are most prevalent, those from the east and north having the maximum prevalence in the other period. Annual medium or resultant direction -........ --- —. --- —---. S. 58~ 42' E. Medium semiannual direction: June to October, inclusive. —..-................5.. ---.. S. 32~ 41/ W. November to May, inclusive -......... ---. --- —..... N. 70~ 30' E. From the continuous record of the force and direction of the wind in many years, the following important conclusions are drawn: 1. The calms or very light winds prevail in all the months during the hours of the night, their maximum prevalence being from 6 to 7 a. m., and most commonly at 7 in the morning, except in the months of November and December, when, according to observations, calms occur mostly at 9 o'clock at night. 2. The minimum prevalence of calms takes place at about 12 o'clock noon, or, in other words, at the time of greatest heat. 3. From the month of December to April, both inclusive, the winds of the third quarter very rarely take place during the night, or after 8 o'clock in the morning. 4. Nevertheless, these winds from south to west generally prevail in all the months of the year from 9, 10, or 11 o'clock in the morning until 3 or 4 o'clock in the afternoon, owing to the sea breezes, which in Manila blow in that direction or quarter. In the month of April these breezes often prevail until 1 p. m., giving way then to the winds from east-southeast, which are proper in this month and which are often strong in the few hours of the afternoon. 5. In those months in which the winds of the third quadrant prevail, in the first few hours of the day the winds of the first and second quadrants also prevail to a certain extent. In the month of June these give a maximum frequency from 8 o'clock at night until 8 o'clock in the morning. 54 Ihourly, annual, and semiannual frequency.-In Table 35 we give the final results of hourly observations, that is to say, the yearly summary and the corresponding percentage for each twenty-four hours of the day, and the principal direction. TABLE 35.-Frequency of the wind in Manila, with direction noted by hours, for period 1892-1898. 1 A. M. 2 A. M. 3 A. M. 4A. M. 5A. M. 6A. M. DIRECTION. N............ NNE....... NE........ ENE........ E.......... ESE........ SE.......... SSE........ 8........... SW....... sw......... w.......... WNW...... NW......... NNW....... Calm....... Number of cases. 230 188 190 100 160 142 150 69 63 88 94 65 '30 19 29 47 886 Per cent. 6.6 5.5 4.9 4.0 3.6 3.9 4.3 3.9 3.0 3.2 1.9 1.3 1.0 1.5 3.0 4.8 6.6 Number of cases. 242 233 235 135 151 116 117 66 39 99 78 62 32 25 25 48 837 * Per cent. 6.9 6.8 6.0 5.4 3.4 3.2 3.3 3.8 2.2 3.6 1.6 1.2 1.0 1.9 2.6 4.9 6.3 Number of cases. 255 264 245 133 141 105 104 45 53 69 81 58 23 16 25 50 873 Per Num Per Num- Per Num Per ce berof berof cent er ofcent. cases. cases. cases. 7.3 7.7 6.3 5.3 3.2 2.9 3.0 2.6 3.0 2.5 I 1.6 1.2 0.7 1.2 2.6 5.1 6.5 261 262 297 153 142 97 89 58 40 65 64 52 28 18 19 50 845 7.4 7.6 7.6 6.1 3.2 2.6 2.5 3.3 2.3 2.4 1.3 1.0 0.9 1.4 2.0 5.1 6.3 254 221 294 170 172 94 62 33 34 47 51 36 21 15 28 39 969 7.2 6.4 7.5 6.7 3.9 2.6 1.8 1.9 1.9 1.7 1.0 0.7 0.7 1.2 2.9 4.0 7.2 227 222 270 160 164 102 60 38 39 45 48 31 19 7 19 48 1,041 6.5 6.4 6.9 6.3 3.7 2.8 1.7 2.2 2.2 1.6 1.0 0.6 0.6 0.5 2.0 4.9 7.8 7 A. M. 8 A. M. 9 A. M. 10 A. M. 11 A. M. 12 NOON. DIRECTION. DIRECTION. Num- Num- Num- Num- Num- Number of cen ber of r of er n ber of er ber of en berof Pen cases. c cas. ases. ct ases. centc. c ases. cases. N.......... NNE........ NE........ ENE........ E......... ESE....... SE......... S8E......... SW........... SSW........ SW......... WSW....... W.......... WNW....... NW....... NNW....... Calm....... 228 232 247 166 158 79 47 35 41 46 50 32 12 10 23 40 1,094 6.5 6.7 6.3 6.6 3.6 2.2 1.3 2.0 2.3 1.7 1.0 0.6 0.4 0.8 2.4 4.1 8.2 243 223 251 118 144 99 79 59 82 71 74 53 37 21 34 65 887 6.9 6.5 6.4 4.7 3.3 2.7 2.3 3.4 4.6 2.6 1.5 1.1 1.2 1.6 3.5 6.6 6.6 178 169 139 85 114 97 101 65 132 138 194 250 197 83 85 87 426 5.1 4.9 3.6 3.4 2.6 2.6 2.9 3.7 7.4 5.0 3.9 5.0 6.3 6.4 8.7 8.9 3.2 92 93 91 44 101 89 85 38 104 168 322 411 403 156 104 75 164 2.6 2.7 2.3 1.7 2.3 2.4 2.4 2.2 5.9 6.1 6.5 8.2 12.9 12.1 10.7 7.6 1.2 64 66 65 54 61 93 80 45 90 159 345 540 472 179 95 40 92 1.8 1.9 1.7 2.1 1.4 2.5 2.3 2.6 6.1 5.8 7.0 10.7 15.1 13.9 - 9.8 4.1 0.7 57 55 68 43 92 98 90 46 72 142 373 589 485 161 62 31 76 1.6 1.6 1.7 1.7 2.1 2.7 2.6 2.6 4.1 5.2 7.6 11.7 15.5 12.5 6.4 3.2 0.6 55 TABLE 35.-Frequency of the wind in Manila, with direction noted by hours, for period 1892-1898-Continued. 1 P. M. 2 P. M. 3P. M. 4 P. M. 5P. M. I 6P.M. DIRECTION. Number of cases. Per cent. Number of cases. Per cent. N........... NNE....... NE......... ENE........ E.......... ESE........ SE.......... SSE........ S........... SSW........ SW......... WSW....... W.......... WNW....... NW......... NNW....... Calm....... 57 75 73 53 94 118 119 66 69 150 379 588 398 143 53 25 80 1.6 2.2 1.9 2.1 2.1 3.2 3.4 3.8 3.9 5.4 7.7 11.7 12.7 11.1 5.4 2.5 0.6 55 80 110 66 115 126 139 85 91 154 375 532 327 112 53 30 90 1.6 2.3 2.8 2.6 2.6 3.4 4.0 4.8 5.1 5.6 7.6 10.6 10.4 8.7 5.4 3.1 0.7 Number of cases. 73 86.11 81 155 148 189 115 87 158 403 436 213 87 59 18 121 Per cent. 2.1 2.5 2.8 3.2 3.5 4.0 5.4 6.5 4.9 5.7 8.2 8.7 6.8 6.7 6.1 1.8 0.9 Number of cases. 79 102 140 99 182 208 224 147 97 151 377 342 122 48 43 25 154 Per cent. 2.3 3.0 3.6 3.9 4.1 5.7 6.4 8.4 5.5 5.5 7.7 6.8 3.9 3.7 4.4 2.5 1.2 Number of cases. 78 121 134 141 247 202 239 121 98 149 348 241 59 34 34 24 270 Per cent. 2.2 3.5 3.4 5.6 5.6 5.5 6.8 6.9 6.5 6.4 7.1 4.8 1.9 2.6 8.5 2.4 2.0 Number of cases. 83 106 142 125 326 252 211 93 89 129 321 189 36 26 26 17 369 Per cent. 2.4 3.1 3.6 5.0 7.4 6.9 6.0 5.3 6.0 4.7 6.5 3.8 1.1 2.0 2.7 1.7 2.8 7 P.M. 8 P. M. 9 P. M. 10 P. M. 11 P. M. 12 MIDNIGHT. _.__.___ _____Total DIREC- obTION. Num- Num- r Num er Num- Num- Nu- serva-.. Perberof P Per Per Per ber ofen ber ofcen ber of ber of ber of berofc tions. case e es e nt. icases entcases. centcases. centcases. csecent. N....... 77 2.2 88 2.5 101 2.9 132 3.8 167 4.8 183 5.2 3,504 NNE.... 87 2.5 77 2.2 83 2.4 114 3.3 126 3.7 161 4. 7 3,446 NE..... 124 3.2 115 2.9 112 2.9 121 3.1 144 3.7 188 4.8 3,906 ENE... 119 4.7 90 3.6 98 3.9 104 4.1 94 3.7 92 3.6 2,523 E........ 370 8.4 349 7.9 292 6.6 255 6.8 232 5.3 188 4.3 4,405 ESE..... 269 7.3 245 6.7 245 6.7 248 6.8 216 5.9 175 4.8 3,663 SE...... 218 6.2 206 5. 9 254 7.3 238 6.8 205.9 191 5.5 3,497 SSE..... 91 5.2 93 5.3 95 5.4 96.5 8 4.8 75 4.3 1,759 S........ 89 5.0 93 5.2 89 5.0 78 4.4 73 4.1 43 2.4 1,775 SSW.... 150 5.4 141 5.1 125 4.5 105 3.8 100 3.6 105 3.8 2,754 SW...... 272 5.5 207 4.2 161 3.3 123 2.5 100 2.0 87 1.8 4,927 WSW... 132 2.6 118 2.3 82 1.6 62 1.2 62 1.2 69 1.4 5,032 W....... 46 1.5 31 1.0 35 1.1 40 1.3 38 1.2 29 0.9 3,133 WNW... 18 1.4 24 1.9 26 2.0 25 1.9 19 1.5 18 1.4 1,290 NW..... 17 1.7 24 2.5 24 2.5 33 3.4 31 3.2 28 2.9 973 NNW... 13 1.3 26 2.6 44 4.5 40 4.1 52 5.3 49 5.0 983 Calm.... 448 3.3 613 4.6 674 5.0 726 5.4 796 5.9 859 6.4 13,390 From this table, and considering the whole year, we reach the following conclusions: 1. The frequency of the calms reaches its marxitnum at 7 in the morning, then diminishes from 8 to 12, and increases from 1 in the afternoon until 1 in the morning; the frequency at 2, 3, and 4 a. m. is a trifle less than that of 1 a. m., increasing again from 5 to 7 a. in. 2. Between 1 and 8 a. m. the prevalence of the winds from the north and northeast is very apparent. 3. In like manner the prevalence of the winds of the third quadrant is more apparent at 4 and 5 in the afternoon. 4. From 6 p. m. to 12 midnight, winds from east and southeast mostly prevail. formnal average of the wind in diferent montkh of the year.-Table 36 contains the monthly, annual, and semiannual equivalent averages of 56 the daily velocity of the wind in kilometers, taken from hourly observations in this observatory during 1885-1898. In ascertaining the average of the whole period of fourteen years we have obtained for each month the normal averages which are at the foot of the table. Accordingly, they show that the force of the winds increases gradually from January to May, decreases a very little in May, increases again in June and July, and decreases for the second time in August, reaching its maximum in September, and decreases again from October to December, in which latter month the minimum annual velocity is attained. The annual average of the daily velocity of wind resulting from the fourteen years of study is 217.8 kilometers. The greater or less degree in which they differ from this annual average and different monthly averages can be seen from the following table: TABLE 30.-Monthly and annual averages of the daily velocity of the wind in Manila during the period 1885-1898. [Kilometers.] YEAR. Jan. Feb. Mar. Apr. May. June. Juily. Aug. Sept. Oct. Nov. Dec. Aver1885.............. 232.4 301.5 353.4 367.5 381. 8 414.7 449. 7 428.3 306.5 218.7 263. 5 247.6 330. 56 1886............... 245. 5 268.8 345. 9 323.0 229. 5 223.8 196.4 223.3 288. 9 133. 9 136. 9 126. 5 228.5 1887............. 120.9 150.4 178.5 197.0 178.4 153.6 415.4 141.9 360.3 165.9 122.1 100.3 190.4 188............... 116.4 188.7 169.8 189.8 168. 7 299.3 364.9 337.1 181.1 121.2 105.3 109.5 196.0 1889............... 113.7 115.6 181.0 193.9) 186.1 173.5 174.7 191.9 110.9 1,54.1 119.9 158.3 156.4 1890.............. 106.4 116.3 159.9 147.6 110.5 109.0 209.8 199. 6 287.1 163.9 119.0 100.5 152.5 1891............... 112.0 163.1 185. 4 1814.9 187.6 194.0 291.1 247.8 345.5 77.4 120.5 115.0 185.4 1892............... 132.8 132.1 169.1 1 187.6 187.3 172.7 270.73 127.8 312.0 160.0 109.8 95.3 171.4 1893...............199.9 219.3 2&3. 9 239. 0 324. 2 171.2 330. 2 299. s 454.11 242. 1 220. 9 190.6 260.9 1894............... 213.1 201.9 259.3 257.9 226.6 302.5 281.5 324. 2 347. 8 214.5 189.1 209.4 252.5 1895............... 192. 7 214.5 250.1 265. 1 288.2 255.8 291.2 299.5 391.5 182.1 179. 9 171.9 248.5 1896............... 114.3 121.7 131.5 235. 8 337.2 203.9 274.7 353. 6 258.8 315.4 133.0 169.8 220.8 1897............... 216. 4 25r 8 281.31 277. 8 210. 1 332. 3 203.1 210. 9 241.0 196.6 136.9 157.1 226.9 1898...............205.8 247. 2 240.3 190.2 222.8 276.2 166.5 447.1 188.8 206.6 206.6 138.1 228.0 Average.... 65.9 192.9 2241 232.7 231.4 234.5 280.0 273.8 291.0 182.3 151.5 149.3 217.8 MON TH. Month Difference. average. January......................................................................... 165.9 -51.9 February........................................................................ 192.9 -24.9 March...................................................................... 224.8 + 7.0 April............................................................................ 232.7 +14.9 M ay.............................................................................. 231.4 + 13.6 June............................................................................ 234.5 + 16.7 Julyn.............................................................................. 234.5 +16.7 Jully...............2. August........................................................................... 273.8 +56.0 September....................................................................... 291.0 +73.2 October.......................................................................... 182.3 + 35.5 November..............................................................I 154.5 — 63.3 December....................................................................... 149.3 — 68.5 Y ear....................................................................... 217.8............ Extreme annual and monthly averages of the period: The greatest annual average was 330.5 km. (1885); the least, 152.5 km. (1890). The maximumll monthly average reached 454.1 km. in September, 1893; the minimum, 77.4, in October, 1891. PLATE XI. ANNUAL VARIATION OF THE DAILY VELOCITY OF THE WIND AT MANILA 1885 - 1898 I { I I | i | f km Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nou. ec. r I }- I r | I I I I I e I km EEIEEEIaE[IEH 275 _ I \ _ i....... = =._._._._._._ _ _ - _ ____ svv. _ _. ^ _^ ___ _ _ = _ = =- _ -J - - - - '1:_ _._:^^^^~^=~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 175 __ - _ - __ __ __ __ __ _ __ __ __ __ _ _ __ _ __ _:L _ __ _ _, 175 150 _ _ _-_-___________ -_._-_____ s- ] 150 125 - _-_ __ __________ _____ 125 100oo " _ _ _ _ _.. _ _ _ _ _ _ I _ 100........100 ________________l___1G 58 Comparison of the normal averages and the extremes of each month: In the following summary we give the maximum and minimum averages of each as compared with the corresponding normal average: Normal MONTH. monthly Positive. Negative. averages. January...................................... 165.9 79.6 (1886) 59.5 (1890) February....................................... 192.9 108.6 (1885) 77.3 (1889) March..................................................... 224.8 128.6 (1885) 93.3 (1896) April......................................................... 232. 7 134.8 (1885) 8.1 (1890) May.............................................. 231.4 150.4 (1885) 120.9 (1890 Ju e....................................................... 234. 5 180.2(1885) 125.5 (1890) July..................................................... 280.0 169.7 (1885) 113.5 (1898) August................................................. 273.8 173.3 (1898) 146.0 1892) September........................................... 291. 163.1 (1893) 180.1 (1889) October.................................................... 182.3 133.1 (1896) 104.9 (1891) November............................................... 154. 109.9 (1885) 49.2 (1888) )ecemnbet.r............................................ 14. 3 8.3 (1885) 54.0 (1892) The greatest number of maxirmum positive differences are for the year 1SS5 and the greatest number of maximuni negative differences for the year 1890, being the respective years to which belong the maximum anId minimlum annual averages of the period..Jl;atxmn (im anlid minhmuim dail iy veoci i.n MAanila.-Tables 37 and 38 embody, respectively, the malximum and minimum daily velocities of tlhe wind registered in this observatory during the period 1885-1898. TA.BLE 37. —Af(it(im7L daily velocity of the wind in Manila during the period 1885-1898. Y i A It. JAN I Kill. 1885........ 366.0 1 86......... 1i78.5 1887......... 263.0 1888........ 229.3 1889........ 174. (; 1890......... 233. 0 1891......... 1169.8 1892......... 285.8 1893........ 272.5 1.94........... 312. 1895.......... 22.0 189......... 195. 4 1897........ 305. 5 1898.........! 6.0 Average. 3. 18 MA RCH. APRIL. I )1 te. XOt 9) 21i' I71 278 221 211 3 8J 29j Kmi. )ate. 407.0 2( 398.0 1 238.9 ( 405.9 4 431.5 1( 215.71 17 25,55.1 21 193. 5 20 313.1 15 300.41 6 299.81 5 220. 7 23 389.0 21 316.0 15 242.2....... KIu. Date. 188.0 26 478.0 8 271.2 31 254.8 26 268.5 8 250.8 20 247.6 31 288.9 26| 398.3 20' 380.5 231 356.8 28 230. 7 8 3353.5 121 438.5 16 6.1....... K62. 627. 436. f 612. 6 250. 1 310. 277.1 314.3 252. 9 337. 1 331.7 358. 374.7 374. 299., 368.: Dl)ate. 1 18 265 14 30 1 21 1 22 15 8 8 I- -'I. MAY. Kmn. Date. 589.5 17 415. 6 8 383.9 27 293.8 18 255. 3 28 217.7 1 262.8 15 319.5 10 1,007.5 1I 413.0 8 780.6 14 1,042.0 17 282.0 15 821.0 31 506.0 77.. - -- -I JUNE. Km. 1,031.5 641.5 361.0 525.5 333.3 207.2 384.4, 422.3 218.3 990.0 808.7 650.4 701.5 598.0 562.4 Date. 28 12 15 14 11 29 8 9 25 26 24 6 27 18 YEA R. 1885........ 18H6....... 1887........ 18........ 18 9........ 1890........ 1891.....,.. 189........ 1893........ 1894.... 1.95....... 1896........ 1897........ 1898........ Average. ITYI,Y, Kin. Date. 977.5 23 522. 2 1 2 994.6 24 1,00.1 14 450. 0 11 634.8 15 1,2. 3 17 941.5 i 2 1, (#. 5 24 647. 0 19 702.81 21 730. 4 2 773. 5 26 423.fi 31 AlUTGUST. K. iDaIt te. 458.5 13i 440. 3 1 765.3 15 606;. 2 21 342.2 6 80. 5 2:369. 5 15 706.9 3 31 786. 2 791.5} 22 821.2i 8 770. Oi 9 1, 03. 0; 4 SEPTEMBIER. I OCTOBER. NOVEMBER. Ki|. Date. Km. lDate.i Km. Date. 816. 4 4 1 11,159.5 4 558. 6 211 574. 2 9 440.8 18 1,051.1 19 844.9 65 373.6 27 8-47.6 27 284.0 23' 263.0 16 219 25 1.9 575.0 29 336. 4 4 1,477.6 30 723.2 1711,037.3 11 847.8 12/ 197.3 16 732.2 16 752.4 7 609.8 9 526.9 22 1,420.51 30 749.9 11 388.3 22 1,311.8 17:' 912.7 31 458.0 17 1,212.0 4 509.0 1 536.0 2 503. 51 91 191.5 4 203.5 3 777.5 14' 752. 5 131 249.5 13 429.0 30 6 629.5 25fi 843.5 13 875.6.....1 638.4...... 539.2...... i DECEMBER. Km. Date. 412.6 30 367.2 18 174.61 2 315.5 5 542.1 4 170.9 13 487.6 23 155.8 4 4,55.5 5 483.2 22 265.0 17 299.0 23 313.0 31 331.0 9 340.91. --- 3I, 9 Annual maximum (km.). 1,1,59.5 641.5 1,051.1 1,008.1 606.2 i,477.6 1,022.3 941.5 1,420.5 1,311.8 1,212.0 1,191.5 777.5 1,038.0 1,061.4 773 i......9...... 79 676.9...... 59 TABLE 38.-Minimum daily velocity of the w ind ini Manila dd ring tlie period 188s5-1898. JANUARY. FERUARY. MARCHe. A1PR IL. M A Y. I 1NE. YEAR. Km. Date. Kmi. D)ate. Kin. Date. Kin. Date. Kin. Dat e.; Kn Date. 1885......... 150.5 9 195.0 1 20). 0 " 2 211.0 23 252.0 16 i 217 0 5 1886.......... 137.5 6} 127.0 12 253.0 13 195.6 30 122. 23 51. I4 24 1887.......... 66.0 26 102.5 6 88.0 6 87.7 2 78.9 20 10.5 20 1888.... ---.- 49.1 24 109.2 2 112.9 12 135.5 30 87.8 8 108.1 18 1889.......... 66.5 30 75.9 15 114.4 1 141.51 2 2 6 25 51 2.. 2 28 1890.......... 49.3 1! 63.7 3 81.7 3 68.0 29 15.1 30 I 53.1 22 1891.......... 72.7 5 75.4 8 107.8 1 i 11 8.9 9 51.3 31 4.3 1 24 1892.......... 57.7 10 56.0. 9 97.8 7 107.1 29 100. 29 i 78.5 30 1893.......... 132.5 9 150.6 12 104.6 1 155.5 9 155.5 30 99.; 20 1894......... 132.6 12 138.2 4 163.7 19 199.8 3 1 133. 5 26; ) 122.0 10 1895.......... 113.3 6 135.0. 1 140.0 1 143.2 29 | 145.3 22 1 1. 1:3 1896...... 19.2 30 50.6 5 46.8 2 152. 9 22 11S.0 27 52. 5 9 1897........ 122.5 22 124.0 11 136.5 15 1814.5 18 1:1.) 29 135. 0 17 1898....... 108.0 21 97.5 27 112.5 26 l 114.5 I 3 j 96.0 2 I 86. 5 8 Average... 91.2....... 107.2....... 126.1....... 16.1....... 113.1....... 90.5...... _ _ _ _ _ II _ _ _ _ / / JULY. AUGUST. SEI'TEMBER. OCTOBER. NOVI:MBEit. DEX E iL I EiM R. AllYEAR. --- —. - inIKm. Date. Kin. Date. Kin. Date. Kin. Date Kin Date. Km. Date. kill.. 1885.......... 163.0 13 149.5 28 159.0 9 168.5 41 124. 0 10 131.5 2 12-1.0 1886.......... 65.6 7 53.7 28 56.4 28 54.8 21 1 42.0 20 1 40.2 1 I 0.2 1887.......... 49.4 7 33.5 13 58.8 1 60.7 9 45.8 1 1 47.4 1 13.5 1888.:........ 90.9 18 107.1 23 70.9 19 413.9 29 16.4 9 5(i.6 8 18 6.4 1889..... 61.9 25 16.9 9 25.1 17 27.0 6 44 4 7 i 22.0 6 16.9 1890......... 30.6 22 39.0 18 45.2 21 46.7 26 18.2 18' 618 11 15.1891......... 47.8 23 51.8 17 364.2 15 28.4 2 13.5 27 7 42.1 18 131.5 1892.......... 54.6 4 49.0 21 57.5 19 24.0 17 10.1 6! 41. 0 9 10.1 1893. 120.2 18 100.2 231 120.7 11 97.2 16 106.0 27 72.5 21 72.5 1894.......... 139.5 15 74.8 21 100.5 5 102.0 30 1014.0 5 I111.4 24 71.8 1895...... 118.6 28 121.5 5 122.0 9 115.7 23 105.0 23 1101. 22 101.3 1896........ 102.5 11 132.1 4 95.5 27 84.5 26 78.0 9 r 70.7 19.2 1897......... 105.0 8 70.5 23 53.0 18 94.5 11 62. 4 80.5 20 53.0 1898.......... 79.0 6-19 149.5 18 86.5 27 62.5 19-23 3.0 3 | 35.5 3 |. Average... 87.8 82.1....... 72.25....... 2.4 According to the results at the foot of Tables 37 and 3S, the average of the annual maximum velocity is 1,061.4 kil., and the minimmiti annual velocity 42.4 kmi., there being a difference of 1,019 kim. A gradual increase is to be observed from one month to another in the average values of the maximum and the mininum velocities. The first increase is from February to July, inclusive, decreasing somewhat in August, and increasing to the annual maximnum average in September. In the following month it decreases gradually until it reaches the annual minimum average velocity in February. Far different is the relation between the monthly average difference and that of the daily minimum averages. In effect the maxitmumn average values correspond to the month of April, decreasing later without stopping until they reach the minimum average velocity in the month of November. From December they again increase without interruption until the month of April. The greatest minimum averages are those of February, March, April, and May. This we believe is due to the fact that in normal days these are the four months in which 60 the winds often increase in force, and even though in the season of atmospheric disturbances there are normal days to be found in which the minimum velocity of the wind is recorded, generally more in the remaining months of the year than those above mentioned. The maximum daily velocity during the period 1885-1898 (1,477.6 knm.), was recorded the 30th day of September, 1890, when a violent typhoon crossed the center of Luzon, north of Manila. The minimum velocity was recorded on the 30th of November, 1898, during which the wind blew 3 kilometers. In the following summary is shown the nlaxinmum and minimum daily velocities during the whole periods corresponding to each of the twelve months in the year: [Kilometers.] MONTI. Maximum. Minimum. January................................................................. 478.5 (1886) 19.2 (1896) February................................................................ 431. (889 50. (1896 March............................................................... 433.0 (1886 46.8 (1896) A pril............................................................... 647.5 (1885 68.0 (1890) May.................. -........................................ 1,042.0 (1896) 15.4 (1890) June............................................................ 1,031. (1885 40.5 1887 Jul-. 1,031.5 (1885) 40.5 (187) July..................................................................... 1,022.3 (1891 30.6 (1890) August............................................................. 1,033.0 (1898 16.9 (1889) September............................................................ 1,477.6 (1890) 25. 1 (1889 October.............................................. 1,191.5 (1896) 24.0(1892 November- 1,159.5(1885 3.0(189 November........................................................... 1,159.5 (1885) 3.0 (1898 Decem ber.............................................................. 542.1 (1889) 22.0 (1889 Decemnber — 542.1 (1889) 22. Jlontildly di, tSribttio