OBSERVATORIES: MEAN TEMPERATURES. 647

observatories are situated at all elevations, from the highest, LEH (11,502 feet above mean sea-level) and CHAKRATA (7051 feet), to SAGAR ISLAND, 25 feet, and NEGAPATAM, only 15 feet above mean sea-level.

OBSERVATIONS.-The observations taken at Indian meteoro- Observa

logical stations record (1) temperature of solar and oftions. nocturnal radiation, (2) air temperature, (3) atmospheric pressure, (4) direction and velocity of the wind, (5) humidity, (6) cloud proportion, and (7) rainfall. For full information on each of these subjects, the reader is referred to the valuable and deeply interesting reports of Mr. F. Blanford and Mr. Eliot, printed at the Government Press, Calcutta, and available to all inquirers at the India Office, London.

SOLAR RADIATION.-Although, theoretically, differences in Solar the height above ground of the registering thermometer produce radiation. little difference in the amount of radiation from the ground, yet the nature of the surface forms an important feature, the action of which differs very considerably in different parts of India, and interferes with an exact comparison of results obtained from different stations. Thus, the radiation from the parched, heated, and bare surface of the soil in the North-Western Provinces in May, must be considerably greater than from the moist grass-covered surface of the soil at the coast stations of Bengal and Western India in the same month.

The following figures are obtained from Bengal stations Returns. where the instruments are believed to be accurate and comparable. The yearly average maximum equilibrium temperatures of compared sun thermometers in vacuo, varied in these stations from 121'5° F. at Darjiling (much the lowest average) and 1313° at Goálpárá (the next lowest), to 1456° at Bardwán and 1474° at Cuttack. The excess of the above over the corresponding maximum shade temperatures was :— at Dárjíling, 59′1°; at Goálpárá, 48°4°; at Bardwán, 57°; and at Cuttack, 55.8°.

air.

TEMPERATURE OF THE AIR.-From the average annual mean Temperatemperatures of 117 stations (derived from the means of three ture of the or more years), the following figures are taken. In the two following stations in this list, the average mean yearly tem- Mean perature was over 82° F. :-Trichinopoli, 821°; Vizagapatam, yearly 82.8°. Both of these stations are in the Madras Presidency. The tures. next highest means are returned by Madras, 82°; Madura (also in Madras), 819°; Negapatam, 81.6°; Masulipatam, 81.3°; Karnúl, 81.2°; Sironcha, 81°; Cuttack, 80.7°; Bellary and Salem,

tempera.

Hill stations.

804; Port Blair, 80-3°; Bikáner, 80°; False Point, 79'3°; Go, 79'9°; Cochin, 79'6°; Ságar Island, 78.6°; Deesa, 79°9°; and Calcutta, 77.8°. The mean annual temperature of Bombay is 79'7°. The lowest means are obtained at the hill stations of Dárjíling, 51.8°; Simla, 55°; Murree, 56°1°; and Chakráta, 56.3°. Between these and the next coolest stations is a gap, Masuri (Mussoorie) following with 59'2°, Ráníkhet with 602, Pachmarhi with 68·7°, and Ráwal Pindi with a yearly mean of 693. The highest mean monthly temperatures given are:947 at Jhansi, in May; 94'4° at Múltán, in June; 937' at Monthly Lahore, Delhi, and Agra, in June. The lowest monthly means tempera- are returned by the four coldest hill stations mentioned above, the figures being :-Murree-January 39°, February 394; Simla January 40'4°, February 414°; Chakráta — January 423, February 43'4°; Dárjíling-January 39'4°, February 412°. The mean temperature at Leh in January is 171, and in December 23.1° F.

tures.

Atmospheric pressure.

Wind.

Humidity.

Cloud proportion.

ATMOSPHERIC PRESSURE.-The Meteorological Report for 1883 contains a table showing the annual mean pressure at III stations, corrected (except in the case of Madras) to the Calcutta standard, which reads o'011 inch higher than that of Kew. From that table the following figures are obtained. The mean yearly pressure in inches at the highest stations is : -22944 at Dárjiling, 23°224 at Chakráta, 23°275 at Simla, 24059 at Ráníkhet, 26'392 at Pachmarhi, and 26-924 at Bangalore. The greatest annual mean pressures returned are: -29 889 at Cochin, 29'845 at Negapatam, 29 840 at Madras, and 29.821 at Bombay. These pressures are not reduced to the level of the sea.

WIND. The general directions of the wind in different parts of the peninsula have already been noticed in the introductory portion of this chapter describing the meteorological geography of the country.

HUMIDITY. The humidity figures given in the Report for 1877 are, according to Mr. Eliot, the Officiating Meteorological Reporter to the Government of India, not generally intercomparable, as the mean relative humidity is deduced from a varying number of daily observations.

CLOUD PROPORTION.-The Report for 1883 gives the averages of estimated cloud proportion for 113 stations in India, an overcast sky being represented by 10 and a clear sky by o. Some of the extreme figures follow. The average annual proportion of clouded sky is represented at Sibsagar by 7:19; at Merkára by 6·68; at Dárjíling by 6'44; at Trichinopoli by

STATISTICS OF RAINFALL.

649

6.04; at Coimbatore by 5:19; at Salem by 4'66. The lowest proportions recorded are:- for Jhánsí, 1.20; Hyderábád (Sind), 169; Múltán, 166; Dera Ismail Khán, 2'04; Ságar (Saugor), in the Central Provinces, 2'43.

RAINFALL. The average annual rainfall at 435 stations is Rainfall. recorded in the Meteorological Report for 1883, from which the following figures were derived.

In the Punjab, the highest average fall (12491 inches) is at The Dharmsála, which is situated on the face of the hills, and Punjab. exposed to the full force of the monsoon; the next highest recorded is little more than half that amount, or 7124 inches, at Simla. The lowest average falls in the Punjab are:-5.88 inches at Muzaffargarh, 707 at Múltán, 703 at Dera Ghází Khán, and 8:46 at Dera Ismail Khán. All these stations are protected by the Suláimán range from the monsoon.

and Cen

In Rájputána and Central India the minimum is 12'07 Rájputána inches at Pachbadra, and the maximum, 63°21, at Mount Abú, tral India. the highest point in this part of India.

Provinces.

In the North-Western Provinces the heaviest rainfalls are Northat Masuri (9472 inches), Naini Tál (91*17), and Dehra (74'91), Western all of which lie high; the minimum average fall is 25 28 at Muttra, the next lowest figures being 26:06 at Aligarh, 25'66 at Agra, and 25.70 at Bulandshahr-all stations on the plains.

In Oudh, the maximum rainfall is at Bahraich, 43:48 inches; Oudh. and the minimum at Rái Bareli, 32 18 inches.

The following stations of Bengal have an average rainfall of Bengal. more than 100 inches:-Baxa, 220'91; Jalpáigurí, 129.21; Mongpú, 128:43; Dárjiling, 12085; and Kuch Behár, 130.89-all at the base of the hills; Noakhálí, 11175; Demagiri, 11297; Cox's Bazaar, 14160; and Chittagong, 104:58, all near the north-east corner of the Bay of Bengal. The lowest averages are returned by Keunjhar, 3261 inches; Buxar, 3904; Chhapra, 39'15; and Gayá, 40°29. The average rainfall throughout Bengal is 67 inches.

Assam possesses in Cherra Poonjee (Chárá Punjí) the Assam. station with the largest rainfall in the world. Former returns gave the fall at 368 inches; later and fuller returns at 48180 inches. A total fall of 805 inches was reported in 1861, of which 366 were assigned to the single month of July. In 1850, Dr. Hooker registered 30 inches in twenty-four hours, and returned the fall from June to November of that year at 530 inches. In the four days 9th to 12th September 1877, 56.19 inches were registered. The cause of this extraordinary rainfall is

noticed in the chapter on Physical Geography. The following stations in Assam have also a very high average rainfall:Silchár, 118.85; Sylhet, 156′12; Dibrugarh, 113'53; and Turá, 123 80. The lowest recorded averages in Assam are at Samaguting (52:58 inches) and Gauháti (69-26 inches), both on the northern side of the hills separating Cachar from Assam.

Central In the Central Provinces, the highest average falls are at Provinces. Pachmarhi, 77.85 inches, and Bálághát, 65'92; lowest

averages, Khandwá, 33'29 inches, and Arvi, 35-09 inches. Bombay. In Bombay, two stations on the Gháts are recorded as having an average rainfall of over 250 inches, viz. :—Malcolmpet (Mahábleshwar), 25849; and Baura (Fort), 255 28. Next in order come Matherán, with 245 24 inches; Lonauli, with 165 13; Honawár, 13808; and Igatpuri, Kárwár, Vingirla, and Ratnagiri, with 124°19, 116·03, 110·89, and 104:55 inches respectively. The lowest average rainfalls recorded in Bombay are:-18.82 inches at Mandargi; 20'97 at Dhulia; and 2141 at Gokak. The average rainfall in Bombay is 67 inches.

Sind.

Madras.

British
Burma.

Port Blair.

Sun-spot cycles.

In Sind, the average rainfall is very low, varying from 16:17 inches at Nagar, and 11'09 at Umárkot, to 4'65 at Shikárpur, and 433 at Jacobábád.

In Madras, the highest local averages recorded are:-132-87 inches at Mangalore; 129:68 at Cannanore; 128:21 at Merkára; 125:66 at Tellicherri; 115:04 at Calicut; and 115:02 at Cochin-all on the west coast. The lightest falls recorded are:

at Bellary, 17 64; Tuticorin (sheltered by the Gháts), 1944; Guti (Gooty), 21'79; and Coimbatore, 21°34. All these stations lie low. The average fall at the stations on the east coast is about 41 inches. A fair average rainfall for Madras Presidency is 44 inches.

The rainfall along the coast of British Burma is heavy, as might be expected, the following averages being recorded:Sandoway, 21203 inches; Tavoy, 19702; Akyab, 19761; Maulmain, 189*37; Kyauk-pyu, 174'79. The smallest rainfall is at Thayet-myo (47'37) and Prome (53'00), sheltered by the Yoma range.

The rainfall at Port Blair and Nancowry is also heavy, the averages being returned as 118:38 and 108.91 inches respectively.

SUN-SPOT CYCLES.-These alleged cycles have formed the subject of several separate papers, and the results were popularly summed up in a joint article by Mr. Norman

Lockyer and the present author in the Nineteenth Century for November 1877. It will therefore suffice here to state the views of the Indian Meteorological Department on the intricate questions involved. The following are the inferences which the meteorology of India appears to suggest, if not to establish. There is a tendency at the minimum sun-spot periods to prolonged excessive pressure over India, and at the maximum sun-spot periods to an unusual development of the winter rains, and to the occurrence of abnormally heavy snowfall over the Himalayan region (to a greater extent probably in the Western than the Eastern Himálayas). This appears also to be usually followed by a weak south-west monsoon. The characteristics of a weak monsoon are, great irregularity in the distribution of the rainfall over the whole of India, and the occurrence of heavy local rainfalls, which tend, by a law of rainfall and of air-motion, to recur over the same limited areas. The irregularity of rainfall distribution is often shown by the persistence of dry land winds and the prolonged absence of rain over considerable areas. These areas of drought and famine are partly marked off by nature, depending to a certain extent on the geographical features and position of the district. Thus, the rains are more likely to fall below the amount necessary for cultivation in the dry region of the Deccan or in Upper India, than over the Malabar coast area or the Province of Bengal.