The peninsula south of the Sátpura range consists chiefly Southern plateau. of the triangular plateau of the Deccan, terminating abruptly on the west in the Sahyadri range (Western Gháts), and shelving to the east (Eastern Gháts). This plateau is swept by the south-west monsoon after it has surmounted the western barrier of the Ghats. The rainfall is consequently light at Poona and places similarly situated under the lee of the range, and but moderate over the more easterly parts of the plateau. The rains, however, are prolonged to the north of the Satpuras three or four weeks later than in Southern India, since they are brought there by the easterly winds which blow from the Bay of Bengal in October and the early part of November; when the re-curved southerly wind ceases to blow up the Gangetic valley, and sets towards the Karnatic. This was formerly thought to be the north-east monsoon, and is still so spoken of by some writers; but the rainy wind is really a diversion of the south-west monsoon. At the junction of the Eastern and Western Ghats rises the Anamalai bold triangular plateau of the Nilgiris, and to the south of Hills. them come the Anamalais, Palnis (Pulneys), and Travancore Hills. These ranges are separated from the Nilgiris by a broad depression or pass known as the Pálghát gap, some 25 miles wide; the highest point of which is about 1500 feet above the sea. This gap affords a passage to the winds, which elsewhere are barred by the hills of the Ghát chain. The country to the east of the gap receives the rainfall of the south-west monsoon; and during the north-east monsoon, ships passing Beypur meet with a stronger wind from the land than is felt elsewhere on the Malabar coast. According to Captain Newbold, this gap affords an outlet to those furious storms from the eastward which sweep the Bay of Bengal, and, after traversing the peninsula, burst forth through it to the neighbouring sea.' coast strips. In the coast-strip of low country which fringes the peninsula Southern below the Ghats, the rainfall is heavy, the climate warm and damp, the vegetation dense and tropical. The steep slopes of the Ghats, where they have not been artificially cleared, are also thickly clothed with forest. Ceylon should, for meteorological purposes, be included Meteorin our survey. The country both south and west of the ology of Ceylon. hills which occupy the south centre of the island is very rugged down to the coast. The rainfall is here frequent and Rainy heavy; and the temperature being high and equable, the south-west vegetation is dense and very luxuriant, such as is characteristic region. coast. trast. of islands in tropical seas, and also of the coast of Travancore. Drier east The plains on the east coast are drier, and both in climate and vegetation bear much resemblance to those of the Karnatic. When the south-west monsoon is blowing in May and June, and discharging torrents of rain on the forest-clad spurs and slopes that face to windward, the contrast presented by the eastward face of the same hills is very striking, and the two phases of climate are sharply demarcated. Newara Eliya The con- (7000 feet), day after day, and even week after week, lies under a dense canopy of cloud, which shrouds all the higher peaks, and pours down in almost incessant rain. But let the traveller leave the station by the Badulla road, and cross over the main range at a distance of two or three miles from Newara Eliya. As he begins the descent towards Wilson's bungalow, he emerges on a panorama of the grassy downs of the lower hills, bathed in dazzling sunshine; while on the ridge above he sees the cloud-masses ever rolling across from the west, and dissolving away in the drier air to leeward. Hence the east and west coasts of the island are as strongly contrasted in climate as those of the southern extremity of the Indian peninsula. British Upper In British Burma, the western face of the Arakan Yoma hills, like that of the Indian Western Ghats, is exposed to the full force of the south-west monsoon, and receives a very heavy rainfall. At Sandoway, this amounts to an annual mean of 218 inches. It diminishes to the northwards; but even at Chittagong, it amounts to 106 inches annually. The country around Ava, as well as the hill country of North Burma, is the seat of occasional severe earthquakes, one of which destroyed Ava city in 1839. The general meridianal direction of the ranges and valleys determines the direction of the prevailing surface winds; subject, however, to many local modifications. But it would appear, from Dr. Anderson's observations of the movement of the upper clouds, that throughout the year there is, with but slight interruption, a steady upper current from the south-west, such as has been already noticed over the Himalayas. The rainfall in the lower part of the Irawadi valley, viz. the delta and the neighbouring part of the province of Pegu, is very heavy, about 190 inches; the climate is warm and equable at all seasons. But higher up the valley, and especially north of the Pegu frontier, the country is drier, and is characterized by a less luxuriant vegetation, and by a retarded and more scanty rainfall of about 56 inches. -- tories. Observatories. Meteorological observatories have been Observaestablished at 109 stations in India (including British Burma and the Andamans). These observatories are situated at all elevations, from the highest, LEH (11,538 feet above mean sealevel) and CHAKRATA (7051 feet), to NEGAPATAM (15 feet) and SAGAR ISLAND, the lowest, which is only 6 feet above mean sea-level. Observations.-The observations taken at the meteorological Observations. stations record (1) temperature of solar and of nocturnal radiation, (2) the 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, I refer the reader 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 radiation. produce little difference in the amount of radiation from the ground, 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 where Returns. 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 Dárjiling (much the lowest average) and 131.3° at Goalpára (the next lowest), to 1456° F. at Bardwán and 147'4° at Cuttack. The excess of the above over the corresponding maximum shade temperatures was:- at Dárjíling, 591; at Goalpára, 484°; at Bardwán, 57°; and at Cuttack, 55.8°. air. Mean Temperature of the Air.-From the average annual mean Temperatemperatures of 83 stations (derived from the means of three ture of the or more years), the following figures are taken. In the following four stations in this list, the average mean yearly temperature was over 82° F. :-Trichinopoli, 82.8°; Vizaga- temperapatam, 827; Madras, 82'4°; and Madura, 82.2°. All of tures. these stations are in the Madras Presidency. The next highest yearly Hill stations. means are returned by Negapatam (also in Madras), 81°9°; Cuttack and Port Blair, each 80'5°; False Point, 80.2°; Goa, 79'9°; Cochin, 79.8°; Ságar Island, 79'5°; Deesa, 79'4°; and Calcutta, 792°. The mean annual temperature of Bombay is 78.8° F., so that it is the coolest of the three Presidency towns. The lowest means are obtained at the hill stations of Dárjíling, 53'9° F.; Simla, 54'4°; Murree, 558°; and Chakráta, 56.1° F. Between these and the next coolest stations is a great gap, Ráníkhet following with 604°, Pachmarhi with 68.7°, and Rawal Pindi with a yearly mean of 694° F. The highest mean monthly temperatures given are :-95° at Múltán, in June; 943° at Delhi, in June; 94'1° at Jhánsí, in May; Monthly 936° at Agra, in June. The lowest monthly means are tempera- returned by the four coldest hill stations mentioned above, the figures being:-Murree-January 377°, February 39′4°; Simla -January 39.6°, February 41'1'; Chakráta-January 40'8', February 429°; Dárjiling-January 40'7°, February 43'2° F. The mean temperature at Leh in January is 17.6°, and in December 24'4° F. tures. Atmospheric pressure. Wind. Humidity. Cloud proportion. Atmospheric Pressure.-The Meteorological Report for 1877 contains a table showing the annual mean pressure at 72 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: 23274 at Chakráta, 23'371 at Dárjíling, 24058 at Ráníkhet, 26416 at Pachmarhi, and 26'932 at Bangalore. The greatest annual mean pressures returned are:-29.862 at Negapatam, 29.856 at Madras, 29 822 at Bombay, and 29.821 at False Point. 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 section 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 1877 gives the averages of estimated cloud proportion for 67 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 Síbságar by 7'59; at Dárjíling by 6'45; at Trichinopoli by 6'10; at Coimbatore by 5'36; at Salem by 5:29. The lowest proportions recorded are:-for Jhánsí, 148; for Múltán, 179; Derá Ismáil Khán, 2'13; Ságar (Saugor), in the Central Provinces, 2*15. Rainfall. The average annual rainfall at 306 stations is Rainfall. recorded in the Meteorological Report for 1877, from which the following figures have been obtained. In the Punjab, the highest average fall (123.21 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 68.61 inches at Simla. The lowest average falls in the Punjab are:-6'16 inches at Muzaffargarh, 6'93 at Múltán, 7:35 at Derá Ghází Khán, and 823 at Derá Ismáil Khán. All these stations are protected by the Suláimán range from the monsoon. In Rájputána and Central India the minimum is 20°27 Rájputána inches at Jaipur (Jeypore), and the maximum, 60 85 at Mount and CenAbu, the highest point in this part of India. tral India. Provinces. In the North-Western Provinces the heaviest rainfalls Northare at Naini Tál (94°17 inches) and Dehra (7006), both of Western which lie high; the minimum average fall is 24°32 at Aligarh, the next lowest figures being 26'18 at Muttra (Mathura), 26'46 at Agra, and 26'74 at Etah—all stations on the plains. In Oudh, the maximum rainfall is at Sultánpur, 46'72 inches; Oudh. and the minimum at Rái Bareli, 37.99 inches. The following stations of Bengal have an average rainfall of Bengal. more than 100 inches :-Jalpaiguri, 122:16; Dárjiling, 119'25; and Kuch Behár, 119'05-all at the base of the hills; Noakhálí, 107.52; and Chittagong, 105.61, both on the north-east coast of the Bay of Bengal. The lowest averages are returned by Chhapra, 37'06 inches; Patná, 38°21; and Gáyá, 41*38. The average rainfall throughout Bengal is 67 inches. Assam possesses in CHERRA POONJEE (Chárá Punji) the Assam. station with the largest rainfall in the world. Former returns gave the fall at 368 inches; later and fuller returns at 523 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 section on Physical Geography (pp. 29, 30, ante). |