Considering, however, his energy, a rare quality in these countries, I should not be surprised at his yet cutting a figure in Bhotan, if not in Sikkim itself: especially if, at the Rajah"s death, the British government should refuse to take the country under its protection. The Singtam Soubah and the other culprits live disgraced at their homes. Tchebu Lama has received a handsome reward, and a grant of land at Dorjiling, where he resides, and whence he sends me his salaams by every opportunity.
CHAPTER XXVII.
Leave Dorjiling for Calcutta--Jung Bahadoor--Dr. Falconer-- Improvements in Botanic Gardens--Palmetum--Victoria-- _Amherstia_--Orchids spread by seed--Banyan--_Cycas_-- Importation of American plants in ice--Return to Dorjiling--Leave with Dr. Thomson for the Khasia mountains--Mahanuddy river-- Vegetation of banks--Maldah--Alligators--Rampore-Bauleah-- Climate of Ganges--Pubna--Jummul river--Altered course of Burrampooter and Megna--Dacca--Conch sh.e.l.ls--Saws--Cotton muslins--Fruit--Vegetation--Elevation--Rose of Bengal-- Burrampooter--Delta of Soormah river--Jheels--Soil-- Vegetation--Navigation--Mosquitos--Atmospheric pressure-- Effects of geological changes--Imbedding of plants--Teelas or islets--Chattuc--Salubrious climate--Rains--Canoes--Pundua --Mr. Harry Inglis--Terrya Ghat--Ascent to Churra--Scenery and vegetation at foot of mountains--Cascades.
I was chiefly occupied during January and February of 1850, in arranging and transmitting my collections to Calcutta, and completing my ma.n.u.scripts, maps, and surveys. My friend Dr. Thomson having joined me here, for the purpose of our spending a year in travelling and botanising together, it became necessary to decide on the best field for our pursuits. Bhotan offered the most novelty, but it was inaccessible to Europeans; and we therefore turned our thoughts to Nepal, and failing that, to the Khasia mountains.
The better to expedite our arrangements, I made a trip to Calcutta in March, where I expected to meet both Lord Dalhousie, on his return from the Straits of Malacca, and Jung Bahadoor (the Nepalese minister), who was then _en route_ as envoy to England. I staid at Government House, where every a.s.sistance was afforded me towards obtaining the Nepal Rajah"s permission to proceed through the Himalaya from Dorjiling to Katmandu. Jung Bahadoor received me with much courtesy, and expressed his great desire to serve me; but begged me to wait until his return from England, as he could not be answerable for my personal safety when travelling during his absence; and he referred to the permission he had formerly given me (and such was never before accorded to any European) in earnest of his disposition, which was unaltered. We therefore determined upon spending the season of 1850 in the Khasia mountains in eastern Bengal, at the head of the great delta of the Ganges and Burrampooter.
Ill.u.s.tration--DR. FALCONER"S RESIDENCE, CALCUTTA BOTANIC GARDENS, FROM SIR L. PEEL"S GROUNDS.
I devoted a few days to the Calcutta Botanic Gardens, where I found my kind friend Dr. Falconer established, and very busy.
The destruction of most of the palms, and of all the n.o.ble tropical features of the gardens, during Dr. Griffith"s inc.u.mbency, had necessitated the replanting of the greater part of the grounds, the obliteration of old walks, and the construction of new: it was also necessary to fill up tanks whose waters, by injudicious cuttings, were destroying some of the most valuable parts of the land, to drain many acres, and to raise embankments to prevent the encroachments of the Hoogly: the latter being a work attended with great expense, now cripples the resources of the garden library, and other valuable adjuncts; for the trees which were planted for the purpose having been felled and sold, it became necessary to buy timber at an exorbitant price.
The avenue of Cycas trees (_Cycas circinalis_), once the admiration of all visitors, and which for beauty and singularity was unmatched in any tropical garden, had been swept away by the same unsparing hand which had destroyed the teak, mahogany, clove, nutmeg, and cinnamon groves. In 1847, when I first visited the establishment, nothing was to be seen of its former beauty and grandeur, but a few n.o.ble trees or graceful palms rearing their heads over a low ragged jungle, or spreading their broad leaves or naked limbs over the forlorn hope of a botanical garden, that consisted of open clay beds, disposed in concentric circles, and baking into brick under the fervid heat of a Bengal sun.
The rapidity of growth is so great in this climate, that within eight months from the commencement of the improvements, a great change had already taken place. The grounds bore a park-like appearance; broad shady walks had replaced the narrow winding paths that ran in distorted lines over the ground, and a large Palmetum, or collection of tall and graceful palms of various kinds, occupied several acres at one side of the garden; whilst a still larger portion of ground was being appropriated to a picturesque a.s.semblage of certain closely allied families of plants, whose a.s.sociation promised to form a novel and attractive object of study to the botanist, painter, and landscape gardener. This, which the learned Director called in scientific language a Thamno-Endogenarium, consists of groups of all kinds of bamboos, tufted growing palms, rattan canes (_Calami_), _Dracaenae,_ plantains, screw-pines, (_Pandani_), and such genera of tropical monocotyledonous plants. All are evergreens of most vivid hue, some of which, having slender trailing stems, form magnificent ma.s.ses; others twine round one another, and present impenetrable hillocks of green foliage; whilst still others shoot out broad long wavy leaves from tufted roots; and a fourth cla.s.s is supported by aerial roots, diverging on all sides and from all heights on the stems, every branch of which is crowned with an enormous plume of gra.s.s-like leaves.* [Since I left India, these improvements have been still further carried out, and now (in the spring of 1853) I read of five splendid _Victoria_ plants flowering at once, with _Euryale ferox,_ white, blue, and red water-lilies, and white, yellow and scarlet lotus, rendering the tanks gorgeous, sunk as their waters are in frames of green gra.s.s, ornamented with clumps of _Nipa fruticans_ and _Phoenix paludosa._]
The great _Amherstia_ tree had been nearly killed by injudicious treatment, and the baking of the soil above its roots. This defect was remedied by sinking bamboo pipes four feet and a half in the earth, and watering through them--a plan first recommended by Major M"Farlane of Tavoy. Some fine _Orchideae_ were in flower in the, gardens, but few of them fruit; and those _Dendrobiums_ which bear axillary viviparous buds never do. Some of the orchids appear to be spread by birds amongst the trees; but the different species of _Vanda_ are increasing so fast, that there seems no doubt that this tribe of air-plants grows freely from seed in a wild state, though we generally fail to rear them in England.
The great Banyan tree (_Ficus Indica_) is still the pride and ornament of the garden. Dr. Falconer has ascertained satisfactorily that it is only seventy-five years old: annual rings, size, etc., afford no evidence in such a case, but people were alive a few years ago who remembered well its site being occupied in 1782 by a Kujoor (Date-palm), out of whose crown the Banyan sprouted, and beneath which a Fakir sat. It is a remarkable fact that the banyan hardly ever vegetates on the ground; but its figs are eaten by birds, and the seeds deposited in the crowns of palms, where they grow, sending down roots that embrace and eventually kill the palm, which decays away. This tree is now eighty feet high, and throws an area 300 feet*
[Had this tree been growing in 1849 over the great palm-stove at Kew, only thirty feet of each end of that vast structure would have been uncovered: its increase was proceeding so rapidly, that by this time it could probably cover the whole. Larger banyans are common in Bengal; but few are so symmetrical in shape and height. As the tree gets old, it breaks up into separate ma.s.ses, the original trunk decaying, and the props becoming separate trunks of the different portions.] in diameter into a dark, cool shade. The gigantic limbs spread out about ten feet above the ground, and from neglect during Dr. Wallich"s absence, there were on Dr. Falconer"s arrival no more than eighty-nine descending roots or props; there are now several hundreds, and the growth of this grand ma.s.s of vegetation is proportionably stimulated and increased. The props are induced to sprout by wet clay and moss tied to the branches, beneath which a little pot of water is hung, and after they have made some progress, they are inclosed in bamboo tubes, and so coaxed down to the ground.
They are mere slender whip-cords before reaching the earth, where they root, remaining very lax for several months; but gradually, as they grow and swell to the size of cables, they tighten, and eventually become very tense. This is a curious phenomenon, and so rapid, that it appears to be due to the rooting part mechanically dragging down the aerial. The branch meanwhile continues to grow outwards, and being supplied by its new support, thickens beyond it, whence the props always slant outwards from the ground towards the circ.u.mference of the tree.
_Cycas_ trees abound in the gardens, and, though generally having only one, or rarely two crowns, they have sometimes sixteen, and their stems are everywhere covered with leafy buds, which are developed on any check being given to the growth of the plant, as by the operation of transplantation, which will cause as many as 300 buds to appear in the course of a few years, on a trunk eight feet high.
During my stay at the gardens, Dr. Falconer received a box of living plants packed in moss, and transported in a frozen state by one of the ice ships from North America:* [The ice from these ships is sold in the Calcutta market for a penny a pound, to great profit; it has already proved an invaluable remedy in cases of inflammation and fever, and has diminished mortality to a very appreciable extent.]
they left in November, and arriving in March, I was present at the opening of the boxes, and saw 391 plants (the whole contents) taken out in the most perfect state. They were chiefly fruit-trees, apples, pears, peaches, currants, and gooseberries, with beautiful plants of the Venus" fly-trap (_Dionaea muscipula_). More perfect success never attended an experiment: the plants were in vigorous bud, and the day after being released from their icy bonds, the leaves sprouted and unfolded, and they were packed in Ward"s cases for immediate transport to the Himalaya mountains.
My visit to Calcutta enabled me to compare my instruments with the standards at the Observatory, in which I was a.s.sisted by my friend, Capt. Thuillier, to whose kind offices on this and many other occasions I am greatly indebted.
I returned to Dorjiling on the 17th of April, and Dr. Thomson and I commenced our arrangements for proceeding to the Khasia mountains.
We started on the 1st of May, and I bade adieu to Dorjiling with no light heart; for I was leaving the kindest and most disinterested friends I had ever made in a foreign land, and a country whose mountains, forests, productions, and people had all become endeared to me by many ties and a.s.sociations. The prospects of Dorjiling itself are neither doubtful nor insignificant. Whether or not Sikkim will fall again under the protection of Britain, the station must prosper, and that very speedily. I had seen both its native population and its European houses doubled in two years; its salubrious climate, its scenery, and accessibility, ensure it so rapid a further increase that it will become the most populous hill-station in India. Strong prejudices against a damp climate, and the complaints of loungers and idlers who only seek pleasure, together with a groundless fear of the natives, have hitherto r.e.t.a.r.ded its progress; but its natural advantages will outweigh these and all other obstacles.
I am aware that my opinion of the ultimate success of Dorjiling is not shared by the general public of India, and must be pardoned for considering their views in this matter short-sighted. With regard to the disagreeables of its climate, I can sufficiently appreciate them, and shall be considered by the residents to have over-estimated the amount and constancy of mist, rain, and humidity, from the two seasons I spent there being exceptional in these respects. Whilst on the one hand I am willing to admit the probability of this,* [I am informed that hardly a shower of rain has fallen this season, between November 1852, and April 1853; and a very little snow in February only.] I may be allowed on the other to say that I have never visited any spot under the sun, where I was not told that the season was exceptional, and generally for the worse; added to which there is no better and equally salubrious climate east of Nepal, accessible from Calcutta.
All climates are comparative, and fixed residents naturally praise their own. I have visited many lat.i.tudes, and can truly say that I have found no two climates resembling each other, and that all alike are complained of. That of Dorjiling is above the average in point of comfort, and for perfect salubrity rivals any; while in variety, interest, and grandeur, the scenery is unequalled.
From Sikkim to the Khasia mountains our course was by boat down the Mahanuddy to the upper Gangetic delta, whose many branches we followed eastwards to the Megna; whence we ascended the Soormah to the Silhet district. We arrived at Kishengunj, on the Mahanuddy, on the 3rd of May, and were delayed two days for our boat, which should have been waiting here to take us to Berhampore on the Ganges: we were, however, hospitably received by Mr. Perry"s family.
The approach of the rains was indicated by violent easterly storms of thunder, lightning, and rain; the thermometer ranging from 70 degrees to 85 degrees. The country around Kishengunj is flat and very barren; it is composed of a deep sandy soil, covered with a short turf, now swarming with c.o.c.kchafers. Water is found ten or twelve feet below the surface, and may be supplied by underground streams from the Himalaya, distant forty-five miles. The river, which at this season is low, may be navigated up to t.i.talya during the rains; its bed averages 60 yards in width, and is extremely tortuous; the current is slight, and, though shallow, the water is opaque.
We slowly descended to Maldah, where we arrived on the 11th: the temperature both of the water and of the air increased rapidly to upwards of 90 degrees; the former was always a few degrees cooler than the air by day, and warmer by night. The atmosphere became drier as we receded from the mountains.
The boatmen always brought up by the sh.o.r.e at night; and our progress was so slow, that we could keep up with the boat when walking along the bank. So long as the soil and river-bed continued sandy, few bushes or herbs were to be found, and it was difficult to collect a hundred kinds of plants in a day: gradually, however, clumps of trees appeared, with jujube bushes, _Trophis, Acacia,_ and _Buddleia,_ a few fan-palms, bamboos, and Jack-trees. A sh.e.l.l (_Anodon_) was the only one seen in the river, which harboured few water-plants or birds, and neither alligators nor porpoises ascend so high.
On the 7th of May, about eighty miles in a straight line from the foot of the Himalaya, we found the stratified sandy banks, which had gradually risen to a height of thirteen feet, replaced by the hard alluvial clay of the Gangetic valley, which underlies the sand: the stream contracted, and the features of its banks were materially improved by a jungle of tamarisk, wormwood (_Artemisia_), and white rose-bushes (_Rosa involucrata_), whilst mango trees became common, with tamarinds, banyan, and figs. Date and _Caryota_ palms, and rattan canes, grew in the woods, and parasitic Orchids on the trees, which were covered with a climbing fern (_Acrostic.u.m scandens_), so that we easily doubled our flora of the river banks before arriving at Maldah.
This once populous town is, like Berhampore, now quite decayed, since the decline of its silk and indigo trades: the staple product, called "Maldy," a mixture of silk and cotton, very durable, and which washes well, now forms its only trade, and is exported through Sikkim to the north-west provinces and Tibet. It is still famous for the size and excellence of its mangos, which ripen late in May; but this year the crop had been destroyed by the damp heats of spring, the usual north-west dry winds not having prevailed.
The ruins of the once famous city of Gour, a few miles distant, are now covered with jungle, and the buildings are fast disappearing, owing to the bricks being carried away to be used elsewhere.
Below Maldah the river gets broader, and willow becomes common.
We found specimens of a _Planorbis_ in the mud of the stream, and saw apparently a boring sh.e.l.l in the alluvium, but could not land to examine it. Chalky ma.s.ses of alligators" droppings, like coprolites, are very common, buried in the banks, which become twenty feet high at the junction with the Ganges, where we arrived on the 14th.
The waters of this great river were nearly two degrees cooler than those of the Mahanuddy.
Rampore-Bauleah is a large station on the north bank of the Ganges, whose stream is at this season fully a mile wide, with a very slow current; its banks are thirty feet above the water. We were most kindly received by Mr. Bell, the collector of the district, to whom we were greatly indebted for furthering us on our voyage: boats being very difficult to procure, we were, however, detained here from the 16th to the 19th. I was fortunate in being able to compare my barometers with a first-rate standard instrument, and in finding no appreciable alteration since leaving Calcutta in the previous April.
The elevation of the station is 130 feet above the sea, that of Kishengunj I made 131; so that the Gangetic valley is nearly a dead level for fully a hundred miles north, beyond which it rises; t.i.talya, 150 miles to the north, being 360 feet, and Siligoree, at the margin of the Terai, rather higher. The river again falls more considerably than the land; the Mahanuddy, at Kishengunj, being about twenty feet below the level of the plains, or 110 above the sea; whereas the Ganges, at Rampore, is probably not more than eighty feet, even when the water is highest.
The climate of Rampore is marked by greater extremes than that of Calcutta: during our stay the temperature rose above 106 degrees, and fell to 78 degrees at night: the mean was 2.5 degrees higher than at Calcutta, which is 126 miles further south. Being at the head of the Gangetic delta, which points from the Sunderbunds obliquely to the north-west, it is much damper than any locality further west, as is evidenced by two kinds of _Calamus_ palm abounding, which do not ascend the Ganges beyond Monghyr. Advancing eastwards, the dry north-west wind of the Gangetic valley, which blows here in occasional gusts, is hardly felt; and easterly winds, rising after the sun (or, in other words, following the heating of the open dry country), blow down the great valley of the Burrampooter, or south-easterly ones come up from the Bay of Bengal. The western head of the Gangetic delta is thus placed in what are called "the variables" in naval phraseology; but only so far as its superficial winds are concerned, for its great atmospheric current always blows from the Bay of Bengal, and flows over all northern India, to the lofty regions of Central Asia.
At Rampore I found the temperature of the ground, at three feet depth, varied from 87.8 degrees to 89.8 degrees, being considerably lower than that of the air (94.2 degrees), whilst that of a fine ripening shaddock, into which I plunged a thermometer bulb, varied little from 81 degrees, whether the sun shone on it or not. From this place we made very slow progress south-eastwards, with a gentle current, but against constant easterly winds, and often violent gales and thunder-storms, which obliged us to bring up under shelter of banks and islands of sand. Sometimes we sailed along the broad river, whose opposite sh.o.r.es were rarely both visible at once, and at others tracked the boat through narrow creeks that unite the many Himalayan streams, and form a network soon after leaving their mountain valleys.
A few miles beyond Pubna we pa.s.sed from a narrow ca.n.a.l at once into the main stream of the Burrampooter at Jaffergunj: our maps had led us to expect that it flowed fully seventy miles to the eastward in this lat.i.tude; and we were surprised to hear that within the last twenty years the main body of that river had shifted its course thus far to the westward. This alteration was not effected by the gradual working westwards of the main stream, but by the old eastern channel so rapidly silting up as to be now unnavigable; while the Jummul, which receives the Teesta, and which is laterally connected by branches with the Burrampooter, became consequently wider and deeper, and eventually the princ.i.p.al stream.
Nothing can be more dreary and uninteresting than the scenery of this part of the delta. The water is clay-coloured and turbid, always cooler than the air, which again was 4 degrees or 5 degrees below that of Calcutta, with a damper atmosphere. The banks are of stratified sand and mud, hardly raised above the mean level of the country, and consequently unlike those bordering most annually flooded rivers; for here the material is so unstable, that the current yearly changes its course. A wiry gra.s.s sometimes feebly binds the loose soil, on which there are neither houses nor cultivation.
Ascending the Jummul (now the main channel of the Burrampooter) for a few miles, we turned off into a narrower channel, sixty miles long, which pa.s.ses by Dacca, where we arrived on the 28th, and where we were again detained for boats, the demand for which is rapidly increasing with the extended cultivation of the Sunderbunds and Delta. We stayed with Mr. Atherton, and botanised in the neighbourhood of the town, which was once very extensive, and is still large, though not flourishing. The population is mostly Mahometan; the site, though beautiful and varied, is unhealthy for Europeans. Ruins of great Moorish brick buildings still remain, and a Greek style of ornamenting the houses prevails to a remarkable degree.
The manufacture of rings for the arms and ancles, from conch-sh.e.l.ls imported from the Malayan Archipelago, is still almost confined to Dacca: the sh.e.l.ls are sawn across for this purpose by semicircular saws, the hands and toes being both actively employed in the operation. The introduction of circular saws has been attempted by some European gentlemen, but steadily resisted by the natives, despite their obvious advantages. The Dacca muslin manufacture, which once employed thousands of hands, is quite at an end, so that it was with great difficulty that the specimens of these fabrics sent to the Great Exhibition of 1851, were procured. The kind of cotton (which is very short in the staple) employed, is now hardly grown, and scarcely a loom exists which is fit for the finest fabrics. The jewellers still excel in gold and silver filagree.
Pine-apples, plantains, mangos, and oranges, abound in the Dacca market, betokening a better climate for tropical fruits than that of Western Bengal; and we also saw the fruit of _Euryale ferox,_* [An Indian water-lily with a small red flower, covered everywhere with p.r.i.c.kles, and so closely allied to _Victoria regia_ as to be scarcely generically distinguishable from it. It grows in the eastern Sunderbunds, and also in Kashmir. The discoverer of Victoria called the latter "_Euryale Amazonica._" These interestiug plants are growing side by side in the new Victoria house at Kew. The Chinese species has been erroneously considered different from the Indian one.] which is round, soft, pulpy, and the size of a small orange; it contains from eight to fifteen round black seeds as large as peas, which are full of flour, and are eaten roasted in India and China, in which latter country the plant is said to have been in cultivation for upwards of 3000 years.
The native vegetation is very similar to that of the Hoogly, except that the white rose is frequent here. The fact of a plant of this genus being as common on the plains of Bengal as a dog-rose is in England, and a.s.sociated with cocoa-nuts, palms, mangos, plantains, and banyans, has never yet attracted the attention of botanists, though the species was described by Roxburgh. As a geographical fact it is of great importance, for the rose is usually considered a northern genus, and no kind but this inhabits a damp hot tropical climate. Even in mountainous countries situated near the equator, as in the Himalaya and Andes, wild roses are very rare, and only found at great elevations, whilst they are unknown in the southern hemisphere. It is curious that this rose, which is also a native of Birma and the Indian Peninsula, does not in this lat.i.tude grow west of the meridian of 87 degrees; it is confined to the upper Gangetic delta, and inhabits a climate in which it would least of all be looked for.
I made the elevation of Dacca by barometer only seventy-two feet above the sea; and the banks of the Dallisary being high, the level of its waters at this season is scarcely above that of the Bay of Bengal. The mean temperature of the air was 86.75 degrees during our stay, or half a degree lower than Calcutta at the same period.
We pursued our voyage on the 30th of May, to the old bed of the Burrampooter, an immense shallow sheet of water, of which the eastern bank is for eighty miles occupied by the delta of the Soormah.
This river rises on the Munnipore frontier, and flows through Cachar, Silhet, and the Jheels of east Bengal, receiving the waters of the Cachar, Jyntea, Khasia, and Garrow mountains (which bound the a.s.sam valley to the south), and of the Tipperah hills, which stretch parallel to them, and divide the Soormah valley from the Bay of Bengal. The immense area thus drained by the Soormah is hardly raised above the level of the sea, and covers about 10,000 square miles.
The anastomosing rivers that traverse it, flow very gently, and do not materially alter their course; hence their banks gradually rise above the mean level of the surrounding country, and on them the small villages are built, surrounded by extensive rice-fields that need no artificial irrigation. At this season the general surface of the Jheels is marshy; but during the rains, which are excessive on the neighbouring mountains, they resemble an inland sea, the water rising gradually to within a few inches of the floor of the huts; as, however, it subsides as slowly in autumn, it commits no devastation.
The communication is at all seasons by boats, in the management of which the natives (chiefly Mahometans) are expert.
The want of trees and shrubs is the most remarkable feature of the Jheels; in which respect they differ from the Sunderbunds, though the other physical features of each are similar, the level being exactly the same: for this difference there is no apparent cause, beyond the influence of the tide and sea atmosphere. Long gra.s.ses of tropical genera (_Saccharum, Donax, Andropogon,_ and _Rottboellia_) ten feet high, form the bulk of the vegetation, with occasional low bushes along the firmer banks of the natural ca.n.a.ls that everywhere intersect the country; amongst these the rattan cane (_Calamus_), rose, a laurel, _Stravadium,_ and fig, are the most common; while beautiful convolvuli throw their flowering shoots across the water.
The soil, which is sandy along the Burrampooter, is more muddy and clayey in the centre of the Jheels, with immense spongy acc.u.mulations of vegetable matter in the marshes, through which we poked the boat-staves without finding bottom: they were for the most part formed of decomposed gra.s.s roots, with occasionally leaves, but no quant.i.ty of moss or woody plants. Along the courses of the greater streams drift timber and various organic fragments are no doubt imbedded, but as there is no current over the greater part of the flooded surface, there can be little or no acc.u.mulation, except perhaps of old canoes, or of such vegetables as grow on the spot.
The waters are dark-coloured, but clear and lucid, even at their height.
We proceeded up the Burrampooter, crossing it obliquely; its banks were on the average five miles apart, and formed of sand, without clay, and very little silt or mud: the water was clear and brown, like that of the Jheels, and very different from that of the Jummul.
We thence turned eastwards into the delta of the Soormah, which we traversed in a north-easterly direction to the stream itself.
We often pa.s.sed through very narrow channels, where the gra.s.ses towered over the boats: the boatmen steered in and out of them as they pleased, and we were utterly at a loss to know how they guided themselves, as they had neither compa.s.s nor map, and there were few villages or landmarks; and on climbing the mast we saw mult.i.tudes of other masts and sails peeing over the gra.s.sy marshes, doing just the same as we did. All that go up have the south-west wind in their favour, and this helps them to their course, but beyond this they have no other guide but that instinct which habit begets. Often we had to retreat from channels that promised to prove short cuts, but which turned out to be blind alleys. Sometimes we sailed up broader streams of chesnut-brown water, accompanied by fleets of boats repairing to the populous districts at the foot of the Khasia, for rice, timber, lime, coal, bamboos, and long reeds for thatching, all of which employ an inland navy throughout the year in their transport to Calcutta.
Leeches and mosquitos were very troublesome, the latter appearing in clouds at night; during the day they were rarer, but the species was the same. A large cray-fish was common, but there were few birds and no animals to be seen.
Fifty-four barometric observations, taken at the level of the water on the voyage between Dacca and the Soormah, and compared with Calcutta, showed a gradual rise of the mercury in proceeding eastwards; for though the pressure at Calcutta was .055 of an inch higher than at Dacca, it was .034 lower than on the Soormah: the mean difference between all these observations and the contemporaneous ones at Calcutta was + .003 in favour of Calcutta, and the temperature half a degree lower; the dew-point and humidity were nearly the same at both places. This being the driest season of the year, it is very probable that the mean level of the water at this part of the delta is not higher than that of the Bay of Bengal; but as we advanced northwards towards the Khasia, and entered the Soormah itself, the atmospheric pressure increased further, thus appearing to give the bed of that stream a depression of thirty-five feet below the Bay of Bengal, into which it flows! This was no doubt the result of unequal atmospheric pressure at the two localities, caused by the disturbance of the column of atmosphere by the Khasia mountains; for in December of the same year, thirty-eight observations on the surface of the Soormah made its bed forty-six feet _above_ the Bay of Bengal, whilst, from twenty-three observations on the Megna, the pressure only differed + 0.020 of an inch from that of the barometer at Calcutta, which is eighteen feet above the sea-level.
These barometric levellings, though far from satisfactory as compared with trigonometric, are extremely interesting in the absence of the latter. In a scientific point of view nothing has been done towards determining the levels of the land and waters of the great Gangetic delta, since Rennell"s time, yet no geodetical operation promises more valuable results in geography and physical geology than running three lines of level across its area; from Chittagong to Calcutta, from Silhet to Rampore, and from Calcutta to Silhet. The foot of the Sikkim Himalaya has, I believe, been connected with Calcutta by the great trigonometrical survey, but I am given to understand that the results are not published.