258 JHEELS OF BENGAL. Chap. XXVIII. 



thence turned eastwards into the delta of the Soormah, 

 which we traversed in a north-easterly direction to the 

 stream itself. We often passed through very narrow 

 channels, where the grasses 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 compass nor map, and there were few 

 villages or landmarks ; and on climbing the mast we 

 saw multitudes of other masts and sails peering over the 

 grassy 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 w r e 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 ches- 

 nut-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-flsh 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 cotem- 



