SUMATRA. tl 
of the fouch weftern rivers, and render them impra^^ticable to boats of 
any draught of water. Thefe labor too under this additional inconve- 
nience ; that fcarce any^ except the largeft, run out to fea in a dired: 
courfe. The continual ad^ion of the furf, more powerful than the ordi- 
nary force of the ftream, throws up at their mouths a bank of fand, which 
diverts their courfe to a direction parallel with the ihorc, between the 
cliffs and the beach, till the accumulated waters at length force their 
way wherever there is found the weakcft refiftance.* In the foutherly 
Monfoon, when the furfs are ufually higheft, and the rivers, from the 
drynefsof the weather, leaft rapid, this parallel courfe is at the greatelt 
extent ; but as the rivers fwell with the rain, they gradually remove 
obftrudtions and recover their natural channel. 
The heat of tHe ui* i=. by «*-oric fn inrenfe as might be expected, Air, 
in a country occupying the middle of the torrid zone. It is more tem- 
perate than in many regions without the tropics, the thermometer, at the 
moft fukry hour, which is about two in the afternoon, generally flu6:ua- 
ting between 82 and 85 degrees.-f I do not recollect to have ever feen 
it higher than 86 in the lhade. At fun rife it is ufually as low as 70 ; 
the fenfation of cold, however, is much greater than this would feem 
to indicate, as it occafions fhivering and a chattering of the teeth ; doubt- 
lefs from the greater relaxation of the body, and opennefs of the pores 
in that climate ; for the fame temperature in England would be efteemcd 
a conCtcferable degree of warmth* Thefe obfervations on the ftate of the 
air, apply only to ^la^iJ^^ n^ar the. fea coaft, where, from their com- 
paratively low fituation, aod the greater compreflion of the atmofphere, 
the fun's rays operate more powerfully. Inland, as the country afcends, 
the degree of heat dccreafes rapidly, info much, that beyond the firft 
range of hills, the inhabitants find it expedient to light fires in the morn- 
ing, and continue them till the day is advanced, for the purpofe of 
J Moco Moco river takes a couife, at times, of three miles, in this manner, before itmixet 
With the fea. 
* At Calcutta in Bengal, the thermometer, in the Imt feafon, rifes to 95*. up the cofuntiy ' 
fomctimesto loi^ia the Jl«idei and even after fwn fttj ithas been obfetrcd at " 
warming 
