XXIV INTRODUCTION. 
over-ruled by the well known fact, that on the banks of the 
lower parts of the river are whole forests of the mangrove, 
the wood of which possesses the peculiar quality of burning 
in its green state better than when dry ; but it was not 
known to what extent these forests might reach, though 
it was fair to presume, that, in an equinoctial climate, 
where water was to be found, wood would not be wanting. 
At the same time it could not escape notice that the labour 
of felling and preparing fuel for the boiler of a steam 
engine to the amount of about three tons a day, im such a 
climate, might be fully as fatiguing, and in all probability 
more fatal to the crew, than the occasional operation of 
rowing. If, however, it could have been certain that this 
vast and rapid river was navigable beyond the cataracts, 
and its banks well wooded, a steam engine might prove 
a good auxiliary ; and accordingly it was determined that 
a vessel, capable of being navigated by steam should forth- 
with be constructed. 
But another difficulty presented itself. The vessel was 
not only to be constfucted so as to be adapted to the flats 
and shallows that might occur in the river, but so as to 
ensure her a safe passage across the Atlantic; this was 
thought by many persons to be no easy task. The burden 
of the vessel was not to exceed one hundred tons, her 
draft of water four feet: of this tonnage it was calculated 
that the engine of 24 horses power would alone occupy 
one-third part, and, of her measurement, the whole breadth 
of the vessel, and twenty feet in length. Such a vessel, 
however, with so heavy a burden and so small a displace- 
ment of water, Mr. Seppings, the surveyor of the navy, 
undertook to construct, and at the same time to give her 
