STEAM-BOAT*. 637 
ticlcs. The steam-packet proceeded, however," against the 
stream, in a gallant style, at the rate of six or seven mile* 
an hour j and a band of music, playing lively airs on the 
deck, combined, with the steadiness of the motion, to ren- 
der the effect delightful. An examination of the steam- 
engine, and of her rate of working, proved that no possibi- 
lity of danger exists. It appeared that the boiler had been 
proved at twenty-five pounds to the square inch j but that 
tlie valve was held down by a weight of only four pounds, 
and that the mercurial gauge did not indicate an employ- 
ment of actual pressure of above two pounds and a half per 
square inch. Hence it follows, that, although the engine 
was capable of sustaining a pressure of at least twenty-five 
pounds, only four pounds, or less than a sixth, wa.s the 
whole force which the valve would permit to be exerted ; 
and that, in point of fact, a pressure of only two pounds 
and a Iwlf to the square inch, or only one-tenth of the 
proven power of the boiler, was employed. There is, 
tlierefore, less danger in passing some hours in contact with 
such a machine, than there is in sitting near a boiling tea- 
kettle, tea-urn, or saucepan, under circumstances in which 
they are often used. Opposite Greenwich a fine com- 
mentary was afforded of the value of steam as a navigating 
power, in preference to winds and tides, a Margate sailing- 
packet passing towards London, which had been a day and 
two nights on its passage, a period of time which it ap- 
pears is not uncommon. In short, with uninterrupted 
pleasure, and in an hour sooner than the captain had named 
at start’ng, the vessel was carried along-side Margate-pier, 
havieg employed nine hours in performing a voyage of 
ninety mile*s. In this case it appeared, that a pressure of 
two pounds to the square inch produced about forty iota- 
tions per minute of the acting water-wheels ; and, as these 
Were ten feet in diameter, the motion of the impelling 
floats, or wheel-paddles, would be at the rate of fif'een 
miles an hour ; and proved sufficient to carry the vessel, 
with or against the stream, at an average of ten miles aii 
hour. The consumption of coals during the voyage was 
less than a chaldron ; but it was described as amounting 
frequently to a chaldron and a half. On the whole, nothing 
could be more demonstrative of the worth and security of 
this mode of navigitiou ) and tliere can be little doubt but. 
