342 
the bearings upon which the shafts 
work, and the links connecting the 
piston with the beam, to get loose; and 
In some cases from making them so 
tight, that the bearings heat; and also 
from not attending carefully to the 
steam-valye when ihe vessel is ex- 
posed to a heayy sea, Mr. Watt says, 
“‘with the experience now obtained, 
we make no doubt ‘but that we shall 
be able to construct machinery less 
liable to accident ; but much must 
always depend npon the yigilanee and 
experience of the men who work the 
engines.” Mr. James Brown, being 
asked what were the causes of acci- 
dents to the machinery, replied, ‘they 
depended more on the engine-keepers 
than any thing else.” _. 
Mr. Donkin says, ‘‘ I have reason to 
believe that some of the steam-boat 
companies have suffered severely from 
a want of regular professional inspec- 
tion;” and being asked, ‘‘ Do you con- 
ecive that the injury to engines from 
neglect is greater than the injury 
arising from. the actual working of 
them?’ replied, “Yes, I do;” and 
being furthér asked, “ Has that beena 
constant defect in the management of 
steam-boats up to this period?” re- 
plied, ‘“‘ Yes, I conceive so.” 
All the evidence is so decidedly in 
favour of making boilers of copper, 
that it is necessary only generally to 
refer to it.. Messrs. Fenton and Mur- 
ray, of Leeds, say, ‘‘ The boiler ought 
to be what we call a combined boiler, 
viz, three distinct boilers put together 
to form one boiler, with the fire passing 
three times through each, and so con- 
structed as to be taken up and down a 
hatchway without pulling up or de- 
stroying the decks.” 
All the witnesses agree in opinion 
as to the necessity of keeping the ma- 
chinery as low as possible in the ves- 
sel: Mr. Watt says, ‘‘this will dimi- 
nish the top weight, make the vessel more 
steady at sea, improve the action of the 
machinery, and add to the safety of the 
vessel.” Messrs. Maudslay and Field 
say, “The best arrangement of the 
machinery, and in which engineers are 
most agreed, is to place the boiler or 
boilers afew feet abait the centre of buoy- 
ancy of the vessel ; the two engines on 
each side a few feet forward of this 
point ; and the coals on the centre of 
buoyancy : this arrangement brings the 
fuel, whichis constantly variable, on a 
point that will not affect the trim of the 
vessel; it also brings the wheel-shaft, 
Proceedings of Public Societies, © 
[Now. 1, 
which is at the foremost end of the en- 
gine, to its best position, as regards the 
length of the vessel, viz. at about one- 
third from the head: the weight of the 
boiler, engine, and coal, is thus spread 
pretty equally over the space allotted 
for them, and’ partial and intense 
weight on any one part is thus 
avoided,” 
Messrs. Mandslay and Field state, 
that the fire-places and boilers are fre- 
quently burned and injured from the 
incrustations made by deposited salts 
in the boilers, through neglect to 
change the water and clean the boil- 
ers; and Mr, Denkin says: he has 
known great inconvenience from the 
same cause. In one instance, going to 
Margate, one out of three boilers in the 
vessel produced very little steam, in 
consequence of the incrustations on the 
bottom, a circumstance that was disco- 
vered by its requiring very little water 
to be introduced into it. Mr. Donkin 
further says, that he knows only of two 
methods by which the deposition of 
salt can be prevented. “In. the 
Regent steam-boat they employed a 
method very successfully, that of pump- 
ing hot water through the boiler, and 
allowing a certain quantity constantly 
to be discharged from it into the sea; 
by these means the water was.always 
kept in a sulliciently diluted state,-so 
as to prevent its becoming saturated 
with salt, and consequently none could 
be deposited. No other inconvenient 
effect was produced than a greater 
consumption of fuel. ‘The other mode 
is the common and ordinary one of 
taking out the whole of the water when 
the vessel arrives at the place of desti- 
nation, and, if there is any deposit of 
salt, taking that out also.” - 
Mr. T. Bramah says, ‘ you cannot 
have too much power; indeed it is 
always of advantage to have as much 
power as can be obtained.” Messrs. 
Maudslay and Ficld say, ‘‘withregard 
to the quantity of power proper to put 
into a sca-vessel, the only limit should 
be the weight of the engine and fuek 
the vessel will carry and contain; no 
vessel ever had too much power, even 
in still water, much less when contend- 
ing against a heavy head-wind.”.““ Two 
engines,” they go on to say, ‘Sof half 
the power each, are more: manageable, ’ 
and possess many advantages over ono 
of the whole power; they produce a 
perfectly uniform rotation .in © the 
wheels, and are not subject, like single 
engines, to be stopped on the centre in, 
heavy 
, 
