MR. BESSEMER'S SALOON STEAMER FOR 
; THE CHANNEL PASSAGE 
T HE prevention of sea-sickness by means of a swinging 
cabin has nothing novel about it, but the originality 
mii merit in the suspended saloon devised by 
r. Bessemer, and now about to be actually constructed 
in a ship specially designed for it by Mr. Reed, the late 
chief Constructor of the Navy, are of the highest order. 
‘The association of those names is in itself a sufficient 
guarantee that the idea will be carried into execution with 
complete security as respects the safety of the passengers 
and the seaworthiness of the ship, and a full knowledge of 
the scientific principles involved. 
_ Persons suffering from sea-sickness complain not only 
f giddiness arising from themselves and everything 
out them being continually in motion, but also in 
icular of a qualm which comes over them every 
time the ship, or the part of it on which they are 
standing, is descending, sinking, as it were, from under 
their feet. An approach to this qualm is commonly felt 
a garden swing during the descent, and also in 
jumping from considerable heights. There can be very 
e doubt that this is due to the fact that the intestines 
e then wholly or partially relieved from their own weight, 
and therefore exercise an unusual pressure against the 
Stomach, liver, and diaphragm. This pressure produces 
e qualm, and its rapid and frequent alternations cause 
Sufficient irritation to produce in most people sea-sickness, 
nd i in some persons more serious effects. Physiologists 
re by no means agreed as to how much of sea-sickness is 
to this cause, and how much to the reaction upon the 
mach of the brain-disturbance, due in part, perhaps, to 
actual motion of the head, but largely to the optical 
t of the motion. It is pretty certain that all these 
Causes contribute to produce the effect of sea-sickness, It 
beyond doubt that they all aggravate it. 
Mere swinging cots or small cabins go but a very little 
ay to remedy any of these evils. Even if suspended in 
wo directions, like a compass or barometer upon jimbals, 
translatory motion, whether up or down, or to and fro, 
emains wholly unaltered, and even the gecilatory motion 
‘not got rid of, but only altered in character, being re- 
ed toa minimum at a point near the middle of the 
The distressing effect upon the eye of the relative 
on of surrounding objects also remains. These effects 
not be wholly eliminated by Mr. Bessemer’s inven- 
pn ; but some of them will be very much reduced, and it 
ains to be seen whether the.reduction is sufficient to 
rid of the sickness. 
The design, as settled by Mr. Bessemer and Mr. Reed, 
cludes the construction of large steam vessels of light 
aught, 350 feet long, 40 feet beam, drawing 7 feet of 
ater, and worked by two pairs of paddle-wheels. In the 
e of each of these is provided a well, or hole, for the 
ion of asaloon 70 feet long, 20 feet wide, and 20 feet 
constructed so as to form a box girder in itself, and 
ended at its extremities upon a pair of trunnions, on 
lich it can turn, so that it may be kept steady as the 
el rolls from side to side. The saloon is not allowed 
ng quite freely, but its motion is controlled by hy- 
No, 160~-vot, vit, : 
NATURE 
| draulic machinery, acting either upon a rocking arm or a 
4l 
tangent bar (it does not appear as yet which has been 
selected), which enables a man to regulate its position at 
his discretion. This man sits opposite a spirit level, and, 
by merely turning a handle which opens certain valves, 
can keep the bubble of the spirit level at zero, so as to 
keep the saloon virtually upright at all times. The chief 
novelty of the invention consists in two points—the great 
size of the swinging cabin or saloon, and the controlling 
of its motion by hand, instead of trusting to self-adjust- 
ment. Both these are very important improvements on 
the simple swinging cabin. 
This attempt to neutralise the motion of the vessel 
addresses itself to one phase of motion only, namely the 
rolling. Mr. Bessemer makes no attempt at correcting 
either the translatory part of a ship’s oscillation, or the 
pitching. Heconsiders that in large vessels such as he 
proposes to use, both these motions will be small, and 
not sufficient to cause sickness when once the rolling 
motion is got rid of. We think there is very much to 
bear out his view of the case ; but we also think that, 
considering the difference which always exists between 
experimental and actual circumstances, and especially 
when we bearin mind that the plan does not correct the 
whole of the motion, its absolute and entire success is 
not by any means to be looked upon as a certainty. 
The experiment recently made at} Denmark Hill must 
be regarded rather as {showing the efficiency of the 
hydraulic apparatus for regulating the motion, than the 
effect of its being so regulated. 
In the regular heaving of the sea, after the wind has 
blown sufficiently long to cause regular waves or swell, 
each particle of water describes a circle in a vertical 
plane. At the surface, the diameter of these circles is the 
whole height of the wave from valley to crest, These 
circles rapidly diminish in size as their depth below the 
surface increases. Taking into account this diminution, 
as well as the effect of a ship’s breadth, it is certain that 
the ship will not follow this circular motion at all to the 
same extent as a cork floating on the surface. In mode- 
rately heavy weather, it is probable that in such a ship 
as is proposed by Mr. Bessemer, any fixed point could 
describe a circle of five or six feet in diameter, quite 
independently of any rotatory (or rocking) motion. It is 
much to be regretted that the model at Denmark Hill 
was not mounted ona crank or eccentric, so as to combine 
this motion with the simple rocking, and to ascertain 
how far it remained as a cause of real uneasiness, when 
the rocking had been eliminated. 
It is to be observed that a level does not give a fixed 
direction when a ship is moving upon waves. Apart from 
any rolling of the ship’s own, it gives, when its centre is 
describing a circle uniformly, not the direction of actual 
gravity, but the resultant of gravity and of the centrifugal 
force. In fact, instead of being horizontal with reference 
to the earth, it is horizontal with reference to the effective 
wave surface. But as this is also the direction with re- 
ference to which a man has to balance himself in sitting 
or standing, it tells us what is practically, though not 
actually, the upright, and therefore is probably a better 
guide than a truly vertical or horizontal line. 
It must not be supposed that the feeling of the deck 
sinking under one, or the motion which produces this 
D 
