Mr Fraser an a Method of Propelling Vessels. I ID 
quantity in the cistern is kept up by the pump) with such force 
as to propel the vessel forward. But if the plugs 0 0 are shut, 
and S opened, the water will issue through the tubes M M, and 
give the vessel stern- way. 
In order to turn the vessel round, four tubes I, I, I, I, may 
be attached to the sides of the tube any where between the 
plugs H and S, and carried to the head and stern of the vessel, 
so as to terminate at t , t and a, a at right angles to the keel. 
The plugs are united transversely, so that either pair being 
opened, the water may issue near the bow on one side of the 
keel, and near the stern on the opposite side of the keel a a. 
These plugs are situated at b , b. b, b , with piston rods connected 
by pairs, as shewn in Fig. 7, but transversely. When great 
dispatch in turning is necessary, the plugs at S and O O must 
be shut. 
The condenser E F has a tube X, extending from its upper 
part to within a foot of the bottom, and through this tube the 
water will rise, in order that its power may be measured by 
means of an ordinary safety-valve T, applied to the upper end 
of the tube, and so adjusted as to allow the water to issue when 
its power is greater than what the condenser can properly sustain. 
The plugs O O have piston-rods r r attached to them as in 
Fig. 7, and united at c, so as to act together b}^ means of the 
single piston-rod d. 
The plug at S is constructed as shewn in Fig. 8 and 9, the 
former being a cross section, and the latter a longitudinal section. 
A piston W, with a piston-rod r, passing through a stuffing- 
box, may be forced into the lower cylinder, so as to stop the 
main tube G at that place, and, being drawn up again, shall 
leave that tube open. This piston must be rendered pervious 
to the water by one or two tubes in the same direction with its 
piston-rod, to admit of its ascent or descent into the water. The 
plugs 0 0 and II may be constructed on the same plan with S, 
and all of them must be perforated by a strong copper piston-rod 
s <?, passing through a stuffing box in the lower end of each 
cylinder, to direct and enable them to withstand the pressure of 
the water in their ascent and descent. 
The machinery which has now been described, with the ex- 
ception of the tubes for repelling, and those for turning the 
