IMPROVEMENTS IN APPARATUS TO BE USED IN DEEP-SEA SOUNDING FOR ASCERTAINING THE PRESSURE AND FOR RAISING SPECIMENS OF THE WATER
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by George Charles Wallich at the
Office of the Commissioners of Patents, with his Petition, on the
16th December 1862.
I, GEORGE CHARLES WALLICH, M.D., Retired List H.M.I. Army, of 17,
Campden Hill Road, Kensington, in the County of Middlesex, do hereby.
declare the nature of the Invention for "IMPROVEMENTS IN APPARATUS TO BE
USED IN DEEP-SEA SOUNDING FOR ASCERTAINING THE PRESSURE AND FOR RAISING
SPECIMENS OF THE WATER," to be as follows:-
This Invention has for its object improvements in apparatus to be used in
deep-sea sounding, for ascertaining the pressure and for raising specimens of
the water.
For the purpose of ascertaining the pressure of the water a strong cylinder
or vessel is closed at one end by a fixed bottom, and at the other it has a
moveable piston fitting water-tight within it. Inside the vessel I place a mass
of a solid compressible material, such, for example, as india-rubber; this
compressible mass does not entirely fill the space within the vessel, but room
is left around the solid for an incompressible or nearly incompressible liquid,
such as mercury, and with this the remainder of the space is filled. When
the vessel is lowered to a great depth into the sea the heavy pressure of the
water upon the outer surface of the piston causes it to move inwards, the
compressible mass being made to occupy a sinaller and smaller space as the
pressure around it is increased. The liquid within the vessel ensures the
pressure being applied to the solid mass equally in all directions. A record is

page_text: kept of the distance the piston enters the vessel by placing on the rod or stem
of the piston (which works between suitable guides) a projection which, as
the piston descends, moves a slider along a graduated scale conveniently placed
on the side of one of the guides. When the instrument is drawn up after
having been sunk the position of the slider in respect to the graduations on the
scale shows the pressure and also the depth to which the instrument has been
sunk.
In order to bring up specimens of water from any required depth below
the surface, I suspend from the sounding line a horizontal cylinder, open at
each end; this cylinder is fitted with caps, which, however, when the cylinder
is lowered are not on in their places, but they are held in positions above the
axis of the cylinder; they have india-rubber springs, which tend to draw them
together; they are, however, unable to approach each other because the
cylinder is between them, and keeps them apart. When the apparatus thus
arranged has been sunk to the depth from which it is desired to raise a
sample of water, a messenger weight is placed on the sounding line, and
allowed to run down it. When it arrives at the apparatus it strikes bars
connected with the two caps, and pushes them down to the level of the
cylinder, and when they are truly concentric therewith the springs draw the
caps together, and thus close accurately the ends of the cylinder; suitable
guides are employed to ensure that when the caps are pushed down they shall
come truly into position to be drawn on to the ends of the cylinder by the
springs. To allow the surplus water to escape as the caps approach each
other, there is at the centre of the cylinder a hole fitted with a slide; through
this hole the water issues, and it is the last act of the caps as they come
together to push the slide over this hole, and so to close it.