A NEW OR IMPROVED MODE AND MEANS OF CONSTRUCTING BUOYS OR APPARATUS FOR FLOATING BODIES IN DEEP WATER, AND THUS SAVING · LIFE AND PROPERTY
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by John Stewart at the Office
of the Commissioners of Patents, with his Petition, on the 25th
June 1873.
I, JOHN STEWART, of Glasgow, in the County of Lanark, North'
Britain, Manufacturer, do hereby declare the nature of the said In-
vention for "A NEW OR IMPROVED MODE AND MEANS OF CONSTRUCTING BUOYS OR
APPARATUS FOR FLOATING BODIES IN DEEP WATER, AND THUS SAVING · LIFE AND
PROPERTY," to be as follows, that is to say :-
This said Invention has reference to new or improved modes and
means of constructing cork buoys, such as belts, jackets, or rings of
various shapes for the said purposes, by which improvements greater
buoyancy, durability, and imperviousness is given to these than the cork
buoys as heretofore constructed.
1
The nature of this Invention consists, first or mainly, in roasting or
burning the cork until it comes to a brownish black elastic char
throughout, when it will also be seen to have swollen or expanded very
considerably and becomes very much more impervious to water, and from
a fifth to a third more buoyant and proportionally less in specific

page_text: gravity than before it was so roasted. The cork may be of the ordinary
cheapest kind, such as the waste parings or shavings left by the cork-
cutters in making corks for bottles, and bungs and stoppers for other
vessels, and other cork articles, which cork residue and shavings are
preferred to be first ground to about the size of barley pickles or coarse
meal before being roasted as described, but it might also be roasted with-
out being ground whether in large pieces or shavings, as for some of the
larger class of life or other buoys. The cork may be ground in any
ordinary construction of stone or metal mills with roughened or sharp
toothed surfaces of the disc face or barrel class, either cylindrical or
conical, such as used for decorticating or grinding grain or other sub-
stances, and the cork when so ground may be roasted as described in
ovens or kilns or on hot plates over fires or hot flues, or in close or open
sheet metal or wire gauze revolving cylinders or pans, such as used for
roasting coffee or other substances, to the desired blackness and lightness,
when it is then cooled and filled into the bags for making the buoys,
which bags are preferably made of light tough oil or other waterproof
cloth of a suitable size and shape to suit the form of the interior of the
buoy desired to be made by a number of these small interior bags
encased within a canvas or other strong durable outer and inner pro-
tecting case. By this means should the outer case be cut or pierced by
any sharp instrument the water would merely get in through it to the
particular small inner waterproof bag which got cut along with the outer
case, and saturate it to some extent, leaving all the other small bags
perfectly tight; and the cork in the bag, even did the water get into it,
would absorb very little indeed owing to its being roasted or burned as
described, compared with the cork. in its ordinary state as heretofore
used.

page_text: the strings for tightening and fastening it round the waist. The water-
tight bags would preferably be about two or three inches thick, and four
or five inches broad, and of a length to form the full width of the belt at
the different parts and give a soft flexible fit to the body; but it will be
evident that they might also be made of other sizes and shapes to suit
the particular form and shape of buoys desired.
The essentially new features or parts of the Invention are the roasting
or burning of the cork as described, whether ground or unground, and
the making of the buoys of small internal waterproof bags filled with
the said burnt cork, which two improvements are so far distinct that
the first may be used without the latter, the thoroughly burned cork,
whether ground or not, being placed in the large cases forming the
buoys, whether these are made of waterproof material as preferred or
not.