METHOD OR METHODS OF MANU- FACTURING GLASS
Year: 1816

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MACNAMARA, of East Smithfield, in the County of Middlesex, Plate Glass
Manufacturer, send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Letters Patent under the Great Seal of His United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-third day of
March, in the fifty-sixth year of His reign, give and grant unto me, the said
William Macnamara, my exors, admors, and assigns, His especial licence, full
power, sole privilege and authority, that I, the said William Macnamara, my
exors, admors, and assigns, during the term of years therein mentioned,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, the Invention communicated
to me by a Foreigner residing abroad, of the "METHOD OR METHODS OF MANU-
FACTURING GLASS;" in which said Letters Patent there is contained a proviso
that if I, the said William Macnamara, shall not particularly describe and
ascertain the nature of the said Invention, and the manner in which the same
is to be performed, by an instrument in writing under my hand and seal, and
cause the same to be inrolled in His Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
Letters Patent, that then the said Letters Patent, and all liberties and advan-
tages whatsoever thereby granted, shall utterly cease, determine, and become

page_text: void, as in and by the same, relation being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Macnamara, do hereby declare that the improvements which I have
introduced in the manufacture of glass for pictures, coach glasses, windows, &c.,
are as follows, vizt:-
First method. The glass is gathered in the pipe in the usual manner, but
instead of marveling it on the marveling table, it is rolled or marvelled in a
hollow block of wood or other materials, into which water is put from
time to time. In this block the blowing is commenced, and then by alter-
nately blowing and -swinging the glass in a perpendicular circular direction,
and occasionally heating it, it is fashioned into the form of a cylinder,
which may be opened by the method practised in Britain; but the mode
here preferred is by heating up the end furthest from the pipe in the
furnace, or any other working hole, and blowing through it. It is then swung
until all the edges form themselves into a continuation of the cylinder; or the
ragged edges may be cut off with a pair of scissars; or this end may be cut
off by the application of cold water when hot, or by applying a hot piece of iron
or other metal when cold, or a thread of hot glass. The end next to the pipe
is, then detached in the same manner, after which it is split up the side with
either of the same materials. By this process cylinders may be made from
twenty-four to thirty-eight inches in length by ten or twelve inches in diameter;
but, for producing larger plates, the following process is followed:―
Second method. After gathering the quantity of metal required, the mar-
velling is commenced, as before described,, in the block or blocks of wood, or
other metal or ware, (for different-sized holes are required to be used in the
different stages of the gathering), blowing it at the same time; and when a
hollow, space is blown in the glass, from two to six inches in length,, more or
less, the workman then raises the glass and pipe above his, head,, which is
reversed, and, looking upwards, he continues to blow until the cylinder has
acquired at the end next to the pipe the diameter required. The glass is then
reheated, when, by marvelling, swinging, and blowing occasionally, as before
described, a cylinder from forty-two to forty-eight inches in length by eighteen
to twenty in diameter is produced. This cylinder may also be opened by the
method practised in Britain; but the mode here preferred is to commence at
the end farthest from the pipe by putting or fastening thereon a little piece of
hot glass, when,, by putting this. end of the cylinder into the working hole or
other furnace,, and blowing into the pipe, on the mouth of which the finger is
to be placed to prevent the air from escaping), it follows, that the air therein

page_text: becomes rarified, and acting as a spring on the soft part of the glass next to
the furnace, it generally bursts open with a loud report, otherwise the blowing
must be repeated until this operation is performed. The glass is then swung
and heated occasionally, as mentioned in the preceeding method, until the
cylinder is completed. The cylinder is then placed in an earthen pot, heated
to the same temperature as the glass, where it cools gradually; after which,
the end that was next to the pipe is cut off, and split or cracked up the side
by one of the fore-mentioned processes. Both the small and large cylinders
are flattened in the same manner. They are carried to a spreading kiln,
which may be made according to the usual form given to kilns used for
plate glass, but the form here preferred is represented in the annexed
Plans No. 1 and 2, where the cylinder is introduced at a, and, when
sufficiently warmed, it is placed on a plate of glass, china, or other ware,
which lays in the kilu A. It is then opened, flattened, and rubbed down with
a wooden block or polisher; after which it is pussed off the plate of glass,
china, or ware, into the kiln B, where it is piled up on one of its edges when
sufficiently cooled; or a number of them may be piled flat one on the other.
When the kiln B contains as many as it can conveniently, it is closed in the
usual manner; and the glass is drawn in the course of six or eight days,
according to circumstances.
In witness whereof, I, the said William Macnamara, have hereunto set
my hand and seal, this Twenty-third day of August, in the year of our
Lord One thousand eight hundred and sixteen.