CERTAIN IMPROVEMENTS IN LAMP GLASSES
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
STEVENS, of Birmingham, in the County of Warwick, Glass Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twenty-second day of April, in the fifteenth year of Her said Majesty's
reign, did give and grant unto me, the said James Stevens, my exors,
admors, and assigns, and such others as I, the said James Stevens, my exors,
adiñors, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term of years therein
mentioned, should and lawfully might make, use, exercise, and vend, within
that part of the United Kingdom of Great Britain and Ireland called England,
the Dominion of Wales, and Town of Berwick-upon-Tweed, my Invention
of "CERTAIN IMPROVEMENTS IN LAMP GLASSES;" in which said Letters Patent
there is contained a proviso that J, the said James Stevens, shall particularly
describe and ascertain the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, to be enrolled in Her said Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
recited Letters Patent, as, reference being thereunto had, will more fully and
at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Stevens, do hereby declare that the nature of my said Invention, and

page_text: circumferences of all kinds of lamp glasses, whereby I am enabled to obtain
greatly increased brilliancy of light from the same quantity of illuminating
power.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a view of the form of glass known as the spheroidal, shewing
the lenses attached thereto. Figure 2, a section of same through the lenses.
Figure 3, a view, shewing the same in the first stage of manufacture. Figure 4,
a view, shewing the same in a more advanced stage. Figure 5, a view of the
shape known as the vesta lotus. Figure 6, a section of the same through
the lenses. Figure 7, the globe shape. Figure 8, the railway roof lamp.
Figure 9, the hemisphere. Figure 10, ship cabin lamp. These Figures serve
to shew a few only of the forms to which my Invention is applicable, the
process of manufacture being alike in all.
I will now proceed to describe the mode in which I manufacture the
spheroidal form of glass, Figures 1, 2, 3, 4, and for this purpose I use an
ordinary mould and plunger. The mould having spaces or hollows indented
to its inner surface, to receive a sufficient amount of "glass metal" to form
the lenses of the required size, the glass is then pressed in in manner well
known, and on leaving the mould assumes the form shewn in Figure 3,
having a solid bottom; to this solid bottom I attach a "punty," and work
the glass into the form shewn at Figure 4. I then attach a "post" (well
known in the trade as being an iron tube, having a solid glass foot on the
end) to the top of the glass, and I knock off the bottom from the "punty,"
after which I "warm in " the globe and blow it up to any required size. The
bottom is then cut off, and, if required, a rim or neck is made in the ordinary
mode. The bottom being completed, another " post" is attached to it, the
one at the top removed, and I proceed to make the top to any required form
in the usual way, and if the glass be not sufficiently large in the bulge, I
increase the size by means of a blow pipe, and then knock off the bottom post,
when the glass is complete. Thus far the same plan is adopted in the
manufacture of all the various forms of lamp glasses, and I need only state
that in the forms shewn by Figures 5 and 9, videlicet, the vesta lotus and
the hemisphere, the neck is formed and attached afterwards by the modes