AN IMPROVEMENT IN THE MOUNTING OF GLASSES COMMONLY CALLED OPERA GLASSES
Year: 1804

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
WARRIS, of Sheffield, in the County of York, Optician, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Fourth day of August,
in the forty-fourth year of His reign, did give and grant unto me, the said
William Warris, my executors, administrators, and assigns, His especial
licence, full power, sole priviledge and authority, that I, the said William
Warris, my executors, administrators, and assigns, during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England and Wales and the Town of Berwick-upon-Tweed, my
Invention of "AN IMPROVEMENT IN THE MOUNTING OF GLASSES COMMONLY CALLED
OPERA GLASSES;" in which Letters Patent there is contained a proviso
obliging me, the said William Warris, under my hand and seal, to cause a
particular of the nature of my said Invention, and in what manner the
same is to be performed, to be inrolled in His Majesty's High Court of
Chancery within one calendar month next and immediately after the date of
the said in part recited Letters Patent, as in and by the same (relation
being thereunto bad) will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Warris, do hereby declare that my said Invention of An Improve-
ment in the Mounting of Glasses called Opera Glasses is fully described and
ascertained as follows, that is to say :-
The mountings of all opera glasses of the common construction possess more
or less the conical form, having one tube, spring, or draw, raised above
another (see Figure 1, which represents a mounting of a nine-draw opera
glass of the common construction when shut). My Invention consists
in making the mountings of such glasses to occupy the least or nearly
the least possible space to which they are capable of being reduced. This
I perform by reducing the tops or heads of the tubes, springs, or draws,
to an horizontal, plane, or level surface, or nearly so, so that the same number
of tubes, springs, or draws, represented in Figure 1, may be contained
within the space of the exterior case a, b, c, d, of that Figure. To mount a
glass to occupy the least possible space, I make a groove or cavity in the
bead of each tube, spring, or draw, sufficiently deep to receive the next
within it; the interior tube or head having a ring E, or other contrivance
within it's cavity, by which the tube may be drawn out; see section Figure 2.
But as it will be found, perhaps,, equally convenient and less expensive that
the head of the first or interior tube should project above the others, I make
them as represented in Figure 3, which occupies nearly the least possible
space.
I apprehend that, by referring to the Drawings in the margin of these
Presents, the nature of my Invention, and the manner of carrying the same
into execution, will be evident to the meanest capacity.
Fig 1 represents a nine-draw opera, glass, of the common construction,
shut up.
Fig 2 is a section of my improved opera glass, exhibiting the manner in
which the grooves are made, and the tubes, springs, or draws connected together.
Fig 3 represents my improvement shut up, with the head of the first or
interior tube projecting.
Fig 4 exhibits the same with the whole of the tube sunk within the exterior
case.
The above-described. improvement permits all the tubes to be drawn out to
their full length, so as to give the greatest possible, extension; whereas, in
those of the common construction, the widest draw is as much shorter than
the smallest, as the conjoint thickness of the spring, heads, being nearly one
third part of the opera glass, Fig 1. From the form of the opera glasses of
the common construction, the edges of the springs are very liable to be
injured by wear, which inconvenience is obviated by my improvement.