IMPROVEMENTS IN PREPARING CERTAIN TRANSPARENT SUBSTANCES FOR SPECTACLES AND OTHER PURPOSES
Year: 1832

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
SOLOMONS and ELIAS SOLOMONS, of Bedford Square, in the Parish of Stepney,
in the County of Middlesex, Opticians, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Sixteenth day of February, in the second year of His
reign, did, for Himself, His heirs and successors, give and grant unto us, the
said George Solomons and Elias Solomons, His especial licence, sole privilege
and authority, that we, the said George Solomons and Elias Solomons, our
exors, adñiors, and assigns, or such others as we, the said George Solomons and
Elias Solomons, our exors, adiñors, or assigns, should at any time agree
with, and no others, from time to time and at all times 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 of "IMPROVEMENTS IN PREPARING CERTAIN TRANSPARENT SUBSTANCES
FOR SPECTACLES AND OTHER PURPOSES," communicated to us by a certain
Foreigner residing abroad; in which said Letters Patent is contained a proviso
that we, the said George Solomons and Elias Solomons, shall cause a particular
description of the nature of the said Invention, and in what manner the same
is to be performed, to be inrolled in His 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 in and by the same, reference
being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that, in compliance with the said proviso, we, the said
George Solomons and Elias Solomons, do hereby declare the nature of the
said Invention which has been communicated to us by a certain Foreigner as
aforesaid, consist in preparing amber by grinding and polishing it into lenses
for spectacles and other purposes. We will observe that the peculiar nature
of amber will be found, when properly prepared, particularly beneficial to the
preserving the sight, but in order to its being useful, great care is required in
the process of shaping and grinding the surfaces of the lenses; and in order
that this may be understood and carried into effect, we will proceed to
describe the means we have pursued and find to answer for producing the
necessary figures or shapes of the lenses to suit any particular focus, and also the
means for giving to the surfaces a highly smooth polish. The amber must be
chosen clear of spots or any cloudy appearances which are often distinguish-
able in some descriptions of amber; the only descriptions of amber suitable for
the purpose of being prepared into lenses are those which are perfectly
transparent. The means we use to discover whether any piece of amber is
suitable for the purpose is by removing with a chissel the rough exterior
surface; and by holding the amber to the light it will readily be perceived
whether there be any spots or cloudy appearances, and to what extent they
exist, and these are to be removed in the shaping the piece of amber in the
description of lenses which are to be cut therefrom, whether of a circular
or cliptical form. Having cut the piece of amber into the shape required,
which is performed by the means of a chissel and a small saw, the piece is to be
filed, by which means it is got more nearly to the shape required; it is then to
be scraped with a steel scraper, which will produce a sufficiently smooth surface
for the operator again to examine whether there are any cloudy appearances, and
when none can be distinguished, the piece of amber thus far produced is to be
divided by means of a small saw into as many thicknesses as the piece will
allow, and each piece (the thickness of which will depend on the description of
the lens intended) will now be ready to go to the next stage of the process,
which is the placing one at a time in a chuch of a lathe, and turning the two
surfaces parrallel with a chissel.
The next part of the process or preparing a lens is the grinding it of
either a concave, convex, plain, or a compound of two of these figures,
as is well understood by opticians, according to the object to which the
lens is to be applied. In grinding the lens into the figure required, we pro-
ceed as follows:-We prepare two cast-iron tools, the one concave and
the other convex, being both portions of the sphere of the same radius as
the focal length desired. These tools are very accurately ground together

page_text: with emery, as is usually the practice with opticians in preparing this
description of tools when they are intended to be used in grinding glass or
pebble lenses. One of these tools, either the concave or convex (as the case
may be) is fixed in a lathe; if the lens is desired to be concave, then the tool
is to be convex. Under the tool is placed a trough of water in such a position
that the tool is immersed in the water to a small depth; into the water there
is put some emery or finely-ground pummice-stone, so that the curved surface of
the tool will constantly be supplied with water and emery or pummice-stone. A
piece of amber, which has been prepared in the manner above described, is held
by the hand against the convex surface of the tool, by which the lens will be
ground concave on that side which is held to the grinding tool; and when both
sides are to be concave, then the lense is to be turned against the grinding
surface, and will also become concave.
By the above description it will be evident that according to the intended
figure to be given to the lens, so will be the tool to be placed in the lathe. The
lens is now in a state to receive the first or rough polish, which is performed as
follows: The grinding tool is to be removed from the lathe, and the surface
well washed, and then it is to be fixed in a bench, when the lens is to be
rubbed with a slight pressure on the surface of the tool by hand, applying
water and fine emery, by which means the surfaces will be brought to a fit
state to go to the next operation, and which is thus performed:-A tool having
either a concave or convex surface, as the case may be, and of the same radius
and sphere with the grinding tool already described, is covered with fine
woollen cloth, care being taken that it is so smoothly laid and fixed to the tool
that it keeps to the portion of the proper sphere to agree with the grinding
tool; on to the woollen cloth a small portion of linseed oil, and some fine
powdered charcoal of the wood of the poplar tree, is to be placed, and the lens is
lightly rubbed thereon with very moderate pressure, by which the surfaces are
brought to a considerable degree of smoothness; and if there does not appear
any scratches, the lens is in a state to be finally polished, which is performed
on a similarly formed tool to that last described; but in place of using charcoal
and linseed oil, there is to be placed on the cloth a small portion of soft soap,
and either finely-ground powder of putty or whiting, which is to be moistened
with spirits of wine. The lens is to be rubbed with care, and with very mode-
rate pressure, when the surfaces will become of a beautiful polish; the edges
of the lens are to be bevelled off by means of a file, and will then be ready to
be set in a frame, if it be intended for spectacles. It will not be necessary to
show the various uses to which such lenses may be applied, as they will be
obvious to persons engaged in this department of science; and it will be only

page_text: desirable further to add that such lenses may be prepared to the desired focus
by forming tools to the portion of the sphere, as is well understood in grinding
lenses of glass or pebbles.
Having now described the nature of the Invention, as communicated to us
from abroad, and the manner of performing the same, we would have it under-
stood that we are aware that much of the process assimilates to the preparing
and grinding pebbles and glass for the production of lenses; we do not therefore
claim that as new, but what we claim as the Invention is the preparing
amber by grinding and polishing into lenses suitable to spectacles and other
purposes.
In witness whereof, I, the said George Solomons, have hereunto set
my hand and seal, this Seventh day of May, in the year of our Lord
One thousand eight hundred and thirty-two.