THE LOOKING-GLASS MAKER.

The Looktng-Glass Maker is a person who lays tin foil on polished pieces of glass, by the assistance of quicksilver, so as to produce reflection by effectually obstructing the rays of light, and, afterwards, fits the glass to frames of various sizes, either for the use of chambers and dressing-rooms, or for the purpose of decoration in the houses and mansions of the opulent.

Nature offered to mankind the first mirrors, in representing objects upon the surface of water when it was still. Human industry and ingenuity has, from time to time, improved upon such suggestions, and has not only equalled, but very far exceeded the original model. The discovery of metals considerably assisted man in the progress of this art. Mirrors were at first made of polished brass, of tin, or of burnished iron, and, also, of a mixture of tin and brass. A person named Praxiteles, not the sculptor of that name, who was cotemporary with Pompey the Great, made mirrors of silver. These last were preferred to all the other kinds, and the use of them was only abandoned, when glass coated with tin, as we now have it, was introduced. The precise time in which the ancients began to use glass for mirrors is not known; the first, we think, was furnished from the glass-houses of Sidon, where glass was worked in a variety of ways, both for use and ornament. As to the stone which the Romans adapted to their windows, in order to keep out the rain and weather, it does not appear that they ever employed it as mirrors.

In the thirteenth century, the Venetians were the only people who had the art of making looking-glasses of crystal. The great
glass works at Murano, in the neighbourhood of Venice, furnished all Europe for centuries, with the finest glasses that were made. The first plates for looking-glasses were made in England, at Lambeth, in 1673, by the encouragement of the Duke of Buckingham, who in 1670 introduced a few Venetian artists.

The polishing of the plates for this business is usually effected by other hands, before they come to the Looking-Glass Maker, but we can just mention, that the usual mode of making glass smooth, and in every respect proper to receive the tin foil and quicksilver,
is to use first of all, fine sand and water, then emery of different degrees of fineness ; and, lastly, colcothar of vitriol, or as it is more
commonly called, crocus martis, or purple brown. The polishing instrument is a block of wood, covered with several folds of cloth
and carded wool, so as to make a fine elastic cushion. This block is worked by the hand ; but, to increase the pressure of the polisher, the handle is lengthened by a wooden spring, bent to a bow three or four feet long, which, at the other extremity, rests against a fixed point to a beam placed above. The plate is now fastened to a table with plaister, covered with colcothar, and the polisher begins his operation by working it backwards and forwards over the surface of the plate till one side is done ; then the other is to be polished in the same manner.

It is well known, that glass when smoothed and polished, does not acquire the property of reflecting objects till it has been silvered,
as it is called, an operation effected by means of an amalgam of tin and quicksilver. The tin-leaf, or as it is more commonly called,
tin-foil, which is employed for the purpose, must be of the same size as the glass, because, when pieces of that metal are united by
means of mercury, they exhibit the appearance of lines. Tin is one of those metallic substances which become soonest oxydated by
admixture with mercury. If there remain a portion of the oxyde of a blackish grey colour on the leaf of tin, it produces a spot, or stain in the mirror, and that part cannot reflect objects presented to it : great care, therefore, must be taken in silvering glass, to remove whatever portion of oxyde there might be from the surface of the amalgam.

The process is as follows : the tin-foil is laid on a very smooth stone table, usually prepared for the purpose, With grooves on its
edges, or with ledges to preserve the waste quicksilver, and mercury being poured over the metal, it is extended over the surface of
it, by means of a rubber made of bits of cloth. At the same moment, the surface of the tin foil becomes covered with blackish oxyde, which must be removed with the rubber. More mercury is then to be poured over the tin, where it remains at a level to the thickness of more than a line, without running off. The glass must be applied in a horizontal direction to the table at one of its extremities, and being pushed forwards, it drives before it the oxide of tin, which is at the surface of the amalgam. A number of leaden weights covered with cloth, are then placed on the glass, which floats on the amalgam, in order to press it down. Without this precaution, the glass would exhibit the interstices of the crystals resulting from the amalgam : in this state, it is generally suffered to remain several days, till the mixture adheres firmly to the glass.

To obtain leaves of tin, which are, sometimes, six or seven feet in length, with a proportionate breadth, they are not rolled, but hammered after the manner of gold-beaters. The prepared tin is first cast between two plates of polished iron, or between two
smooth stones, not of a porous nature. Twelve of these plates are placed over each other ; and they are then beaten on a stone with heavy hammers, one side of which is plain, the other rounded. The plates joined together, are first beaten with the latter : when they become extended, the number of plates is doubled, so that they amount, sometimes, to eighty or more. They are then smoothed with the flat side of the hammer, and are beaten till they acquire the length of six or seven feet, and the breadth of four or five and a line and a quarter in thickness. When the leaves are of a less extent and thin, from eighty to a hundred of them are smoothed together.

This is a trade which is, comparatively, in very few hands, and is, in consequence, one of considerable profit : it is, however, not
always carried on alone, but is often combined with that of a carver and gilder; some cabinet makers also undertake it.