Scratches, if not deep, may sometimes be ground or 'blocked out,' but this must be done by one accustomed to the work. Defects in the silvering can only be got rid of by resilvering, which, of course, is not done by the cabinet-maker. Any plate with more than a reasonable number of seeds should be rejected. In provincial towns the purchaser must often take what he can get, but in London there are many dealers actually doing both silvering and bevelling on their own premises. Prices it will be found, on comparing lists, vary enormously, even among the London houses, and it does not always follow that the dearest means the best, though no one with an atom of experience would expect to get the finest qualities from those who habitually quote bottom figures. As a rule, glass can be bought more advantageously in London than in the provinces, where in many instances the prices are decidedly high. As every now and again amateurs announce they have made what to them is a discovery, viz., that some wholesale dealer, trade beveller or silverer, or whatever he may be called, will execute a small retail order: of course he will, as all bevelling is done for 'the trade,' and all is fish that comes to his net; but it does not follow that the occasional or retail buyer is charged trade prices - probably not. He need not, therefore, go to much trouble to find a trade silverer or beveller if he can more easily get his wants supplied otherwise. Possibly some of the larger firms might decline a retail order, but I do not know of their existence. If the retail buyer meets with any difficulty in obtaining glass occasionally, it may be useful for him to know that he can get it through any good cabinet-maker. Even allowing for the profit to the latter, it will probably cost him no more than if he bought it direct, and other things being equal, there are general advantages in getting what one wants in his own locality.
Glass and silvering are reckoned by superficial measurement. If the buyer has a price list he can calculate the cost himself. Fractions of an inch are generally reckoned as full inches, so that they are of importance; and an appreciable saving may be effected by watching them carefully, both when setting out work and when measuring for glass. Thus, a plate 361/8 ins. x 361/8 ins. would be reckoned as a 37 in. square, totalling up to 9 ft. 4 ins. super, while if a 36 x 36 could be managed with, it would contain only 9 ft. The saving here in actual measurement might not be much, but then the fact that the rate per foot increases considerably with the size of the plate must be taken into account. For the sake of an inch or two in the superficial contents the price may be 2d. or 3d. per foot higher than if it had come just under the next lower footage rate. On a large plate this is an item of consequence which the cabinet-maker will do well to make a note of. Thickness of glass is not taken into account unless it is exceptional. Very thick glass, however, is never required in furniture, though occasionally the thin patent plate is necessary. It is expensive, and only used in small pieces where the thickness of the ordinary kind would render it useless.
Bevelling is charged for according to the width of the bevel at per foot run, that is, the measurement all round, so that on a plate 1 ft. 6 ins. x 1 ft. there would be 5 ft. of bevelling. The width of bevel varies by 1/8 of an inch. It is usual to charge extra for bevelling plates above, say, 10 ft. (super), and also for those with fancy corners or shapes, such as shown by Figs. 152 to 154, as with these there is considerably more risk of breakage than with straight, square - cornered plates. For ordinary purposes, bevels 7/8 in. to 11/4j ins. are useful widths.
Figs. 152 to 154. - Shapes of Bevelled Glasses.
When getting quotations it is very usual to get them for the silvered bevelled plate complete, without specifying rates, but the inquirer must state exact size of glass and width of bevel required.
The silvering by which the reflecting property is given to glass is of two kinds - the old-fashioned mercurial process and the 'patent' process, in which a thin film of silver is precipitated on to the glass by chemical action. In the former, which is now seldom used, an amalgam of quicksilver and tinfoil is caused to adhere mechanically. It is, compared with the newer process, costly and tedious. For a considerable time there was a good deal of prejudice against the new process, but this has almost entirely died away, for in the result it is found equal to the other. Although familiarly spoken of as the new or patent process, it has been in common use for many years, and anybody may practise it. In the mercurial process the metal is visible behind the glass, but with the silver one it is protected by a kind of paint which allows it to be much more freely handled than the other. The silvering by means of it can now be done in a few hours instead of days, as used to be the case. It is, however, well to order the glass, especially if it is to be bevelled, as soon as its size can be determined from the job itself - not from the drawing, as there may be trifling differences in this - so that it may be ready when wanted. It must be remembered that the work of selecting, cutting, bevelling, etc, has all to be done after the glass-dealer receives the order, and this generally takes from a week to a fortnight to execute. As a matter of favour, plates may be got in two or three days sometimes.
As I frequently receive letters from amateurs asking how to do silvering, I may take this opportunity of telling my readers that it is not suitable work for them to take up by either process. To manage properly on any but the smallest bits of glass, special appliances are wanted, and a fair amount of experience, which can only be got practically. For those untrained to the work to attempt silvering is only to court failure. Even if they could manage to do it satisfactorily there would be no pecuniary saving, as the silvering rates are almost ridiculously low.