“Several prophecies in the Old Testament plainly ascribe the destruction of the Jewish church and nation to their rejection of the Messiah. The words in Deuteronomy xviii. 19 are remarkably strong. ‘Whosoever will not hearken unto my words, which he shall speak in my name, I will require it of him.’ Daniel expressly assigns this as the cause of the destruction of their city and temple; and Zechariah describes the future repentance and mourning of the whole nation for their sin of ‘piercing’ or crucifying Christ, as preparatory to their general restoration.
“And,” added my uncle as he finished, “Let us hope that the time is fast approaching, when instead of a wandering and despised people, we may see the whole Jewish nation repenting of their former obduracy, and yielding up their unbelief to a full though tardy conviction.”
24th.—We claimed my uncle’s promise this evening of describing the mode of polishing the glass. “When the grinding operation,” said he, “has been completed on both sides of the glass, it is again secured in plaster on a flat table, and the surface is rubbed with a block of wood covered with several folds of woollen cloth. The workmen supply the cloth with polishing powders, such as crocus, tripoli, and putty, beginning with the coarsest, and changing gradually to the finest.”
Wentworth observed that he had never seen putty in a powdered state.
“The putty of which you are thinking,” my uncle replied, “is a mixture of chalk, or whiting with linseed oil, for the use of glaziers; but the putty to which I alluded is the oxide of tin. Crocus is a preparation of the brown oxide of iron; and tripoli is a natural earth, which was formerly imported from Tripoli in Africa, but is now found in other countries. Both the grinding and polishing of plate glass is performed in the large manufactories by the steam-engine.”
We begged of my uncle to describe to us the process of silvering, so as to make looking-glasses. “The coating a plate of polished glass with a thin pellicle of quicksilver, in order to give it the power of reflecting, is a very pretty and easy operation. I think Wentworth might readily perform it on a small piece of glass. Blotting paper is first spread on the table and sprinkled with powdered chalk; and over the paper is laid a sheet of tin foil; that is, tin beaten out in the same manner as gold leaf. On the tin foil quicksilver is poured and equally distributed, and cleaned from every speck by means of a hare’s foot. Over that a sheet of thin smooth paper is to be spread: fan paper is the best; and on this paper the glass is placed. With the left hand you are to press down the glass, while with the right the paper is drawn out, and with it most of the superfluous quicksilver. The plate is then to be loaded with a great weight, to squeeze out more of the mercury; and lastly the glass is set nearly upright that every particle that is not amalgamated with the tin may ooze out; for the thinner the coating of mercury, the more perfectly the metal adheres to the glass.”
If ever I should be in the neighbourhood of a plate-glass manufactory I will endeavour to see the whole process; in the mean time even the little knowledge one can pick up from a general description is better than entire ignorance. Wentworth lost no time in making an experiment of the silvering operation. My uncle furnished him with tin foil and quicksilver; my aunt supplied paper, and a small rubber of cloth instead of the hare’s foot; and we all assisted. There was a little bungling at first, but after a few trials we succeeded in making a scrap of looking-glass, which Wentworth intends to frame for Grace’s doll.
“As glass was comparatively a late invention, uncle, what were the looking-glasses which are mentioned in Scripture?”
“The word,” said my uncle, “should have been translated mirrors; they were formerly made of brass, or of a mixture of brass and silver, which takes a very high polish; and this inadvertence of the English translators is the more singular, because the context removes every difficulty. In the passage of Exodus[2], to which you refer, the laver is described to be made ‘of brass of the looking-glasses.’ Glass could not possibly have been converted into brass; but if the word be rendered by mirrors, the sense would be complete; that is, the laver and the foot of it were made of brazen mirrors.
“In Turkey, the common domestic mirrors at this day are made of brass; but I have heard that in Persia they are sometimes made of steel, and slightly convex. The metallic mirror, or speculum, which is now used in a reflecting telescope, is composed of about two parts of copper and one of tin; but what metals were employed by the ancients in their burning mirrors is not known.”