The manufacture of the finer kinds of glass was introduced into England not many years ago from Germany, and German operatives were employed at very high wages. We understand that the English glass is now superior to the German. There is only one plate-glass factory in the United States. It was commenced only two years ago near New York, and we understand that it has met with encouraging success. Soon after the introduction of the business into this country, a very great improvement in the mode of manufacture was introduced. Pallat, in his admirable work on glass, alludes to the American invention in only a few words, and passes it by as of but slight importance; but it has brought about a very great change, and is destined to exert a still greater; in fact, it has revolutionized the whole system of the flint-glass manufacture, simply by mould machines for the purpose of pressing glass into any form. It is well known that glass in its melted state is not in the least degree malleable, but its ductility is next to that of gold, and by steady pressure it can be forced into any shape. The writer has in his possession the first tumbler made by machinery in this or any other country. Great improvement has of course taken place in the machinery, insomuch that articles now turned out by this process so closely resemble cut-glass that the practised eye only can detect the difference. Still, the entire field of improvement is not occupied, and greater advances will yet be made. The tendency, in this particular, has been so to reduce the cost of glass that it has multiplied the consumption at least tenfold; and there can be no reasonable doubt but that, at this period, a much larger quantity of flint-glass is made in this country than in England. The materials composing glass are all of native production, and may be considered as from the earth. The pig lead used is all obtained from the mines in the Western States; ashes from various sources in other States; and silex is also indigenous. The materials consumed yearly, in the manufacture, are something near the following estimate:-- Coal, for fuel, 48,000 tons; Silex, 6,500 " Ash, Nitre, &c. 2,500 " Lead, 3,800 " for the flint manufacture. How much more is consumed by the window-glass manufacturers, the writer is without data to determine. We have recorded the progress of improvement in the manufacture of glass, and now, relevant to the subject, we propose to examine the various improvements in working furnaces and glass-houses. To this end we present to our readers the drawing of a furnace for flint-glass,[1] with the interior of a glass-house as used by the Venetians, at the highest point of the art, in the sixteenth century. [1] See drawing No. 1, at end of book.