Various - Harper's New Monthly Magazine, No. IX.—February, 1851.—Vol. II.

Ency. Brit.

Lard. Cyclo.

The most plausible reason assigned is that of the expansion of the tube toward the fire by the influence of the heat. The fallacy of this theory is at once shown by the fact that, although heat does expand bodies, it does not increase their weight; therefore, notwithstanding that one side of the tube may be expanded, its equilibrium will remain unimpaired.

Diodorus Siculus, Tzetzez, Galen, Lucian, Anthemius, and others.

This story is attested, with slight variations, by several writers, Petronius, Dion Cassius, Pliny, and Isidorus. Pliny says that the populace, imagining that their interests would be injured by the discovery, destroyed the workhouse, tools, and dwelling of the artificer.

Blancourt.

Ibn Abd Alhakim.

For details see Loysel "Sur l'Art de la Verrerie;" and Lard. Cyclo.

In this respect plate-glass is treated differently from crown and broad glass, which is always placed on its edge in the annealing furnace.

Lard. Cyclo.

To such an extent has this jealousy been carried, that many adroit expedients have been employed to mislead and baffle curiosity. Hence the infinite variety of receipts for the production of different sorts of glass that have been launched upon the public, a vast number of which have been got up expressly for the purpose of deceiving and misdirecting the inquirer. To this circumstance may be referred the remarkable contradictions and inconsistencies that may be detected in all treatises on the subject.