Henry Peacham (1638) The Valley of Varietie, Chapter XVII, pp. 144-150.
Of Glasse made malleable, to be beaten forth every way.
IT is reported, that in the time of Tiberius the Romane Emperour, there was invented Glasse of that temper, that it would abide the hammer, and bee beaten in length or breadth like lead, and pliable to bend every way like paper; and that the Inventor heereof was put to death, upon this occasion: When hee had built a most magnificent Pallace in Rome, which after the building began to sinke, and was likely to fall, and Tiberius having paid him for his worke, commanded him to depart, and never to look him in the face again. He shortly after having invented the way to make Glass Malleable, or to abide the Hammer, and came to shew the same to Tiberius, expecting a reward (as Dio reports1) for his Invention; His whole Shop, saith Plinie, was pulled downe, and laid waste, lest Brasse, Gold and Silver should be undervalued in their price and esteeme. Others report, That Tiberius did it out of malice and envie, because hee naturally hated learned, vertuous, and all ingenious men.
More at large, Petronius [Sat. LI] reporteth this matter after this manner, saying, There was a skilfull Crafts-man, who made Cups, and vessels of Glasse, of that strength and firmness, that they would no more breake, then Pots of Silver and Gold.
Now when hee had made a Viall of this most pure and solid Glasse, and thought the same a Gift worthy to be given to Cæsar, (meaning Tiberius) hee was brought with his present before Cæsar, who much commended the manner of the making, and the skilfull hand of the Workeman; his gift was taken, and his good-will accepted of.
This Work-man, more to amaze all the beholders by, and that he might make himselfe a farther way into the Emperours favour, tooke the Glasse-viall againe out of the Emperours hand, and threw it downe upon the Pavement, with so great a force, that had it been made of Gold or Silver, it had beene either bruized or broken. Tiberius hereat, was not onely astonied, but waxed very fearfull. The Maker tooke up his Glasse againe, which was a little bruized, but no where broken; as if, saith Petronius, the substance of Brasse had converted it selfe to Glasse: then taking a Hammer out of his bosome, he beat out the bruize, and brought it againe into fashion, as a Tinkner should beat out a bruized Kettle.
Which being done, hee thought that hee had purchased Heaven, gaining at once, Cæsars familiaritie and admiration; but it fell out otherwise. For Cæsar demanded, if any other knew the Art of making that kind of Glasse, but himselfe: Hee answered, None that he knew. Wherupon Tiberius commanded, That hee should be beheaded; for (quoth hee) if this Art were publikely knowne, Gold and Silver would be no more esteemed of then Clay.
Coelius Rhodoginus reports also this same Historie, taxing the vanitie of Tiberius, who was of a craftie and a catching disposition, dissembling, and making the World beleeve hee would doe those things which hee never meant, and what hee meant to doe, hee would not; as seeming angrie with those whom hee meant to prefer, and friendly to others, whose throats hee meant to cut.
As this Glasse-maker, so all great Wits must be working upon new Inventions, one after another, which indeed is the fewell or food of Wit; which the same Rhodoginus doth elegantly expresse, l. 29. cap. 16. but as one saith, Raræ ingeniorum præmia, rara item & merces. Eumolpus in Petronius [Sat. LXXXIII] maketh also the same complaint: one asking him the question why he went so poorely apparelled? for this reason, quoth hee, Amor ingenii, neminem unquam divitem fecit. The love of Wit, (or witty Inventions) never made any man rich. And afterward hee addeth, Nescio quomodo bonæ mentis soror est paupertas; I know not how it comes to passe, that Povertie is alwaies the Sister of a vertuous, or honest mind. And true it is that Apuleius saith,2 Paupertas est Philosophiæ vernacula, Paupertas; or, Povertie is the mother tongue, or proper language of Philosophie.
1. Dio. lib. 57. [21.5-21.7; Pliny HN 36(66) 194-195]
2. In Apolog. 
This page is by James Eason.