The glass-workers of Murano--the great glass-making centre in Venice--were, however, a close corporation, the workmen being stringently bound, under penalty of death, not to carry their trade secrets to any other country or to teach them to foreigners. In spite of this, eight Muranese glass-workers were induced to settle in England in 1549, and built their furnace in the monastery of the Crutched Friars--one of the minor orders. They derived their name Crutched (_i.e._ Crossed) from the ornamental cross which adorned their habits. Of the eight, seven returned to Venice in 1551, having previously petitioned the Council of Ten to remit the penalties against them. It is a reasonable assumption--but still only an assumption--that during their stay they did much to further the art of glass-making, although they merely produced glass and sedulously refrained from teaching their “mystery.” The “Breviary of Philosophy,” published in 1557, remarks: “As to glassemakers they be scant in this land Yet one there is as I doe understand, And in Sussex is now his habitacion, At Chiddingfold he works by his occupacion.” Evidently, therefore, the old Sussex industry had survived. The product of the Chiddingfold furnaces was probably, however, a coarse green glass, and by no means to be compared with the Venetian article. In 1564 Cornelius de Lannoy, an alchemist from the Netherlands, came to England, at the invitation of the Government, to teach the art of glass-making as practised in the Low Countries. He took up his abode and set up his furnace in Somerset House. He failed, however, with the materials then available, to produce any very effective results; in particular, the clay used for the pots failed to withstand the great heat required to produce transparent glass. Moreover, de Lannoy proved to be more alchemist than glass-maker, and left various persons in England the poorer for their quest after the philosopher’s stone which they had undertaken under his guidance.