TOUGHENED GLASS A SUCCESS.

New Zealand Tablet, Volume VII, Issue 356, 13 February 1880, Page 11

TOUGHENED GLASS A SUCCESS.

M. be Lt-yxes has recently communicated to the French Society of Encouragement, in the name ofM.dc Labastie, further information ™ti P^ grCSS Wih.lChW i h . lCh th e mdnstiy in hardened or tempered glass has lecently been making. He showed to the meeting numerous specimens, which presented the most varied and accurate forms. There were tubes for lamps, both gas and oil, goblets of various forms, mortars and pestles, &c. As to the latter, M. de Luynes reminded the Society how frequently accidents happened with them : the least fall breaks them, whereas with hardened glass they stand any amount of hard usage He also showed capsules for phaimacy and chemistry, of all sizes and shapes., plates of glass, crystal and enamel, coffee and tea-cups in white enamel. He finished by making a striking experiment. Ordinary glasses were placed in a basket with drinking-glasses of the same shape in hardened glass ; after several shakings, the orai 7 s es were all broken while all the hardened glasses were intact Thus it would seem that all the difficulties of the question have been solved. But, what is more important, the processes of manufacture have been simplified and combined with the ordinary operations of glass-blowing, so as considerably to diminish the expense and give more regular forms and more perfect execution. Objects made with the liquid material, when they are still red, are thrown directly into the tempeiing bath, and axe not again heated to the melting point as at first, which often causes a change in their form Bottles, drinking-glasses, lamp-glasses, and other concave objects containing air are received on a curved tube, a sort of siphon, which at the moment of immersion allows the air to escape, while the liquid enters the cavity without difficulty. All these improvements have been adopted at the glass-works of Choisy-le-Roi, and it is confidently expected that in a very short time ebjects in hardened glass win be quite as cheap as those made in the ordinary way.