SPONTANEOUS EXPLOSION OF TOUGHENED GLASS.

Thames Star, Volume VIII, Issue 2942, 20 July 1878, Page 2

SPONTANEOUS EXPLOSION OF TOUGHENED GLASS.

In tlie Bohemia, Professor Bicard, of Trchewan, tells the following tale:— -" A. child's drinking glass was bought one day at Saaz for about seventy kreutzers, and, for six months, it sustained its character of unbreakable glass. But about nine o'clock one evening in the sixth month it was used in drinking eau sucree, and wag then placed, with a silver spoon in it, upon a large oaken table. Suddenly I heard from my room a violent explosion like a pistol shot, and a metallic sound. I ran in and saw the whole floor strewn with needles and splinters of. glass scattered thinly and widely, and not only upon the floor, but the bed, the table, the washstand, the carpet, and the clothes* hung up were covered with these shreads. I looked everywhere for the cause of this explosion, and at last remarked that the child's drinking cup was gone. The empty glass hud exploded—without the approach of a light and having a spoon in it—with such, extraordinary force that the whole household was frightened. I relate this story, therefore, not only for the information of chemists and natural philosophers, but also of those families who believe that in this so-called unbreakable glass they possess remarkable and unspoilable playthings or useful household goods, to show., them when such an explosion occurs it may causa not only fright but mischief." To the foregoing the editor of the Polytechn Nottizblatts adds that such explosions of toughened glass, often without any apparent cause, have beon pretty frequent of late, and appear to be on the increase—a circumstance likely to prevent < people from using'toughened glass until the cause of this evil property has been discovered and removed by a change in the process of manufacture. The explosion is, doubtless,_caused by sotno change in the extreiui. <i>^lon of the fibres of the toughened glass, and it' is probable that if the tension were removed the glass would no longer be tough. " -/;;'-- • ,: '- .-'