THE UTILITY OF GLASS.

Lyttelton Times, Volume LVII, Issue 6509, 6 January 1882, Page 6

THE UTILITY OF GLASS.

A Home paper says.-—We know of no valid objection to the me of the cheaper grades of gloss for water pipes, and for many other purposes where iron or terracotta are at present generally used. In fact, we think that glass in many respect* is greatly superior to either of the above-named materials for these uses, and especially for water conduits. Glass in the form of tubes will compare verj favourably in strength with cast iron, and is much stronger than terracotta. It is absolutely impervious to moisture, and almost completely proof against corrosion or chemical action, to which iron is notoriously susceptible, and to which even glazed terra cotta is not wholly indifferent. The suggestion to use a substance like glass, which is commonly associated with the quality of brittleness, for purposes where considerable strength is required, seems at first like going contrary to common experience, but this anomaly is apparent rather than real, for although glass is very friable in the form of thin sheets or vessels with thin shells, it loses its brittleness when in massive form, and in this condition is really surprisingly strong. A practical proof of this is seen in the very general use of glass for paving and flooring. On this point some figures from Trautwine may be interesting. He gives the tensile strength of gLsa at from 2500 to 9000 pounds per square inch, according to kind; crushing strength, 6000 to 10,000 pounds per square inch; transversely, by his own trials, flooring glass, one inch square, and one foot between the end supports breaks under a centre load of about 170 pounds, consequently it is considerably stronger than granite, except as regards crushing, in which the two are about equal When we consider the . many admirable qualities that glass possesses, we confess to something like surprise that it has not long ago found its way into very general use for an immense number of applications, where other and much inferior materials are still exclusively employed ; and j we do not question but that the time is near j when we shall find it supplanting other ma-1 terialß very generally. There can be no objection to its general use on the score of cost, as it may be produced more cheaply than cast iron; and, by the utilisation of blast furnace slag, it could be made even cheaper. It is already in considerable use for flooring, and it has lately been successfully experimented with for railway sleepers under exceptionally severe conditions. We believe that, in the near future, the applications of glass will be very widely extended.