A NEW USE OF THE SAND BLAST.

Otago Witness, Issue 1243, 25 September 1875, Page 3

A NEW USE OF THE SAND BLAST.

The producing, upon plated ware or silver, of a lusterless very finely grained surface, tclrmed by the trade satin finish has heretofore been accomplished by the use of swiftly rotating brushes made of fine wire. Messrs Simpson, Hull, &Co of Wallingford, Conn., have recently found that the saud blast performs this stippling work much more rapidly and more effectually, and have introduced the necessary apparatus for its employment m their large silver-plate manufacturing establishment. Air is compressed by the driving engine of the works into an ordinary reservoir, and thtnce distributpd through pipes which extend along the front of the workmen's tables ; and above the latter is a sand receptacle, V-shaped from which a stream of sand falls, and is met by a downward blast from the pipe, which current drives the material in a stream through a small hole in the table, beneath which a receptacle to receive the sand is placed. The workman, whose fingers are covered with rubber to protect them, holds the article in the jet and under the table, watching it through a pane of glass let into the top of the latter. The operation is necessarily very rapid, as the article ha 3 only to be turned so that the blast strikes the required portions, when the work is completed. The exposure to the jet, even for an instant, would cut through the Britannia, upon which the plating is afterward deposited. By the interposition of rubber' screens of suitable shape, against which the sand has no abrading effect, any fancy pattern or letters are easily imprinted on the surface, the latter of course being satin-finished, while the spaces protected by the screens are afterwards burnished. The screen or patterns are cut out by girls, of whom numbers are employed for that purpose.— Scientific American.