THE SAND BLAST.

New Zealand Herald, Volume XVIII, Issue 6261, 10 December 1881, Page 3

THE SAND BLAST.

Among the wonderful and useful inventions of the times is the common sand blast. Suppose you desire a piece of marble for a, gravestone, you cover the stone with a sheet of wax no thicker than a wafer ; then you cut in the wax the name, date, &e, leaving the marble exposed. Now pass it under the blast, and the sand will cut it away. Remove the wax and you have the cut letters. Taking a piece of French plate glass, say two by six feet, cover it with line lace, and pass it under the blast, and not a thread of the lace will he injured, but the sand will cut deep into the glass, wherever it is not covered by the lace. Now remove the lace, and you have a delicate and beautiful figure raised upon the glass. In this way beautiful figures of all kinds are cut in glass at a small expense. The workmen can hold their hands under the blast without harm even when it is rapidly cutting away the hardest glas3, iron, or stone ; but they must look out for finger nails, for they will bo whittled oil' right hastily. If they put on steel thimbles to protect the nails, it will do little good, for the sand will soon whittle them away ; but if they wrap ;i piece of soft cotton around them they arc safe. You will at once see the philosophy of it. The sand whittles away and destroys any hard substance, even glass, but does not all'cet substances that arc soft and yielding, like wax, cotton, or line lace, or even the human hand.