OCR Text |
Show How a Diamond Cuts Glass. It has been ascertained by a seriest of experiments that a diamond doe not cut glass file-fashion but forces; the particles apart, so that a contlnn-, ous crack is formed along the line of the intended cut." The crack once be-j gun, very small force la necessary taj carry it through the glass, and thusi the piece is easily broken off. Thai superficial crack or cut need not ba deep ; a depth, according to fine meas-i urements, of a two-hundredth part of' one inch is quite sufficient to accom-; plish the purpose, so that the application appli-cation of much force in using the dla-, mond only wears out the gem without; doing the work any better. Numerous; stones, such as quartz and other mini erals, when ground into proper form,,' will cut glass like a diamond, but they are not so valuable for that pur-; pose, lacking the requisite hardness and soon losing the sharp edge neces-j sary to make the operation a success |