Glass

■Il is tiiföcult to ïoresee to whatperfection tiie manufacture of 1ÏS3 mny be brought, to wliat purpose the uticlc may yet be cpplieil. Tlie balance spring of u chronometer id uow mode of glass, asaub stitute for steel, and poKscsíCs a greater power of resisting the allcinalions of heat und culd. A chroiioiueier vvitli a glass balance spring was sent to the North Sea oxposed to a cotnpolition with nino othcr Clironomclcrs, ni;d llc rcfiilt óf t ie experiment was a report in favor uf the clironomctcr witb a glabé spring. In a maimiactory In Franc-, iney nie iVow maImg gftsè pipo? lor the conveyance of witter, whiclfcóst ncarly 50 pur cent less tbanihe iron piped now used, uni vvill beara iar grcaicr ■oxiernal pressine.