§ 46. Making Ground Glass. — [*]

§ 47. Glass-cutting. — [*]

§ 48. Cementing. — [*]

§ 49. Fusing Electrodes into Glass. — [*]

§ 51. The Art of making Air-tight Joints. — [*]

APPENDIX TO CHAPTER I [*]

ON THE PREPARATION OF VACUUM TUBES FOR THE PRODUCTION OF PROFESSOR ROENTGEN'S RADIATION [*]

CHAPTER II [*]

GLASS-GRINDING AND OPTICIANS' WORK [*]

§ 61. Details of the Process of Fine Grinding. — [*]