In a shop in a certain optical munitions factory I met the first woman who worked a centring machine in that area. She was formerly a housemaid, and told me that, at first, all the men had discouraged her from the job and had said it was 'impossible for a woman to do such work'. But she 'stuck it'--so she said--and in a few weeks, to her own surprise and the men's dismay, this peculiarly skilled job became familiar to her. 'Now I feel I am doing something,' she said in triumph. This sentiment was echoed by another worker in that factory who was accomplishing the surprising task of 'chamfering', or putting a tiny bevel onto the edge of a lens. The large lenses measure only 2 inches in diameter; the smaller ones are about the size of a threepenny bit, and every operation, whether grinding, trueing, smoothing, polishing, or centring, must be accomplished with the utmost care. Even the final process in the manufacture of the lens or prism, 'wiping off', is fraught with responsibility to the operator. 'Wiping off,' or cleaning the lens, can only be done with a silken duster, for the finished glass, like a dainty lady, will tolerate the touch of nothing coarse. In cases where the glass is graticulated, or marked with fine lines for measurement purposes, the task of 'wiping off' is of extraordinary difficulty; in the opinion of at least one foreman with whom I have discussed this question, the operation is only perfectly successful when performed by a girl's fingers. It is of supreme importance that no speck of dirt or hint of grease from a finger-mark be left on the glass when finally adjusted, or the instrument would become a source of danger to the user. No wonder that the feeling of the optical instrument workshop expresses itself in the words: 'Cleanliness is more than godliness at this job.' The completed glass at length reaches the stage where it is set in its instrument, be it periscope, dial-sight, telescope, and so on. Although the most exact measurements have been observed both in the metal part and on the glass, small adjustments are necessary; for the fit must be so perfect that even if the metal case suffers shell-shock, the glass must still not rattle. But it is the metal alone which is submitted to alteration, and it is wonderful how women have been able to obtain sufficient dexterity to make these infinitesimal changes in the metal parts. One can see a mere girl undertaking such a task by giving the metal three or four delicate strokes from a file so fine that it would not hurt a baby's skin. Meantime, the lens or prism is finally examined (also by women) for size, scratches, and other imperfections, and is then re-cleaned. Girls and women take a full share in the production of the metal parts for the optical instruments and also assemble, or collect the parts, for the adjustment of the glass, but so far they do not generally adjust or test the completed instrument.