OBSERVERS of the undercurrents of scientific progress in this country cannot have failed to note during the past twelve months a very remarkable movement at work amongst the opticians, especially amongst the younger men in the optical trades. An intelligent scientific study of the principles of optics has hitherto never been required of the optician, who from the first day of his apprenticeship might grow up in the business entirely untrained in everything save the mere buying and selling of optical goods. All this is rapidly changing, as indeed was to be desired. Half a century ago, the qualification for practising as a surgeon was practically a mere serving of indentures, while the trade of druggist might be practised by one who had never had any instruction in even the elements of chemistry. There was no organisation to examine the candidates, or to certify them if qualified; there was little stimulus to study. Hence, in the absence of any controlling body, the young men growing up in the optical trades have had little inducement to acquaint themselves with even the elements of the science on which their industry is based. Even those who might be studiously inclined found little to encourage them; for, strange to say, the existing text-books of optics are of little or no use to such. They are written mostly from a different standpoint, to enable University candidates to pass academical examinations, and fail to deal with many of the problems that present themselves to the practical optician. Further, great examining bodies, such as the Science and Art Department and the City and Guilds of London Institute, have never formulated any examinations in optics or optical instrument making.