20 INTRODUCTORY ADDRESS: 



Mr. Barnard showed in his Address that whilst the resolving power 

 of a given instrument depends upon its design, it also depends upon 

 the w^ave-length of the light used to illuminate the object under 

 examination. Thus, if the object is illuminated with ultra-violet 

 rays greater resolution still can be obtained, but, of course, the results 

 are not directly visible and must be recorded photographically. 



In a paper recently read before the Royal Microscopical Society by 

 Colonel J. Clibborn, CLE., B.A., on " A Standard Microscope," it was 

 stated by Mr. Conrad Beck that the Manufacturers of Microscopes 

 worked under great difficulty during the War. It was not until after 

 the 11th November, 1918, that any Microscopes were allowed to be made, 

 all the Factories being fully engaged on other Optical Instruments. 

 It is interesting to note, however, that these Firms are now spending 

 large sums in manufacturing tools for the production of Microscopes, 

 many of them to be made under the Specifications brought forward 

 by the Committee on Microscopes appointed by the British Science 

 Guild. 



At the recent British Scientific Products Exhibition an excellent 

 set of Exhibits was shown by the British Optical Instrument Manu- 

 facturers' Society, Ltd. Some dozen or more of the principal firms 

 exhibited Optical Instruments and Glasses. 



As pointed out in the valuable Catalogue of that Exhibition, the 

 Optical Instrument-making Industry originated in most of its Branches 

 in Great Britain. Newton, Young, Faraday, Clerk Maxwell and Rayleigh 

 were the pioneers of Optics. The Achromatic Telescope was invented 

 by DoUand, and the modern form of Achromatic Microscope by Lister. 

 Let us therefore show that we are trying to be worthy successors of 

 these great men. 



The Optical Association has published an illustrated booklet on 

 Scientific Instruments, which includes, with a brief description, the name 

 of every known instrument both current and obsolete, together with a 

 key to the British Makers. The Trade has set up a powerful Research 

 Association and has participated in the inauguration of a Scheme of 

 Education in Optical Engineering which is being developed by the 

 Imperial College of Science and Technology at South Kensington. 

 It may be mentioned that the Governing Body of the Imperial 

 College of Science and Technology recognises the importance of 

 Technical Optics in their relation to the needs of the Nation by pro- 

 viding in the Estimates of their new Scheme of Development the sum 

 of £50,000 for expenditure on Land, Buildings and Equipment, and the 

 sum of £4,000 annually for maintenance and carrying on the work. 



Messrs. Chance Brothers commenced the manufacture of Optical 

 Glasses in England in 1848. During the recent War they increased 

 their output some twenty-fold. They make something like seventy 

 different types of Optical Glasses together with a number of new types 

 which have been recently introduced. They have rendered great 

 service to our Empire. 



Professor J. C. McLennan, F.R.S., of the University of Toronto, who 

 was in England during the War, informed me that he had examined 

 the Fluorite from South Africa and found it to be excellent in quality. 



