82 PROGRESS OF MICROSCOPY: 



The British maker has always excelled in microscopes of high 

 class, involving skilled hand-work. No instruments in the world 

 to-day vie with the beautiful hand-made first-class microscope stands 

 which have emanated from British workshops. 



There is no question that this procedure has been highly approved 

 by expert workers, who found in the best English microscopes the 

 power to use their optical systems with an exactness and variety 

 of adjustment which is not supplied so completely in instruments 

 of other countries. 



Students' microscopes, made by the same methods with constant 

 variation, could not compete with standard models made by 

 machinery. 



It became evident, therefore, to those who were anxious to 

 establish the English microscope on a sound basis, that a definite 

 model for a definite purpose must be made, and a specification for 

 €ach type not subject to variation drawn up to the satisfaction 

 of those who directed the purchase and use of microscopes, thus 

 justifying manufacturers in putting down plant for their production 

 in large quantities under economical conditions. 



A Committee was accordingly formed by the British Science 

 Ouild, consisting of representatives of the many branches of Science 

 and Industry and Government Departments for which microscopes 

 were required, and eventually definite specifications for students, 

 research and other instruments were prepared, which have received 

 universal approval. 



This was a great step in a forward direction for the optical 

 manufacturers. Works and manufacturing facilities had grown 

 very substantially during the war, but the hand- workers of the 

 past had been greatly reduced by dispersal and death, and it was 

 no longer possible to make microscopes in sufficient quantity in the 

 customary manner of bygone days. They were therefore able to 

 apply much of their plant and machinery to the production of 

 machine-made microscopes for students' use while reserving for 

 the few hand-workers available the refined special work of first-class 

 instruments. 



The amateur, who has not had his requirements satisfied for 

 several years, is pressing for supplies of the best patterns of English 

 microscopes, but the quantity demand comes from teaching institu- 

 tions, and particularly from medical workers. Of these latter 

 there are a larger number than in pre-war days, and it is believed 

 that the machine-made microscopes on the specifications referred 

 to will be found satisfactory. 



On the optical side, the production of microscope objectives 

 and achromatic condensers has been fraught with difficulty. Very 

 little, if any, of the pre-war optical glass remained, and the nearest 

 substitutes had to be used instead, until such time as the British 

 glassmakers were able to give all the varieties that were required 

 for the purpose. Honour is due to them for the success they have 

 achieved in making nearly all the types of glass that have been 

 called for. 



Even for a fresh melting of the same glass it is generally 

 necessary, on account of slight differences, to make changes in curves 

 or distances of components, but when several glasses by a fresh 



