INTRODUCTION. XXI 



or 450 diameters. Such microscopes are manufactured by 

 very many makers ; but as the narrow limits of this intro- 

 duction compel rigid selection, our descriptions will be con- 

 fined to a few representative forms of (price taken into 

 consideration) good quality, and capable of sufficiently 

 satisfactory work as judged from the beginner's standpoint. 

 The price of each is affixed. 1 



Ross, Limited, 111 New Bond Street, London, W. 



1. New Model Medical School and Educational Microscope. A modification 

 of the makers' well-known "Eclipse" stand, with horseshoe foot, 

 jointed back, rack-and-pinion coarse adjustment and micrometer 

 screw fine adjustment, with two eye-pieces, f and objectives, in 

 mahogany case, price 6 17s. Accessories are : Simple substage, with 

 condenser, 2 3s. ; double nose-piece, 15s. ; iris diaphragm, 10s. ; 

 objective, 2 10s. 2 



R. & J. BECK, Limited, 68 Cornhill, London, E.G. 



1. A new Students' Microscope by this firm is illustrated on p. 2 and 



described in the text. Price, as described, 5 7s 6d. 



2. Continental Model Microscope, No. 29. Stand with horseshoe foot, 



jointed back, spiral rack-and-pinion coarse and micrometer screw 

 fine adjustments, swinging arm for substage condenser, graduated 

 draw tube, two eye-pieces, f and objectives, in mahogany case, 

 price 8. Accessories are : " Abbe " condenser, with iris diaphragm, 

 , 15s. ; double nose-piece, 12s. 6d. ; objective, with correction collar 

 (very desirable with any power above ), 3 10s. 



SWIFT & SON, University Optical Works, 81 Tottenham Court Road, London, 

 W., have an exceptionally high reputation as mechanicians, and their 

 microscope stands have shown more independent and original thought 

 than those of probably any maker. 



1. New Histological and Physiological Microscope. Body swung upon 

 tripod stand of unusual stability, with sliding cloth-lined coarse and 

 micrometer screw fine adjustment, large horseshoe stage, with one 

 eye-piece, 1 inch and T V objectives, in cabinet, 5 5s. Double nose- 

 piece, 10s. extra. 



1! The subjoined memoranda of microscopes are not intended to give 

 complete specifications, or to obviate the necessity of the personal study of 

 microscope catalogues, or appeal for skilled assistance if accessible. They are 

 to be looked upon as suggestions as to where to look and what to look for. 

 All the microscopes mentioned are, however, of sound and reliable quality. 



- It may be noted that nearly all objectives, British and foreign, are now 

 made with screws of uniform diameter (the English Microscopical Society's 

 standard screw), and therefore are mutually interchangeable. It must, how- 

 ever, be noted that objectives made for a short-bodied (" Continental ") stand 

 are not suited for use with a long-bodied (" English ") stand, and vice versd. 



