XXli INTRODUCTION. 



2. A similar stand, but with spiral rack-and-pinion coarse adjustment, 

 two eye-pieces, 1 inch and objectives, and double nose-piece, 7 12s. 

 Accessories are : " Abbe " condenser, with iris diaphragm, 2 2s. ; 

 objective, 2 10s. 



W. WATSON & SONS, 313 High Holborn, London, W.C. 



1. Edinburgh Students' Microscope, Stand B, with horseshoe foot and 



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

 adjustment, two eye-pieces, 1 inch and J objectives, "Abbe" con- 

 denser, in mahogany case, 8 15s. Double nose-piece, 15s. 



2. " Pram " Microscope. Body swung upon tripod stand of well-arranged 



form and with horseshoe stage, diagonal rack-and-pinion coarse and 

 micrometer screw fine adjustments, two eye-pieces, 1 inch and ob- 

 jectives, double nose-piece, " Abbe " illuminator with iris diaphragm, 

 in case, 9. 



JAMES PABKES & SON, Vesey Street, Birmingham, manufacture a series of 

 inexpensive students' microscopes of simple but sound construction, 

 suited for elementary histological work. 



1. " Worker" Microscope, with body slung on a tripod foot, fine adjust- 



ment of hardened steel and gun metal, working in solid machine- 

 planed box, and coarse adjustment by sliding tube in cloth-lined 

 collar, one eye-piece, 1 inch and % objectives, in mahogany case, 

 3 15s. ; or the same with diagonal rackwork coarse adjustment, 

 4 10s. 



2. The " Century " Microscope, with body slung on tripod foot, large 



stage, diagonal rackwork coarse and improved micrometer screw 

 fine adjustment (this latter placed in a new position to ease strain 

 upon it), one eye-piece, f and objectives, in case, 5 10s. Acces- 

 sories are : Swinging substage, with screw adjustment, 1 ; " Abbe " 

 condenser, with iris diaphragm, 1. 



Of Continental makers, while noting the name of ZEISS, 

 Jena (English office, 29 Margaret Street, Kegent Street, 

 London, W.), world-renowned for the quality of his optical 

 appliances, I think best to limit the attention of the student 

 to a German firm which in the last twenty years has won 

 for itself a repute of the highest kind for fine and re- 

 liable mechanical and optical workmanship, combined with 

 moderate price, viz. : 



E. LEITZ, Wetzlar (London agent: R. Kanthack, 18 Berners Street, W.). 



1. Students' Microscope, II. B, with body jointed to tripod foot, rackwork 

 coarse and micrometer screw fine adjustments, two eye-pieces, and 

 I objectives, magnifying from 60-525 diameters, double nose-pieoe 

 and worm screw, to which a substage condenser can be subsequently 

 added, 6 5s. 



