ADVERTISEMENTS. 
W. WATSON & SONS’ 
^ A1VT ' T EURCK MICROSCOPE. 
DESIGNED ESPECIALLY FOR HIGH POWER WORK AND 
PHOTO-MICROGRAPHY. 
An instrument of the highest class, replete with every mechanical 
convenience and of up-to-date design. The best microscope obtain¬ 
able. Made in three models : 
The Van Heurck No, i. 
The Circuit Stage Van Heurck (with complete rotation to the stage). 
For full particulars see catalogue No 2 . 
THE MALES-WATSON is simple, effective, and 
ingenious, and can be supplied with any of Watson's 
new microscopes. 
THE WATSON MULTIPLE SPEED milled head 
^can be fitted to any microscope for 5 s. 6d. 
WATSON’S HOLOSCOPIC OBJECTIVES, 
EYEPIECES, AND CONDENSERS. 
Watson’s Holoscopic Series of Objectives and Condensers are constructed on a new principle, 
with a triple back combination which reduces spherical aberration in a wonderful manner. 
These Objectives have large apertures and are of finest performance, and satisfy the needs of 
the expert and the amateur in every way. 
The SERIES OF CONDENSERS are: Oil Immersion (high power); the “Universal" 
(medium power) ; the Macro Condenser (for Planars and Holostigmats). All yield full 
aplanatic cones. 
The HOLOSCOPIC EYEPIECES can be used with any OBJECTIVES— Achromatic 
or Apochromatic—and are provided with an adjustment for introducing the effect of over and 
under correction. These eyepieces are comfortable in working, and beautifully effective. 
PRICES—Student’s pattern, 17 6; large capped pattern, 22 6 each. 
Watson's Illustrated Catalogue (No. 2) of Microscopes consists of 150 pages, giving particulars of the 
latest and best Microscopes and Apparatus. It will be sent post free on application. The above are 
fully described therein. 
ARE YOU A SUBSCRIBER TO WATSON’S CIRCULATING MICRO SLIDES? 
You can have a selection of 240 specimens from the finest collection in the world for examination 
for 21 /- 
WATSON’S CATALOGUE No. 3 i OF MICRO OBJECTS GIVES FULL DETAILS. 
Contractors to the Admiralty, War 
Office, Indian and many Foreign 
Governments, 
Established 1837 313 , High Holborn, LONDON, W.C. 
Branches: 
16, Forrest Road, EDINBURGH, and 
78, Swanston Strest, MELBOURNE, AUSTRALIA. 
