Thomas Sf Richard Willats. 63 



. *. d. 

 six objects mounted in balsam, low powers, achromatic, 



complete in case or cabinet fig. 16, from 8 8s to 15 15 



Large Compound Achromatic Microscope, on improved con- 

 struction, rendering the instrument perfectly firm and 

 steady, with fine rack work adjustment, fine screw ad- 

 justment to stage movements, two eye-pieces, plane and 

 concave mirrors, detached condensing lens, speculum, 

 aquatic box, brass forceps, six objects mounted in 

 balsam, the whole packed in neat mahogany cabinet, 



fig. 13, from 21 



Ditto ditto of smaller size, without stage movements, and 



screw adjustments from 15 15 



German and French Achromatic Microscopes from 550 



Achromatic Object Glasses, from the l-12th to 1-inch focal 

 length, and with magnifying powers, varying from 50 to 

 1400 diameters, of British and Parisian construction, 



from 1 I 



Condensing Lens, with joint to attach to stage of Micro- 

 scope from 050 



Ditto ditto, mounted in brass frame with universal joint, 



on sliding stand fig. 20 



Improved Argand Lamp for microscopic purposes, mounted 



on sliding pillar, with chimney & japanned shade, fig. 19 1 14 



Aquatic Box, for viewing animalculae from 046 



Plate for exhibiting the circulation of the blood in frogs, 



fish, etc 14 



Jointed Crutch and Forceps 050 



Micrometers, from l-20th to the l-1000th of an inch 



Amalculoe Tubes in sets 



Triplets, Doublets and Single Lenses from, each 050 



Wollaston's Doublets 



Solar and Lucernal Microscopes 



Surgical Microscopes, for examining cutaneous eruptions . , 



