24 



2. * Improved Aplanatic Lenses, Nos. 9 and 10; possessing an excep- 

 tionally large and flat field. Magnifications 6 and 10 X, the diameter of the 

 lenses being 22 mm in the case of the former (Fig. 9 and 10) and 13 mm in 

 the latter case. 



The advantages derived from the size and flatness of the field of these 

 lenses can only be utilized to the fullest possible extent by holding them 

 correctly, i. e., close to the eye. 



Fig. 9. 

 Improved Aplanatic Lens 6 X ^- 9. 



(Full Size.) 



The improved aplanatic lenses are also, if desired, supplied in the form of 

 Folding Lenses, Nos. 11 and 12, (Fig. 10), at an additional cost of Marks 3.. 



Fig. 10. 

 Improved Aplauatic Lens 6 X? as a Folding Lens, No. 11. 



(Full Size.) 



Both types of the improved aplanatic lenses (Nos. 9 and 10) are adapted 

 for use with any of our dissecting stands, except P V, as well as with lens holders, 



