" 



BAIRD &.TATLOCK (LONDON) LTD. 



1290-1294 



Doublet Magnifiers (Bausch & Lomb's) . Composed of two separated piano convex 

 lenses in three styles of metal mounting. Give satisfactory results and are recom- 

 mended for use wherever a good lens is wanted at a very reasonable cost. 



E. F. = equivalent focal length. 



1295-1302 



Coddington Magnifiers (Bausch & Lomb's) . Composed of a cylinder of glass, with 

 a deep groove cut in at equal distance from the ends, acting as a diaphragm. The 

 ends of this cylinder are ground spherically to form the lens surfaces. These magnifiers 

 give good definition and wide field, although, owing to construction of the lens, the 

 corrections are not of the order of the Hastings Triplets or Triple Aplanats. Furnished 

 in two styles of metal mounting, engraved " Coddington " with the focus. 



EMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 



259 



