CHAS. LENTZ & SONS 
The diagrams are accurately etched on the best polished patent plate glass 
about j\ inch thick. They are removable and interchangeable. Wolfhagel's 
rectilinear diagram is provided, or Lafar's diagram of concentric circles divided 
into equal sectors, with subdivisions to aid in counting small and numerous 
colonies. 
No. 2558 
2556. With 
one etched plate (Wolf hiigel's diagram), without lens . . $5 50 
2556. With one etched plate (Lafar's diagram), without lens . ... 850 
2558. With one etched plate (Wolfhugel's diagram), without lens . 7 50 
2558. With one etched plate (Lafar's diagram), without lens ... 10 00 
2556. With both etched plates 10 50 
2558. With both etched plates 12 00 
Tripod Magfnifier (not achromatic), extra 50 
2560. Achromatic magnifier (as shown in cut), giving exceptionally 
largfe field and excellent definition^ extra 7 50 
Ahhough this apparatus is not constructed for miquel flasks (as 
they are seldom used in this country), they can be employed by 
inserting a hard rubber plate, with circular aperture, behind 
diagram, in slot provided. The colonies are then counted with 
the flask in an inverted and inclined position. Hard rubber 
plate, extra 1 qq 
