CHAS. LENTZ & SONS 
Cfte Bacuriolosisfs ana PDpsician's 
microscope 
BB 
NEW CONSTRUCTION 
This microscope cannot be equalled for laboratory work in medical micro- 
scopy. It exactly satisfies all demands for practical work in bacteriology, pathol- 
ogy, histology, urinalysis, blood examination, biology, pharmacy, etc. 
The demand for this stand since its introduction, about four years ago, has 
been phenomenal, and every microscope that we have sent out during this 
period has gfiven perfect satisfaction. We have yet to hear of a single complaint. 
The BB microscope is elegant in design and finish. It is of brass through- 
out, highly polished and finished in permanent lacquer. The base is large, of 
special horseshoe form, heavily leaded to insure greater stability. The joint has 
cone-shaped bearings, so that the tube will remain firm at any inclination ; it is 
provided with steel stops, to ensure parallelism of body of microscope and table 
when used for photography. The mirrors are extra large, plane and concave, 
and are adjustable on the mirror bar, which can be swung on its support, and has 
a click for central illumination. 
The substage has set-screws for centering condenser and is vertically adjust- 
able by the quick-acting screw shown at the side. The substage ring has been 
increased to the large standard size, giving full value of the illuminative power of 
the Abbe condenser, and is so arranged as to be quickly swung to one side from 
under the stage for changing accessories, etc. The stage is large, square, and 
exceedingly firm, the construction being indicated in the special description on 
page 12. 
The fine adjustment is by delicate micrometer screw having graduated head 
for measuring thickness of objects. The micrometer screw acts directly on the 
triangular bearing of the arm, which is constructed after a new (patented) 
method, whereby we do away with set-screws and springs, which, by their relaxa- 
tion and wear, produce lateral motion or shifting of the field of vision. These 
instruments are entirely free from this fault. The coarse adjustment is by diagonal 
rack and pinion of the greatest accuracy. The pinion is fitted with a special 
device by which all wear is automatically compensated^ thus insuring the per- 
manency of the adjustment. The main tube carries graduated and nickeled draw 
tube working in cloth-lined sleeve. The polariscope can be used with the micro- 
scope. All the edg-es of stand are rounded. 
