The advertisement below is from the Annals of Anatomy and
Surgery Vol. II, 1880.
"The Physician's
Microscope is designed to supply microscopists with a
first-class instrument, of more compact form than the
usual large stands, while the convenient arrangement
of its parts, the excellence of its workmanship, its
portability and price, render it very desirable. The
Physician's Microscope is made entirely of Brass,
handsomely finished throughout, particular attention
being bestowed to have the working portions
accurately and substantially fitted; thus ensuring
freedom from tremor or vibration with the highest
powers."
Typical of the microscopes manufactured by T.
H. McAllister is that the coarse focus mechanism
utilizes fusee chain instead of the much more common
rack and pinion method used by most other
manufactures. The fine adjustment knob has the
unusual location being behind the limb and at the
level of the stage; the mechanism raises and lowers
the tube that is attached to the limb (a similar mechanism
was used by L. Schrauer with the early version of his
Physician's model and by J. Zentmeyer with his
Student's model).