This form of drum
microscope was originally introduced by Trécourt and
Oberhauser in the early 1830's as shown on the left.
The fine adjustment was designed to work by the positioning
of the stage thereby making the upper stage-plate move
up or down in a horizontal position by means of a screw
and socket at one end and a guide-pin at the other
end. Accessories include three objectives, four eyepieces, and a tube mounted stage condenser on a jointed arm.
(1798-1868) is credited with the development of
the "Continental" style microscope, which by the end of
the 19th century had become a standard design that was
produced by most manufacturers of the period. The
continental model evolved from the drum type
microscopes, an example of which is shown here.