MICROSCOPE-ANTIQUES.COM © 2013-18.

MARTIN OR DRUM-TYPE MICROSCOPE

Covered in Red Shagreen

MODEL: 'Pocket Reflecting Microscope'

c 1760

Private Collection

Martin Drum Microscope

DESCRIPTION:
This attractive microscope, not in my collection*, has a brass base supporting a pasteboard cylinder, the lower part of which contains a mirror, with a small opening to the front. The mirror sits on a piece of cork and is fixed. The pasteboard of the cylinder is covered with reddish shagreen. The stage is a brass disc and behind it the pasteboard cylinder is cut out to take a slider or a vial. The outer cylinder is fully cut away in front rising to support a brass collar at its top. Inside the cylinder slides the body tube, of pasteboard covered with green vellum, stamped at its lower end with the signature of 'B. MARTIN, LONDON', and 'tooled' or embossed at its upper end with a fancy design. The glass fitted in the aperture of the stage has a shallow cavity. Some authors consider this a condensing lens, but more likely it is simply a depression slide for examination of a liquid medium such as pond water. The Martin signature appears upside down from these photographs, but the user with his eye above the eyepiece can read the signature easily as it is oriented for the user's position.

*I am very grateful to the owner of this exquisite microscope for sharing his images with us.

HISTORY:
The drum microscope was apparently invented by German makers in the early 1700's. But Benjamin Martin about 1738, introduced his form which he popularized. His name became associated with these, and they are to this day often still referred to as a 'Martin-Type' although 'Martin Drum Microscope' is more descriptive, particularly since Martin had developed many other designs of microscopes.

Martin's earliest known forms were apparently handheld, not designed to rest on a table, and were to be used mainly with opaque objects. These could be had with a crude eyepiece micrometer, which registered on a dial near the eyepiece.

The second form we know of would stand on a table, but still was designed mainly for opaque objects. No complete example of his earliest forms survive. A single example of a partly restored version, similar to the engraving seen here, with an eyepiece micrometer is known.

The slightly later versions of what we now call the 'Martin' or 'Drum' type, as shown at the top of this page, and to the left, were first made of cardboard and wood, often with ornate covering as seen on this page. In these early models, brass was used only for protecting the ends of the pasteboard tubes and as dust covers for the eyepiece.

As time went on, more of the microscope was constructed of brass. It was not long until the entire instrument was constructed mainly of brass. The image shown here to the left is typical of Martin's early all-brass microscopes.

The 'Drum' design is grossly inferior to even early 19th century microscopes, but compared to others remained one of the least expensive to produce. For this reason the production of drum microscopes, initially non-achromatic, continued for many years and even into the twentieth century. The higher class examples, made by both the French and Germans, were equipped with achromatic objectives and, in some cases a more accessible stage and even a continental fine focusing arrangement, as in the French example by Nachet shown to the left. Nachet made these large drum microscopes from no later than 1854 through the 1860's. Student or 'toy' types by the French(see below) and also most by the English(right) were usually equipped with non-achromatic objectives. Note the sliding coarse focus and continental screw fine focus on the achromatic Nachet example to the left. The circa 1850 English version, on the right, had rack and pinion focusing, but non-achromatic objectives.

Some examples of French drum microscopes were designed to be mounted on their box, as shown here in this example by Hartnack, circa 1865. The Hartnack example shown to the left has a tilting stage type of fine focus.

Newcomers to the antique microscope market, including many people selling on Ebay, often do not appreciate that these small cheap versions were made by the tens of thousands and were still being sold e.g. by Sears in the 1930's. The ad shown to the right is from 1929.