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c. 3rd to 4th Qtr of 19th Century

Unsigned, but possibly by Molteni of Paris

Serial Number: None


Bertrand-type Furnace Drum Microscope


Furnace Microscope Furnace Microscope 3 Furnace Microscope 5 This is an example of the diminutive "Furnace" Drum microscope, apparently first popularized in Paris about 1859 and continued to be made into the 1880s. A slightly larger version, still mounting to the dovetail on top of its box was made from about 1900 to the 1920s and 1930s. This, the early type, is very small and its small size makes it a bit difficult to use; for that reason its base dovetails into a slot on the top of its box. In this position, on the box, the entire assembly closely resembles an old furnace (as seen below), hence the name.


Furnace Microscope6Furnace Microscope7 The drum microscope was apparently invented by the Germans in the first years of the 18th century, but it was Benjamin Martin who refined the design introducing it in England about 1730. The original versions were first made of cardboard and wood, sometimes with ornate shagreen rayskin covering. The Martin 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. They were, in the third quarter of the 19th century, equipped with achromatic objectives by the French, but usually nonachromatic objectives by the English.

As time passed, the design was limited to small versions but usually about twice the size of the Furnace Microscope and these smaller cheaper ('toy') versions were nearly all produced in France, exported in large numbers; there are several examples of these smaller less expensive drum microscopes in this collection and they continue to be plentiful on the antique market, even in the twenty-first century. The small cheap versions were still being sold by Sears in the 1930's.

It is unclear for how long the miniature Furnace microscope was made for, but the author is aware of some that are nickel or chrome-plated, suggesting their production continued long after they were first introduced. Even the original model was still being made in the 1880's. Notice the structure of these 19th century furnaces and the resemblance to the Furnace Microscope.

Although the Furnace microscope was attributed to Bertrand of Paris by the author of the Billings Collection Catalog, we are grateful to Brian Stevenson for providing evidence that Bertrand was unlikely ever the maker of any commercial microscopes, especially the Furnace type, and refer the reader to his review of the subject.