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Toy "Furnace" Miniature Microscopes, ~1850-1900


This page refers to a class of French miniature microscopes, all of the "drum" category, which were made to be slid into a slit on top of their small wooden boxes. The top of the box has either a dovetailed slot or a brass depression to receive the base of the microscope. This way the miniature instrument is enhanced and stabilized which facilitates its use. Shaped like the typical French "microscope à tambour" (drum microscope), with their typical few accessories and accompanying miniature slides, these instruments were undoubtedly French. Yet their makers and dates of manufacture are uncertain.


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Inv. YG-20-028, an early version of the microscope à niche, probably dating to the 1850s.

Microscopes of this kind are rather common and often appear in collections and on the antique scientific instruments market. They are normally made of brass, having one to three or stacking button objectives (probably achromatic) and often a sleeve with two fixed knurled buttons that can be slid downwards to hold the slide pressed to the tiny stage (Balasse). They are often referred to as "furnace microscopes" perhaps due to their overall shape slightly resembling a 19th-century furnace (Microscope-Antiques).

The authors of The Billings Microscope Collection of the Medical Museum at Walter Reed Hospital (Billings) attribute the manufacture of what is then referred to as "mineral or furnace style microscope" to a certain François Bertrand, French optician, dating it to about 1840. It is unclear to the present author who was this Bertrand, and the writers of the Billings collection catalogs do not present any further data. It is undoubtedly not Émile Bertrand (1844–1909), the French mineralogist and co-founder of the Société française de Minéralogie, designer of the lens on the polarizing microscope to determine the position of the optical axes of a crystal, as well as some refractometers. The only other reference to such a name that we found was to Sergeant François Bertrand (1823 – 1878), aka the Vampire of Montparnasse, who was arrested in 1841 for necrophilia. But he was undoubtedly not the maker under discussion. 


Inv. YG-20-020, another version of an early microscope à niche, ca. 1850s.

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In any case, the date given by the Billings catalog is undoubtedly too early. These microscopes can be roughly dated to the second half of the 19th century, but specimens such as the one seen here (Inv. YG-19-004) can easily be attributed to the turn of the 19th century, as evident by the nickel plating, the wood of the case, and the accessories. It is high time to let the references to Bertrand and the furnace rest when regarded with this microscope, and define it as a toy case-mounted miniature microscope or any such nickname. This is not unique, as in other places on this website I suggested to omit other archaic and inaccurate terms such as "Wilson screw-barrel microscope", "Ellis aquatic microscope", and so forth. And at the same time, a new and updated catalog with sharp color photos and modern scientifically-based dates and attributions should be published in the Billings collection. One may hope that The Walter Reed Army Medical Center and the United States Army Medical Corps can dedicate a small fund to this purpose.

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