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François-Antoine Jecker Type "Drum Microscope", ca. 1810

 

This is an early French drum microscope (microscope à tambour), unsigned but very probably made by François-Antoine Jecker (November 14, 1765 - September 30, 1834). 

A more or less complete biography of Jecker is presented in Brian Stevenson's excellent website. However, some additional historical background may be added to place some aspects of Jecker's activity in its historical context. François-Antoine Jecker was born in Hirtzfelden, Upper Alsace, a community in the Haut-Rhin department in Grand Est in north-eastern France. This region is bordered by Switzerland to the south and its eastern border with Germany (or the German lands in the 18th century). Only in 1790 it became one of the original 83 departments, created during the French Revolution, through the application of the law of 22 December 1789 in respect of the southern half of the province of Alsace (Haute-Alsace). Therefore, though politically belonging in France, the region was very much influenced by the Swiss and German cultures. Being the seat of the shepherds from the 16th to the 18th century; the inhabitants then led a pastoral and agricultural life. Among the bourgeois weavers, dyers, blacksmiths, innkeepers and farmers were the Jeckers, who came from Switzerland in 1645. When François-Antoine Jecker left primary school, he attended his grandfather's forge. 

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Being the brother of Laurenz Jecker (1769 - 1834), a needle manufacturer, François-Antoine obtained permission study for a year under a watchmaker in Besançon. Then, at the age of 19, he attempted to merge into the industry, following by some ways his younger brother. In 1783, at the age of 14, Laurenz Jecker sailed to England, where, after appropriate training, he ran a needle factory as a mechanic until 1803. Then he returned to the German lands and settled in Aachen, where together with partners, he set up a brass pin factory. Laurenz acquired a property with the express permission of Napoléon Bonaparte at an extraordinarily low price for the time, due to his collaboration with brass wire factories in nearby Stolberg, an important supplier for his plant. This made Jecker's pinhead factory the first of its kind on the continent. 

Like his brother, François-Antoine Jecker travelled in 1786 to England to begin an apprenticeship in precise mechanics. This became possible due to a rare historical opportunity.

The Eden Treaty (named after the British negotiator William Eden), signed between Great Britain and France in 1786, effectively ended for a brief time the economic war between the two countries and set up a system to reduce tariffs on goods from either country. The agreement eventually became beneficial to the British, and the unequal protection on certain industries ended up hurting the French economy. But this new and short-lasting positive atmosphere between the two rival countries of the past (and of the future after 1792), probably enabled young François-Antoine Jecker to settle in London and begin an apprenticeship with the prominent British mathematician, astronomical and scientific instrument maker Jesse Ramsden, FRS FRSE (1735 –1800). Several sources tell that Jecker and Ramsden soon became friends, and remained so for life.

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Jecker's leaving of London in 1792 and return to France was undoubtedly related with the establishment of the Première République in the latter and the beginning of the French Revolutionary Wars in the same year. At the same time, all economic agreements between Great Britain and France ceased, and the atmosphere towards French nationals in England became unfriendly. Like his brother Laurenz, Jecker probably aimed his newly established workshop towards the needs of the French Army, where undoubtedly, his period with Ramsden, the pre-eminent inventor and maker of the sextant and other precision surveying instruments proved very useful and gained him an officer's rank. During these years of The French Revolutionary Wars (1792-1802), no doubt, his production of microscopes must have been secondary to that of the engineering instruments and telescopes, which are common. During the Napoleonic Wars (1803–1815), France was certainly in need for sextants, telescopes and surveying equipment. 

Jecker's microscopes

Jecker's microscopes are indeed rare, and present very unique forms. Besides the extremely rare horizontal reflecting microscope, there are two types of early drum microscopes (see Stevenson's microscopist.net).

The microscope seen here is known to us in only few examples. None of them is signed, but their unique design is very much in line with his perhaps earlier, smaller type of drum microscope (ibid). It may very well be the following model, still in line with Benjamin Martin's last form of his Pocket Microscope but  with modifications.

Benjamin Martin's later pocket microscope (YG-13-006) and the microscope discussed here.

The microscope seen here has an unusual focusing. The base has a compartment for accessories, with fitting tweezers and a live-box. Above this the concave mirror lights a plain stage, and the two sides of the drum go on to support the body-tube. This focuses by means of a screw inside a collar, against which acts a spring keeping the tube up against its top. The three-button pre-achromatic objective and the two-lenses eyepiece provide a fairly adequate image. In the example seen here, the cylinders of the base compartment and the focusing device had been coated by an attractive green leather. Another microscope of this type, sold in an internet auction site, has similar coating but with green rayskin. It was defined there as Microscope baril de voyage modèle de Jecker. Two other microscopes of this type are found in the Science Museum London collection: Inv. A56410, defined as "English, mid 19th century", and the identical A56415, defined as French of the same time. The microscope from our collection is the only one so far having the original case, made of wood covered outside with impressed green leather, and inner lining by purple velvet.