Circa 1749-50, probably made under the supervision of the duc de Chaulnes, the ormolu possibly by Jacques and Philippe Caffieri, the mechanics attributed to Claude-Simeon Passement, the micrometers attributed to Andr Maingaut

Circa 1749-50, probably made under the supervision of the duc de Chaulnes, the ormolu possibly by Jacques and Philippe Caffieri, the mechanics attributed to Claude-Simeon Passement, the micrometers attributed to Andr Maingaut
THE MICROSCOPE: the optical tube is covered in polished fishskin dyed green. It is topped by an urn-shaped finial, which unscrews to reveal the eye-cup that positions the eye correctly for viewing the image. The eyelens is contained in another section of the gilt mounting, and where this attached to the body is a micrometer. Further down the body is the field lens, and at the end is a mounting to the nosepiece on which screw the objective lenses in their cells. There are six objective cells, engraved on their sides with the numbers 1-4 and 6. No. 5 is not engraved, and nos. 2 and 3 have lost their lenses. The optical tube is attached to a composite side-pillar focusing arrangement to the design of the English maker, John Cuff (1708-1772), who published such a design in 1743. Coarse focusing is by adjusting a collar on the pillar to a suitable position, and fine focusing is effected by turning a knurled wheel on a long vertical screw that acts on the collar. The bottom of the pillar ends in a rounded base and curved bracket in the same manner as a Cuff microscope. It is fitted to an elaborate gilded rococo base with four curved supports to the stage. Illumination is provided by a concave lens in a swivel mounting fixed to the base of the stand.

A particular feature adapted from the invention of the duc de Chaulnes (1714-1769) is the micrometer. This is in two parts, one pointer is the plane of the specimen the other between the eye and field lenses. Attached to the top of the stage plate is a long screw that moves a pointer next to the specimen, the distance moved recorded by an index moving over an enamel dial that is divided into 100 units. To help locate the pointer a toothed arc with worm drive is provided. At the image plane is another pointer with dial and screw drive, and an opposing pointer that is simply drawn in or out to mark one edge of the image.

THE CASE: the microscope has a close-fitting wood and gilt-embossed leather case, the leather dyed a dark red. On the outside it is gold tooled, and has brass escutcheons, and brass handles. The inside is covered in green velvet lined in gold braid. In the bottom of the case is a drawer for specimens; none of the original circular preparations is present. At the back of the drawer is a second drawer that now contains some early nineteenth-century sliders and home-made glass preparations. It also holds the objective lenses, and stage forceps on a thin rod. This fits into a boss set into the stage plate. Currently fitted to the upper stage specimen support is an aperture wheel with five holes of different sizes. Below the main stage is a light-limiting cone.
The microscope 19 in. (50 cm.) high; 10 in. (26.5 cm.) wide; 8 in. (20.5 cm.) deep
The case: 26 in. (66 cm.) high; 13 (33.5 cm.) wide; 10 in. (26 cm.) deep
Rothschild inv. no. AR410.
J.-N. Ronfort, 'Science and Luxury: Two Acquisitions by the J. Paul Getty Museum', The J. Paul Getty Museum Journal, 17, 1989, pp. 66-81.
G.L'E. Turner, Collecting Microscopes, London, 1981; for further information on John Cuff see pp. 52-57.
Vienna, Kunsthistoriches Museum, inv. no. 9870, since 1948.
Sale room notice
A prism for attachment to the body-tube, inscribed with the microscope inventory number 9870, has been recovered. This accessory is of a later manufacture and maker unknown, 19th century, possibly French. The prism measures 2 3/4 in. (7 cm.) wide.

Lot Essay

Jacques Caffieri, sculpteur, fondeur et ciseleur du Roi (1678-1755) and his son, Philippe (1714-1774), matre in 1754.

The duc de Chaulnes' Microscopes

As J.-N. Ronfort argued in his well-researched article, 'Science and Luxury: Two Acquisitions by the J. Paul Getty Museum', The J. Paul Getty Museum Journal, 17, 1989, pp.66-81, this superb Rococo microscope belongs to a group of eight instruments closely associated with Michel-Ferdinand, duc de Chaulnes. A celebrated amateur, de Chaulnes was the first in France to apply the ocular micrometer to microscopes built under his supervision, but the innovative introduction of a micrometric stage - which features on all eight microscopes in this group - was an invention of de Chaulnes' and appears to have no antecedents elsewhere in relation to microscopes. Although not published by de Chaulnes until 1768 in the paper presented to the Acadmie Royale des Sciences, this important technical advance was certainly in place before 1749, as its existence is testified to by both Alexis Magny (1712-1807) and Claude-Simon Passement (1702-69) in their respective memorandums of 1751 and 1750 (ibid., pp.79-82, appendices I and II).

The eight known microscopes belonging to this group comprise:-
-the Rothschild microscope offered here
-that in the Muse de l'Ecole Polytechnique, Paris
-that in the Muse National des Techniques, formerly in the collection of the Acadmie Royale des Sciences
-that in the collection of Michel Meyer, Paris
-that in the muse des Beaux-Arts, Lille
-that in the J. Paul Getty Museum, Malibu, California (86.DH.694)
-that in the muse des Beaux-Arts, Nancy
-and a final example in a Private Collection, Antwerp, formerly in the collection of the Vicomte de Noailles and subsequently sold by Arturo Lopez-Willshaw, Sotheby's Monaco, 23 June 1976, lot 23.

Louis XV and Madame de Pompadour

Undeniably masterpieces of the ciseleur-doreurs' art, these microscopes also represent significant technical and scientific innovations. Given their elaborate nature and the considerable cost involved in their manufacture, it is important to remember, therefore, that the de Chaulnes microscopes would only have appealed to the highest echelons of the Court, who were also members of the scientific elite. Foremost amongst these was Louis XV himself.

An intimate of the duc de Chaulnes, Louis XV established a Cabinet d'Optique et de Physique at the chteau de la Muette as early as 1756. Initially endowed with the immediate transfer of a portion of Louis XV's personal collection of scientific instruments (and subsequently enlarged with further pieces from the King's collection which had been stored with Dom Nel at the Abbey of Saint-Germain-des-Prs), Louis XV's scientific instruments were comprehensively recorded in a series of engravings by Dom Nel entitled Cabinet du Roi. Now in the Bibliothque Nationale, Paris, Nels' engravings depict a microscope that corresponds direcly with the de Chaulnes group (pls.14-16), and it would seem only logical (although at the present time only hypothetical) that the duc de Chaulnes would have overseen the presentation to the King of one of the very first prototype copies of his microscope.

Louis XV's interest in scientific instruments and innovations was almost matched by that of his mistress, Madame de Pompadour and the Inventory taken following her death in 1764 listed not only a telescope, but also automatons, mathematical instruments and barometers. Although the majority of the marquise's effects were sold publicly in Paris from 19 November 1764 to the end of July 1765, with further pieces included anonymously in subsequent sales throughout the 1760s, the auctioneers' records have tantalisingly been destroyed. However, on 13 August 1767, an advertisement in Paris offered for sale 'un beau MICROSCOPE provenant de la vente de Mad. la Marquise de Pompadour. Il est regard comme un des plus beaux morceaux qu'on encore vu en ce genre. Il a t achet 1200 liv, ladite vente: on se contentera d'un petit bnefice. Il faut s'adresser au Sr. Laurent, chez le Sr de Sve, Md. de vin en gros, rue de la Tissanderie'. As Ronfort argued (ibid., pp.74-5, f.65) 'the price quoted practically excludes any other known model than the de Chaulnes one', and whilst the Pompadour provenance was claimed for the example from the Lopez-Willshaw Collection in 1976, without further documentary evidence the Pompadour provenance could equally well apply to any of the de Chaulnes group.

Jacques and Philippe Caffieri and Claude-Simo Passement

The Rothschild microscope, like all of the de Chaulnes group, is neither signed nor dated and thus although undoubtedly assembled under de Chaulnes' direction, the attribution of its constituent elements can only be tentative. Ronfort (ibid, p.78), however, has tentatively suggested that Andr Maingaut may have been responsible for the micrometers, Claude-Simon Passement for the lenses and mirror and Claude Javois, a fondeur-fondant, for the casting of the Getty microscope.

Passement was certainly extensively patronised by the Court, and this is confirmed by the microscope in the Oxford Museum of the History of Science, which is signed 1Passement Ingnieur du Roi au Louvre A Paris. The traditional attribution of the ormolu mounts to the fondeurs-ciseleurs, Jacques and Philippe Caffieri, however, whilst by all means possible, lacks supporting documentary evidence. That the Caffieri were extremely active between 1747 and 1755 is clearly seen by their turnover of 233,205 livres during the period; that they produced ormolu cases for scientific instruments is revealed by the astronomical clock presented by Passement to Louis XV in 1753; and that their documented oeuvre displays related chasing is also demonstrated by Ronfort (ibid., p.79). However, on the basis of quality and innovative design alone, contemporary bronziers like Jean-Joseph de Saint-Germain, Franois-Thomas Germain, Jean-Claude Duplessis, Edm-Jean Gallien and Nicolas Vassoult could equally well qualify, as could the ciseleurs working for the Caffieri themselves, such as Jean-Baptiste Osmond and Jean Maravaux, to name but a few.

In the past, the de Chaulnes group of microscopes has been attributed to Alexis Magny, on the mistaken interpretation of the paper he presented to the Acadmie des Sciences in 1751. As Ronfort has shown (ibid.),however, this paper actually reveals that Magny was armed with the details of the already extant de Chaulnes model in order to complete, in eight days, a microscope that could be used in a sitting position by Stanislas Leszcynski, King of Poland. Now in the muse Lorrain, Nancy, this latter microscope is signed and dated 'Magny 1751' and inspired several further variants, all of which are also numbered and often signed.

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