An extremely rare Dutch achromatic compound microscope, c.1805,

細節

An extremely rare Dutch achromatic compound microscope, c.1805,
unsigned, but attributed to Harmanus van Deijl of Amsterdam, with accessories in a mahogany box and a set of microscope preparations, c.1800, in ivory mounts with an accompnaying folded paper signed by the celebrated Amsterdam maker Abraham Ypelaar and another by his successor Daniël Scholte, in a two-drawer cabinet.

The Microscope
The stand is that of a typical compound microscope of the late 18th century. The flat folding tripod has a bevelled shoe into which slides the foot of the rectangular-section pillar. Into the central part of the pillar is cut a rack so that the stage may be moved by pinion. The pinion is turned by a knurled wheel that can be detached from the iron shaft. At the top of the pillar is a small drum with a slot to take a bar, which is held firm by a strip spring. The drum is so mounted that it allows the bar to move to the left or right for the so-called aquatic movement. The nosepiece of the optical tube screws into a ring at the end of the bar. The stage attaches by a bracket to the carriage of the rackwork focusing device. At the centre of the stage is a large circular opening to take the brass Bonanni spring stage, a plain glass disc, a brass or a wooden live box. On either side are wings, each with a hole for accessories. Unusually, the wing on the left is threaded, because the above-stage bull's-eye condensor is on a rod, which can move inside a sleeve that is screwed into position. The hole on the right-hand wing is plain, to accept the peg under the fish-plate, or the stage forceps. A lieberkuhn mirror can be screwed to the nosepiece of the optical tube once it is in position on the bar. Because the nosepiece is wooden and has shrunk slightly, the fit is now loose. Fitted to the front leg of the foot is a one-sided concave mirror, aperture 4cm. Over the mirror may be placed one of two light limiting discs, diameter 4.8cm., turned from lignum vitae. These reduce the reflected beam of light to apertures of 1.9cm. or 1.7cm. Hand tweezers are also provided.
It is the optical tube that is the remarkable feature of this microscope. It is constructed from wooden tubes covered in embossed black leather (outer) and green vellum (inner). All the mounts and the nosepiece are made of lignum vitae, as are the two eyepieces and the two objective mounts that screw into place on the nosepiece. The eyepieces have screw-on dust protective caps, and the biconvex lenses are spaced at a distance of about 4cm. on the longer eyepiece (not numbered) and 3cm. on the shorter, which has attached to the side a small paper label with the umber 2 in ink. Both objectives are fitted with two lenses, as required to form an achromatic doublet. The lenses are close together, with a thin air gap. The more powerful objective has a small paper label bearing the number 6; the other no longer has a label. In use, the microscope gives a good image at a magnification of about 40x and 50x.
The mahogany box is lined with green baize and contains most of the parts of the instrument in specific positions. At one side of the box is a drawer that contains the light limiting discs, the glass disc and the wooden live-box, as well as three long sliders, 13 x 1.7cm., of glass with spaces for 21 specimens in apertures cut into paper strips, each numbered. These specimens are listed, in Dutch, on pieces of paper. A modern tin box contains scraps of paper that hold specimens. The paper has writing in Dutch and the lid of the box is embossed "MARO" FABRIEKEN ROTTERDAM. There are a few other miscellaneous items that include two small ebony cups and two ebony discs for viewing white opaque objects, four brass washers, and some glass strips.
Overall height closed -- 13½in. (34.5cm.); radius of foot -- 3.1/8in. (8cm.); length of optical tube closed -- 6¾in. (17cm.); diameter -- 1¼in. (3.2cm.); the case -- 9½ x 8 x 3¾in. (24.2 x 20.3 x 9.5cm.)

The Cabinet of Microscope Preparations
The mahogany and oak cabinet holds two drawers, the upper with 72 single ivory cells, diameter 1.2cm., and the lower with 12 ivory sliders, 8.2 x 1.2cm., comprising 48 specimens. For both series, the numbers and names of the objects are listed by hand in the folders, and the numbers are inscribed on the cells and sliders. With the cells, the specimen is held between a pair of glass discs secured in position by a brass split ring. All cells are present, but two are damaged. The specimens include parts of insects, plants, seeds and hairs. The twelve sliders each hold four specimens, a majority of which are sections of plants or wood. The specimens are between glass discs held by brass split rings. The outer leaf of the folder naming the 72 cells is inscribed Transparante voorwerpen voor het Microskoop geprepareerd en opgelegd Door Daniël Scholte. The folder for the sliders is inscribed Transparente voorwerpe voor het Microskoop geprepareerd en opgelegd door AYpelaar & Comp. This signature is a stamp, as is customary for Ypelaar. The handwriting of both lists is the same, apart from Scholte's signature. The craftsman has not been identified.
The cabinet -- 7.13/16 x 3.15/16 x 16in. (19.8 x 10 x 3cm.)

See Colour Illustrations

出版

van DEIJL, Harmanus, "Kort bericht der trapswijze Verbeteingen aan achromatische Verrekijkers en het Stam-microscoop, door Jan en Harmanus van Deijl te Amsterdam", Natuurkundige Verhandelingen van de Koninglijke Maatschappij der Wetenschappen te Haarlem, III (1807) pp.133-152
van CITTERT, P.H., Descriptive Catalogue of the Collection of Microscopes in the charge of the Utrecht University Museum with an Historical Survey of the Resolving power of the Microscope (Groningen, 1934) pp.64-67
ROOSEBOOM, Maria, "Some notes upon the Life and Work of certain Netherland Artificers of Microscopic Preparations at the end of the XVIIIth Century and the beginning of the XIXth", Janus, XLIV (1940) pp.24-44
----, "Die holländischen Optiker Jan und Harmanus van Deijl und ihre Mikroskope", Janus, XLIV (1940) pp.185-197
PURTLE, Helen R., ed., The Billings Microscope Collection of the Medical Museum Armed Forces Institute of Pathology (Washington, D.C., 1967) pp.191-192
TURNER, G. L'E., Descriptive Catalogue of Van Marum's Scientific Instruments in Teylers Museum (Haarlem/Leiden, 1973) pp.301-302, no.268; pp.305-307, nos 273, 274

拍品專文

Harmanus van Deijl (1738-1809) was the son of Jan van Deijl (1715-1802), both well known optical instrument makers of Amsterdam, producing both telescopes and microscopes of quality. Harmanus is held to be the first to have manufactured commercially an achromatic microscope. His description of his microscope was published in 1807 together with an engraving (see illustration). Since he died two years later, the production of instruments must have been small. At present, only six of his microscopes are known, apart from the present one. There are two in the Utrecht University Museum, two in the Boerhaave, Leiden, one in Teylers Museum, Haarlem, and one in the Armed Forces Institute of Pathology Museum, Washington, D.C. The stand and the boxes of these other examples follows closely their counterparts on the present instrument. The optical tubes, however, are of brass. The match of all these microscopes, including the present one, with Van Deijl's engraving is remarkable, and it appears to have been drawn from an instrument with a brass optical tube, not a wooden one. It could be that the present microscope was made earlier than the others, and is therefore datable before the engraving, say about 1805. It may, perhaps, be regarded as the very first commercial achromatic microscope.
The optics of the Utrecht and Leiden instruments have been collated for their magnifications and resolving powers by Maria Rooseboom. The best resolution obtainable is about 2 micrometers, comparable to a simple microscope of the period.
Abraham Ypelaar (1736-1811) was a preparer of microscope specimens of very great repute. The quality of his production is apparent in this cabinet. Other examples of his work are in the Mueum Boerhaave, Leiden, and in Teylers Museum, Haarlem. Ypelaar began to make preparations commercially during the 1780's, and was helped by his cousin, Marten Sas (1754-1811). Later they went into partnership, and founded what they called a 'factory' under the name 'A. Ypelaar & Comp.' The two men died within a day of each other in December 1811, and Daniël Scholte (1757-1832) took over the 'factory' by 1815. As the handwriting on the two lists of preparations appears to be the same, the set of sliders signed A. Ypelaar & Comp. may be one of the last, while the set of cells may be the first to be sold under the name of Scholte. This would date them to 1811-1812.