Accession No
2991
Brief Description
achromatic compound microscope, by W. Watson and Sons Ltd., English, circa 1940
Origin
England; London; 313 High Holborn
Maker
W. Watson and Sons Ltd. Beck [objectives] Swift [objective] Browning [eyepieces]
Class
microscopes
Earliest Date
1940
Latest Date
1940
Inscription Date
Material
metal (brass; metal alloy, white metal, steel); glass; wood (cork and one other)
Dimensions
overall height 440mm; breadth 244mm; depth 280mm; box height 440mm; depth 292mm; breadth 325mm; lieberkuhn and brush in bag length 210 mm; breadth 125 mm
Special Collection
Provenance
Purchased from Christie’s, South Kensington, London, England; lot 132, 01/12/1983. Purchased with the assistance of grant-aid from the Science Museum (related letters in history file) (PRISM)
Inscription
‘W. WATSON & SONS, LTD
313 HIGH HOLBORN
LONDON.’ (on hind leg)
‘26865’ (on hind leg)
‘x1.5
W. Watson & Sons, Ltd
London’ (on eyepiece holder)
Description Notes
Van Heurck Grand Model. Cork-shod tripod in metal alloy finished in black paint. Curved limb. Tailpiece with swinging plano-concave mirror. Compound substage with rack work rotation and clamps and variable aperture for condenser lens, mounted on a bar sliding in dovetailed fitting with clamp. Rack-work movement. Circular stage with racked edge divided [0] - 360˚, numbered by 10˚, graduated to 1˚, with Vernier reading to 5´. Horizontal and lateral motion for stage. Scale on front edge divided 0-60 mm numbered by 10 divided to 1 with vernier divided to 0.1. and scale on side divided 0 - 40 mm numbered by 10 divided to 1, with vernier divided to 0.1. Blued steel spring clips for slide. All screws in knurled brass. Brass body with coarse and fine focus. Racked draw tube divided [32.5]-[23.3] and [23.5]-[14.3], numbered by 1, graduated to 0.1.
Fitted wooden box with sliding trays containing 4 objectives: 1/8 inch, 1/16 inch, 1/12 inch and 1/7 inch parachromatic. 3 objectives by R & J Beck and one by Swift. Pair of holoscopic eyepieces 1 x 7, 1 x 10, and 12 that fit diagonal eyepiece including 3 by Browning. Various other accessories including brush and stage forceps.
Condition: good
References
Events
Description
This instrument is a fine example of Watson’s Van Heurck ‘Grand Model’ microscope, which was first designed in 1891 to the specifications of Professor Henri Van Heurck.
Van Heurck was a Dutch microscopist working in particular on microphotography at the Botanical Gardens in Antwerp, and the ‘Grand Model’ was the most sophisticated of the three in the range, the others being the ‘No.1’ and the ‘Circuit Stage’.
The principle differences between the models lies in the stage and substage construction; the Grand Model has fine adjustment for the substage and complete rotation to the stage. Watson described the instrument as “the largest and most completely fitted of the three Van Heurck stands. It is specially recommended to those who require the very highest grade instrument for the most critical work.”
The purchase of this instrument for the Museum was made possible by the allocation of a Grant-in-aid administered by the Science Museum.
22/08/2006
Created by: updated by Ruth Horry on 22/08/2006
FM:40062
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