Year/Period |
1860-1880 |
Maker |
ONBEKEND/UNKNOWN |
Country |
United Kingdom |
Signature |
Unsigned |
Category |
Microscopes |
Optical 1 |
Compound |
Optical 2 |
Achromatic |
Size of the box (h x w x d) |
26.5 × 16.9 × 14.8 cm |
Size of the microscope (h x w x d) |
34 × 12.5 × 13 cm |
Inventory number |
SM 4 |
The microscope goes with its original box with drawer, lock and key.
The microscope can be inclined between trunnions on its inverted Y-shaped foot. Below the table a revolving stop and an adjustable mirror mounted in a swinging bracket.
Coarse adjustment works on the body tube while fine adjustment works in the usual way on the nosepiece by means of a lever and a micrometer screw. The objectives use the modern RMS thread, which dates this microscope like SM 3 after circa 1860.
There is a Huygenian eyepiece of 23.3 mm diameter, the standard value for continental microscopes. Its focal length is 51.3 mm, the magnification is 4.87×.
There are two objective lenses, one of ‘1 1/2’, the other is made up of two combinations, ‘1/2’ and ‘1/4’. The ‘1/2’ combination is loose in its mount, we improved this a bit but the contrast remained bad.
The following values were measured at the microscope’s own tube, using a Bleeker eyepiece type H5, magnifying 5×:
| Objective lens | 1 1/2 | 1/2 | 1/4 |
| Focal length (mm) | 24 | 8.76 | 5.85 |
| Magnification | 34.4 | 111.5 | 167.3 |
| Numerical aperture | 0.086 | 0.30 | 0.46 |
| Resolving power (µm) | 5 | 2 | 1.6 |
| Star test | coma | coma | coma |
info@stichtinghistorischemicroscopie.nl
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2288 ER Rijswijk
The Netherlands
RSIN: 804217361
KVK: 41182753
IBAN: NL53INGB0007728414
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