PORTABLE COMPOUND MICROSCOPE

C. 1925

SIGNED: 'BECK'

SIGNED ON BOX: 'R. & J. BECK LTD

SERIAL NUMBER: 40002

MODEL: BABY LONDON MICROSCOPE

DESCRIPTION

HISTORY

DESCRIPTION:

This is a small well-made compact portable folding microscope. When packed, the case measures about 5.5 x 3 x 2 inches (140 x 76 x 51mm), about double the size of a 19th century Gould Pocket microscope case. Although advertised as a 'pocket microscope' this size box would be a tight and bulky fit for a modern pocket. The microscope measures about 5 X 2 ³/₈ inches (127 x 60mm) when collapsed and folded, and is about 10 inches (254 mm) high unfolded and in working position. Coarse focus is push-pull on the main optical tube; fine focus is by a small knob on the rear of the instrument which tilts the stage. This does shift the image a little. The single mirror is on a rod which extends down from its housing tube, which extends through and above the stage. There are two stage clips and a single eyepiece. One objective is signed X10/.17 ACHRO and another is signed Beck 60 mm n.a.0.07. There are two removable stage clips. When folded to pack in the box, all three legs fold up against the body, and the mirror support is pushed back up towards the stage as the rod goes into its tubular casing above the stage.

 

HISTORY: This model was listed as a new instrument in the Journal of Scientific Instruments of 1924, volume 2, pages 60-61. This is an example of a small portable microscope, a type that became very popular in the 1920's and 1930's in England, Germany, and America. Some of the other makers made microscopes which were very similar to this one (e.g. Watson, Bausch & Lomb), while other makers came up with totally different designs (e.g. Lietz, Hensholdt, Spencer). The Baby London bears a striking resemblance to the earlier B & L Pocket Microscope, which is also in this collection, as are many other small portable microscopes of this time period. There were many different firms competing for this market, and such microscopes are not rare, so it is apparent the demand must have been substantial. Competitors included Hensoldt, Wollensak, B & L, Spencer, Watson, Baker, Lietz, and others. A set of polarizing accessories was available, and an Abbe condenser was also offered. The polarizing apparatus included a tiny rotating calibrated stage, a polarizer which screwed underneath the stage, and an analyzer eyepiece. As one can see from the price list, this polarizing apparatus was relatively expensive, doubling the cost of the instrument. Although this example is not equipped for polarized light microscopy, one of the 425X Wollensak microscopes in this collection is equipped for polarized light use. More than one of the other companies making similarly sized microscopes had polarizing apparatus offered as accessories, some were fancier than others, and prices varied tremendously. Some examples of small portable scopes from the 1920's-30's are shown here.