One of the delights of buying old microscopy books is the interesting bits of paper sometimes found folded in the leaves.
I purchased the classic book 'The Microscope' by Conrad Beck (published in 1921) sometime ago and found the following A5 sized advert folded inside entitled 'Microscope for the Pocket' describing the 'Beck Baby London'. The pocket microscope by R. & J. Beck of London looks a simple design but very practical. I believe the advert and price list is dated about 1924. I note the microscope was priced about four to five pounds. I can't judge whether this is expensive although I note the modest sized book itself was priced two shillings and sixpence (one eighth of a pound) in 1924 .
'The "Baby
London" is a complete and efficient microscope folding away
into a small case which will slip into a coat pocket, but when
extended for use the instrument is capable of work with high
powers and possesses the necessary adjustments for such work. The
case in which it is carried measures 5.25 x 2.5 x 2 ins. It has a
sliding coarse adjustment and an extending drawtube giving a tube
length of 160 mm. The low power lenses can be used with the
drawtube closed, giving lower magnifying powers. Its fine
adjustment is sufficiently perfect to enable a 1/12 in. oil
immersion object glass to be focussed. The thread into which the
object glasses screw is the standard R.M.S. thread to which all
object glasses are made. The eyepieces are the standard .917 in.
diameter, thus all kinds and makes of standard object glasses and
eyepieces can be used: The 2/3 in. object glass (No. 3231B.) is
mounted so that the microscope will pack into its case when it is
in position. An Abbe condenser and iris diaphragm with patch
stops and a complete line of apparatus can be added, making the
instrument thoroughly serviceable for naturalists, travellers and
medical use. The mirrors concave and is provided with all
adjustments. A flat mirror can be supplied for use with the
substage condenser.'
Comments to the compiler Dave Walker welcomed.
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