R. & J. Beck, 31 Cornhill, London, #5703

The Large Best model binocular microscope, c.1871

R. & J. Beck, 31 Cornhill, London, #5703. The Large Best model binocular microscope, c.1871
R. & J. Beck, 31 Cornhill, London, #5703. The Large Best model binocular microscope, c.1871 R. & J. Beck, 31 Cornhill, London, #5703. The Large Best model binocular microscope, c.1871
R. & J. Beck, 31 Cornhill, London, #5703. The Large Best model binocular microscope, c.1871
R. & J. Beck, 31 Cornhill, London, #5703. The Large Best No. 1 model binocular microscope. c.1871
stage sub-stage

R. & J. Beck, 31 Cornhill, London, #5703. The Large Best No. 1 model binocular microscope. c.1871. Two cases of accessories

Among the accessories are included four Beck objectives (3, 1 1/2, 2/3, and 1/10-inch), three W. Wales objectives (4/10, 1/5, and 1/10-inch), and two Gundloch objectives (1/2 and 1/16-inch {immersion}). The presence of American made objectives suggests that this microscope was used in that country. Other accessories include three matched pairs of eyepieces, two additional very high power eyepieces labeled D and F, an achromatic condenser with centering adjustments, a parabolic reflector in a brass case, two eyepiece micrometers, a double objective changer, two Lieberkuhn illuminators, a right angle prism mounted to replace the mirror, a sub-stage dark-well holder and three dark-wells, a stage bullseye condenser, an erector, Wenham's parabolic reflector for dark field use, a draw-tube for monocular use, an Amici prism, a Beck-Sorby microspectroscope, a camera lucida, a sub-stage polarizing prism in a rotating holder, an eyepiece analyzing prism, a rotating analyzing prism mounting over the objective, a vertical illuminator, a Darker's series of selenites and holder, a stage forceps, a hand forceps, a limb mounted silvered side reflector, a stage mineral holder, a Maltwoods Finder in a leather case, a parallel compressor with a small wood box containing extra glasses for the compressor, a simple live box, large glass trough for wet work, and a separately cased Beck live trap. Under the stage is attached an iris diaphragm on a swing-away mounting. The accessories can be identified with reference to the accessory section of the R. & J. Beck 1882 catalog. A portable version of this microscope is also represented in this collection.

microscope in the case

Extracted from the 5th edition of Carpenter's The Microscope, 1875:

Messrs. Becks' First-class Microscope- It was by this Firm that the Jackson model was first adopted, for which the Author has already expressed his preference; the support of the Body along a large proportion of its length, upon the substantial Limb to which the Stage is securely attached, giving it a decided advantage in steadiness over any form of instrument (not exceeding it in massiveness) in which the Body is attached at its lower extremity only to an Arm between which and the Stage there is no fixed connection; whilst the Rack-and-pinion movement giving the coarse adjustment can be made to work more easily on this construction, than where it is requisite that the stem moved by it should be fitted as tightly as possible. On the other hand, it must be admitted that the 'fine' adjustment can be more effectually made by the longer leverage provided in the Ross model, than by the attachment of the screw to the lower end of the body, as in the instrument before us. The Stage of the older form of this instrument was furnished with the usual traversing movements, and was made (by an arrangement first devised by Messrs. Smith and Beck, and since adopted by other makers) so thin as to allow of extremely oblique illumination; but although the platform which carries the object could be made to rotate upon the traversing apparatus, yet the object was liable to be thrown out of centre by this rotation. This has been completely remedied in the newer pattern shown in Plate VII. the Stage of which has a nearly complete rotation in the optic axis of the instrument. This rotation is effected by a milled-head and pinion; which, by a shifting movement can be thrown out of gear, so as to allow the Stage to be rotated rapidly by hand, which is often advantageous. This Stage is furnished with a graduated circle, to which a Vernier can be attached when desired for the measurement of angles.



Beck The Large Best model binocular microscope

Below the stage is the ingenious 'Iris Diaphragm.' The new concentric stage can be added at a moderate cost to the first-class stands on the old pattern beneath the stage in either form is a continuation of the gun-metal 'limb' which carries the body; and this is ploughed out into a groove for the reception of a sliding-bar, which carries what may be termed the Secondary Body- namely, a short tube (seen beneath the stage) capable of being moved up and down by a milled-head, which answers the same purpose as the secondary stage of Ross's Microscope being made to work in a groove which is in perfect correspondence with that wherein the principal body works (this correspondence being secured by the action of the planning-machine that ploughs both grooves), the secondary body always has its axis so perfectly continuous with that of its principal, that no special adjustment is needed to 'centre' the greater part of the Illuminating apparatus. The 'secondary body' or 'cylindrical fitting' is so constructed as to carry the Achromatic Condenser at its upper end, the Polarizing prism at its lower, and the Selenite plates between the two; it has not, however, any rotatory movement of its own; but its fittings may be turned in the tube which carries them. The Mirror is hung in the usual way between two centers; but the semicircle that carries these, instead of being at once pivoted to the tube which slides upon the cylindrical stem, is attached to an intermediate arm; and by means of this it may be placed in such a position as to reflect light very obliquely upon the object. Though the mode in which the body is supported has the disadvantage of separating the focal adjustments from each other and from the stage-motions more widely than is the case in the three preceding instruments, yet the difference is scarcely perceptible in practice. The milled-heads acting on the former are both of them in positions in which they are easily reached by the left hand, when the elbow is resting on the table; whilst the right hand finds the milled-heads of the traversing stage and of the secondary body in close proximity to each other.

A short history of the R. & J. Beck firm

Home-Antique Microscopes       Site Index

email: wissnera@verizon.net