In the 1892 Swift & Son catalog, this microscope was referred to as the 'Best Challenge Microscope', No.2. Other, less elaborate members of the Challenge series are referred to as Models A, B, and C or as Models No.5, No.4, and No.3, respectively. Also included in the Challenge series is what is described as the 'Large Presentation Microscope', No. 1, which is nearly identical to, though slightly larger than, the microscope shown here. An example of Model A also resides in this collection.
The microscope is constructed entirely of lacquered brass. It measures 15-inches in height when fully closed down, with the eyepieces removed. When set up for use and inclined as shown in the images, it measures 17.5-inches tall. The microscope came to me without the storage case. It is supplied with two eyepieces and one objective. The sub-stage holds Swift’s Universal Condenser, which is missing its optical elements. Above the tube-slide holding the Wenham prism is another slide holding an analyzing Nicol prism.
The following description of this model was extracted from the 1892 Swift & Son catalog:
No.2—This instrument is similar in mechanical construction to No.1 but of smaller size.
COARSE ADJUSTMENT by spiral rack and pinion; Swift’s “Climax” fine adjustment, which is perfectly steady and reliable with the highest magnifications.
CIRCULAR ROTATING STAGE moved by rack and pinion, which can be put out of gear for rapid rotation by hand, divided on the edge to 360°. Rectangular mechanical movements; the stage plates divided on silver to 1/20th of an inch, with vernier reading to 1/1000th, to serve as a Finder or for measurements. Sliding object holder with tension springs and clamps. Centering adjustments, so that the whole stage can be made to rotate truly with any objective.
SUB-STAGE with complete adjustments for focussing and centering, and rotatory movement by circular rack and pinion. The whole slides in transverse dovetailed grooves, and can be instantly removed with all its fittings when not required, thus leaving the space under the main stage perfectly free for any desired manipulation. The same arrangement applies to the other instruments of the “Challenge” series.
LARGE FIRM TRIPOD BASE; extra, large mirrors mounted on double crank arm. Sliding fitting for analyser of polariscope..
PRICE: as Monocular with two eye-pieces in plain cabinet ... ... £27 10 0
with Binocular body, having rack adjustment to the draw-tubes, which are graduated, and two pairs of eyepieces, A and B, in cabinet ... ... £31 10 0
