Hugh Powell Compound Microscope (No. 152)

Age:  1840
Made by: Hugh Powell
Made in: England

This is an early microscope made by Hugh Powell (1799–1883), an instrument maker residing at 24 Clarendon St., Somers Town, London. Hugh Powell made microscopes and microscope components under his own name until 1842 when he joined with his brother-in-law Peter Lealand to form the famous microscope firm of "Powell and Lealand". The microscope shown here appears to be an early Hugh Powell instrument as the stage does not have the fine focus wedge introduced by Powell in 1841. Powell's microscopes evolved quickly between 1840 and 1842, culminating with the introduction of the Powell and Lealand Model No. 1. Thus, this early Hugh Powell instrument in the Golub Collection represents an important evolutionary step in the development of microscopy.

This Powell microscope consists of a broad tripod base supporting a stout, non-telescoping support pillar. The microscope body is screwed into a cantilevered arm, itself attached to a triangular focusing pillar. There is only coarse focus available with this instrument, actuated by conventional rack & pinion. The large bifacial mirror is connected to the focus pillar via an articulated arm. The stage has X and Y movement actuated by concentric thumbscrews on the right side, with only Y-movement thumb screw on the left. Additionally, the stage top plate rotates. The bottom plate of the condenser has two notches allowing quick attachment of one of three condenser accessories: a Nicol prism polarizer, a darkfield condenser, or aperture disc. For examining samples using PLM, a Nicol prism analyzer can be inserted between the body and objective. Imaging is excellent.

There are four objectives with this instrument, all appear to be achromatic. The two lower magnification objectives have removable Lieberkuhn reflectors. The two included eyepieces are both Huygenian having two plano-convex lenses each. In total the instrument stands 43cm tall. There are four accessories with this instrument: a stage forceps, a stage sample basket, live box sample holder and a spring sample holder. The mahogany storage case is 27x25x28(h)cm.

Microscope featured 03/2011

Fri, Dec 28, 2012