Description

A once used pair of binocular body tubes plus head stock measuring 7 1/2 inches (19 cm.) in length plus a pair of 33 mm. low power eyepieces (oculars) in mahogany case with original lock and key and later carrying handle.

My research has shown that this accessory could only have been made by James Smith (apprenticed to Andrew Ross) for his earliest microscopes when he went into business on his own, as the prism had to have been mounted BELOW the bar/ limb headstock. All of his contemporaries had the binocular prism (withdrawable) mounted above and  after a few years of sole proprietorship when he joined Beck, the prism position switched. See early Jas. Smith models please.

So, if purchasing this item be aware that this will only adapt to an early (1845) James Smith monocular model with optional prism threaded into this headstock. In this manner, the entire prism assembly and objective move by worm and screw.

The body tubes have no provision for fine focus to the eyepieces (no rack and pinion or sliding bar to the reverse). Therefore, focus is achieved by worm and screw behind the body tubes (flawless operation). The golden lacquer is 99% and only exhibits a scuff to the underside of the limb for a one? time fitting. The separate case would indicate that this was an optional accessory.

Originally I thought that something must be missing as there is a concave slot in the box just ahead of the confluence but it is too shallow and short for either an objective or prism. Instead, it was used as a finger access point to lift the headstock from the deep box (mahogany case measures 10 x 5 x 4 1/2 inches deep). Functional lock with key. An interesting survivor from this innovator of microscopy.

James Smith collaborated with J.J. Lister for optical and body design for a short time and then teamed with Richard Beck in 1847 (thence Joseph Beck in 1851). Standardization of threads and diameters (RMS) lead to many design changes.