INTRODUCTION | DESCRIPTION | ACCESSORIES | HISTORY |
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Aristocratof the Victorian period of
brass and glass.This particular example is unusual, in that it comes with a comprehensive and virtually complete set of accessories, including almost all of those listed in the firm's 1875 catalogue. This would have cost its original owner the then considerable sum of £264 7s, (about $27,500 (US) in 2018). Even without the accessories, the P & L No.1 was so expensive, that only the wealthy could afford to buy one on their own.
For Low Powers and Opaque objects. This is of the classic Wenham design, producing stereoscopic vision through a single objective with focal lengths down to ½ inch, and an angle of aperture not much more than 50 degrees. The other is engraved
Powell & Lealand No 105 patent. This features a prism arrangement of their own design, intended to produce binocular non-stereoscopic vision at high powers of magnification. Inevitably with this arrangement, the image seen with the left eye is much fainter than the right.
P & L N.A. 0.92 Apo condenser F=0.29" Dry OKin the unmistakeable handwriting and annotation of the late Horace Dall (1901-1986), optical genius, of Luton, England, by many considered to have been the last person who was capable of repairing defective Powell & Lealand objectives.
truncated, i.e. all optical parts are combined in a single brass cell, which screws into the top of the sleeve. In their 1895 catalogue, Powell & Lealand advertise this version as having an N.A. of 1.40, the cost being 1 Pound 10 Shillings extra. This condenser was also made for other microscope makers, such as the firm of Watson, which at that stage did not as yet make their own oil immersion condensers. This particular example was made to be fitted into an under stage sleeve. The present owner has added an adaptor which allows it to be used in the original P & L substage. The engraved illustration shows the condenser in its usual guise.
elevator, taking the stops up to the required position, so that they could be changed while the condenser remained focused on the slide. On this design, an achromatic version (N.A. 1.30)was constructed in 1886, and one on the apochromatic principle (N.A. 1.40) in 1891. Apart from being listed in Powell & Lealand's own catalogues, this condenser was also advertised by W. Watson & Sons in 1902:
Powell & Lealand's Apochromatic oil immersion condenser, 1.4 N.A. mounted in P & L's special carrier, with stops, complete GBP 12 0 0 .Unfortunately, in this particular example of this rare device the front lens element was missing, which the owner has aimed to rectify by creating a replacement, which optically appears to work satisfactorily, save for resulting in a lower N.A.
Rainey’s light modifier.
Improved Large First Class Microscopeare found on this site, and still have struts supporting the tube. The more detailed account of the Improved Large First Class model, dated 1854, includes many additional details about it and its history. As seen in the image to the left, the Improved First Class stand of 1856, is similar to the 1843, stand other than the position of the fine focus knob, the rack and pinion substage, the design of a heftier tripod, and the rectangular and heavier tripod legs.
Messrs Hugh Powell, Andrew Ross, and James Smith each to furnish a standard instrument made to their own peculiar views. Powell’s massive model(left) as delivered to the Society is still part of the R.M.S. collection today, and features a solid triangular post, as well as the first example of an English microscope equipped of an achromatic condenser. A small number of this large model continued to be made until 1849.