Description

Background to J. B. Dancer (source – Microscope Museum website):

John Benjamin Dancer was a well-known Manchester optician and instrument maker, born in London in 1812, the son of Josiah Dancer, also an optician and manufacturer of optical, philosophical and nautical instruments. Josiah and his family moved from London to Liverpool in 1817. JB Dancer took over his father’s business in 1835 and continued in business in Liverpool until 1841, when he entered into partnership with A. Abraham, a scientific instrument maker of Lord Street, Liverpool. He moved to Manchester to establish a branch of the business as Abraham & Dancer at 13 Cross Street. The partnership ceased in 1845. Dancer continued in business under his own name until 1878, when part of the business was transferred to his daughters Elizabeth Eleanor and Anna Maria (he had to give up his business activities because of ill health and poor vision). The business continued trading under the name of EE Dancer & Co. until 1900, when the entire stock and the process of producing quality microphotographs were sold to the London microscope dealer Richard Suter. Dancer became well known for the quality of his microscopes and received several honours, including a prize medal at the International Exhibition in London. He was appointed Optician in Manchester to the Prince of Wales. Dancer is perhaps best known for his photographic work, in particular on microphotography and the stereoscopic camera. He took the earliest known photograph of Manchester, showing a cutler’s shop on Market Street in 1842.

In terms of the technical details, the instrument stands on a brass Y-shaped foot giving good stability, with twin slender uprights leading to the main pivot joint, which can be adjusted for tension if required.  There’s a long Lister-type upper limb giving a good range of coarse focus travel.  The instrument tilts for inclined viewing and holds in position throughout the usable range of inclination.  Coarse focus is single-sided with friction tube and is visually reminiscent of the system used by Powell & Lealand on one of their student “iron-claw” models of a similar period.  The monocular tube holds in position as it should on adjustment throughout the coarse focus working range.  Fine focus is controlled via a separate brass thumb-wheel towards the front of the optical tube, acting one the nose-piece only  working with limited range and there appears to be a historic application of solder to the underside of the mechanism.

With its optics, this instrument is monocular form with two eyepieces unmarked but presumably by Dancer:

– 6x magnification
– 8x magnification

There’s also a single objective lens in brass, as under – note the instrument is RMS in terms of objective thread diameter:

– 3/2 inch – 4x magnification approx by Wray with brass canister

The magnification range available is therefore as presently configured is around 24x to 32x.

The mechanical rectangular brass stage is of a novel design and is a quirky but a well engineered feature, with nice smooth action to its moving parts.  It’s got two thumb-wheel x/y adjusters off-set at 45 degrees located to the rear for both axes, with smooth operation.  The x/y controls have a nice solid stable feel about them, requiring a little practice to master the diagonal movement and offering control of specimen positioning. There’s no top-plate supplied and this seems to be a missing component, however the arrangement appears to work as is with under-size slides, some of which are supplied in one of the case drawers. I will endeavour to find a top-plate and add to the listing if/when I can.

Turning to the sub-stage, we have a brass ring-mount to which will fit plug-in accessories as demonstrated in the listing photos.  There’s also a swing-over arm to which fits accessories such as a dark well, also as shown.  Overall, the sub-stage is surprisingly well thought out.

Lighting is via a plano-concave mirror in a brass carrier on a height/rotation adjustable brass support arm and gimbal fitted to the limb tailpiece, with period silvering that’s in good condition to the plane side, with crazing to the concave. 

Accessories:

– sub-stage nicol prism polariser with rotation
– fixed aperture stop
– live box
– slide preparation spatula
– small brass tool for tightening thumb-wheels
– lock for case (no key)
– glass filter
– small quantity of blank slides
– some small-size prepared slides 
– untested 1/4 and 1/8th inch pre-RMS brass objectives with canisters

There’s a quality period hardwood case for the instrument, with superb exterior period sheen and a series of internal drawers that can accommodate the accessories and a collection of slides.  There’s a good solid brass carry-handle to the case and there’s also a latch fitted to keep the door closed.  The case has the Dancer paper label inside which remains in good readable condition.  The case appears to have a shrinkage crack across the front of the door, but it’s still perfectly presentable.

The instrument and its controls have been very gently dusted, lightly lubricated so that moving parts and friction surfaces operate smoothly with age-appropriate signs of wear and condition points as described, very much as one would expect for an instrument of this quality and age.  With its bright lacquer finishes, it’ll make a great display piece in the right setting and is also a usable instrument currently set up for low power work.  It presents really well and I’m certain it will look the part in a library or home office. 

Owing to the weight and delicacy of this antique microscope, it will be partially dismantled, carefully wrapped for shipping and dispatched by UPS or Royal Mail Special delivery within the UK, UPS insured expedited for certain overseas territories and eBay Global Shipping elsewhere.

Thanks for looking and just message seller if additional photos or details are required.