George IV Cased Pancratic Eyetube Telescope on Stand by Dollond of London

£2,400.00

Vendor: Jason Clarke Antiques

Title: Default Title

For sale, a George IV mahogany cased Kitchiner pancratic eye tube telescope with stand by Dollond of London.

This rare example contains a superbly preserved mahogany barrelled three draw telescope with two sectioned stand with tripod base. The sectioned stem of the tripod may be unscrewed in order to reveal a protruding screw which may be inserted into a branch or gatepost for field observations and where a tripod may not be practical. The one and a half inch objective lens retains its original dust cap and the telescope measures nine and a half inches closed and twenty eight and a half inches when fully extended. The smallest draw is engraved to, “Dollond, London” with original dust slide retained at the eyepiece.

All the contents are neatly contained within a beautifully figured mahogany case with neatly sectioned and baized interior and quite unusually, the telescope retains its original locking tool for tightening the head of the pivoted tripod mount.

In itself this magnificent set is a fine example from the most renowned maker of optical instruments of the period but it is further exemplified by an additional “pancratic eye-tube” invented by the equally renowned optician, inventor and cook, William Kitchiner, (a fascinating man who is also considered to be the inventor of the potato chip or crisp). The eyetube which may be added in replacement to the ordinary eyetube of the main telescope extends the length of the telescope to thirty six and a half inches and has magnification stops engraved along the three smallest additional draws. The largest is further engraved with “The Pancratic Eyetube, Dollond, London”. Conceived by Kitchiner to increase magnification of the standard telescope, the manufacture of his invention seems to have been entirely gifted to The Dollond family whose optical work Kitchiner is known to have admired.

Kitchiner described his invention in detail within his 1824 publication, “The Economy of the Eyes” but the less lengthy and earlier passage taken from The Philosophical Magazine of 1820 is worthy of reproduction to provide a contemporary explanation:  

Particular respecting the Pancratic Eye-Tube invented by William Kitchiner, MD., Author of “Practical Observations on Telescopes, Spectacles etc, made only by Dollond of London.

It has long been known that the magnifying powers of telescopes could be augmented by increasing the distance between the two glasses next to the eye, and the two that are next to the object glass, to almost double the power of the eyetube in its usual form, ie from 30 to 55. This is the utmost that opticians have at any time accomplished; yet this variation is so desirable, that I think it only requires to be generally known, to be generally desired.

“A few months ago, I saw an eyetube, made by Mr Cauchoix, with a scale of magnifying powers from 25 to 73; but upon trial, I found the vision was good only between 35 and 45. My attention was strongly excited by the idea of one eyetube effecting the whole business of magnifying; and after several experiments, I combined lenses of such proportions that they admitted of being separated from each other so as to magnify at one extremity, more than double they did at the other, the vision continuing uniformly distinct to the extreme edges of the field of view.

Having now done more than was previously effected, I brought it to you. The great approbation you expressed of what I had done, so encouraged me, that I applied unceasingly, determined to perfect the object in view, which I have now accomplished.

I beg to present to you the following accurate measurement of the powers, and faithful account of the performance of THE PANCRATIC EYE-TUBE, which gives a neater and better defined image of a fixed star, and shows double stars decidedly more distinct and perfectly separated, than any other eyetube, and will enable the observer to determine the distances of these very delicate objects from each other in a more perfect manner than has been possible heretofore.

This eyetube applied to the achromatic refractor of forty four inches focus, produces, in the most perfect manner, every imtermediate degree of magnifying power between 100 and 400, the vision continuing uniformly distinct to the extreme margin of the field of the telescope.

The tube is graduated; and the change from one power to another may be made instantaneously, even in the dark, with the utmost facility and certainty. It is presumed that the advantage of my Pancratic Eye-Tube over common magnifiers, in variety of effective magnifying power, convenience and portability is as 300 to 1.

This eyetube is applied to the telescope in the same manner as other eyetubes, and is adjusted to distinct vision by the same pinion motion. For the lowest magnifying power, the whole of the tubes must be shut up; and when the magnifying power is to be increased, the smallest of the sliding tubes, A, must be drawn out to either of the numbers engraved upon it; care being taken not to draw out any part of the other sliding tubes, B and C, until the whole of the first A, is pulled out; the second tube B, may then be drawn out to either of the numbers engraved thereon; and in like manner the third tube. The numbers denote the magnifying power of the telescope.

To change the power, for any less power than the one to which the tubes have been drawn out, the reverse of the above described mode of proceeding must be observed; and the largest tube must be returned first, and so on, until they have been brought back to the number required. Each alteration of the magnifying power will require a new adjustment of the pinion; and as the magnifying power is increased, the distance between the eyeglass and the object glass must be diminished”.

The exact date of Kitchiner’s invention is not entirely clear, from his writings, he was certainly working on the eyetube in 1819 and he wrote in 1820 to Sir Joseph Banks – President of The Royal Society where the above extract was read at a Royal Society meeting on the 20th of April. Just how long it took the Dollonds to start manufacturing is unclear but it is certain from Kitchiner’s later publication in 1824 that it was then available for purchase.

The Dollond Company was set up in Hatton Garden in 1750 by Peter Dollond with his father John joining him shortly after. John Dollond’s invention of the achromatic lens (although bitterly disputed) led to his award of the Copley Medal by The Royal Society in 1758 and following this success, Dollond moved to The Strand where the company was appointed optician to George III and the Duke of York in 1761.

Following the deaths of John in 1804, Peter Dollond took his nephew George Huggins into partnership and after a change in surname, the company became P&J Dollond until Peter’s death in 1820, the same year that they were jointly made opticians to George IV.

The company continued its association with royalty and went on to win a Great Exhibition Medal in 1851, a year before George’s death. His nephew (also George) succeeded in the ownership until his death in 1866 wherafter his son William continued to run the business. William was the final Dollond family member to run the company, finally selling out to a former employee of the company, JR Chant in 1871. Chant continued to use the company name until was acquired by James Aitchison in 1927 whereafter it became Dollond & Aitchison. In 2009 it became part of Boots the Opticians.

Kitchiner died in 1827, seven years after Peter Dollond (1820) so this telescope must have been manufactured under the stewardship of George Dollond owing to the timing of Kitchiner’s invention and its subsequent manufacture in about 1824.

A fabulous piece of optical history and in superb condition.

Circa 1824 - 1830

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