For sale a cased Regency period Wollaston type camera lucida by Thomas Rubergall, London.
First produced by the eminent scientist William Hyde Wollaston in 1804 and patented in December 1806 (Patent No: 2993), the camera lucida was essentially a scientific solution to Wollaston’s inability to draw during a picturesque journey through The Lake District.
In operation, the instrument was fixed by the clamp to a surface with a sheet of plain paper below it, the effects of the lucida were produced by reflection of a distant object with the use of a four sided prism. The reflection was then viewed from above at the back edge of the prism and the image provided to the eye would then be traced on to the paper in an effective form of dual vision allowing the user to see both their hand and also the distant image in the same field.
Wollaston also included both a double concave and double convex lens to his new invention to assist both short and long sighted users. The convex would rotated to a horizontal position underneath the prism whilst the concave would be elevated to stand vertically to the front as required. It also helped with the copying near and distant objects as did the telescopic arm on which the prism was attached. Adjustment of the height would increase or decrease the size of the object on the paper according to a scale that was produced on the instrument’s arm.
This fine and early example is equipped with all of the above associated features and aligns exactly to Wollaston’s invention down to the engraved scale on the smallest telescopic draw. As with all of Thomas Rubergall’s output the brasswork is beautifully conceived and beautifully engraved with the maker’s details. “Thomas Rubergall Optician to HRH The Duke of Clarence, 24 Coventry Street, London.”
The case is equally well preserved, consisting of a hinged black leather case with silvered and vacant cartouche to the lid and hook and eye locking catches. The interior retains its original silk velvet lined padded coverings.
Thomas Rubergall was active from 1802 until 1854 in London and traded from three different addresses throughout those 52 years. Princes St, Soho from 1802 to 1805, 27 Coventry Street, London from 1805 to 1823 and then from thereafter to number 24 Coventry Street. Rubergall seems to have been from Huguenot French descent and may be related to earlier well known Chelsea market gardeners of the eighteenth century with the same name. He was renowned enough to have been appointed optician to George III and mathematical instrument maker and optician to the Duke of Clarence (later William IV) and to Queen Victoria.
The site of the Rubergall’s shop was situated between Piccadilly and Leicester Square.
A superbly executed instrument from one of the most prominent scientific instrument retailers of the first half of the nineteenth century. The dating of this instrument can be reduced to a seven year period between 1823 & 1830. The time between Rubergall’s move to 24 Coventry Street and the point at which the Duke of Clarence became King William IV. Thereafter, the engraved dedication would have become defunct.
If we assume that Wollaston’s patent extended for a fourteen year period, this example could have been produced just three short years after the expiry in 1820.