Beschreibung:

A George III lacquered brass solar microscope William and Samuel Jones, London, circa 1800 The square brass plate signed W & S JONES, 135 Holborn, Fecerunt, London to the raised circular front panel with two knurled screws one for adjusting the angle of the brass framed rectangular mirror, the other for the position of the three-part body-tube fitted to the threaded centre aperture and incorporating large primary lens at the plate end opposing rack and pinion focus adjustment, condensor and objective lens slots at the other with sprung specimen supporting platform between, in original mahogany box with accessories including low power lieberkuhn objective lens, six further high power objectives arranged in a brass slider, three condensor lenses mounted in individual brass sliders, three bone specimen sliders and other accessories, the inside of the lid with pasted trade label for JOHN CAIL, Mathematical & Philosophical, INSTRUMENT MAKER.. GREY STREET, NEWCASTLE UPON TYNE.., the box 25.5cm (10ins) wide. The partnership between the brothers William and Samuel Jones is recorded in Clifton, Gloria Directory of British Scientific Instrument Makers 1550-1851 as operating from several addresses in Holborn, London 1792-1859 (including 135 Holborn 1792-1800). John Cail is recorded by Clifton as working from various addresses in Newcastle upon Tyne 1825-65 (including 21 Grey Street 1855-65), a trade label identical to that pasted to the inside of the lid of the current lot is also reproduced by Clifton. The solar microscope was developed by John Cuff in the mid 18th century. The instrument would have projected a view of the specimen by focussing reflected sunlight through the body tube. Condition report disclaimer