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Lot Essay
The stage and accessories
The mechanical stage is of Hugh Powell manufacture, and is to the pattern of Edmund Turrell, where the X and Y motions are on concentric shafts. Turrell was an engraver of 46 Clarendon Street, Somers Town, while Powell was at 24 Clarendon Street from 1832 to 1846. The stage was published in the Transactions of the Society of Arts in 1833, Turrell having been awarded by the Society the Silver Isis Medal in 1832. This example of the stage is also fitted with, at the left, a lateral, X movement by micrometer screw, the fixed edge of the stage being engraved with a scale covering 0.15 of an inch divided in 1/100ths. The micrometer wheel is divided into 100 parts and numbered in tens. The stage plate adjacent to the wheel is engraved: One turn of Micrometer 1/100 of an Inch. On the right side of the stage is another micrometer, which drives a wedge under the stage to give a measure to the fine focus. The stage plate is engraved One turn of Micrometer 1/400 of an Inch, and the micrometer wheel which is divided in 30 parts. Under the stage is a collar with a pair of notches into which lugs on the aperture disc insert. An upper stage plate 4½ x 3 5/8in. (11.5 x 92cm.) with slide rest and grip bar is provided in the case.
There are three eyepieces, engraved on the side 1, 2, 3, each with a cap held in place by a bayonet catch, characteristic of Powell's earlier microscopes. The middle-sized eyepiece has a diaphragm between the lenses to support a crosswire (missing). The diaphragm is moved for focusing by a pair of pegs running in slots in the body tube. Six achromatic objectives are supplied, each with the narrow Powell screw thread, and typical of his work. Each is in its own can with the power engraved on the lid and on the side: 2iIn. Objective Glafs (2In.); ½In. Objective Glafs (½In.); ¼In. Objective Glafs (¼In.); 1/8In. Objective Glafs ( 1/8In.); 2In. Objective Glafs (2In.). Lieberkuhn fitted to ½ and ¼; cover-slip correction collar fitted to ¼. The sixth objective is another ½in. and is probably a few years later than the others. The can is engraved on the side and on the lid ½; the objective is not marked. It is made with a correction collar with the position limits labelled Uncovered/Covered.
The remaining items in the accessory drawer are: a brass fish-plate; a vial holder in the form of a cylinder with sprung cushion; a small brass can containing glass discs for the live-box; a stage disc of ebony and cork; a dark-well on an arm. A brass arm on a dovetail bar is all that remains of a super-stage bull's-eye lens on a square-sectioned rod: a Powell product from a later period. The one intruder is a simple lens in a turned mount. Also included are two stage mounts.
Hugh Powell and Dollond
Hugh Powell (1799-1883) was already making instruments before embarking on his specialism of microscopes in the 1830's. His first publication was in 1836, describing a fine adjustment on the stage in the form of a wedge with micrometer screw, just as on the present microscope. In 1842 Powell took into partnership his brother-in-law, Peter Lealand, and the firm then traded as Powell & Lealand.
John Dollond and his son Peter founded their firm in 1752. Peter died in 1820, and the business continued under George Dollond, a nephew who changed his surname to Dollond. In the 1830's Dollond was making, or retailing, sundials, magnetic compasses, theodolites and eyeglasses. Dollond & Co. amalgamated in 1927 with Aitchison & Co. to form Dollond & Aitchison, which continues to make eyeglasses to the present day.
It is extremely rare to find a Powell microscope bearing the name of another London workshop. There is evidence that he did not always sign some of his earlier microscopes. However, after the new Microscopical Society of London was established on 3 September 1839, Powell, who was a Founder Member of the Society, signed and dated his instruments; one of 1840 is in the Society's collection. The microscope described above is exactly like Catalogue no.113 in the Collection of the Royal Microscope Society, which is signed Hugh Powell, London, but is not dated. The same trade card is inside the door of its case. Closely similar are no's 114 and 115: all have the same Turrell micrometer stage. Another closely similar was sold by Christie's on 3 March 1994. However, there is one Powell microscope of exactly this type that has the same Dollond signature as on the present microscope. It is in the Billings Microscope Collection, Washington D.C.
The mechanical stage is of Hugh Powell manufacture, and is to the pattern of Edmund Turrell, where the X and Y motions are on concentric shafts. Turrell was an engraver of 46 Clarendon Street, Somers Town, while Powell was at 24 Clarendon Street from 1832 to 1846. The stage was published in the Transactions of the Society of Arts in 1833, Turrell having been awarded by the Society the Silver Isis Medal in 1832. This example of the stage is also fitted with, at the left, a lateral, X movement by micrometer screw, the fixed edge of the stage being engraved with a scale covering 0.15 of an inch divided in 1/100ths. The micrometer wheel is divided into 100 parts and numbered in tens. The stage plate adjacent to the wheel is engraved: One turn of Micrometer 1/100 of an Inch. On the right side of the stage is another micrometer, which drives a wedge under the stage to give a measure to the fine focus. The stage plate is engraved One turn of Micrometer 1/400 of an Inch, and the micrometer wheel which is divided in 30 parts. Under the stage is a collar with a pair of notches into which lugs on the aperture disc insert. An upper stage plate 4½ x 3 5/8in. (11.5 x 92cm.) with slide rest and grip bar is provided in the case.
There are three eyepieces, engraved on the side 1, 2, 3, each with a cap held in place by a bayonet catch, characteristic of Powell's earlier microscopes. The middle-sized eyepiece has a diaphragm between the lenses to support a crosswire (missing). The diaphragm is moved for focusing by a pair of pegs running in slots in the body tube. Six achromatic objectives are supplied, each with the narrow Powell screw thread, and typical of his work. Each is in its own can with the power engraved on the lid and on the side: 2iIn. Objective Glafs (2In.); ½In. Objective Glafs (½In.); ¼In. Objective Glafs (¼In.); 1/8In. Objective Glafs ( 1/8In.); 2In. Objective Glafs (2In.). Lieberkuhn fitted to ½ and ¼; cover-slip correction collar fitted to ¼. The sixth objective is another ½in. and is probably a few years later than the others. The can is engraved on the side and on the lid ½; the objective is not marked. It is made with a correction collar with the position limits labelled Uncovered/Covered.
The remaining items in the accessory drawer are: a brass fish-plate; a vial holder in the form of a cylinder with sprung cushion; a small brass can containing glass discs for the live-box; a stage disc of ebony and cork; a dark-well on an arm. A brass arm on a dovetail bar is all that remains of a super-stage bull's-eye lens on a square-sectioned rod: a Powell product from a later period. The one intruder is a simple lens in a turned mount. Also included are two stage mounts.
Hugh Powell and Dollond
Hugh Powell (1799-1883) was already making instruments before embarking on his specialism of microscopes in the 1830's. His first publication was in 1836, describing a fine adjustment on the stage in the form of a wedge with micrometer screw, just as on the present microscope. In 1842 Powell took into partnership his brother-in-law, Peter Lealand, and the firm then traded as Powell & Lealand.
John Dollond and his son Peter founded their firm in 1752. Peter died in 1820, and the business continued under George Dollond, a nephew who changed his surname to Dollond. In the 1830's Dollond was making, or retailing, sundials, magnetic compasses, theodolites and eyeglasses. Dollond & Co. amalgamated in 1927 with Aitchison & Co. to form Dollond & Aitchison, which continues to make eyeglasses to the present day.
It is extremely rare to find a Powell microscope bearing the name of another London workshop. There is evidence that he did not always sign some of his earlier microscopes. However, after the new Microscopical Society of London was established on 3 September 1839, Powell, who was a Founder Member of the Society, signed and dated his instruments; one of 1840 is in the Society's collection. The microscope described above is exactly like Catalogue no.113 in the Collection of the Royal Microscope Society, which is signed Hugh Powell, London, but is not dated. The same trade card is inside the door of its case. Closely similar are no's 114 and 115: all have the same Turrell micrometer stage. Another closely similar was sold by Christie's on 3 March 1994. However, there is one Powell microscope of exactly this type that has the same Dollond signature as on the present microscope. It is in the Billings Microscope Collection, Washington D.C.