William Ladd Fusee Chain-Drive Presentation Microscope, Lacquered Brass, 1851-55
SaleHere we have a rare and fine English presentation microscope, with a fusee chain-drive focusing mechanism. This design was patented and pioneered by William Ladd of Walworth, London, England. While it is unmarked aside from the presentation inscription, it is marked with his patent. Circa 1851-1855.
The inscription on the microscope reads: "To B.P. Davidson, Esqr. From the Members of the Armagh Natural History Society In Token of Their Sense of His Valuable Exertions for that Institution." The bar limb is marked "Chain Adjustment REGISTERED May 18th 1851."
This microscope was originally purchased by the estate owner in 1975, and the original sales description includes the following:
"Bright brass, original lacquer finish, 14" h (min) extending to 16 1/2", chain drive coarse focus and nose piece fine focus screw, two axis driven mechanical stage 2 1/2" sq with rotating aperture disc and 2" dual mirror below. The stand is derived from Ross with the bar limb supporting the 7 3/4" long microscope tube. Included are 2 oculars, objective with triple button lenses (achromatic?), live box, paired Nicol prisms, stage forceps, stage condenser, and fitting and lens for conversion to a simple microscope. Original dovetailed mahogany case 7 1/2" x 6" x 10 3/4" h. Case in very good, microscope in very fine condition.
Although unsigned, this is an example of the early work of William Ladd who seems to have been the first instrument maker to use a chronometer fusee chain to control the large scale focusing motions of a microscope...The R.M.S. in their catalog describing the Ladd microscope in their collection notes, "Motion is imparted to the body not by rackwork but by a chain coiling round a spindle controlled by a milled head, giving a remarkable smoothness of motion and freedom from backlash." In his later work, Ladd developed unique structures too, but here he has worked with a standard design giving further evidence that this is an early instrument produced to establish a priority for his chain drive."
The cosmetic condition of the scope and case overall is very nice, minor spotting and scratches on the lacquer finish. The fusee chain drive is intact and functions, although occasionally wants to slip. The slide lens attachment is cracked. There is a crack in the back of the case, and the double sided mirror is delaminating. There is evidence that the mirror attachment point has been repaired with solder at some point. Overall, this is a fine piece, and particularly unique with the inscription from the Armagh Historical Society of Armagh, Ireland.
The inscription on the microscope reads: "To B.P. Davidson, Esqr. From the Members of the Armagh Natural History Society In Token of Their Sense of His Valuable Exertions for that Institution." The bar limb is marked "Chain Adjustment REGISTERED May 18th 1851."
This microscope was originally purchased by the estate owner in 1975, and the original sales description includes the following:
"Bright brass, original lacquer finish, 14" h (min) extending to 16 1/2", chain drive coarse focus and nose piece fine focus screw, two axis driven mechanical stage 2 1/2" sq with rotating aperture disc and 2" dual mirror below. The stand is derived from Ross with the bar limb supporting the 7 3/4" long microscope tube. Included are 2 oculars, objective with triple button lenses (achromatic?), live box, paired Nicol prisms, stage forceps, stage condenser, and fitting and lens for conversion to a simple microscope. Original dovetailed mahogany case 7 1/2" x 6" x 10 3/4" h. Case in very good, microscope in very fine condition.
Although unsigned, this is an example of the early work of William Ladd who seems to have been the first instrument maker to use a chronometer fusee chain to control the large scale focusing motions of a microscope...The R.M.S. in their catalog describing the Ladd microscope in their collection notes, "Motion is imparted to the body not by rackwork but by a chain coiling round a spindle controlled by a milled head, giving a remarkable smoothness of motion and freedom from backlash." In his later work, Ladd developed unique structures too, but here he has worked with a standard design giving further evidence that this is an early instrument produced to establish a priority for his chain drive."
The cosmetic condition of the scope and case overall is very nice, minor spotting and scratches on the lacquer finish. The fusee chain drive is intact and functions, although occasionally wants to slip. The slide lens attachment is cracked. There is a crack in the back of the case, and the double sided mirror is delaminating. There is evidence that the mirror attachment point has been repaired with solder at some point. Overall, this is a fine piece, and particularly unique with the inscription from the Armagh Historical Society of Armagh, Ireland.
