This is a brass binocular dissecting microscope with a copper nameplate screwed on front showing: “Swift & Son”. Backing this nameplate is a rectangular mirror to reflect the image from a two-part image splitting prism to the angled binocular tubes. The prism delivers images of the sample separated by a fixed parallax. The eyetubes are attached to the front of a 9cm horizontal arm, which is connected by a screw to a vertical 2cm wide pillar. There are two Ramsden eyepieces. Interestingly, this microscope has no adjustment for interpupillary distance.

Focusing is by a double milled-head pinion attached to the back of the pillar. The black glass stage plate (11 x 9.8cm) has a central 2.5cm dia. opening for the condenser, below which is a revolving disc of five apertures (one of which is a darkfield aperture). The gimbaled mirror is attached to a cylinder which screws into the underside of the stage plate. Two brass legs support the front and one curved, cast-iron leg supports the rear. On each side of the stage plate are arm rests, curved to fit the forearm and covered with leather (now shrunken and dried from age and use). The one 2/3" objective lens at the nosepiece is engraved “J. Swift & Son, London WC.” Imaging is poor due to poor illumination. The overall height is approximately 32cm.

Hogg (1898) described a Swift-Stephenson microscope identical to this instrument in The Microscope. There is a similar instrument (#191) in the RMS Collection (as described by Turner).

Featured 09/2007