Accession No

6697

Brief Description

achromatic compound microscope, No. 1 Stand, by Powell and Lealand, English, 1884

Origin

England; London; 170 Euston Road

Maker

Powell and Lealand

Class

microscopes

Earliest Date

1884

Latest Date

1884

Inscription Date

Material

metal (brass); glass; wood; felt; silk; paper

Dimensions

555mm (height) x 273mm (width) x 333mm (depth)

Special Collection

Michael J. Clark Bequest

Provenance

Inscription

POWELL & LEALAND
170 EUSTON ROAD
LONDON.

1884

Description Notes

Compound microscope, No. 1 Stand, by Powell & Lealand, English, 1884.

Microscope and comprehensive box set of accessories are contained in a purpose-made varnished wood box, with lock and key, felt-lined interior modifications, front-opening side-hinging lid, and folding brass handle on top.

Microscope sits on a solid brass tripod with rectangular feet. At base of pillar, a swivelling planoconcave mirror in a gimbal, on a double-pivoting arm that can also be raised or lowered manually along the pillar. Below the stage is a short cylindrical tube in a platform, which can accommodate various included accessories (e.g. condenser or illuminator): this platform can be moved from side to side, front to back, and up and down (fine movement), using the three surrounding milled knobs; the fourth milled knob, at an angle to the platform, rotates the cylindrical tube. A fifth milled knob that sits behind the platform provides a coarser height adjustment.

The stage itself is Turrell-type, with a slide holding mechanism consisting of two plates; one plate is fixed, and the other slides along a track in order to adjust for slide height; the tiny milled screw allows for movement of the L-shaped bracket to adjust for slide width. Spring-loaded bars at the end of the movable plate maintain pressure on the slide being held. The stage can be moved forward and backward using two concentric milled knobs on either side; the inner concentric milled knob on one side allows the stage to be moved side to side. For both kinds of movement, a scale is provided at the rear of the stage, labelled every 10 units. The stage can be rotated 360 degrees using a milled knob that protrudes from the bottom of the stage at an angle; a pointer on the stage indicates position on a circular scale from 0-360 in half-degree increments, labelled every ten degrees.

At the top of the pillar is an arm that holds the body tube; the height of the body tube is adjusted coarsely by large concentric milled knobs on either side of the pillar, and finely by a milled knob on top of the pillar with a brass pointer and scale. The set contains both a monocular and binocular body tube; the binocular tube has a milled knob which allows the height of the eyepieces to be adjusted; the monocular tube has a drawtube graduated with a scale.

All accessories are contained in a purpose-made box with hinging lid, except for a large bullseye condenser on a stand which sits in the same box as the microscope and binocular body tube. The box is of varnished wood and has a lock mechanism (key not extant). Accessories:

Eight eyepieces of varying strengths
Eyepiece with brass micrometer
Eight objective lenses of various strengths (note: not all are Powell & Lealand; e.g. one is signed "Perken, Son & Rayment")
Polarizing eyepiece? (black at eye end but with a prism)
Two small polarizing accessories (small cylinders near centre of box)
Large polarizing eyepiece
Parabolic illuminator
Long brass tube (eyepiece insert?)
Two patch stops or substage condensers? (brass lenses with adjustable apertures)
Stage forceps
Flat brass slide with crank (function unclear)
Reflector on ball joint at end of arm, with semi-circular brass case
One brass livebox
Probe on brass stand
Brass accessory resembling binoculars with movable eyepiece, function unclear, may be an accessory for the binocular body tube?
Three darkwells of varying strengths
Two prisms, each in a maroon leather box within a felt-lined box with thin wooden lid and ivory knob; prisms are labelled "Powell & Lealand No.125 Patent" and "For Low Powers and Opaque Objects"
One lieberkuhn
Two empty brass cylindrical boxes (in upper left corner -- one may have contained cover slips and other an objective lens?)

In lid:
Brass frog plate
Black card box with various coloured discs
Blue card box with green ribbon, for frog plate
Long probe (?) made of light metal (possibly not contemporary)
Green card box with two slides
Thick pane of glass with etched grid, rows numbered 1-12
Brass tweezers
Ivory-handled probe

References

Events