Accession No

4051

Brief Description

spherometer, by Cambridge Scientific Instrument Company Ltd., English, 1902

Origin

England; Cambridge

Maker

Cambridge Scientific Instrument Company Ltd.

Class

weights & measures; metrology

Earliest Date

1902

Latest Date

1902

Inscription Date

Material

metal (brass); wood; cloth (felt); hide (leather); glass

Dimensions

box length 155mm; depth 120mm; height 145mm

Special Collection

Cambridge Instrument Company Collection

Provenance

Donated by the Cambridge Instrument Company.

Inscription

‘CAMBRIDGE
SCIENTIFIC INSTRUMENT CO LTD
No 1429’ (disc of spherometer)
‘SCIENTIFIC
INSTRUMENT CO., LTD
CAMBRIDGE’ (plate in lid of box)

Description Notes

Circular horizontal brass disc with control screw axis supported by a metal support with three legs which form an equilateral triangle. Micrometer screw works through centre of disc and form a central leg with a point. Just below the knurled knob is a vertical disc with cog graduated 0 - 9 round its circumference and with vertical pointer. Large brass disc is marked into 100 divisions and calibrated 0 - 9. The large disc turns one complete revolution for 1 division on the vertical disc. One of the feet carries a support with a spring lever which allows the micrometer screw to be turned clockwise only by sitting in the teeth on the edge of the disc. Second leg carries glass prism and support. Third leg supports a spring lever attached to the micrometer screw which moves the horizontal disc on half a graduated at a time.
Fitted wooden case lined with green felt; brass hinges and hook fastener; leather carrying handle.

Condition

References

Events