Accession No

3480

Brief Description

refracting telescope, telescopic rangefinder, by Etienne Lenoir, French, 1800 (c)

Origin

France; Paris

Maker

Lenoir, Etienne

Class

astronomy; optical

Earliest Date

1800

Latest Date

1800

Inscription Date

Material

metal (brass); stone (crystal); glass

Dimensions

length 429mm; maximum diameter 48mm

Special Collection

Provenance

Purchased from Tesseract, Hastings-on-Hudson, New York, USA, 1986.

Inscription

‘Lenoir’ (near base of scale, on tube)

Description Notes

Refracting telescope, telescopic rangefinder, Ettiene Lenoir, French, circa 1800.

Single draw brass refractor. Within the tube is a doubly refracting crystal prism, whose position can be adjusted by a handle, with a vernier, moving along a linear scale indicating angles and divided to 10 seconds of arc. The position where the two images of an object just touch indicates its apparent angular diameter, which yields a measure of distance for an object of known size. Lens cover.

Condition: fair; complete.

References

Events