NMS


 

Record

Contact goniometer

< 8 of 17 > Back

made in France

Contact goniometer
Add to album

A contact goniometer is a device for measuring the inter-facial angles of crystals. (Crystals of the same material always have the same angles between crystal faces.) This example was made in France in the early 19th century.

The instrument (pictured in its leather case) consists of a brass protractor with adjustable steel arms to fit the angle between crystal faces, held together by a screw. The base of the protractor is engraved 'Pixii Neveu et Suc.eur de Dumotiez a Paris'.

French crystallographer, Rene Just Haiiy (1743-1822) proposed that the external appearance of the crystal's facets was a reflection of its internal structure. He used a contact goniometer of this type.

Record details

To search on related items, click any underlined text below.


< 8 of 17 > Back