Pair of bulbs after Violle

Jules-Louis Gabriel Violle, French physicist (1841-1923).
Two bulbs, consisting o thin sheet cooper, one in dull black on the outside, the other polished and gilt. Both bulbs are jet black internally. Each carries a thermometer divided in 1/5 Celcius.

Functioning:
Used for measuring the thermal radiation of the sun.

This instrument was made in Russia.

Data

Inventory Number: 

THE04

Date: 

1930 (c.)

Dimensions: 

Diameter : 12cm, Height : 47cm

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