Herbert Smith Refractometer No. III

J H Steward, London


The Herbert Smith refractometer is used to measure the refractive index of gems. This helps to tell genuine gemstones from fakes.

In case with with chart of refractive indices for sodium light.
Please Note - The bottle shown in the photograph is not included.

Case 10x10x8cm

Late 19th century

Please Note: Bottle not included

Please Note: Bottle not included