Maker's Name: 
Griffin, London
Where made: 
38 × 0.6 × 0.6 cm

Mercury in glass themometer with a range from 49 to +105 C, with 1/10 C graduations.

It is marked Griffin, London "Jena Normal' 16 III Glass 23027 No. 13

Jena Normal Glass was developed by Otto Schott especially for thermometers as it was found that ordinary soda glass softened enough even at moderate temperatures that the volume of the bulb increased permanently, depressing the readings. It is also more resistant to the actions of acids and alkalies.