Andrew Nethercott Antiques has dated this piece to the 1890s.
The one inch diameter, engine engraved silver dial with blued steel pointer marked
MAYER & MELTZER LONDON PATENT
Hand painted red and black scales in Fahrenheit and Centigrade, 98.4 F marked with a black arrow

Unmarked solid sterling silver pocket watch style case with original fancy chain and ring.
In good working order, quickly responds and is accurate.
In very good sound condition, noting insignificant dents to the case edge
Case diameter 28mm gross weight 11.8 grams
Similar instruments were also marked by S.Maw and Pillischer
Andrew Nethercott Antiques has dated this piece to the 1890s.
Works of art, collectables, scientific and decorative antiques from the 17th - 20th century
You can view the stock and full dealer information on the Andrew Nethercott Antiques Profile Page