Hydrometer, Twaddle No 1, Range 0-24o, 160mm Long

Hydrometer, Twaddle No 2, Range 24-48o, 160mm Long
Hydrometer, Twaddle No 3, Range 48-74o, 160mm Long
Hydrometer, Twaddle No 4, Range 78-102o, 160mm Long
Hydrometer, Twaddle No 5, Range 102-138o, 160mm Long
Hydrometer, Twaddle No 6, Range 138-170o, 160mm Long