There are many jigger sizes in operation today. A standard shot is either 25ml or 35ml. We include both in the package along with a 50ml.
Before 1963 it was not required by law to use a standard measurement for a drink. However, with the introduction of the Weights and Measurements Act in 1963, it legalized and formalized measurements for the general public - so as not to get short-changed by Publicans and bars!
Measurements that were introduced were:
1/4 gill (35.5 ml),
1/5 gill (28.4 ml)
1/6 gill (23.7 ml)
However they have now been replaced by 25ml and 35ml with Publicans/landlords being able to choose which measure they wish to give as a standard single shot (since 1985). 50ml and 70 are thus classed as 'doubles'.
Thimbles, Measure and Jiggers are all the same term. It is said the word 'Jigger' was first coined in 1836 in America referring to a 1.5 ounce shot-glass measure; being derived from the 1756 word 'Chigger' meaning "tiny mite or flea".