An ache in the tuppence.
This is a story about a very small act, the resound of which will be shown scientifically to be real and large in appearance and effect.
It is entitled ‘the ache of the tuppence’ or something like that because the tuppence (two pence piece) is both large and small. Large coin, small in value. It is a meaningful coin to a child, and useful to an adult.