Not worth a tinker's dam

 

I had always assumed this phrase was 'Not worth a tinker's damn' - i.e., not worth so much as the swear word from a tinker. Apparently the dam doesn't have an 'n' at the end.

Tinkers - not to be confused with true Romanies - were a gypsy like people who travelled from place to place and were known for mending metal goods like pots and pans. (I use the past tense because tinkers as we knew them in our youth no longer seem to exist in this society where everything is thrown away and replaced rather than mended.)

The dam was a plug made of bread which was used to fill the hole in the kettle or whatever was being mended. The solder would then be held in place by the dam while it set. The dam itself was, of course, worthless.

Interestingly I'm not the only person who has failed to appreciate the origin of the phrase because I have also heard it expressed as 'Not worth a tinker's cuss'.