My friend Catherine Hennessey is turning 80 years old this September. Catherine and I share an interesting age-related mathematical pattern: she was born in 1933, I was born in 1966, so when I was 33 years old, she was 66 years old. And when I was 44 years old, she was 77 years old. In 8 years, when she turns 88, I will turn 55. And in 19 years, when she turns 99, I will turn 66.

In any case, her 80th birthday is, among other things, an occasion to downsize, and as part of that effort she is holding a silent auction: it starts online right now, and continues on September 21, 2013 at her birthday party. I’ve just finished loading up all of the auction items and, if I don’t say so myself, there are some great bargains to be had.

I’m particularly fond of the Dominos and Rummoli collection, the Souris school desk, the old Stanley plane and the board of nautical knots. And, of course given my numerical fascinations, the PEI license plate from 1966.

Send all your friends to auction.catherinehennessey.com.