Many thanks to all of you for sexagesimal. Since I do much of this X-word on educated guesswork, I'd tried various misspelled versions of this so am delighted not to have been too far off the mark!
I rely on Google as well, Sarumite! Not to mention a hard core of exceptional AB'ers - yourself, Aquagility, Argee, Pauline Ward, Jim Jools. I assuage my guilt over this because I do the X-word for interest, generally at about 2 in the morning and often on Sunday night, not for the prize - have long given up sending them in!