Long ago, the Ada's Technical Books space on 15th Ave used to be a used bookstore called Horizon Books. In 2009, Horizon moved to an underground space on 10th Avenue between Pike and Pine. And now, this message from Horizon bookseller Don Glover started circulating on social media:

Fellow booksellers, friends, and long time customers, It's come that time, to finally close the shutters, and hinge the doors of Horizon Books, but it's been a grand run these past 47 years. Come join us for one last jaunt - 50% off sale through July, with deeper discounts through August, and always a deal to be made if you're loading up. 1423 10th Ave Studio A - Between Pike and Union, down the loading ramp, in the basement level, open most days 12pm-5pm. Feel free and give Don a ring at 206 523 4217, and stop on in.

Horizon is one of those bookstores that will horrify people with OCD tendencies: if the shelves were ever alphabetized, you'd never know it now. But Glover knows his stock well, and if you're looking for a particular subject, odds are good he can help you find it. It's always sad when an eccentric bookstore closes, but I don't want to get too maudlin over Horizon closing: 50 years of bookselling is quite an achievement. Go enjoy what you've got while it's still there.