I know there is an intense amount of speculation about what goes on a slide rule convention. Now you know. It isn't really a convention - it is the West Coast Meeting of the Oughtred society. oughtred.org
There is a short business meeting but mostly it is about showing off new additions to your collection and buying and selling slide rules. Here I'm looking over another collector's rules.
I was not the youngest person there - believe it or not. I was pretty close, though.
It is a great opportunity to see things you likely will see nowhere else.
Bob is a legendary collector. He invited the group to his house for dessert after dinner at another collector's home. Driving down the street you would never imagine his home filled with 17 century mathematics books and an unparalleled collection of slide rules. Those ten rules under his name card might sell on eBay for $4000 or more. All quite rare.
Here Conrad looks over my display.
The meeting was held at the Computer History Museum in Mountain View, CA. This is serial number 2 of a Babbage Difference Engine. It was designed in the early 1800s to calculate log tables. It was finally built a few years ago under the patronage of a Microsoft executive. Lots of interesting stuff there. I recommend it for the technology inclined.
This is the back side. The museum is closed for the month of July for a major exhibit installation.