David's calculating sticks: collection of slide rules

I've mailed him about the E-6B flight computer missing in his database and collection. The E-6B is still in production and widely used, not only for pilot training. I'm using it for sailing, and have not yet found any other intuitive modern calculator for drift/vector calculations(1). Smartphones have big problems with sunlight, and with wet fingers. Not to talk about the problem that most smartphones dislike water.

(1) Lets say your boat runs 7 knots, you have a current of 2 knots from 123⁰. What course do you talk to reach a target 321⁰. Those type of calculations are trivial on the backside of an E-6B. And the frontside contains all those practical conversations between imperial, nautical and metric systems, e.g. whats the weight of 10 gallons of fuel in metric tons would be a question that is trivial to answer on the frontside.

I didn't see any Keuffel and Esser slide rules listed. They were one of the leading brands back in the day. Here's a link for those who are interested in exploring more slide rules:

http://www.sphere.bc.ca/test/ke-sliderule.html

About a month ago I got an old slide rule from my Grandfather that he'd used in engineering school. It's a little thing, but it's amazing to hold something that was some decades ago the standard tool for certain types of computation. It really puts into perspective just how far we've all come in such a short time.

I still have the one I got for high school chemistry.

A bit of trivia: slide rules survived into the 1980s and maybe beyond as "proportion wheels" used by graphic artists to calculate the reductions needed on images. I'm sure that most of these folks had no idea that these were essentially circular slide rules.