Slide Rule Lecture

Went to an interesting talk stemming from lockdown (when he really started collecting in earnest) where a former ICI executive showed off his extensive slide rule collection and demonstrated to the youngsters in the local university ChemSoc audience how to use a slide rule.

Presentation was a little odd using OHP slides rather than PPT.

He even had some "chemistry" slide rules that had atomic masses encoded on them and the ability to solve redox and stochiometric composition equations.

The one with chemical masses on must be incredibly rare. I saw one in the flesh at his talk but I can't find an example anywhere on the ISRM collection of circular slide rule.

The audience profile was very bimodal - students who had never even seen a slide rule before and friends and associates of the lecturer who had used them extensively early on in their own careers.

I learnt one new trick in the lecture (due to Newton) - how to solve a cubic polynomial equation using three identical slide rules equally spaced on a table and a straight edge - extremely cunning trick.

He had examples of ones used on the Manhattan project, Concorde design and his pride and joy was an 8" Gilson circular slide rule equivalent to a straight one 7' long! Identical to this one (possibly is this one)

Needs incredibly good eyesight to use it. He also had Fowlers pocket watch style slide rule where the winders move the verniers inside a glass fronted case (allegedly once belonging to J.J. Thompson).

This one would even be on topic here! And of course a classic linear workhorse the Picket S226

Apparently MIT and a couple of other top universities have started running freshman slide rule courses to help students grasp the idea of "right order of magnitude" in physical problems.

You can waste ages on the ISR museum site :

BTW one of this guy's other claims to fame was that he solved the problem of polycarbonate fighter aircraft canopies crazing due to UV exposure. The bad news is that what he did is still a classified secret.