Looks to me like it is a Lawrence/Engineering Instruments slide rule.

Jim Clark

=======================================

--- In sliderule@yahoogroups.com, François Boucher
<francois.boucher@c...> wrote:

> Another view of Crick's slide rule:
>
> http://www.blc.arizona.edu/INTERACTIVE/DNA3/watsoncrick.gif
>
> François
> ______
> http://www.boucher.cc/