Grandad's job role

I'm trying to find out what kind of job my grandad did when he was younger. This is all I have from the 1939 England and Wales Register - Assistant Compiling Stearn P Stat. He was 16 at the time. Sorry it's a bit vague! He lived in Coventry. Thanks for any help! Edited by member, 9th May 2018 5:48 pm

It looks like it might be "steam" not "stearn" - but it doesn't help Perhaps he compiled steam pressure statistics Do you know where he worked?