I got the slide rule during my time as a "slide rule collecting nut", never expecting I would ever identify a previous owner from the name embossed on the leather case. It looked like 'Biro' but way too early, so I think a 303 round was used.

So here he is at the Haworth Historical Research Laboratory, University of Manchester. Captain Philip Theodore Haworth RFA, born 25 April 1897, wounded 28 April 1917, died of wounds 3 May 1917. His mother had died the day after his birth. "In thy presence is fullness of joy".