Carruthers in office with Signal Sergeant

Photo of Major Bruce Carruthers at his desk. Also present is a Signal Sergeant (unnamed), a signalling telescope, a heliograph and a Begbie lamp.

So, when was this photo taken? Carruthers is a Major so it's after March 1904. There is a calendar on the wall showing a year of 190? and this makes sense since Carruthers died in 1910. It also shows a month with 31 days and starting on a Wednesday if the calendar follows the typical Sunday to Saturday layout. So, between March 1904 and December 1909 the following months meet that criteria: March 1905, August 1906, May 1907, January and July 1908 and finally, December 1909. Assuming the calendar was on the right month, it's down to one of those six!

Credit: Military Communications and Electronics Museum Archives