Master-at-Arms 1908 1909 Khaki Scout badge
The Master-at-arms badge could have been worn by first and second class scouts as well as scout masters. This badge was introduced in 1909.
According to Scouting for Boys 1909
This badge was worn on the lower part of your right arm, starting from the cuff upwards. Badges were positioned in order of achievement.. If you were a Scout Master the badge was worn on the left of your hat / Cap.
To earn this badge you had to achieve
the following.
Become Proficient in three out of these six subjects; Single Stick, Boxing, Ju-Jitsu, Wrestling, Quarter Staff, and Fencing.