SUPERNUMERARY STAFF
The following information is taken from The History of the Corps of Royal Engineers, Volume IV, pages 176 and 177:
There were two groups of Warrant Officers and Non-Commissioned Officers in the Royal Engineers that assisted the Officers in many ways. One of these groups was called the Regimental Staff and the other came under the general name of Supernumerary Staff.
"The Supernumerary Staff included several distinct classes; one of the first to be formed, which dates from about 1870, was that of Engineer Clerks and Draughtsmen and this group developed in several ways until there were Engineer Clerks for duty at the War Office, for Regimental work at the depots, Engineer Clerks and Draughtsmen for Engineer services and for what was called Regular and Militia duties at the headquarters of the units of Engineer Militia."
"Engineer Clerks and Draughtsmen were appointed from men of good education in the ranks of the Corps and, after a period of probation, they were appointed Sergeants on the Supernumerary Staff, R.E. They were promoted to the rank of Company Sergeant Major after three years' service as Clerks and to Quartermaster Sergeant after six years, and then by selection to fill vacancies on an establishment of Sergeant-Major Clerks."
"There was a special list for the probationers, who were termed Temporary Engineer Clerks and Draughtsmen and, if not of higher rank, were appointed Lance Corporals. They were excused all Regimental duties and were, for all practical purposes, part of the permanent staff. In 1907 this class of temporary clerks was abolished and the work was done by NCOs or Sappers drawn as required from the R.E. units at the station; at the same time 'Clerk' was included among the authorized trades."