The following is from Volume II of the Journal of Sieges by Major General Sir John Jones, RE, 346-348 in the Notes section of the volume. It is interesting from an organizational point of view.
‘After a perusal of the foregoing journals, and observing how very much the want of sappers and miners prejudiced every siege operation in Spain, it will be learnt with surprise that, during the whole war, from 1793 inclusive, England paid, fed, clothed, and lodged a very large body of engineers’ troops, legitimately sappers and miners.
These, however, being designated the Corps of Royal Military Artificers, and composed chiefly of mechanics, were considered as more immediately intended for permanent works; and the most limited number were reluctantly spared for field service, it being difficult to make it understood how mechanics could be required in any great number with an army.
Previously to 1807, the companies of Royal Miltiary Artificers were stationed independently of each other in particular garrisons; but in that year they were consolidated into a corps of 32 companies, of 126 rank and file each, and a regimental staff being appointed, a general system of drill, discipline, and organization was established. Each company had, however, only one officer, a sub-lieutenant, permanently attached to it, and was commanded for the moment by the senior captain of engineers who might happen to be placed on duty wherever the company might be; so that it was not infrequent for a company to be commanded by five or six captains in as many months.’
On the failure of the attack on Badajos, in 1811, the most pressing application was made, that half a dozen companies might be selected from the Royal Military Artificers to be formed into a body under the name Royal Sappers and Miners, that officers should be permanently attached to the companies so selected, and, after some instruction in their art, the six companies should be sent out to aid the troops in their future siege operations.
This application was repeated in the most forcible manner previously to the siege of Ciudad Rodrigo, and enabled General Mann, recently appointed Inspector-General of Fortifications, to procure the name of the whole Corps of Royal Military Artificers being changed to that of Royal Sappers and Miners.
This change of name operated like magic. Every one in an instant saw the propriety, nay, absolute necessity, of the whole body being instructed in sapping and mining, and an institution was created by Lord Mulgrave for that purpose at Chatham.
The formation of the Institution at Chatham was followed by another simple change of equal or even paramount utility, viz., obliging the officers of engineers, whilst amongst a stated number of the junior of the several ranks of Second Captain, First Lieutenant, and Second Lieutenant, to be for that period actually the regimental officers of the companies of sappers.
This measure, by linking together the men and officers, and closely connecting their mutual interests, gave discipline and pride to the soldier, whilst it conferred the utmost benefit on the engineers, by obliging each officer, during three periods of his military service, to perform regimental duty, and to acquire due experience in the drill, discipline, and interior economy of troops. On the strict and impartial observance of this role, and making every officer take his chance of the station and service on which his company may be employed during the whole period of his being on the list for regimental duty, the efficiency of the Corps of Sappers and Miners, and the zeal and assiduity of the officers, will every mainly depend. Neither commanding influence nor petty favoritism should be allowed to interfere with this regulation.
The company at San Sebastien was the first which entered the field after these great changes, and the men were found useful and intelligent…it may be observed that a most happy selection was made of an officer as Director of the Institution at Chatham, in Lieutenant-Colonel Pasley, who, uniting great zeal and unwearied perserverence to good talents, has succeeded in extending the course of instruction far beyond the original objects of the institution, and has filled the ranks of the sappers with good scholars, good surveyors, and good draftsmen…’