Throughout the Peninsular war the services of the corps were invaluable; in sap, battery, and trench work, in the making of fascines and gabions, in repairing broken batteries and damaged embrasures, in constructing flying bridges over the Guadiana, the Artificer vied with the regular engineers. Major Pasley, R.E., on his appointment to the Plymouth station, began regularly to practise his men in sapping and mining. He was one of those officers who took pains to improve the military appearance and efficiency of his men, and to make them useful, either for home or foreign employments. He is believed to have been the first officer who represented the advantage of training the corps in the construction of military field-work. After the failure at Badajoz (1811) the necessity of this measure was strongly advocated by the war officers. Then it was recommended to form a corps under the title of Royal Sappers and Miners, to be composed of six companies, chosen from the Royal Military Artificers, which, after receiving some instruction in the art, was to be sent to the Peninsula to aid the troops in their future siege operations. In April, 1812, a warrant was issued for the formation of an establishment for instructing the corps in military field-work. Chatham was selected as the most suitable place for carrying out the royal orders, and Major Pasley was appointed director of the establishment. Uniting great zeal and unwearied perseverance with good talents and judgment, Major Pasley succeeded in extending the course of instructions far beyond the limits originally assigned, and he not only filled the ranks of the corps with good scholars, good surveyors, and good draughtsmen, but enabled many, after quitting this service, to occupy, with ability and credit, situations of considerable importance in civil life. At Ciudad Rodrigo and Badajoz, and other places made famous in the Peninsular war, the Military Artificers won the praise of Wellington, conducting themselves with the greatest gallantry and coolness. On the 5th of March, 1813, the title of the corps was changed from that of Royal Military Artificers to that of Royal Sappers and Miners. A change of equipment was also introduced. In this respect many irregularities had crept in, the members of the corps in various parts of the world being variously armed, rather to suit their own fancy than to meet the exigencies of the work. Uniformity in the matter was of great importance, and this was gradually and effectually introduced.