At this period, the survey companies were generally employed on confidential duties and dispersed over a vast extent of country; while most of the non-commissioned officers and many of the privates were in charge of parties, performing duties which required the exercise of great judgment and discretion. The additional permanent rank was granted to invest the non-commissioned officers with more weight and authority among their parties, and to supersede recourse to the anomalous expedient of supernumerary promotion. The same reason which diminished the civil strength of the national survey, induced a disposition among the best soldiers of the corps on that duty to purchase their discharge. Several quitted during the tithe survey mania,[355] and the vacancies in the three companies by this and other means, showed that encouragement was wanted to influence them to continue in the service. To afford this, Colonel Colby obtained the power on the 16th August, 1839, to award working pay to the royal sappers and miners under his command, to the maximum of 3_s._ a-day, according to individual merit and exertion, in addition to their regimental pay and allowances. This, however, was not regarded by Colonel Colby as sufficient to meet the emergency. It was hopeless for him to compete in pecuniary payments with the expensive parochial surveys of England, and he therefore asked for two military rewards in addition to the augmented working pay. These were the permanent rank and pay of one sergeant-major and one quartermaster-sergeant. But the Master-General did not view the matter in the same light as the Colonel, and only consented to the appointment of an acting sergeant-major with the pay of the rank. This Colonel Colby did not consider an adequate distinction, and he never availed himself of it.[356] ----- Footnote 355: Several of those who quitted obtained ready employment on these surveys, and their maps in all cases were of the first class. Mr. Chadwick, in his report to the Poor-Law Commissioners, compared the “non-efficiency of persons appointed to make surveys under the Tithe Commutation and Parochial Assessment Acts, with those executed by privates and non-commissioned officers of the sappers and miners. Out of 1,700 first-class maps, not more than one-half displayed qualifications for the execution of public surveys without superintendence. Amongst the most satisfactory surveys were those executed by a retired sergeant of the corps”—Alexander Doull.—‘British Almanac and Companion,’ 1843, p. 38. Footnote 356: