The report of the committee which had been appointed at Tankerville's suggestion is silent on the question of the opening and detention of letters. It had been provided by the act of 1711 that no letters should be opened or detained except under protection of an express warrant from one of the Secretaries of State. The Royal Commission of 1844 reported that from 1712 to 1798, the number of warrants so issued was 101, excluding those which were well known or easily ascertained. The Secretary of State for the Inland Department issued most of them. From 1798 to 1844, 372 warrants were issued, many of them being general warrants and often for very trivial causes. At the trial of Bishop Atterbury, the principal witnesses against him were Post Office clerks, who had opened and copied letters to and from him, under warrant from one of the Secretaries.[184] [184] _Rep. Com._, 1844, xiv, pp. 9-11; app., p. 105 (78); app., p. 107 (79); app., p. 111 (83). In addition to this regular method for intercepting letters, a particular department had been in existence for some time with no other duties than to examine letters. Strictly speaking it had nothing to do with the Post Office and was supported entirely from the "Secret Service Fund." The truth about it came out in the examination of the conduct of Sir Robert Walpole by the "Committee of Secrecy." From 1732 to 1742, £45,675 had been spent upon this department. It had originated in 1718 and the expenses for that year were only £446, but by 1742 they had increased more than tenfold. The Secretary of the Post Office in giving his evidence before the committee, said that this office received instructions from the Secretaries of State and reported to them. The working force consisted of a chief decipherer, assisted by his son and three other decipherers, five clerks, the Controller of the Foreign Office, a doorkeeper and a former alphabet keeper. Either considerable business was transacted there or it was a retreat for useless officials.[185] [185] _Rep. Com_., 1844, xiv, app., p. 112 (84); _Cal. T. B. & P_., 1742-45, p. 669. An account is given in Howell's "State Trials" of the trial of Hensey and of the practice then in vogue for finding treasonable correspondence. His letters were handed over for investigation to the Secretary of State by a Post Office clerk. This clerk in giving his evidence said that when war was declared against any nation, the Postmasters-General issued orders at once to stop all suspected letters. These orders were given to all the Post Office clerks and letter carriers. Such instructions can only be justified as a war measure, for the act of 1711 had provided that no letter should be detained or opened unless by express warrant from one of the Secretaries of State for every such detention or opening.[186] [186] _Rep. Com_., 1844, xiv, app., p. 112 (85); Howell, _State Trials_, xix, col. 1369. This was in 1758.