The discovery in the Society's library of James Theobald's manuscript history of the foundation of the Society of Arts is a satisfying conclusion to a search which has been pursued since the early years of the twentieth century. This search had been stimulated by a statement in a rare eighteenth-century tract entitled: A Concise Account of the Rise, Progress, and Present State of the Society For the Encouragement of Arts, Manufactures and Commerce Instituted at London, Anno. MDCCLIV. Compiled from the Original Papers of the first Promoters of the plan; and from other authentic records. By a Member of the said Society. London: Printed for the AUTHOR, and sold by S Hooper, at Caesar's Head, the corner of the New Church in the Strand. MDCCLXIII. The author, who has been identified as Thomas Mortimer, wrote in his introduction:
Several particulars relative to the origin of this Society having been lost to the public for many years, it may not be improper to mention, least the authenticity of the following narrative should be disputed, that the substance of it was drawn up by the late James Theobald, Esq; one of the first Vice Presidents of the Society, from a verbal relation given him by Mr Shipley; and that the same gentleman afterwards presented a copy of that relation to the Antiquarian Society.