There was no longer any obstacle in Prescott's way, and he set to work with an interest which grew as the richness of the material revealed itself. There came to him from Madrid, books, manuscripts, copies of official documents, and all the _apparatus criticus_ which even the most exacting scholar could require. The distinguished historian, Navarrete, placed his entire collection of manuscripts relating to Mexico and Peru at the disposal of his American _confrère_. The Spanish Academy let him have copies of the collections made by Muñoz and by Vargas y Ponce--a matter of some five thousand pages. Prescott's friend, Señor Calderon, who at this time was Spanish Minister to Mexico, aided him in gathering materials relating to the early Aztec civilisation. Don Pascual de Gayangos, who had written the favourable notice in the _Edinburgh Review_, delved among the documents in the British Museum on behalf of Prescott, and caused copies to be made of whatever seemed to bear upon the Mexican conquest. A year or two later, he even sent to Prescott the whole of his own collection of manuscripts. In Spain very valuable assistance was given by Mr. A. H. Everett, at that time American Minister to the Spanish court, and by his first Secretary of Legation, the South Carolinian who had taken his entrance examination to Harvard in Prescott's company, and who throughout his college life had been a close and valued friend. A special agent, Dr. Lembke,[11] was also employed, and he gave a good part of his time to rummaging among the archives and libraries. Prescott's authorship of _Ferdinand and Isabella_, however, was the real touchstone which opened all doors to him, and enlisted in his service enthusiastic purveyors of material in every quarter. In Spain especially, the prestige of his name was very great; and more than one traveller from Boston received distinguished courtesies in that country as being the _conciudadano_ of the American historian. Mr. Edward Everett Hale, whose acquaintance with Prescott was very slight, relates an experience which is quite illustrative:--