There is no direct evidence to support our belief that it was during the brief period after Castro returned, probably late in 1590, and relieved Cobo of his executive responsibilities, and June 1592 when he left for Japan, that Cobo began intensive plans for the production of bilingual texts. His recorded interest in such books, his influence with the Chinese, his energy and his own linguistic aptitude would naturally have stimulated him to undertake the task. Whether he actually began work on the blocks from which the books were printed, or merely suggested the feasibility of the idea, we do not know, but we feel sure that Juan Cobo was the father of the production of books in the Philippines. There is no need here to go into the history of printing in China; the method used there and its antiquity have been fully described by others. [121] That there were Chinese in Manila who understood this age-old process would seem obvious from the reports of skilled craftsmen whose presence was noted by all the writers of the period. We have already quoted a reference to Juan Cobo's teaching them European trades, and Salazar in his already cited letter speaks of them further: "They are so skillful and clever, that, as soon as they see any object made by a Spanish workman, they reproduce it with exactness. What arouses my wonder most is, that when I arrived no Sangley knew how to paint anything; but now they have so perfected themselves in this art that they have produced marvelous works with both the brush and the chisel.... What has pleased all of us here has been the arrival of a bookbinder from Mexico. He brought books with him, set up a bindery, and hired a Sangley who had offered his services to him. The Sangley secretly, and without his master noticing it, watched how the latter bound books, and lo, in less than [lacuna in MS.] he left the house, saying that he wished to serve him no longer, and set up a similar shop." [122] To turn over a manuscript copy of a book to a Chinaman who had already some familiarity with the production of books in China, or who with a given text could carve the blocks according to tradition, was then not a matter of great difficulty. There were Chinese books which showed what the result would be; there were Spanish books, definitely some from Mexico, which provided samples of European characters and format. Who cut the blocks--that is exactly what Chinaman--we do not know, nor do we know who handled the presswork, but it is logical to assume that the whole process took place under the supervision of the fathers of San Gabriel, Juan Cobo if work had begun before 1592, and certainly Nieva and San Pedro Martyr. One further aide may have been the lay brother, Pedro Rodriguez, who had been sent to San Gabriel with Nieva, and who was a handyman or skilled mechanic, for Aduarte credits him with rebuilding and restoring the hospital.