Page:De Vinne, Invention of Printing (1876).djvu/184

174 In spite of all these impediments, there was a slow but positive diffusion of knowledge among English people. How the knowledge was communicated is not clear, for notices of common schools in England, and indeed on the Continent, are infrequent and unsatisfactory. We have, however, some curious relics of the substitutes for books used by the people. One of them is the Horn-Book, by which the children were taught their letters and the Lord's Prayer. The engraving annexed represents a book that is of no earlier date than the reign of Charles I, but it is a trustworthy illustration of the construction, if not of the matter, of the horn-books in use in the fifteenth century. Another of these substitutes is the Clog, a rude contrivance for marking the order of coming days, which may be considered as the forerunner of the printed almanac.