In 1827 Knight was forced to give up publishing, and became the superintendent of the publications of the Society for the Diffusion of Useful Knowledge, for which he projected and edited "The British Almanack and Companion", begun in 1828. In 1829 he resumed business on his own account with the publication of "The Library of Entertaining Knowledge", writing several volumes of the series himself. In 1832 and 1833 he started "The Penny Magazine" and "The Penny Cyclopaedia", both of which had a large circulation. "The Penny Cyclopaedia", as a result of the heavy excise duty, was only completed in 1844 at a financial loss.