pamphlets, the libelles "slandered the court, the Church, the aristocracy, the academies, the salons, everything elevated and respectable, including the monarchy itself". Le Gazetier cuirassé by Charles Théveneau de Morande was a prototype of the genre. It was Grub Street literature that was most read by the public during the Enlightenment. According to Darnton, more importantly the Grub Street hacks inherited the "revolutionary spirit" once displayed by the philosophes and paved the way for the French Revolution by desacralizing figures of political, moral, and religious authority in France. Book industry The increased consumption of reading materials of all sorts was one of the key features of the "social" Enlightenment. Developments in the Industrial Revolution allowed consumer goods to be produced in greater quantities at lower prices, encouraging the spread of books, pamphlets, newspapers, and journals – "media of the transmission of ideas and attitudes". Commercial development likewise increased the demand for information, along with rising populations and increased urbanisation. However, demand for reading material extended outside of the realm of the commercial and outside the realm of the upper and middle classes, as evidenced by the bibliothèque bleue. Literacy rates are difficult to gauge, but in France the rates doubled over the course of the 18th century. Reflecting the decreasing influence of religion, the number of books about science and art published in Paris doubled from 1720 to 1780, while the number of books about religion dropped to just one-tenth of the total. Reading underwent serious changes in the 18th century. In particular, Rolf Engelsing has argued for the existence of a reading revolution. Until 1750, reading was done intensively: people tended to own a small number of books and read them repeatedly, often to small audience. After 1750, people began to read "extensively", finding as many books as they could, increasingly reading them alone. This is supported by increasing literacy rates, particularly among women. The vast majority of the reading public could not afford to own a private library, and while most of the state-run "universal libraries" set up in the 17th and 18th centuries were open to the public, they were not the only sources of reading material. On one end of the spectrum was the bibliothèque bleue, a collection of cheaply produced books published in Troyes, France. Intended for a largely rural and semi-literate audience these books included almanacs, retellings of medieval romances and condensed versions of