From the 1570s, a new literary genre, the théâtres de machines, spread in Europe. These in-folio books contain commented plates featuring mechanical inventions by their authors, technicians, engineers, and mathematicians. Since then, the variety and diversity of the machines displayed in the théâtres have fascinated the reader, ensuring the genre’s popularity. For a long time these plates have been the main source for studying practical mechanics before the Scientific Revolution. Scholars have considered them as trusty sources for dating the inventions, as well for gauging progress in mastering technical efficiency and applying mathematical and mechanical sciences. As the théâtres, however, did not provide a satisfactory answer to such questions, a certain deception has arisen and such texts came to be seen almost under a negative light. This paper focuses on the hopes and delusions born out of this use of the théâtres as sources in the history of technology. It follows there different levels of analysis: that, descriptive, of the genre, that of the historiographical balance that is brought about by the criticisms levied at the théâtres, and finally the clarifying elements that their authors themselves provided, including under the iconical angle.This critical effort tries to free the scholarship on the théâtres from the burden of conventional wisdom and provide new forms for analyzing them.