picture4

Title:Transactions of the Society of Motion Picture Engineers (1921)
Author: Internet Archive Book Images
Source: https://www.flickr.com/photos/internetarchivebookimages/14785033035/ Source book page: https://archive.org/stream/transactionsofso12soci_0/transactionsofso12soci_0#page/n160/mode/1up
License: This image was taken from Flickr’s The CommonsThe uploading organization may have various reasons for determining that no known copyright restrictions exist