Feature [Photograph]: Diatoms Test Lens Quality Share this:FacebookTwitterPocketRedditPrint By Science News Magazine Issue: Vol. 36 No. #27, December 30, 1939 This article is only available to Science News subscribers. Subscribers, enter your e-mail address to access our archives. Client key* E-mail* Log in Not a subscriber? Science News is a nonprofit. Support us by subscribing now. Subscribe