LettersDiscussion and Correspondence AERIAL OBSERVATION OF PHYSIOGRAPHIC FEATURES By Douglas Johnson See allHide authors and affiliations Science 04 Nov 1921:Vol. 54, Issue 1401, pp. 435-436DOI: 10.1126/science.54.1401.435-a Douglas JohnsonFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears above.