LettersDiscussion and Correspondence LONGITUDINAL ELECTROMAGNETIC FORCES By Carl Hering See allHide authors and affiliations Science 18 Nov 1921:Vol. 54, Issue 1403, pp. 492-493DOI: 10.1126/science.54.1403.492 Carl Hering Find 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.