Technical Comments Mosaic Unit Ruler By Robert L. Mills See allHide authors and affiliations Science 13 Dec 1968:Vol. 162, Issue 3859, pp. 1306DOI: 10.1126/science.162.3859.1306 Robert L. Mills 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.