title: Past tense--future imperfect.
authors.forename: R
authors.initials: R
authors.lastname: Gregory
mesh_terms: D001256:Astronomy / Q000266:history*; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006113:United Kingdom