author
Known today mostly from a handful of hard-to-find listings, this little-documented writer appears to be associated with Urban Climates and with a Project Gutenberg entry for Esperanto: Hearings before the Committee on Education. Very little verified biographical information seems to be available online, which gives the name an intriguing, archival feel.

by Richard Bartholdt, A. Christen
Reliable public information about this author is extremely limited. A book listing on ThriftBooks credits A. Christen as the author of Urban Climates, while Project Gutenberg lists an A. Christen in connection with Esperanto: Hearings before the Committee on Education.
Because those sources provide almost no personal background, details such as full name, dates, nationality, and broader career could not be confirmed here. In cases like this, the surviving catalog record can be more visible than the life behind it.
That scarcity may make A. Christen especially interesting to readers who enjoy overlooked or lightly documented authors whose work survives mainly through library and archive traces.