John Young Buchanan (1844-1925) joined the Challenger expedition as chemist and physicist, publishing results from the expedition and thereafter making contributions to oceanography via his journal articles. The present volume collects fifteen of his papers. According to the prospectus loosely inserted in this copy, a second volume of his papers was in preparation at the time of publication, but in the event further collections of his papers appeared as Comptes Rendus of Observation and Reasoning (1917) and Accounts Rendered of Work Done and Things Seen (1919), each volume being complete in itself.