The Lunar Distance Method in the Nineteenth Century: A Simulation of Joshua Slocum's Observation on June 16, 1896

Abstract

The history and practice of the lunar distance method are described, with special emphasis on its use in the nineteenth century. It is only in the first half of the last century that lunars were widely practiced. The story of Captain Joshua Slocum, the first solitary circumnavigator, is described in some detail. His lunar observation in 1896 was made in its original form, with nothing but the moon as a clock. A simulation of his observations and their reduction by the means available to the nineteenth-century navigator are described, and a short review of these methods is presented.