In 1968 the senior author discovered in a Boston, Massachusetts, bookstore a sketchbook of some 33 watercolours of the Challenger Expedition painted by Benjamin Shephard, a cooper assigned to the Challenger on November 15, 1872, at the age of 31. The paintings were all accomplished between the ship's departure from Gibraltar on January 26,1873, and the completion of her February 1874 work in the Antarctic before departing for Melbourne, Australia.

Shephard's paintings are elliptical in shape and measure 9·75 by 5·5 inches, each within a painted ‘frame’ resembling a leather belt with a ‘buckle’ at the lower left. The paintings themselves are skilfully done and each shows the Challenger at a different location during the voyage.

Since all but one of the paintings were dated by the artist, it has been possible to go back to the official narrative of the expedition and to the published logs kept by the Assistant Engineer, W. J. J. Spry, and by Sub-Lieutenant Lord George G. Campbell to determine just what was happening aboard at the time each painting was made. Excerpts from these logs provide the narrative accompanying the sketches which are to be published in book form to coincide with the Challenger Expedition Centenary celebrations. Black and white photographs of the sketchbook's cover and of four of the 33 sketches are included as part of this paper (Plates 1–5).