Note 1 — BOOK IV. THE PHYSICAL PERIOD
Reading edition
In 1874, when the writer was crossing the Pacific Ocean in H.M.S. “Scout,” Coggia’s comet unexpectedly appeared, and (while Colonel Tupman got its positions with the sextant) he tried to use the prism out of a portable direct-vision spectroscope, without success until it was put in front of the object-glass of a binocular, when, to his great joy, the three band images were clearly seen.