SPIRAL NEBULA IN CONSTELLATION LEO 26 _Photographed by Keeler, February 24, 1900._ NEBULA IN ANDROMEDA 28 _Photographed by Barnard, November 21, 1892._ THE "DUMB-BELL" NEBULA 34 _Photographed by Keeler, July 31, 1899._ STAR-FIELD IN CONSTELLATION MONOCEROS 84 _Photographed by Barnard, February 1, 1894._ SOLAR CORONA. TOTAL ECLIPSE 108 _Photographed by Campbell, January 22, 1898; Jeur, India._ FORTY-INCH TELESCOPE, YERKES OBSERVATORY 170 YERKES OBSERVATORY, UNIVERSITY OF CHICAGO 176 PRACTICAL TALKS BY AN ASTRONOMER NAVIGATION AT SEA A short time ago the writer had occasion to rummage among the archives of the Royal Astronomical Society in London, to consult, if possible, the original manuscripts left by one Stephen Groombridge, an English astronomer of the good old days, who died in 1832. It was known that they had been filed away about a generation ago, by the late Sir George Airy, who was Astronomer Royal of England between the years 1835 and 1881. After a long search, a large and dusty box was found and opened. It was filled with documents, of which the topmost was in Sir George's own handwriting, and began substantially as follows: "List of articles within this box. "No. 1, This list, "No. 2, etc., etc." Astronomical precision can no further go: he had listed even the list itself. Truly, Airy was rightly styled "prince of precisians." A worthy Astronomer Royal was he, to act under the royal warrant of Charles II., who established the office in 1675. Down to this present day that warrant still makes it the duty of His Majesty's Astronomer "to apply himself with the most exact care and diligence to the rectifying of the tables of the motions of the heavens and the places of the fixed stars, in order to find out the so much desired longitude at sea, for the perfecting the art of navigation."