Six Months in Ascension : an Unscientific Account of a
Scientific Expedition. By Mrs. Gill. (Murray.)—Mr. Gill went to Ascension Island in 1877, under the auspices of the Royal Astronomical Society, to observe the opposition of the planet Mars, a phenomenon which "offered, so far as geometrical conditions are concerned, the most favourable opportunity of the century to determine the parallax by observation at a single station." It is satisfactory to know that the expedition was successful, and that "the reductions, now far advanced, promise a result of very great accuracy." This result may be generally stated as proving that the " San's distance is nearer to ninety-three than to ninety-two millions of miles." An Introduc- tion, from the pen of Mr. Gill, sketches in a very lucid and interest- ing way, the general history of the attempt made at this time to measure the Sun's distance. Mrs. Gill opens her "unscientific account" with a brief, popular statement of the problem that had to be solved, and then tells us, in a narrative which never loses its interest, all about the local circumstances of the experiment, the difficulties which had to be overcome, and so forth. Sketches of scenery and social life pleasantly vary the story, and help to make it a very agreeable book. No one who notices this volume should fail to mention the great service which the author rendered to the under- taking, by the energy and courage with which, when that part of the island which had been originally selected for the site of the observations remained covered with cloud as the critical time drew near, she recommended and carried out the transference of the operations to a more favoured spot, a course of action which ended in the happiest results.
Previous page
