_Eclipses of the Sun._—These phenomena deservedly rank amongst the most important and impressive events displayed by the heavenly bodies, and they are specially interesting to the possessors of small telescopes. Solar eclipses have been so often made the subject of observation and discussion, that our knowledge of the appearances presented may be considered to be nearly complete. The various aspects of Nature on such occasions have been so attentively studied in their manifold bearings, that virtually nothing remains for the ordinary observer but to reexamine and corroborate facts already well ascertained. He can expect to glean few materials in a field where a plentiful harvest has just been reaped. But the eclipsed Sun, if it has revealed most of its secrets to previous investigators, has certainly not declined in attractiveness; and the amateur will find the spectacle still capable of exhibiting features which, though not full of the charms of novelty, will be sufficiently striking and diversified to be remembered long after the event has passed. [Illustration: Fig. 21. 1891, June 6. 1899, June 8. 1900, May 28. 1905, Aug. 30. 1908, June 28. 1912, April 17. 1914, Aug. 21. 1916, Feb. 3. At sunset. 1919, Nov. 22. 1920, Nov. 10. 1921, April 8. 1922, March 28. At sunset. At sunset. Solar Eclipses visible in England, 1891 to 1922.] [Illustration: Fig. 22. Total Solar Eclipse of August 19, 1887.] Eclipses recur in cycles of 18 years and 10 days (= 6585 days). This period was determined by the ancients, and called the _saros_. By its means the times and magnitudes of eclipses were roughly computed long before astronomy became an exact science. A solar eclipse is really an _occultation_ of the Sun by the Moon; for the word _eclipse_, in its usual reference, denotes the obscuration of one body by its immersion in the shadow of another. During any single year there are never less than two eclipses, nor more than seven. Whenever there are two only, both are solar. Since the fine solar eclipse of December 22, 1870, no large eclipse of the Sun has been visible in England. It is remarkable that during the thirty years from 1870 to 1900 these phenomena are all of an unimportant, minor character. Within the thirty years following 1891 there will be twelve solar eclipses, for which the Rev. S. J. Johnson has given projections (as shown on p. 98) for the period of greatest obscuration.