Ferguson apologises[154] for the incompleteness of his eclipse information in the following words:—“I have not cited one half of Ricciolus’s list of portentous eclipses, and for the same reason that he declines giving any more of them than what that list contains, namely, that ‘tis most disagreeable to dwell any longer on such nonsense, and as much as possible to avoid tiring the reader. The superstition of the ancients may be seen by the few here copied. My author further says that there were treatises written to show against what regions the malevolent effects of any particular eclipse was aimed, and the writers affirmed that the effects of an eclipse of the Sun continued as many years as the eclipse lasted hours, and that of the Moon as many months.” The most comprehensive (indeed almost the only) modern English book on eclipses is the Rev. S. J. Johnson’s,[155] of which frequent use has already been made in these pages. It contains a vast amount of matter put together in a condensed form but the references to authorities are rather defective and deficient. Less comprehensive in one sense yet exceedingly valuable and interesting as a succinct summary of solar eclipse knowledge up to the date of 1896 is Mrs. D. P. Todd’s excellent little volume[156] which has been several times quoted on previous pages. On various occasions in 1890 and following years Professor J. N. Stockwell contributed to the American _Astronomical Journal_ a number of papers[157] discussing in a very interesting and exhaustive manner many of the eclipses recorded by the ancient classical authors. These papers should be consulted by all who desire to realise the value of eclipse records in connection with mundane chronology. The calculation of eclipses is a matter of some interest. It is beyond the scope of the present work to explain even in outline the methods in use, but with the aid of the books mentioned below[158] a reader possessed of the necessary time, mathematical knowledge, and patience, will be able to pursue this matter as far as his inclination may lead him. Johnson has found very useful the tables given in the eighth edition of the _Encyclopædia Britannica_ (Article, “Astronomy”) but strange to say these tables do not appear in ninth edition of that famous work. Lalande[159] has given numerous references to eclipses of the Sun during the 16th, 17th and 18th centuries which may be useful to those who wish to work at the history of eclipses. FOOTNOTES: [Footnote 144: _Denkschriften der Kaiserlichen Akademie der Wissenschaften_, vol. lii. Vienna, 1887.]