Eclipses definition

It is remarkable that the discussion of ancient eclipses of the moon, and their comparison with modern observations, show only a small and rather doubtful change, amounting perhaps to less than one-hundredth of a second per century.

Chrystal's Algebra, where also may be found details of the application of continued fractions to such interesting and important problems as the recurrence of eclipses and the rectification of the calendar.

The equation of light is the time taken by light to traverse the sun's mean distance from the earth; it can be found by the acceleration or retardation of the eclipses of Jupiter's satellites according as Jupiter is approaching opposition or conjunction with the sun; a recent analysis shows that its value is 498.6", which leads to the same value of the parallax as above, but the internal discrepancies of the material put its authority upon a much lower level.

The treatise on "Mechanics" in Lardner's Cyclopaedia was partly written by him; and his interest in more purely astronomical questions was evidenced by two communications to the Astronomical Society's Memoirs for 1831-1833 - the one on an observation of Saturn's outer ring, the other on a method of determining longitude by means of lunar eclipses.