The writings of the Astronomer Royal are numerous. He has contributed largely to the Cambridge Transactions and the Philosophical Transactions. His pen has notably illustrated the memoirs of the Astronomical Society. He has written abundantly for the Philosophical Magazine, and still more abundantly, under his reversed initials, A. B. G., in the columns of the Athenœum. His principle works, however, are…: “Gravitation,” published in 1837, was written originally for the “Penny Cyclopædia.” “Mathematical Tracts” have reached a fourth edition, as have also his “Ipswich Lectures on Astronomy.” In 1861 appeared his treatise on “Errors of Observation;” in 1869 his treatise on “Sound,” and in 1870 his treatise on “Magnetism.” Sir George Airy’s well-known work on “Trigonometry” was published in 1855. Another work of his, entitled “Figure of the Earth,” has yet to be named, as well as the luminous paper on “Tides and Waves,” contributed by him, first of all, to the “Encyclopædia Metropolitana.” Even while simply Professor of Astronomy at Cambridge his “Astronomical Observations,” issuing… between 1829 and 1838, extended in nine quarto volumes, and were adopted at once as models for that class of publication.