PREFACE TO FIRST EDITION.
It has long been the custom at the Royal Institution of Great Britain to provide each Christmastide a course of Lectures specially addressed to a juvenile audience.
On two occasions, namely, in 1881 and in 1887, the Managers entrusted this honorable duty to me. The second course was in the main a repetition of the first; and on my notes and recollections of both the present little volume has been founded.
I am indebted to my friends Rev. Maxwell Close, Mr. Arthur Rambaut, and Dr. John Todhunter for their kindness in reading the proofs.
ROBERT S. BALL.
Observatory,
Co. Dublin,
Oct. 22, 1889.