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.