TO
RICHARD A. PROCTOR, B.A.,
AUTHOR OF ‘THE SUN,’ ‘OTHER WORLDS,’ ETC.,
EDITOR OF ‘KNOWLEDGE.’

My dear Proctor—The best gifts of life are its friendships, and to you, with whom friendship has ripened into fellowship, and under whose editorial wing some of the chapters of this book had temporary shelter, I inscribe them in their enlarged and independent form.

Yours sincerely,
EDWARD CLODD.