The author and publishers take pleasure in acknowledging the courtesy of

_The Scientific American_

_The Booklovers Magazine_

_The Holiday Magazine_, and

Messrs. Wood & Nathan Company

for the use of a number of illustrations in this book.

From _The Scientific American_, illustrations facing pages 16, 48,

78, 80, 88, 94, 118, 126, 142, and 162.

From _The Booklovers Magazine_, illustrations facing pages 184, 190,

194, and 196.

From _The Holiday Magazine_, illustrations facing pages 100 and 110.