“Land ho!” yelled the curator, waking them all up. “Here’s Aru, boys, dead ahead, and we’ve beaten our proa that was to have come for us by two days!”

THE END

HARPER’S
“TELL-ME-HOW” SERIES


HARPER’S EVERY-DAY ELECTRICITY

By Don Cameron Shafer

Describes all electrical apparatus in common use. Each chapter contains various examples and experiments, amply illustrated with line-drawings.

HARPER’S WIRELESS BOOK

By Alpheus Hyatt Verrill

Part I deals with Principles and Mechanism of Wireless; Part II, Operation and Use of Wireless; Part III, Wireless Telephone; Part IV, Wireless Power Transmission.