ADVENTURES in the UNKNOWN

By CARL H. CLAUDY

Weird! Mysterious! Incredible! Astounding!

Leap back a million years into the dark prehistoric ages. Speed through the dangers of outer space beyond the stratosphere at a thousand miles a minute. Meet the grotesque machine men of Mars. Break into the bounds of the Fourth Dimension. You will meet in these thrilling, fascinating stories many incredible beings and astounding sights that will stagger your imagination.

THE MYSTERY MEN OF MARS

Seventy million miles from home! Three men—a daring scientist and two adventurous boys—take off from the earth in a steel and aluminum sphere that sails through space at 20 miles a second. On the planet Mars they face destruction at the hands of beings who resemble mechanical bugs more than men!

A THOUSAND YEARS A MINUTE

In the world of a million years ago—whence they have been propelled by an old professor’s invention—Alan and Ted find themselves pitted against the dinosaurs, mammoths and savage ape men of a lost world.

THE LAND OF NO SHADOW

Through a violet coil frame in Professor Arronson’s laboratory Ted and Alan leap into the gray and terrifying land of the Fourth Dimension. There they are shadowed by the ghostly forms of menacing, bodiless shapes!