Books in The Mercer boys series series

When Don and Jim Mercer and their buddy Terry Mackson set out in their sloop, Lassie, for a visit to Mystery Island, they were in search of adventure and fun. But they quickly found they were getting more than they bargained for -- real danger, a skirmish with marine bandits, and a fight for their lives. This is a thrilling adventure story of three modern boys -- with action and excitement on every page. [Volume 2 of The Mercer Boys.]

The Radio Boys (II) were created by Gerald Breckenridge and appeared in the ten book "Radio Boys Series," which ran from 1922 to 1931, beginning with The Radio Boys on the Mexican Border. The Boys (II) had an entirely more exciting set of adventures than the Radio Boys (I); The Boys (II) fought bandits on the Mexican border, worked for the Secret Service tracking down counterfeiters, went looking for lost Incan treasure in the Andes, helped rescue a lost Alaskan expedition, tramped through the jungles of the Congo, sought and found Lost Atlantis, acted as mercenaries in Central America, and worked with America's "Air Patrol." The Radio Boys II Series: 1. The Radio Boys On The Mexican Border - (Hardcover, 1922) 2. The Radio Boys On Secret Service Duty - (Hardcover, 1922) 3. The Radio Boys With The Revenue Guards - (Hardcover, 1922) 4. The Radio Boys Search For The Inca's Treasure - (Hardcover, 1922) 5. The Radio Boys Rescue The Lost Alaskan Expedition - (Hardcover, 1922) 6. The Radio Boys In Darkest Africa - (Hardcover, 1923) 7. The Radio Boys Seek The Lost Atlantis - (Hardcover, 1923) 8. The Radio Boys With The Border Patrol - (Hardcover, 1924) 9. The Radio Boys As Soldiers Of Fortune - (Hardcover, 1925) 10. The Radio Boys With The Air Patrol - (Hardcover, 1931)