By Donald Keith
Wikipedia Page, with links to the original stories.
I was the world's worst Cub Scout. In four years, I never earned a single badge.* Every year, we'd get the activity books. There would be ten tasks to do to get your badge, and I'd be lucky if I got five of them. And forget the little arrowheads. I did finish second in the Pinewood Derby, but that's because my father built the car.
About the only thing I got out of it was my subscription to Boys' Life. And my favorite part of my subscription to Boys' Life were the Time Machine series.
The concept was hardly new even back in 1959, when it started. A Boy Scout troop, led by Bob Tucker,** along with Ellsworth "Brains" Baines, discovered a time machine while out hiking. Brains figured out how to run it in about five minutes, and off they went forward and backward in time. Later other people joined the crew, like Kai, a boy from the future, and Dion from ancient Sparta.
The stories were simple. No time paradoxes here -- just a visit to a time in the past or future where an adventure could happen. Occasionally, they'd make minor changes to the course of history.
The series was conceived as something of an educational exercise, where the trips to the past would be history lessons.*** And they were excellent adventures; I still remember the excitement when they ended up at the Johnstown Flood.
The author was a pseudonym for a father-and-son team, Donald and Keith Monroe, though Keith wrote solo after 1974. All and all, 23 stories were published, including three serials. Two of the serials were turned into fix-up novels: Mutiny on the Time Machine and Time Machine to the Rescue.
The stories have faded into the recycling bin, but, for those interested, Google Books has many back issues of Boys' Life, including those that featured the stories. The wikipedia page gives links to them.****
*Except the Bobcat, which you got basically for just showing up.
**A name that leads to some interesting speculation. You see, back then, Wilson "Bob" Tucker was a big name in SF fandom, creator of one of the first fanzines, Le Zombie. He also published some SF and mystery novels and stories. One of his habits was to take the names of real people (usually other fans) and put them into his stories; he did it so much that fans called the practice "Tuckerization." So, was Bob Tucker tuckerized in the book? Hard to say. But Donald Keith has published SF in Galaxy before appearing in Boy's Life, and it's certainly possible he knew of fandom and Bob Tucker.
***Just like the original Doctor Who, but four years earlier. Since it was also quickly established the Time Machine could also travel in space, it looks like it was a precursor to the TARDIS. I doubt the creators of Doctor Who knew anything about the stories -- Boys' Life probably never made it to the UK -- but it's a fun coincidence.
****But only to the first episode of the serials. You'll need to root around to find the rest.