From the atomic age in Atlantis to a world remote in space and time, two incredible ancient races, the Arisians and the Eddorians, are in the midst of an interstellar war - with Earth as the prize.
"Lensman Series is Still Fun"
Triplanetary was first serialized in Amazing Stories in 1934. After the Lensman series became popular, Smith took his Triplanetary story and turned it into the first of the Lensman series, using it as a prequel to give the back story for the protaganists in the Lensmen series. He added six new chapters, doubling it in size and it's really a different book from the serialized novel, being published 14 years after the first. It was put into Gutenberg just last year.