I've always loved these interplanetary romances! Thanks so much to the posters for all these wonderful Argosy, Amazing Tales and book covers, few of which I've seen before. I read all the Boroughs Mars books many years ago, but I've never read Otis Adelbert Kline so that is a pleasure that still awaits.
Pat, I looked up O.A.K in Wikipedia, and found some interesting remarks regarding the alleged feud with Boroughs, which I dont think has been referenced so far:
Kline is best known for an apocryphal literary feud with fellow author Edgar Rice Burroughs, in which he supposedly raised the latter's ire by producing close imitations (Planet of Peril (1929) and two sequels) of Burroughs's Martian novels, though set on Venus; Burroughs, the story goes, then retaliated by writing his own Venus novels, whereupon Kline responded with an even more direct intrusion on Burroughs's territory by boldly setting two novels on Mars. Kline's jungle adventure stories, reminiscent of Burroughs's Tarzan tales, have also been cited as evidence of the conflict.[1] While the two authors did write the works in question, the theory that they did so in contention with each other is supported only circumstantially, by the resemblance and publication dates of the works themselves. The feud theory was originally set forth in a fan press article, "The Kline-Burroughs War," by Donald A. Wollheim (Science Fiction News, November, 1936), and afterward given wider circulation by Sam Moskowitz in his book Explorers of the Infinite. Richard A. Lupoff debunked the case in his book Edgar Rice Burroughs: Master of Adventure. Among the evidence cited by Lupoff discounting the feud: (1) no comment from either writer acknowledging the feud is documented, and (2) family members of the two authors have no recollection of ever hearing them mention it. In response to Lupoff's investigations Moskowitz identified his original source as Wollheim's article, while Wollheim stated, when questioned on the source of his own information: "I made it up!"
I was also very interested to learn that Kline became Howard's literary agent and managed his estate after his untimely death - and may even have completed Howard's Almuric for posthumous publication, though this appears to be disputed.
I wish I could contribute more directly to the discussion. Girasol has published replicas of the early Weird tales and I have some of those on order, so I will look out for the Kline stories therein. (I would love to have nice copies of the Burroughs Amazing Stories issues and will be looking out for them - there are some lower grade copies on Ebay at what appear highly inflated prices.)
The Avon one-shot on Tarrano the Conqueror reminded me that I do have this:
It was absolutely my favourite cover when I first perused the photojournal!