H.C.Mason was a South African astronomer, newspaper editor and veteran of the Anglo-Boer war. Unfortunately there is no more information about him available at present outside of what was written down in his obituary.
This appears to be Mason's only pure novel, he wrote besides this a collection of essays and a book on religion and philosophy. The Devil's Christmas Box itself is somewhat of a mess, a mixture of questionable science fiction, long didactic sermons on socialism and a love story. The whole thing is introduced via confused pseudo-scientific gobbledygook about the novel proper being dictated to a medium from off planet.
The part that is rather hard to swallow is how the author of this mysterious message claims that there are countless worlds with an absolutely identical history to Earth, up to bearing the exact duplicates of every person on Earth. This theory, which appears to have had some life in science fiction circles due to it being presented in Tales of Tomorrow three decades after this book was published, is laughable if only one knows anything about probability. Nor is it helped when the author claims that even the stars as seen from these other planets are exactly identical as seen from the globe. And yet towards the end the narrator goes on about how the duplicate beings on such planets might be united in death as one and in fact function as sort of continous reincarnation of one person into the same life, to try and make a better show of it. He of course completely forgets his own statements as to the absolutely identical nature of all these mirror Earths, down to the most minute detail, where no deviation can occur without some extra planetary influence, like his own. So this seems to me a rather pointless idea of an eternal life.
When the story itself begins, it is just a romance, focusing on Ronald Sanderson, one of those main characters, extremely handsome, strong and an absolute genius, whose statements about his own cardinal importance to the world and the ability to acquire any political seat he should strive for are not, in this one instance, to be taken as vanity, because they are simply stating an absolute truth ! You know, one of those characters you hope get their asses kicked sooner or later. The first part, which deals with an alternate future where a Boer rebellion against the South African Goverment is put down successfully, includes scenes of Ronald's time in the army, terrible crash landing in enemy territory and him being cared for by his one true love while behind enemy lines. It honestly feels this is the strongest part of the book and had Mason simply stuck to this and expanded on it, it may have been a good read.
The second part, with a tyrannical League of nations that the main character tries to depose via bomb threats but ends up accidentally blowing up the world, seems incongruous to the preceding section, and though the ending scene of the world's end is sufficiently grim to at least be entertaining, it's all rather sketchy, with barely any details and is over far too quickly.
The other negatives include a part detailing Ronald's school dayss which simply drags on ad infinitum, or the incessant prattlings of Professor Selliers (who, old man though he is, is friends with Ronald's sister since she is twelve and then marries her later on, nothing at all off-putting about that) about the damnable state of capitalism and the virtues of socialism, which in his view should be based and put in operation in accordance with religion ! Clearly it seems very credible that, like Mason writes in the introduction, the book was written when there was "nothing but propaganda" out talking about Soviet Russia. Because if it was written any later, he would probably have to know how pro-religious his chosen world-view really was.
Another interesting part is how Mason tiptoes around the idea of the native population of South Africa. He never features any until the very end, and even then their emancipation seems to have come in part from the Tyrannical League being in power....though Mason doesn't say that it's a bad thing, he goes on about hurting European resettlement in Africa as if that was in any way important.
In short, a confusing and confused hodgepodge of different ideas and stories which never really comes together.