I have a juvenile novel by John Sylvester titled "The Flying Saucer".
Searching in Internet I have discovered that the real name of this writer was Hector Hawton, who under the pen name of John Sylvester was one of the regular contributors to the boys’ adventure magazine Chums, writing several SF stories for it. These included a serial, “The Master of the World” which began in the May 1930 issue, clearly inspired in Verne (and in George Allan England’s The Flying Legion). It was published as a SF novel for adolescents in 1949, followed in 1952 by “The Flying Saucer”.
So I wonder if his second novel "The Flying Saucer" was also previously serialized in "Chums", supposedly sometime after the flying saucer mania in 1947. Can anybody help?