Early "Pulp" SciFi written from about 1928 to about 1968. It is very junvinile but IMHO contains the semenial roots of much what SciFi was about in the 50and 60's. The guttenburg site has some off copywrite of Smith's material from Amazing stories- essentially shortened versions of what was printed in book form. Unfortunately than are out of print and my Pbooks are shedding pages <sigh>
Bob
pardon my spelling not a strong point.