399. KONSTANTIN TSIOLKOVSKY (1857-1935) Pioneering Russian scientist and rocket designer who laid out the basic principles of modern space flight. Rare partial A.Ms.S., 2pp. 8vo., [n.p. ca. 1930], in Russian, untranslated but undoubtedly making reference to rocketry and space travel. The bottom of the first page bears an original sketch depicting two figures apparently weightless with an air tank forcing air into the structure about which the two figures float. Very good. $600-800