As professional lecturer, as well as enthusiastic speaker to small groups, Gordon gave much of his spare time to this aspect of his work at the Academy of Natural Sciences of Philadelphia. These 19 manuscripts portray his interest in mineral collecting in Greenland, South America and Africa, his desire to educate in the field of specific mineralogical subjects and his wish to interest people in the Academy and its mineral exhibits and research collections. The talks were given to such varied groups as Botany Clubs, Ludwick public lectures of the Academy, radio publicity talks, the New York Mineralogical Club, Philadelphia High Schools and the Geological Society of America. Two texts by other authors are preserved here, the first by Nicola G. D'Ascenzo, “The Stars Give up Their Secrets” and second, “Some Interesting Minerals,” by James Manchester.