Pair of 5.5x7.25” hardcovers with original dust jackets. 1935 edition of "At The Earth's Core" published by Grosset & Dunlap. Cover art by J. Allen St. John. Dust jacket notes sequel to "At The Earth's Core," "Pellucidar." Burroughs, most remembered as the creator of Tarzan, first wrote this sci-fi tale about the Hollow Earth land of Pellucidar in 1914. Dust jacket shows wear with a few faint creases across front cover. 3" tear along front right edge has been repaired. Dust jacket still displays Fine and has not been clipped. Book itself has lightest trace of wear but still remains a high grade copy overall and is essentially N. Mint. Second book is "Pellucidar," the sequel to "At The Earth's Core." This is a 1927 printing of the story that was first serialized in 1915 and collected in novel form for the first time in 1923. Cover art and matching 4 glossy bw illustrated pages by J. Allen St. John. Dust jacket shows some light wear, mostly along edges. Lightly aged and Fine+. Book itself has some light edge wear and is Exc.