MAXWELL, James Clerk (1831-1879). A Treatise on Electricity and Magnetism, Oxford: Clarendon Press, 1873, 2 volumes, 8° (220 x 143mm.), FIRST EDITION, SECOND ISSUE, 20 lithographed plates, illustrations, modern half calf and marbled boards [Horblit 72: "Maxwell here advanced the hypothesis that light and electricity are the same in their ultimate nature"; Norman 1466; PMM 355; Sotheran I, 2925; Wheeler 1872]; An Elementary Treatise on Electricity, Oxford: Clarendon Press, 1881, 8°, 6 plates, illustrations (occasional very light spotting, ownership inscription to title), original publisher's cloth (head and tail of spine chipped, corners bumped). [Sotheran I, 2922] (3)