The Yale Lock Co.; The Micrometer Engineering Co.; Messrs. Marshall and Sons; The Maignen Filter Co.; Messrs. Negretti and Zambra; Messrs. Chubb; The Yale Lock Co.; The Micrometer Engineering Co.; Messrs. Broadwood and Co. [Illustration: ON THE STUDY OF PHYSICS. XII. ON CRYSTALLINE AND SLATY CLEAVAGE. XIII. ON PARAMAGNETIC AND DIAMAGNETIC FORCES [Footnote: Abstract of a Greek philosopher.