As a supplement to Project Physics Unit 4, a collection of articles is presented in this reader for student browsing. The 21 articles are included under the following headings: Letter from Thomas Jefferson; On the Method of Theoretical Physics; Systems, Feedback, Cybernetics; Velocity of Light; Popular Applications of Polarized Light; Eye and Camera; The laser--What it is and Does; A Simple Electric Circuit: Ohm's Law; The Electronic Revolution; The Invention of the Electric Light; High Fidelity; The Future of Direct Current Power Transmission; James Clerk Maxwell, Part II; On the Induction of Electric Currents; The Relationship of Electricity and Magnetism; The Electromagnetic Field; Radiation Belts Around the Earth; A Mirror for the Brain; Scientific Imagination; Lenses and Optical Instruments; and "Baffled!." Illustrations for explanation use are included. The work of Harvard Project Physics has been financially supported by: the Carnegie Corporation of New York, the Ford Foundation, the National Science Foundation, the Alfred P. Sloan Foundation, the United States Office of Education, and Harvard University. (CC)