Hermann L.F. Helmholtz ; with a new introduction (1954) by Henry Margenau
Dover
c1954
2nd English ed. / translated, thoroughly rev. and corr., rendered conformal to the 4th (and last) German ed. of 1877, with numerous additional notes and a new additional appendix bringing down information to 1885, and especially adapted to the use of music students by Alexander J. Ellis
Available at 59 libraries