See piece list for details. Also scrap piece of paper with handwritten reference to 'annalen der physik', 4th series, vol. 26, p. 79-94. Paper by W Zernov (Moscow, March 1908) titled, 'uber absolute messungen der schallintensitat - die Rayleighsche Scheibe'. The English title would be, 'absolute measurements of loudness of sound - Rayleigh Disk'.