"Type C heavy-atom". Work on seal myoglobin, which Kendrew refers to in his 1963 Science article as a close runner-up to the final choice of sperm whale. Material includes notes, calculations, data, EDSAC sheets, electron density contour maps etc., most by Kendrew, but including contributions and/or correspondence from R. Hart and R.E. Dickerson at Cambridge and from H. Scouloudi who continued to work on seal myoglobin for many years at the Royal Institution and later at the Molecular Biophysics Laboratory Oxford. There are two main periods of work, February-November 1956, May-July 1958.