"Fourteen heavy manila envelopes, each containing a verbatim carbon of everything typed for each of the chapters. Providing such a carbon was essential when things were being sent by mail. Their value now, the carbons that is, is that from them one can reconstruct each stage of the manuscript as it developed. Obviously, the carbons do not contain the very heavy hand-written changes I made on the face of the original; on the other hand, they do provide versions which had been pasted over when I edited the original. These carbons are valuable in identifying how I worked, and reworked the manuscript. THESE MUST NOT BE OPENED TO THE PUBLIC UNTIL TWO YEARS AFTER PUBLICATION DATE."