Dr. Eldon Knuth, GALCIT PhD 1954, donated his personal collection of the proceedings of the International Symposium on Rarefied Gas Dynamics.  The biennial conference started in 1958 and continues in July with the 31st International Symposium on Rarefied Gas Dynamics at the University of Strathclyde.  The Caltech Library has collected the proceedings of this important conference from the beginning, but lacked 4 rare volumes which were published in Europe and Asia.  Dr. Knuth’s donation allows the library to provide seamless access to the complete run of the conference proceedings.  We thank for the Office of the Director of GALCIT for facilitating this donation and Dr. Knuth for his generosity.