A MONTH LONG EXPERIMENT USING TELEFACSIMILE EQUIPMENT OFFERED AN OPPORTUNITY TO DEVELOP A SET OF PROCEDURES FOR THE USE OF EQUIPMENT IN LIBRARIES AND TO ANALYZE SYSTEM PERFORMANCE, THE NATURE OF THE DEMAND FOR THE SYSTEM, AND THE SYSTEM COST. FINDING GENERAL PRINCIPLES FOR THE DESIGN OF SUCH SYSTEMS FOR COOPERATING LIBRARIES, COMPARING TELEFACSIMILE WITH OTHER DELIVERY METHODS, AND MAKING RECOMMENDATIONS ABOUT THE DIRECTION OF FUTURE RESEARCH IN THE AREA WERE ALSO PART OF THE STUDY. A ONE WAY LINK FROM THE BERKELEY CAMPUS OF THE UNIVERSITY OF CALIFORNIA TO THE DAVIS CAMPUS WAS ESTABLISHED USING XEROX LONG DISTANCE XEROGRAPHY (LDX) EQUIPMENT. COPIES OF JOURNAL ARTICLES REQUESTED BY FACULTY MEMBERS ON THE DAVIS CAMPUS AND SELECTED SAMPLES OF A VARIETY OF MATERIALS USED TO TEST COPY QUALITY AND RESOLUTION WERE TRANSMITTED. FROM INFORMATION GATHERED ON AN ITEM CONTROL SHEET DURING THE ACTUAL OPERATION ON THE SYSTEM AND FROM A QUESTIONNAIRE DISTRIBUTED TO USERS OF THE SYSTEM, IT WAS POSSIBLE TO DETERMINE BOTH THE DEMAND FOR THIS SERVICE AND ITS COST. THE TIME INTERVAL FROM THE TIME OF RECEIPT OF A REQUEST BY THE STAFF ON THE BERKELEY CAMPUS TO THE NOTIFICATION OF THE REQUESTER THAT THE MATERIAL WAS READY AVERAGED NINE AND ONE-HALF HOURS. OF THIS, 2.3 HOURS WAS NEEDED FOR PAGING AND PROCESSING THE ITEM, 4.5 HOURS FOR TRANSMITTING IT, AND 2.7 HOURS FOR NOTIFICATION OF THE PATRON. FIXED MONTHLY COSTS OF THE ENTIRE SYSTEM WERE ABOUT 4000 DOLLARS. AVERAGE COST PER REQUEST WAS 12 DOLLARS. CONSIDERING THESE FACTORS, MOST MANUAL SYSTEMS SHOULD BE MADE TO OPERATE SMOOTHLY USING AVAILABLE SURFACE TRANSPORTATION BEFORE THE INVESTMENT IN TELEFACSIMILE IS MADE. APPENDICES--(1) LDX PROCEDURES MANUAL, A MANUAL FOR THE OPERATION OF THE SYSTEM, (2) MISCELLANEOUS INFORMATION, INCLUDING EQUIPMENT SPECIFICATIONS, AND (3) SAMPLES OF LDX COPIES AND ORIGINAL MATERIALS. THIS STUDY WAS CONDUCTED UNDER A GRANT FROM THE COUNCIL ON LIBRARY RESOURCES. (CM)