Numbered folders, one for each experiment proposed for the BNL Cosmotron subsequent to the establishment of formal procedures for evaluating such proposals in 1959. The folders contain completed proposal forms, correspondence between the experimenters, the Cosmotron Department, the High Energy Steering Committee (later the High Energy Advisory Committee) and Brookhaven staff scientists and engineers; progress reports; memoranda; drawings and photographs of apparatus and experimental set-ups; technical notes; data; and memoranda from the BNL "Hazards Committee" evaluating the safety of each proposed experiment. There is also a list of experiments (numbered C-1 to C-141) giving the name and affiliation of the principle experimenter, the action taken by the Cosmotron Department of the various scheduling committees; a memorandum on scheduling and instructions to prospective experimenters; and miscellaneous documents on the scheduling procedures followed for the Cosmotron and the filing system used for experiment records and for Cosmotron operational data.