largely concerned essays into the character of the small angle scattering of protons on protons and neutrons. Some very interesting attempts to find simple ways of understanding the complexities of the physics of elementary particles had centered on the analytic character of particle-particle scattering amplitudes. In particular, the amplitudes that determined the forward scattering of protons by protons and neutrons were considered to be governed by causal dispersion relations similar to the Kramers-Kronig relations that held for the scattering of electromagnetic radiation.

If the results of the program were disappointing in that no surprises emerged, the agreement with the consequences of simple causality generated confidence in the validity of causality and special relativity at small distances, a constraint that remains basic to the important particle theories we have today.

During the decades Cool worked on the physics of elementary particles, the complexities of experiments increased greatly. Along with that increased complexity came increased monetary costs and, sociologically most important, a significant increase in the scientific effort required to conduct an experiment. While Rod's early experiments involved two, three, and four scientists with a few technicians, and typically one or two scientist-years of effort, there are sixteen names on the first Fermilab paper, including seven from the Soviet Union, and those names represent perhaps twenty-five scientist-years of effort. Some of the later CERN papers list thirty names that again represented a very large effort. With so many participants in experiments that are so complex the organization of effort is important and that organization and leadership can only be exercised by a physicist who is knowledgeable about all details of the experiment and has the trust and confidence of