The feasibility of measuring a set of triplet phases large enough to solve
the structure of a small protein has been evaluated. A total of about 850 t
riplet phases have been measured from the tetragonal form of hen egg-white
lysozyme. From these triplet phases, about 750 single phases can be derived
. The experimental details of these measurements as well as the results, th
e values of the measured triplet phases, are reported. Additional experimen
tal data from other small proteins are also presented.