In review, the author is struck with a feeling of the relative insignificance of his findings. Other sources of information seem to have a wealth of ideas, a scope far beyond the present investigation, and a variety of means to approach the subject. Upon further consideration, however, and a realization of the comparative expenditures of time, energy, and thought given to the subject, much familiarity has been gained with the general problem, with the factors involved, and their relative importance. Some interesting experiments have been watched, and the groundwork has been laid for more. In this light, the original purpose has been accomplished. / Master of Science