In this paper I will examine the history of the first three, of a sequ
ence of five, experiments performed by the Mann-O'Neill collaboration
at the Princeton-Pennsylvania Accelerator. The experiments were conduc
ted over a period of four years and measured aspects of K+ meson decay
. Each of the experiments was done with essentially the same basic app
aratus, with modifications for each of the specific measurements. We w
ill see the increasing: expertise of the experimenters as the experime
nts progressed. The third measurement was technically more difficult a
nd built upon the acquired knowledge of how the experimental apparatus
worked.