P initiated suit on September 21, 1951, with a Petition Pending Motion for Call which claimed the infringement of twenty-six patents by D. The petition was amended on March 10, 1954; twelve patents were dropped from the suit and six were added. Four years of pre-trial proceedings reduced the number of patents to sixteen. During that period, fourteen witnesses appeared, over one thousand exhibits were presented, and almost fifteen thousand pages of transcript were taken. The trial commissioner issued a 232-page report containing 415 findings of fact. Fifteen of the sixteen patents in suit and eighty-five of their eighty-six claims in suit were found valid and infringed by various D structures. One patent and its one claim were found not infringed. D appealed.