Stephen Johnson Field

“ The difference between the cost of generating heat by the use of the improvements and wet tan, and the cost of producing it by the use of wood as a fuel, could not be the measure of profit, unless, with those improvements or with other methods, wood was the only means besides wet tan of producing the same heat, and that was not shown. ”

“ If other methods in common use produce the same results, with equal facility and cost, the use of the patented invention cannot add to the gains of the infringer, or impair the just rewards of the inventor. ”

“ It does not always follow that because a party may have made an improvement in a machine and obtained a patent for it, another using the improvement and infringing upon the patentee's rights will be mulcted in more than nominal damages for the infringement. ”