Harlan F. Stone

“ This means that the air content of the chamber must make the circuit many times, theoretically from 33 to 200, before an equal volume of fresh air would be drawn in through the intake. Such continuous circulation of the air at constant temperature, lower than that of the more advanced eggs and higher than that of the less advanced, tends to produce the equalization of the temperature of the eggs by flow of heat units from the warmer eggs to the cooler, regardless of the direction of the current in the circuit, and regardless of the particular stage of the eggs which it reaches first. ”

“ Staged incubation is the successive setting of eggs in the same cabinet at brief intervals, of about three days. At the twenty-first day there would thus be several settings of eggs in the incubator, each at a different stage of incubation, part in the endothermic stage and part in the exothermic. Smith arranged the egg trays or racks in tiers, so that air could be freely circulated among the eggs. He subjected them to a continuous current of air of the requisite constant temperature of about 100 F., propelled by a fan so that it would circulate freely and repeatedly throughout the cabinet. ”

“ Claim 1, as already stated, does not call for a current of air moving in any particular direction. Assuming, without deciding, that it calls for a current of air so constant in its movement and direction as not to depart substantially from a well-defined path, one would expect that a fan operating, as in respondents' machine, within a closed chamber under substantially constant conditions, would produce currents of air without substantial variations of path. No valid scientific reason or explanation is advanced for any different result. ”

“ It is manifest that the temperature will remain practically the same throughout the column of eggs, but the air is impelled with sufficient velocity to carry the heat away from the eggs which happen to be in the advanced stage of incubation.' The drawings and specifications show the eggs arranged in tiers on either side of the chamber, with an open space or corridor between, at the top of which a revolving fan forces the air downward in the open space of the corridor. ”

“ That there is a mixture of the air and some confusion of its movement in the corridor, and that at different levels within the space occupied by the tiers of trays the movement is not in the same direction, is immaterial. It is enough that there is a movement of air in current form following substantially defined paths through the tiers of egg trays, sufficient to effect the desired transfer of heat units. ”

“ Extensive testimony and elaborate arguments are presented to support the contention that, notwithstanding the application of force to the air within the closed chamber by the action of respondents' propellers, under practically constant conditions, the results produced are so variable that 'the air goes where it 'listeth"; they are not convincing. ”

“ Before staged incubation, as developed by Smith, it had not been practicable to operate incubators of a capacity of more than about 300 eggs. By use of the new method, it is possible to operate successfully an incubator containing as many as 52,000 eggs, and the percentage of eggs successfully hatched by artificial incubation has been materially raised. ”

“ From the eleventh day until the end of the period the embryo has developed to a point at which the egg generates more heat than is needed to keep the embryo alive. They are then said to be exothermic. ”

“ It is true that drawings and specifications indicate a particular arrangement of the eggs from the top to the bottom of the tiers of trays, according to the stage of the incubating process, the eggs being arranged progressively from the least advanced, placed at the top, to the most advanced, placed at the bottom of the tiers. They indicate also that, as the eggs most advanced are hatched, they are to be replaced by moving downward the trays containing the several successive settings of eggs which are in earlier stages of incubation. ”

“ The respondents' machine exhibits a closed chamber, with restricted outlet for the escape of foul air and an intake for fresh air, with eggs arranged at different levels in staged incubation, with a fan-impelled movement of air which circulates and recirculates throughout the chamber. ”

“ The features emphasized were the superiority, over drafts caused by variations of temperature, of 'current produced by mechanical means' applied to eggs in staged incubation arranged at different levels, the conservation of moisture, and the elimination of foul air by the restricted air outlets, all features of claim 1 which are characteristic of both petitioner's and respondents' incubators. ”