"This thing has been going on for a year or more--but it never touched the Waite Motor Company before." "Um!" said Fabius, eying his son and taking up his paper. From time to time during the evening he would lower his paper enough to peer over it at Potter for a moment, and at such times it seemed as if he were about to offer some remark. From that hour Potter was able to trace a gradual alteration in his father's attitude toward Germany and toward the war--but most of all toward the United States. During these months Potter worked not only on the designs for his aeroplane engine, but upon collecting and preserving information of general importance to the manufacturing of complete aeroplanes in enormous quantities. With all the facilities open to a private citizen he made his inquiries. Twenty millions of feet of the finest spruce must be obtained in order that four millions of feet of perfect spruce might be selected and sawed from it for the frames of the aeroplanes. This alone was a gigantic task. He studied the matter of obtaining linen for the wings, millions of yards of it--and the best linen comes from Ireland. It was a commodity of which England could spare little. Perhaps there would appear a substitute. Potter searched for it. Then there was the matter of metal for the engine, and the staggering problem of manufacturing a score of thousands of such engines as Potter knew would be required for fighting-aeroplanes--engines light in weight, perfect in efficiency, capable of developing two hundred, perhaps two hundred and fifty, horse-power. As best he could he attacked these problems, and stood amazed and terrified by the monstrousness of them. It gave him that quivering, frightened sensation one gets from thinking on infinity.