Kennedy did not, but said nothing.

“A most delightful little girl,” continued Denison thoughtfully. “I have known Mrs. Woods for some time. She wanted to invest, but I told her frankly that this is, after all, a speculation. We may not be able to swing so big a proposition, but, if not, no one can say we have taken a dollar of money from widows and orphans.”

“I should like to see the works,” nodded Kennedy approvingly.

“By all means.”

The plant was a row of long low buildings of brick on the outskirts of the city, once devoted to the making of vanadium steel. The ore, as Denison explained, was brought to Pittsburgh because he had found here already a factory which could readily be turned into a plant for the extraction of radium. Huge baths and vats and crucibles for the various acids and alkalis and other processes used in treating the ore stood at various points.

“This must be like extracting gold from sea water,” remarked Kennedy jocosely, impressed by the size of the plant as compared to the product.

“Except that after we get through we have something infinitely more precious than gold,” replied Denison, “something which warrants the trouble and outlay. Yes, the fact is that the percentage of radium in all such ores is even less than of gold in sea water.”

“Everything seems to be most carefully guarded,” remarked Kennedy as we concluded our tour of the well-appointed works.

He had gone over everything in silence, and now at last we had returned to the safe.

“Yes,” he repeated slowly, as if confirming his original impression, “such an amount of radium as was stolen wouldn’t occasion immediate discomfort to the thief, I suppose, but later no infernal machine could be more dangerous to him.”