Before he cried "stop him!" Harry's hand was on the fastening of the door, and when he reached the door, the boy was half across the street.
He had calculated on smoothing over the rough places of the interview, and preparing a better report of the visit of the lad's friends on the other side of the avenue, but the matter had literally slipped through his fingers.

He closed the door after the retreating boy, and went back to his room without deigning to answer the inquiries that were excited by his loud command to "stop him." Sitting down, and taking to himself his usual solace, and smoking furiously for a while, he said: "D---n!" Into this one favorite and familiar expletive he poured his anger, his vexation, and his fear.

He believed at the moment that the inventor was alive.

He believed that if he had been dead his boy would, in some way, have revealed the fact.
Was he still insane?
Had he powerful friends?
It certainly appeared so.
Otherwise, how could the lad be where he had discovered him?
Was it rational to suppose that he was far from his father?
Was it rational to suppose that the lad's friends were not equally the friends of the inventor?
How could he know that Robert Belcher himself had not unwittingly come to the precise locality where he would be under constant surveillance?
How could he know that a deeply laid plot was not already at work to undermine and circumvent him?
The lad's reticence, determined and desperate, showed that he knew the relations that existed between his father and the proprietor, and seemed to show that he had acted under orders.
Something must be done to ascertain the residence of Paul Benedict, if still alive, or to assure him of his death, if it had occurred.
Something must be done to secure the property which he was rapidly accumulating.

Already foreign Governments were considering the advantages of the Belcher rifle, as an arm for the military service, and negotiations were pending with more than one of them.