* * * * *
"This arm was made by the notorious Protean Bob," said young Jack to his father. "You remember Protean Bob?"
"Yes."
"He was a highly-skilled mechanician, it appears, and that he gave himself thoroughly up to the manufacture of this arm."
"It is certainly a marvellous piece of work," said Doctor Anderson.
"The strangest part of the story is," said young Jack, "that only the inventor knows the exact working of it, and that there is concealed in the springs something deadly to avenge the inventor should the wearer of the arm ever prove wanting in gratitude. And Hunston, as you know—"
"Never troubled anyone with gratitude."
"No, indeed," said Doctor Anderson, reflectively; "the strangest part of that is, he never misses an opportunity of railing against you."
"Against me!" said Harkaway.
"Ungrateful ruffian!" exclaimed Harvey, who entered just as this was spoken.