"Heaven bless you, sir!" said Mr. Minford. "You will be the means not only of relieving me and my dear child, but also of conferring the boon of a great discovery upon mankind. But your terms are too liberal, sir. I shall insist upon assigning one fifth of my right to you, which, mark my prediction, will prove of itself a fortune. Furthermore, I feel that I ought, if only to show my complete confidence in you, to tell you what it is. It is--" Mr. Minford hesitated for a word. "Now I beg, as a particular favor, that you won't tell me," said Marcus, goodhumoredly. "If you bore me with any of those dull details, I'll--I'll take back my offer. As to the proportion of the invention which I am to have, I will accept one fifth, since you insist on it, not because I want it, but that we may not say another word about the matter." "As you please, sir. But how shall I sufficiently thank you?" Marcus, who was already overcome with the gratitude which shone from the large, soft eyes of the young girl, answered, with a laugh and a blush (he had not outgrown the habit of reddening on occasions): "By changing the subject." Mr. Minford was about to protest against this extraordinary method of thanking a benefactor, when a rap was heard at the door. CHAPTER VII. THE BOY BOG. In reply to the invitation, "Come in," a tall boy opened the door, and started back on seeing a stranger. "Do come in, Bog," said Mr. Minford. "I have good news to tell you. This is a friend of ours, Mr. Wilkeson. What with his running of errands, and doing little jobs for us, we really couldn't get along without him. Oh, walk in, Bog; you're always welcome here." "Now _do_ come in, Bog," added the little girl, in a winning tone, rising from her stool, stepping to the door, and placing a hand on his shoulder. The new comer, after a few shuffles on the threshold, and an unintelligible murmur of words, walked in with painful awkwardness, and took a seat upon a corner of the chair which Pet offered him, as if the whole chair were more of a favor than he could conscientiously accept; He was a bony, strongly built stripling, with a record of anywhere from seventeen to nineteen years written in his red, resolute, honest face. He wore a coarse but neat suit of boy's clothes, one inch too small in every dimension, a white turn-down collar, and a black neckerchief fastidiously tied; and carried a slouched cloth cap in his hand, with which he slapped his knees alternately, after he had taken a seat, and continued to do so without cessation. "Well, Bog," said Mr. Minford, kindly, but condescendingly, "you are just in time to hear good news. This gentleman has taken a partnership in my invention (Mr. Minford thought it best to state the case that way), and, with his assistance, I shall be able to complete it and bring it before the public immediately."