He had come to borrow a book.

When a lad he had fallen backward from a ladder thirty-five feet upon the pavement with a load of slates that he was carrying to the roof.

The poor lad was so thirsty for books that he would borrow from booksellers who would loan them to him out of pity, read them and return them.
The _Youth's Companion_ says that Mr.Edison in his new biography--his "Life and Inventions"-- describes the accidental method by which he discovered the principle of the phonograph.

There is a kind of accident that happens only to a certain kind of man.
"I was singing to the mouthpiece of a telephone," Mr.Edison says, "when the vibrations of the voice sent the fine steel point into my finger.
That set me to thinking.

If I could record the actions of the point, and send the point over the same surface afterward, I saw no reason why the thing would not talk.
"I tried the experiment first on a slip of telegraph paper and found that the point made an alphabet.