That kind of thing amuses him vastly.

He says in his last letter to me----" Carelessly, the letter was drawn from an inner pocket.

Only a page and a half; Arnold read it out.

A bluff and rather slangy epistolary style.
"May I see his hand ?" asked Irene, trying to make fun of her wish.
He gave her the letter, and watched her amusedly as she gazed at the first page.

On receiving it back again, he took his penknife, carefully cut out the great man's signature, and offered it for Irene's acceptance.
"Thank you.