I believe they did it partly to diffuse their guide among a larger party.

He was hanging, as they came up, upon Miss Cora's reluctant earring, so to speak, and she was mechanically saying, "Yes! Yes! Yes!" to his representations.

"I suppose," said she inadvertently, "there is no way of preventing their giving one information," and after that when she hospitably pressed the guide upon us we felt at liberty to be unappreciative.
I regret to write it of two maiden ladies of good New York family, and a knowledge of the world; but the Miss Binghams capitulated to Dicky Dod with a promptness and unanimity which would have been very bad for him if nobody had been there to counteract its effects.

He walked between them through the vestibules, absorbing a flow of tribute from each side with a complacency which his recent trying experiences made all the more profound.

There was always a something, Miss Nancy declared, about an American who had made his home in England--you could always tell.