Charlotte, the owner of a new Cadillac automobile, agreed to loan the car to Ellen for the month of February while she (Charlotte) went to Florida for a winter vacation. It was understood that Ellen, who was a small-town Cadillac dealer, would merely place Charlotte's car in her showroom for exhibition and sales promotion purposes. While Charlotte was away,Ellen sold the car to Bob. When Charlotte returned from Florida, she sued to recover the car from Bob. Who has title to the automobile?