HAMPTON BEACH, N. H., July 4 -- Prank W. Horne, of Conway, N. H., operator of the automobile which plunged through the Mile-long Bridge here early today, drowning Miss Louise Dorien, 21, of Lafayette street, Salem, was arraigned in the local court this morning charged with operating an automobile in a dangerous manner.

He pleaded not guilty and the case was continued until July 15. He was released in $200 bail. Horne, in a roadster, was crossing the bridge in company with Miss Dorien, Miss Doris Jaques, 21, of Pingree street, Salem, and George De Arcy, of Dover, N. H., when he claims he was forced off the road by an automobile which was cutting out.

His car swerved and went through the bridge rail into 10 feet of water. Miss Dorien was trapped in the car and the two men and the other girl were rescued by a boat which put out from the end of the bridge.

Frank W. Horne of Conway was found not guilty Monday on a charge of reckless driving in connection with the fatal auto accident on the evening of July 3 when the machine driven by Horne and containing three others crashed through the Hampton mile-long bridge.

Horne was arraigned before Judge Howell M. Lamprey but no evidence was presented to show that Horne was negligent. The body of Miss Louise Dorrien, Salem, Mass., telephone operator, who was drowned when the car went through the bridge into the Hampton river has not yet been recovered.