What the Board Did. The Police Commissioners Made Several Changes. Clay Keenan Promoted. His Faithful Services Recognized at Last. McGark to Have the Next Chance. Numerous Transfers to Take Effect on Sunday Next. The police board, last evening promoted Henry Clay Keenan from the rank of patrolman to that of detective. He takes the place of Michael Kileauley, who resigned as detective some time ago. Keenan hails from the Hudson City section, where he has been known as Detective Keenan for over ten years. The fact is that he has only been acting-detective. On and after September 1 he will get the salary as well as the honors attached to a detective's position. Keenan has been acting-detective almost since the time he was appointed to the force in 1879. During that period he rendered conspicuous services on more than one occasion. It is claimed that a lack of "pull" alone accounts for his failure to attain the rank of detective, long ago. It was in 1881, that Keenan scored one of his most brilliant achievements, by running down the Lindauer gang of burglars. The gang had been committing burglaries and thefts right along, and Keenan was detailed to run them down. He managed to become acquainted with female friends of the leading members of the gang, and he soon gained the girls' favor. They trusted him, and he became one of their boon companions. In the course of his alliance he learned from them many important secrets regarding the burglars with whom these women associated. The gang had its headquarters for some time within a few blocks of New York police headquarters. The New York police were ignorant of the existence of this den. Keenan learned so much about the thieves while with the women that he soon had enough evidence to arrest the gang and land them in jail. Keenan arrested five of the robbers, and they were convicted. That broke up one of most daring band of robbers that ever infested Jersey City. For several years Keenan was attached to the police court on the hill. President Abernethy believes that Keenan will prove a valuable addition to the detective force. Policeman McGurk who was urged as a candidate for Kileauley's place, will be taken care of in due time. He will be promoted at the first favorable opportunity. Keenan has been on the force much longer than McGurk. The board appointed Sherman De Clarke chanceman. He is a finely built young man, of sterling qualities, and was warmly recommended by Assemblyman Drake. He hails from the old third district. Several transfers were ordered. Policeman Heath, of the first precinct, will be detailed in the P.R.R. depot and ferry, in place of Policeman Cody, who has been made roundsman to date from September 1. Sergeant McDevitt goes from the second to the fifth precinct; Roundsman Casey from the fifth to the second; Patrolman Dodson from the second to the fifth; Patrolman Mullins from the fifth to the second; Chance Henry Abernethy to the Central Railroad ferry. Patrolman Dodson is to be acting roundsman in place of Roundsman McIntyre, who was sent from the fifth precinct to police headquarters. The transfers will all go into effect September 1.