The Centre of a System Which Affords Police Protection to the City -- Headquarters of the Police Department -- Telegraph Office; Superintendent Crowley--Third Precinct; Captain Gastlin -- The Harbor Patrol--Superintendent's Chief Clerk, Hopcroft -- Bureau of Inquiry for Missing People -- Commissioner French -- Commissioner Fitz John Porter -- Commissioner Matthews -- Lost Children -- Chief Clerk Kipp--property Clerk's Office -- The Sanitary Company -- Tenement House Squad.

Police Headquarters, at No. 300 Mulberry Street, is a solid, massive structure, extending back to Mott Street. Here are centered the clerical force of the Department, the offices of the Superintendent, First Inspection District, Detective Department, Property Clerk, the headquarters of the Third Precinct (formerly Steamboat Squad), Telegraph Bureau, Matron Webb's rooms for lost children, the Election Bureau, and several other offices of minor importance. The Police commissioners also have their offices here, and, altogether, it is the most important building of its kind in America. Police Headquarters attracts a great many visitors. Its portals open wide to receive alike the beggar and the merchant prince, the swindler and the philanthropist, the journalist and the politician; all meet and mingle here in true democratic fashion; while the great wheels of the visible machinery of the law keep revolving in their tireless course. This is the heart and centre of the elaborate system which affords Police protection to a great city. The entire Police force consists of two thousand eight hundred and eighty-nine men, sub-divided, according to rank, as follows: one superintendent, four Inspectors, thirty-six Captains.

Forty Detective Sergeants, one hundred and fifty-two Sergeants, eight Acting Sergeants, one hundred and seventy-eight Roundsmen, two thousand three hundred and seventy-four Patrolmen, and eighty Doormen. There are, in addition eighteen surgeons.

TELEGRAPH OFFICE.--In the basement, Rooms 1 and 2 are occupied b y the telegraph office. The Superintendent of this Bureau is James Crowley, a most competent official, who has held his present important position for over twenty-five years. The operators are: Michael R. Brennan, George F. Stevens, Charles Wylie, Richard Battin, Robert D. Ferguson. William S. Fraser, lineman; Francis H. Haggerty, battery boy.

The importance of the Police Telegraph cannot be overestimated. It is acknowledged to be the right arm of the service. Without it the Police would be powerless to cope with crime and criminals. What a compass and rudder are to a ship the telegraph is to the Police Department and this branch of the Police system is fortunate in having at its head a man of tried capacity and integrity. The Superintendent, seated at his desk at Police Headquarters, knows almost in an instant what is taking place at the furthest Police point of the city. He is in constant communication with his subordinate officers, and through him, orders are almost instantaneously transmitted to every Police commandant in the city, and through them to the two thousand eight hundred member of the force.

This Bureau, during the riot week, materially assisted in saving the city from being sacked and burned. The staff then consisted of the present Superintendent, James Crowley; Eldred Polhamus, Deputy Superintendent; Charles l. Chapin, John A. K. Duvall and James A. Lucas, Operators.

There are then thirty-two telegraphic stations in the city, all centralizing at Police Headquarters, which were divided into five sections--the North, East, South, West and Central.

The week after the riots the Police commissioners issued an address to the force, in which reference was made to the efficient services of the telegraph corps, as follows:

"Mr. Crowley, the Superintendent of the Police Telegraph, and the attaches of his Department, by untiring and sleepless vigilance in transmitting information by telegraph unceasingly through more than ten days and nights, have more than sustained the high reputation they have always possessed."

The office connected by wire with the various station houses, the Fire Department, hospitals, elevated Railroad Stations, the river fronts and island, the arsenals and armories, etc.

THIRD PRECINCT.--Rooms 3 and 4, in the basement, are occupied by the third Precinct Station (formerly the Steamboat Squad.) This is in charge of Captain George W. Gastlin. The old Steamboat Squad was organized on the ninth of June, 1876, and Captain Gastlin, who was then Sergeant in the Tenth Precinct, assigned to the command. The Steamboat Squad insures very complete protection tot he river front, wharves, and piers, and give more direct and efficient protection to travelers. On December 15, 1876, the command was divided into two squads, the Eastern and Western Steamboat Squads, the former doing duty in the First Inspection District, the latter in the Second Inspection District.

The Third Precinct is bounded on the west side of New York by low water mark on the North river, Fourteenth Street, the centre line of Thirteenth Street, the centre line of Eleventh Street, and the west car track in West Street, to Battery Place, and the south side of Pier 1. On the east side of the city it is bounded by low water mark on the East river, Gouverneur Slip, and the east car track, to the Barge office. It has one central station at Police headquarters, and two sub-stations, one in the United States Barbe Office and one in the building of the Albany Day Line of steamers, at Pier 39, North River. Its officers are: Sergeant Watson Vreedenburhg, who became a Policeman in 1865, was made Roundsman in 1867, and was promoted in September, 1870; Sergeant John J. Taylor, who joined the force in May, 1864, was made Roundsman three years later, and gained rank in November, 1869; and Sergeant Charles H. Reinisch, whose dates are: Patrolman, August, 1868; Roundsman, July, 1876; and Sergeant, September, 1877. This precinct is commanded by Captain George W. Gastlin.

The command was organized in June, 1876, by commissioner Joel B. Erhardt; and Roundsman (now Sergeant) James K. Fuller, first commanded it. Sergeant (now Captain) Gastlin, succeeded him. The force was known as the Eastern and Western Steamboat Squads at one time, then it was amalgamated into the Steamboat Squad, and in January, 1885, the precinct scheme, devised by chief Clerk Kipp, went into force.

CAPTAIN GEORGE W. GASTLIN, of the Steamboat Squad, has done more than any other officer to free the river front from thieves and bunco men. At the time of the formation of the Squad the wharves along the river were in the charge of rowdies of all descriptions. Hundreds of confidence operators and swindlers of every description had, up to the time of his appointment, preyed on unsuspecting emigrants and people who, by the hardest kind of labor and pinching economy, had amassed a little money and wished to return to the old country.

When the Squad was first organized there were two Italian swindlers who passed themselves off as priests, and in this manner won the confidence of several emigrants. One morning, Captain Gastlin, produced these rascals at the Tombs. Their names were Vivaldo Michele and Lorenzo Mazin. A short time before their arrest these two men had met an Italian at Bowling Green who was going to Europe. Mazin, "the [priest," got into conversation with his unsophisticated countryman, whom he told that he was going to Italy, and required an interpreter; Mazin at the same time showed Mono a satchel which he said contained thousands of dollars. Mono agreed to take the situation of interpreter, and gave his money to the priest for safe keeping. The clerical impostor then sent Mono for some fine cigars, but when he returned with the cigars "the priest" had vanished along with his confrere Michele. Bother were sent to State Prison.

John Goss, a well-known confidence operator, who used to lie in wait for the Troy boats and swindle the passengers was the next victim of the Captain's vigilance.

Aleck Anderson alias W. Odell, met a grey-haired old gentleman named Samuel Fraud of Blackstone, Mass., onboard the Newport boat, and told him that he (Anderson) had to pay the freight on some goods which had just come onboard, and would Mr. Fraud oblige him with loan of one hundred dollars against a gold check for eight hundred dollars on Messrs. Reilly & May. Of course, the check was worthless. Anderson was arrested by Captain Gastlin, taken before Justice Wheeler at the tombs, convicted, and sent to State Prison.

A very clever piece of Police work was the arrest of Walter Williams alias Roberts alias Slip Corcoran, and William Foster alias Fitzgerald. These two sharks had operated on a poor Irishman who was returned by a White Star steamer to take out his mother from the old country. They had taken every penny he has from him--one hundred and fifty pounds sterling--and decamped. Captain Gastlin just then arrived on the scene. In order to avoid being recognized as an officer, he told the unfortunate victim that he would lost his passage if he did not get on board at once. With the assistance of a Policeman, Captain Gastlin hustled the man down on board the steamer and pout him down among the steerage passengers. A short time afterwards Captain Gastlin removed the man from the steamer to Castle Garden. This ruse completely threw the confidence men off their guard--of course, there would be no complainant against them now that Henry had sailed for Ireland. Captain Gastlin, a week afterwards, captured the swindlers, and great was their surprise then Henry was produced in court as a witness against them. The prisoners were sent to State Prison.

John Leonard, a passenger by the steamship Pennsylvania from Liverpool, robbed several of his fellow-travelers of sums varying from three to eighty-five pounds sterling. One of the passengers recognized a four-penny bit which was found on Leonard's person, and this was really the only thing by which the thefts could be fastened on him. Captain Gastlin worked up the case. Leonard was arrested and sent to State Prison.

Hilza Von Zaren alias Le Marquis O'Neill de Lassantas, was employed as a waiter in the summer at Newport. In the evening he used to dress as a woman, and become the rage among the young bloods spending the season at Newport. After the Newport season closed, he came to New York, where he was employed at a house on Fifth Avenue as a waiter. He plundered the house and fled. He was afterwards employed in a West Forty-eighth Street house, which he also plundered. His arrest in New York, by Captain Gastlin, created a great sensation and scandal. He was sent to Sing Sing.

Captain Gastlin, who is the son of Policeman is, in a double sense, a born Policeman.

The Special Duty Officers of this precinct are: Euho Hey, Janus Mallen, William Thomas, and R. J. Vail on the North River; and E. Grady and H. E. Van Ranst on the East River; and Nathan Sanford detailed to the Corporation Attorney's office.There are forty-one day posts on the North River, and nineteen day posts on the East River; and nine night posts on the North River, and nine night posts on the East River. The effective force is about ninety-four Patrolmen and six Roundsmen.

The days Posts on the North River are:

Night Posts, North River:

Day Posts, East River:

Night Posts, East River:

This precinct has a peculiar system. One section goes on day duty at seven A. M., and is relieved at six P. M. by a section which is relived at midnight by a section which remains on duty until seven A. M. The day duty men are day duty men all the time. The night duty men change off every Sunday, that is to say, those who have been doing duty from midnight to seven A. M., take the place of those who have been doing duty from six P. M. to midnight.