The necessary expenses of the detection of crime are often considerable. Information must be obtained, even if it has to be paid for liberally. Officers must be in concealment for weeks, and sometimes for months. Long journeys must not unfrequently be made; and in a hundred ways large expenditures will be called for. We were told of a case where a treasury note of the government was counterfeited with consummate skill, and it became a matter of vital importance to obtain the plate from which the counterfeit was printed. One of the most successful detectives was employed to work up the case, who soon found that the cost of securing it would be so great that there was little probability that the treasurer would audit his accounts. He therefore told the government that the cost would be so great that he declined to undertake it; but the possession of the plate, and the information that its capture would give, were so exceedingly important, that the detective was authorized to go on with it. He did so; the plate was obtained; all the information sought for was procured, and the counterfeiters and their abettors were captured. But it cost the government one hundred and twenty thousand dollars to accomplish this result. There were regular vouchers for every payment, and each was carefully scrutinized and verified. There was no doubt whatever that all the expenditures had been made in good faith, and with the utmost economy. Doubtless the government felt that the possession of that plate, and the knowledge gained, were worth all they had cost. TRACKING A MURDERER. The following case, which occurred a few years ago, in a sister city, will show how the detectives track and secure their game: A terrible murder had been committed. The sods were scarcely heaped upon the coffin of the murdered man when one of his murderers was securely confined in the cells of the central station. The arrest was one of unusual difficulty. When the detectives visited the scene of the murder, the only clue to the perpetrators was a blood stained handkerchief and the gag used in strangling their victim. With these faint traces there was little hope of ferreting out the murderer, but Detective Joshua Taggart assumed the task. Returning to the store, he reconnoitered the premises with new diligence. A new trace was then discovered. A new mortise chisel, wrapped in a piece of brown paper, lay on a shelf in the room. The chisel was not the property of the proprietors of the dental depot. It had plainly been brought there by the burglars. To trace it then became the task of the detective. Upon it depended his only hope of tracing the murder from the dead porter to the burglars who had killed the unoffending warden.