THE development of the scientific criminal is one of the most remarkable features of our police records.

      The professional criminal of to-day is not, as was his predecessor, a coarse brute of savage instincts relying on his strength, terrorism, and low cunning as the qualifications of his unlawful calling. He is no longer Bill Sykes. On the contrary, he is frequently well educated, outwardly refined, an expert in all that pertains to the particular branch of crime which he has made his own, a man of resource, daring, and, in many instances, possessing an inventive faculty and a mechanical training of a high order. And it is especially in burglary that this skill in mechanics and inventiveness display themselves.

      Eagerly as the Wall Street financier follows the movements and tendencies of the markets, the professional man of crime follows the latest improvements in mechanical and scientific appliances, always seeking for new aids in his nefarious business.

      "The New Burglar is essentially an expert," said Captain McClusky, Chief of Detectives of New York, to the writer a few weeks ago, in his office at Police Headquarters, Mulberry Street. "He has developed amazingly in cleverness and ingenuity. Frequently he has invented — either as the result of sudden inspiration, or of careful and laborious study — appliances and tools that, were they applicable to legitimate business, would be worth fortunes as patents." This statement from the man who has to cope with the scientific burglar is borne out by a visit of inspection to the room at headquarters where are preserved the illegal implements captured by the police from time to time.

      A wonderful amount of mechanical skill is shown in the construction of many of the more recent burglars' tools. At first glance many of them may appear crude and ill-constructed, but a closer examination reveals how adequately they are made to answer their purpose. They are not highly finished, and have nothing of the nickel-plated polish upon them; they are not made for exhibition purposes, but for work where efficiency is far beyond appearance in the eyes of the owner.

      It is to the breaking open of safes that the burglar has turned his most crafty attention; it is the only feature of his work that presents exceptional difficulties, and the safe is, of course, invariably the objective point of a burglary. To get to the safe is a comparatively easy task, but to get inside — that makes a call upon all his resources. When safes were less well made than they are now, many a burglar used a lead-filled sledge, a cold chisel, and an ordinary" jimmy" with success, but to-day the safe that can be opened by such means is hardly likely to yield enough to make the operation paying. With the improvement in safe-making came the development in safe-breaking. The burglar used gunpowder, dynamite, and other explosives with a large measure of success, and even now this method, despite its obvious objections, is still largely used by criminals, but not by the most expert. The really clever burglar found an explosion rude, clumsy, and alarming, besides being in itself dangerous, and consequently he looked ahead for a better and quieter means of accomplishing the same end. Here it may be remarked that in any appliance used by a criminal, especially by a burglar, the great desideratum must always be its simplicity. A tool that is not portable and easily worked is useless or almost useless for his purpose.

      The most modern, and most complete, of all safe-cracking appliances consists of a horseshoe or, more correctly, magnet-shaped piece of the best steel, pierced at the apex and both ends for stout screws. It is so made as to slip down back of the spindle of a combination lock, and has what one might call its "delta," so narrow that the knob of the handle overlaps both legs of the magnet. It is slipped into position in a moment; the screws are turned a little at a time, alternately, against the body of the safe, forcing out the magnet and with it, of course, the spindle. In sixty seconds the spindle can be forced from the strongest lock. A chisel that fits the aperture made by removing the spindle is then inserted, and with one sharp blow from a noiseless leaden hammer the works of the lock are scattered into the safe. An ordinary piece of bent wire is now sufficient to disarrange the tumblers, and, the handle being turned, the safe is open to the hands of the burglar.

      According to Detective-Sergeant Thomas Adams, who has spent a busy life-time in the detective service of New York, no known device can equal this innocent-looking piece of iron junk. An additional advantage lies in the fact that it can be carried in the pocket of an ordinary coat. Just imagine the massive, imposing, and expensive contrivances of the safe manufacturers yielding so readily to a tool the making of which, in the burglar's hands, does not cost over fifty cents.

      One Michael Cody invented it by sitting down before the latest and most improved pattern of safe and studying its construction closely. It struck him at once that the lock was the most vulnerable part of a safe, and from the birth of that idea grew the completed invention. Louis Lund, a Frenchman, nicknamed "French Louis," burglar and house-thief, also has an invention to his credit of which Edison might be proud. If any one criminal in the United States can be said to have made burglary a science it is Lund. He invented a safe-drilling appliance that is almost perfect in its way, its only weak feature being its bulk and the number of parts of which it consists. It has a finished appearance and polish borne by no other exclusively criminal tool, due to the fact that Lund, who was himself a skilled worker in tools, conceived the plan of having it made in sections to scale in regular tool factories at various places, and then afterwards piecing the parts together himself. This drill Lund used himself in many robberies, but not satisfied with his earnings in that manner he had several of the instruments made, which he loaned out on royalty to other bank burglars less inventive than himself. This instrument was one of many designed by Lund for safe-cracking, and it was while serving a term in Sing Sing for its use that he made the invention of which I have already spoken. It was to him that our prison system owes the lever-lock now in use in every jail in the United States. By means of this lock, the mere shifting of a lever in the warden's office securely seals instantaneously every cell door in the entire establishment. Lund gave his invention freely to the authorities; had it been invented under ordinary circumstances it would most certainly have brought fortune to its maker. It is grievous to think of talents like Lund's squandered in the service of crime.

      "You may safely say," said Captain McClusky, speaking to me of the remarkable genius of Louis Lund, "that every well-organized gang of burglars has at least one skilled mechanic as an active member. Sometimes these fellows who supply the brains of the gang will retain a position in a tool or lock factory for the double reason of the greater security from suspicion or capture that it gives them, and the opportunity it offers for making or having made the tools required in the operations. More frequently, however, the mechanical genius of the party will travel with the rest and superintend the work, especially where a difficult building is to be entered or strong vaults are to be rifled."

      I have already said that the safe is the main point of the burglars' attack, but in the case of banks, safe-deposit vaults, and strongly protected private houses, some outworks have to be overcome before work on the safe can be begun. Those strong curved bars, one to two inches in diameter, that ornament the windows and doors of many such buildings look formidable enough to the unprofessional, but to the burglar they are comparatively easy of attack. An instrument, on the screw principle, which he usually carries down the leg of his trousers, and which is known in criminal circles as a "drag," will distend those bars sufficiently for a fairly large-sized man to pass through in a few minutes.

      Lock manufacturers have for years been fighting, with more or less success, the skeleton key and the professional lock-picker. The lock of to-day is infinitely more complicated than that of fifteen or twenty years ago, but the improvements in locks only seem to call forth a greater degree of skill and cleverness from the lock-pickers. One professional house-thief, at least, has fought the lockmakers to a stand-still. His name is Henry Klein, and it was while confined in Sing Sing prison that he invented and manufactured a set of keys of most delicate workmanship and ingenious construction. The police are now in possession of the set, and regard it with wonder and admiration as the most complete lock-picking outfit ever made. It consists of several distinct shafts, with wards, removable or extendable at will by turning a screw. They can instantly be converted into pivot or hollow keys and the size, position, and number of the wards can be altered into a large variety of combinations. How Klein managed to secure the material from which to make his keys — much less how he contrived to manufacture instruments so minute in detail under the very eyes of his custodians — will always remain a prison mystery. Ordinary collusion with a warden does not explain it. To estimate the value of the little ten-by-twelve card on which these keys are now preserved in the museum at Police Headquarters would be impossible, since there is no standard by which to gauge it.

      Taking him altogether, the modern burglar, bank-breaker, and swell cracksman is a shrewd, inventive fellow, skilful in his unlawful profession. He would escape more frequently than he does were it not for that kink in his character which stamps nearly every criminal. It is not what he does when actually committing a crime as how he conducts himself afterward that frequently gives the police the clew to his capture. The criminal's cleverness and shrewdness ends and his recklessness begins once the job is over. There are, however, some burglars, men known to be guilty of or implicated in bank and other robberies, who go uncaptured and unpunished year after year, because they cover up their tracks so well that they leave no legal evidence behind them. These men are the real masters of their profession. They are never off their guard, never drunk, they only dissipate at rare and regular intervals, and are burglars just as other men are merchants. Even though the calling be legally and morally wrong, it is their chosen business, and they, at least, are happy in the consciousness of work well done. These are the burglars the police respect through sheer admiration of their cleverness.