In the following chapters I have tried to give an account of my finding in the police business, to bring out the facts about the man who makes his living and keeps up a bank account by professional thieving, to tell the truth in regard to "the unknown thief" in official life who makes it possible for the known thief to prey upon the public, and to describe some of the tramps and out-of-works who wander up and down the country on the railroads. There is much more to be said concerning these matters than will be found in this little book, but there are a great many persons who have no means of finding out anything about any one of them, and it is to such that my remarks are addressed. Until the general public takes an interest in making police life cleaner and in eliminating the professional offender and the dishonest public servant from the problems which crime in this country brings up for solution, very little can be accomplished by the police reformer or the penologist. CHAPTER I. WHO CONSTITUTE OUR CRIMINAL CLASSES? The first duty of a policeman, no matter what kind of a police force he belongs to, is to inform himself in regard to the people in his bailiwick who are likely to give him trouble. In a municipal force an officer can only be required to know thoroughly the situation on his particular beat; if he can inform himself about other districts as well, he is so much more valuable to the department, but he is not expected to do much more than get acquainted with the people under his immediate surveillance. In a railroad police force it is different, and it is required of the officer that he study carefully the criminal situation in all the towns and villages on the division on which he is stationed. Some divisions are longer than others, but the average railroad policeman's beat is not less than sixty miles, and in some cases nearly two hundred. Mine, as I have stated, was over two thousand miles long, and it took in five different States and nearly all the large cities in the middle West. I was, consequently, in a position to acquaint myself pretty thoroughly with the criminal classes in one of the most populous and representative parts of the country. Offenders differ, of course, in different localities, and one is not justified in drawing sweeping conclusions concerning all of them from the study of a single type, but my work was of such a nature that, in the course of my investigations, I encountered, indoors and out, the most frequent offenders with whom the policeman and penologist have to deal. It would take a large book merely to classify and describe the different types, but there is a general analysis that can be made without any great sacrifice of fact, and it is this I desire to attempt in this chapter.