The reason for preparing this book is the astonishing variation in the practical efficiency of methods actually employed and prescribed by law or legal custom in different parts of the United States in acquiring land for public purposes, in distributing the cost of public improvements, and in other proceedings essential to the proper shaping of our growing cities to the needs of their inhabitants. Mere variation in method would be of little more than academic interest in itself, but variations that result in obstructing the path of progress in one community and clearing it in another are of large practical importance. The extent and significance of these practical variations have impressed themselves more and more strongly on the writer in the course of an extended practice as a landscape architect, especially in connection with the design and execution of such municipal improvements as parks, playgrounds, public squares, parkways, streets, the placing of public buildings and the improvement of their grounds. Even more notable than the variation in method and in relative efficiency has been the close preoccupation of public officials, especially in the city law departments, with the constantly recurring problem of finding the way of least resistance for navigating a specific improvement through the maze of obstacles imposed by the existing local legal situation, accompanied by an almost fatalistic acceptance of these obstacles as a permanent condition. There has been evident in most cities a very limited acquaintance with conditions and methods to be found elsewhere, and a general lack of strong constructive effort for the improvement of the local conditions and methods on the basis of general experience. Of late years, however, there has been a growing tendency to break away from this indifference and to face these problems in a larger spirit. Feeling the importance of stimulating and assisting such constructive local effort by calling attention to the more important of the variations in actual use, and lacking both the time and the legal training to himself prepare a proper presentation of the subject, the writer of this preface urged the Russell Sage Foundation, some three years ago, to provide the funds for making a systematic survey of the field and for publishing its results. The response was cordial and effective and enabled Mr. Flavel Shurtleff of the Boston Bar to devote a large part of his time for two years to the undertaking. Mr. Shurtleff has done the real work of the book from beginning to end and is responsible for its accuracy from a legal point of view. The writer of this preface has been compelled to limit his collaboration to a general guidance in the gathering and selection of material and its arrangement for presentation, and to a somewhat careful and detailed revision of the manuscript and proofs for the purpose of making the impressions conveyed by the book conform in a common sense way with the observations and conclusions to which he has been led in dealing with actual problems of municipal improvement in many different cities.