Few words are needed to'state the purpose of this work. It represents an earnest attempt to furnish an informative book for the use of coast artillerists With special reference to militia duty in coast defense. The organization of the United States Coast Artillery presents a need which the National Government is not Wholly able to supply. The Coast Artillery Corps of the United States Army at its present strength cannot provide at the utmost for more than, one-half Of one manning detail for the armament of our far-reaching coast fortifications. To supply this deficiency in personnel Congress has authorized the development of a Coast Artillery Reserve to which various coastwise states have transferred specially qualified regiments ~of infantry from their militia organizations. In these regiments, and in other organizations not so transferred Whose services will be required as Coast Artillery Supports and Coast Guard, are many officers and men desirous of fitting themselves for the technical service Of coast defense. A complete programme Of instruction has been issued by the War Department, and it is to supplement this,' as well as to furnish a suitable reference book for the Regular personnel, that the present work was prepared.