The efforts of the unions to adjust themselves to the quickly changing conditions of modern industry are not always successful. Old trade lines are instantly shifting, creating the most perplexing problem of inter-union amity. Over two score jurisdictional controversies appear for settlement at each annual convention of the American Federation. The Association of Longshoremen and the Seamen's Union, for example, both claim jurisdiction over employees in marine warehouses. The cigar-makers and the stogie-makers have also long been at swords' points. Who shall have control over the coopers who work in breweries--the Brewery Workers or the Coopers' Union? Who shall adjust the machinery in elevators--the Machinists or Elevator Constructors? Is the operator of a linotype machine a typesetter? So plasterers and carpenters, blacksmiths and structural iron workers, printing pressmen and plate engravers, hod carriers and cement workers, are at loggerheads; the electrification of a railway creates a jurisdictional problem between the electrical railway employees and the locomotive engineers; and the marble workers and the plasterers quarrel as to the setting of imitation marble. These quarrels regarding the claims of rival unions reveal the weakness of the Federation as an arbitral body. There is no centralized authority to impose a standard or principle which could lead to the settlement of such disputes. Trade jealousy has overcome the suggestions of the peacemakers that either the nature of the tools used, or the nature of the operation, or the character of the establishment be taken as the basis of settlement.