This canon rests on the necessities of a stock company, as those before rest on the nature of scenery and audiences. Every company has its leading man, leading lady, low comedians, old man and old woman, and those ordinary characters which all playgoers know by heart. If the play does not fit these, it will not succeed. The appreciation of this fact is one secret of the great success of Boucicault, Daly, and Lester Wallack as play writers. They know the exact capacity of their stages and companies from long experience, and write their plays to fit them. With even ordinary talents they would have a great advantage to start with over writers of greater genius, writing with vague ideas of what the manager wants. As managers they know exactly what they want, and what their companies can do. To a young writer the difficulties are all in the start, unless he be an actor, or so closely related to actors or managers as to be able to get behind the scenes at all times, and become familiar with scenery, traps, machinery, rehearsals, and all the details of the _business_ of theatricals. In former times, especially two centuries ago, the task of writing a good acting play was far easier than now. Scenery was simple, access behind the scenes easier--there was not such a wall of separation as now exists between actors and audience in a first-class city theatre. Even in those days, however, the writing of plays was confined chiefly to actors, managers, and those men of fashion who were given to haunting the green room. In the present day no amount of talent in a writer seems capable of overcoming the difficulties of technical construction of a drama. It is rare to find an author of acknowledged talent in other departments, especially in America, distinguished as a dramatist, and when one of them tries his hand at playwriting he fails, not from lack of good dialogue and literary finish, but solely from lack of knowledge of the business of the drama, the limitations of actors and scenery, and the technique of dramatic construction.