The next step in advance, and one of the most important in the slow development of the scene-painter's art, took place in France early in the nineteenth century, and simultaneous with the romanticist movement, which modified the aims and ambitions of the artists as much as it did those of the poets. The severe stateliness of the stage-set which was adequate for the classicist tragedies of Racine and Voltaire, generally a vague interior of an indefinite palace, stiff and empty, was hopelessly unsuitable for the fiery dramas of Victor Hugo and the elder Dumas. An even greater opportunity for spectacular regeneration was afforded, in these same early decades of the nineteenth century, by the bold and moving librettos which Scribe constructed for Meyerbeer and Halévy at the Opéra, and for Auber at the Opéra-Comique. The exciting cause of the scenic complexities that we find in Wagner's music-dramas can be discovered in these librettos of Scribe's, from 'Robert the Devil' to the 'Africaine.' For one act of 'Robert the Devil,' that in which the spectral nuns dance among the tombs under the rays of the moon, Ciceri invented the most striking and novel setting yet exhibited on any stage--a setting not surpassed in poetic glamor by any since seen in the theater, altho its eery beauty may have been rivaled by one scene in the 'Source,' a ballet produced also at the Opéra forty-five years ago--a moon-lit tarn in a forest-glade, with half-seen sylphs floating lightly over its silvered surface. This exquisitely poetic set was imported from Paris to New York and inserted in the brilliant spectacle of the 'White Fawn.' The ample effect of these scenes was made possible only by the immense improvement in the illumination of the stage due to the introduction of gas. Up to the first quarter of the nineteenth century the stage-decorator had been dependent upon lamps--a few of these arranged at the rim of the curving apron which jutted out into the auditorium far beyond the proscenium, and a few more hidden here and there in the flies and wings. Early in the nineteenth century gas supplanted oil; and a little later than the middle of the century gas was powerfully supplemented by the calcium light. Toward the end of the century gas in its turn gave way to the far more useful electric light, which could be directed anywhere in any quantity, and which could be controlled and colored at will. It was Henry Irving, more especially in his marvelous mounting of a rather tawdry version of 'Faust,' who revealed the delicate artistic possibilities of our modern facilities for stage illumination.