The impression produced on you when you enter this ancient sanctuary of the Moslem faith cannot be defined, and has nothing whatever in common with that generally caused by architecture; you seem rather to be walking about in a roofed forest than in a building. On whatever side you turn, your eye is lost in alleys of columns crossing each other and stretching away out of sight, like marble vegetation that has shot up spontaneously from the soil; the mysterious half-light which reigns in this lofty wood increases the illusion still more. There are nineteen transepts and thirty-six naves, but the span of the transepts is much less than that of the naves. Each nave and transept is formed between rows of superimposed arches, some of which cross and combine with one another as if they were made of ribbon. The columns, each of which is hewn out of one solid block, are hardly more than ten or twelve feet up to the capitals, which are Arabic-Corinthian, full of force and elegance, and reminding you rather of the African palm than the Greek acanthus. They are composed of rare marbles, porphyry, jasper, green and violet breccia, and other precious substances; there are some even of antique origin, and are said to be the remains of an old temple of Janus. Thus the rites of three religions have been celebrated on the spot. Of these three religions, one has for ever disappeared, with the civilization it represented, in the gulf of the past; the second has been driven out of Europe, where it has now but a precarious footing, to take refuge with the barbarism of the East; and the third, after having reached its apogee, has been undermined by the spirit of inquiry, and is growing weaker every day, even in those countries where it once reigned as absolute sovereign. Perhaps the old mosque built by Abderama may still last long enough to see a fourth religion installed under the shade of its arches, and a new God, or rather a new prophet,--for God never changes,--celebrated with other forms and other songs of praise. [Illustration: MOSQUE, CORDOVA.]