It is not remarkable, then, that the most ambitious effort of monumental art upon the exposition grounds should have taken the shape of a fountain. The erection is due to the energy and public spirit of the Catholic Total Abstinence Union. The site chosen is at the extreme western end of Machinery Hall. It looks along Fountain Avenue to the Horticultural Building. Mated thus with that fine building, it becomes a permanent feature of the Park. The central figure is Moses--not the horned athlete we are apt to think of when we associate the great lawgiver with marble, but staid and stately in full drapery. He strikes the rock of Meribah, and water exudes from its crevices into a marble basin. Outside the circular rim of this are equidistantly arranged the rather incongruous effigies of Archbishop Carroll, his relative the Signer, Commodore Barry and Father Mathew. Each of these worthies presides over a small font designed for drinking purposes--unless that of the old sea-dog be salt. The central basin is additionally embellished with seven medallion heads of Catholics prominent in the Revolution, the selections being La Fayette, his wife, De Grasse, Pulaski, Colonel S. Moylan, Thomas Fitzsimmons and Kosciusko. The artist is Hermann Kirn, a pupil of Steinhäuser, one of the first of the modern romantic school of German sculptors. Kirn is understood to have enjoyed his instructor's aid in completing the statues in the Tyrol. Another religious body ranges itself in the cause of art by the side of one with which it does not habitually co-operate. Dr. Witherspoon, the only clerical Signer, is its contribution in bronze. The Geneva gown supplies the grand lines lacking in the secular costume of the period, and indues the patriot with the silken cocoon of the Calvinist. The good old divine had well-cut features, which take kindly to the chisel. The pedestal is of granite. Of other statues we shall take another occasion to speak. The tinkle of fountains leads us on to Horticultural Hall, where they give life and charm to the flowers. Painted thus in water-colors, the blossoms and leaves of the tropics glow with a freshness quite wonderful in view of the very short time the plants have been in place and the exposure they unavoidably encountered in reaching it. From the interior and exterior galleries of this exquisite structure one can look down, on one side, upon the palms of the Equator and on the other upon the beech and the fir, which interlock their topmost sprays at his feet. Beyond and beneath the silvery beeches railway-trains whisk back and forth, like hares athwart the covert--the tireless locomotive another foil to the strangers from the land of languor and repose. [Illustration: HORTICULTURAL HALL--INTERIOR.]