sentences:  The ornamental work and the dressing round the windows are of Ohio sandstone.The plain surface is faced with a cream-colored sandstone of the Potsdam formation, obtained from Nepean, a few miles from Ottawa.The spandrils of the arches, and the spaces between window-arches and the sills of the upper windows, are filled up with a quaint description of stonework, composed of stones of irregular size, shape and colour, very neatly set together."