Cranes and levers were employed for lifting the huge blocks of stone quarried from the surrounding mountains. Even the rough work was allotted only to workmen of approved ability and reputed industry, while the task of decoration was given to masters of the arts of painting, illuminating, and carving in wood, metal, and ivory. Upon this bleak highland a busy colony of toilers from many parts of Europe sprang up in a few months. Forges, workshops, and saw-pits were set up or constructed amongst the _scoriæ_ or shale of the mountains, and the desert rang with the beating of hammers on metal, the clicking of the mason’s chisel, and the grating of the saws. An immense number of carts and horses were employed, besides pannier-mules and asses, to bring the stone from the quarries and the metal from distant furnaces. Only a part of the work was performed at the Escorial. The bronze was compounded in Zaragoza; the white marble came from the Sierras de Filabres, and the green, black, and variegated marbles were brought from the mountains of Andalusia, while Cuenca and Segovia furnished part of the pine wood. Many of the figures of bronze for the altars were designed and made in Florence and Milan. Toledo supplied lamps, candlesticks, crosses, and incense-burners. Holland provided heavy bronze candle-holders. Spain, Italy, and Flanders were searched for precious stones and metals to beautify the building, and artists and craftsmen were imported from many countries. Juan Bautista de Toledo, and his pupil Juan de Herrera, expended great care and pains in the designs. Models of the various parts of the Escorial were made in wood, and the designs were altered and improved by both architects from time to time. Under the direction of Juan de Herrera every detail of the building was submitted to him for his approval before it was finished. Even the designs of Peregrino and Flecha, the Italian masters, were submitted to the inspection of the master-architect. Juan de Herrera was succeeded by Francisco de Mora as chief architect. The construction of the Principal Choir was a part of the work upon which much forethought was expended. Father Sigüenza describes the Corinthian style of the choir as the most beautiful feature of the Church. He mentions one hundred and twenty-eight as the number of the seats. The Retablo was a costly piece of work, as a large quantity of jasper and precious metal was used in its embellishment, and much gilt employed. The columns are of the Doric order, and the bases are formed of gilded bronze. Father Sigüenza does not stint his praise for the ‘judicious architects and singular painters’ employed by Philip II. at the Escorial, and his book is characterised by a high enthusiasm for the king, and admiration for the great work, ‘this sumptuous fabric,’ in which the worthy _padre_ spent so many years of his life as Director of the Royal Library.