The choirs of the early Christian churches, which were all frequented by the people, were enclosed by open screens, like trellis-work, usually made of brass, and this principle has descended through all ages in churches destined for _parochial worship_ and _the use of the people_, while in cathedral, collegiate, and conventual churches, which were intended more especially for the use of ecclesiastics, the solid screens were invariable, not only across the nave but round the choir, so that the canons and religious were completely enclosed. The introduction of these close screens was coeval with the commencement of the long offices, and were positively necessary for those who were compelled to remain so many hours in choir, and who would have been unable to resist the cold if exposed to the free passage of the currents of air which prevail in these large edifices.[4] But, like every object generated in necessity, the church soon turned them to a most edifying account, and while the great screen was adorned with the principal events of our Lord's life and passion, surmounted by the great rood, the lateral walls were carved with edifying sculptures and sacred histories, many of which still remain, as at Notre Dame, Paris, Amiens, Chartres, Auch, &c. I do not think that the theory, which some writers have advanced, of these _close_ screens being erected to increase the mystery of the celebration, and to procure greater respect for the sacrifice, is tenable; the mass is not more holy in one church or one altar than another, and it is most certain that no parochial churches, built as such, ever had close screens, but always open ones; and, indeed, we very often find altars erected outside these close screens of cathedral and conventual churches, for the benefit of the people, as will be seen by the plates given in this work, which would involve a complete contradiction in principle, supposing the high altar to be hid on symbolical grounds. The _close_ screens belong properly to the choir rather than the altar, as in many Italian churches served by religious, the clergy sat behind the screen, while the altar is partly without, so that the celebration served for both the religious and the people. At Durham Abbey, the Jesus altar was outside of the great screen; and at St. Alban's Abbey, in the screen which traverses the nave, there are the evident marks of an altar which doubtless served for the parochial mass. It will be seen from these remarks that close screens, as a principle, are only suitable for churches intended for cathedral chapters or conventual and collegiate bodies; and they are certainly most unsuitable for any churches to be erected in this country under existing circumstances, where the limited extent of means and number of the clergy render it necessary for all services to be available for the faithful in general, and the bishops' churches, like the original basilicæ, to be in a manner parochial.