Most, if not all, of these churches were fine specimens of the architecture of the Middle Ages, the so-called Gothic architecture, which is characterised by pointed arches, ribbed vaulting, and the constant use of the buttress. These churches were, in contrast to the present condition of most of those that remain, complete with chancel, nave and aisles, towers or spires, bells, stained-glass windows, and furniture, many of them being particularly rich in one or more of these features. The painted windows[9] are especially interesting, for they show the standard of this branch of fifteenth-century art and are valuable historical documents. The rich, mellow tones of colour should be noted, also the incidental pictures of mediæval dress and furniture. It is interesting to compare the fifteenth-century work with that done, for instance, by the William Morris firm to the designs of Burne-Jones (1833-1898), at a time when the revived art, with other forms of decoration, was enjoying a period of great success. In the fifteenth century the church was flourishing materially, at least, and money and gifts were freely given. The offices and services in churches were recited and sung. Organs were used, but were not very large and were capable of being carried about: although working on similar principles to the modern organ they lacked its size, power, and varied capacity. At the Minster there were several organs, for instance "the great organs," "the organs in the Choir," "the organs at the Altar B.V.M." The Chancel was the most sacred part of the church, for there was the principal or high altar. In the Chancel were the stalls or seats of the clergy and officials. The actual seats could be turned up when the occupants wished to stand. Standing for long periods was made less irksome in that the underside of each seat was made with a projecting ledge, which gave some support. It is thoroughly characteristic of the age that this very human device should have existed, and, secondly, that these ledges were carved and ornamented. These misericords, as they are called, were usually curiously, even grotesquely carved. Some of these carvings were founded on natural objects, some were grotesque heads, others represented subjects with man and animals. There were pews for the nobility, but, apart from the few old and weak people who used the rough bench or two in the body of the church, or the stone bench that ran along the walls, the general public stood during the services. Wealthy parishioners left money to the parochial clergy and for the fabric of the church: they generally wished to be buried at some particular place within their parish church. Such distinguished men as Nicholas Blackburn, merchant of York, were commemorated at times in their parish churches by means of stained-glass windows. The portraits of Nicholas and his son and their wives appear in the east window of All Saints', North Street; his arms also are to be seen in this window.