a blind arch of the same width at the southern extremity, and a wider one at the northern. The aisles, like the rest of the transept, are almost perfectly plain. [Illustration: The Exterior, from the North.] The #Chapter-house# is connected with the eastern aisle of the transept by a vestibule projecting three bays beyond the north front. This vestibule then turns eastward for two bays, at which point it joins the chapter-house. Both vestibule and chapter-house are magnificent examples of Decorated work. Their date is doubtful, and is discussed in the history of the building. They are certainly among the finest works of Gothic architecture in Europe. The chapter-house is octagonal in shape, and is crowned by a lofty pyramidal roof. Its chief, almost its only decoration, is provided by the buttresses and the beautiful tracery of the acutely-pointed windows. The buttresses are of very curious design. They are joined to the wall of the chapter-house for nearly half their height, and up to this point are quite plain. They are then narrowed into lofty pinnacles, and these pinnacles are connected with the wall by two small flying buttresses, the lower one plainly moulded and sloping upwards to the wall, the upper one being horizontal and richly decorated with arcading, two arcades to each side of every buttress. At the point at which the buttress narrows into the pinnacle there are cusped gables with gargoyles on the outer side of the buttresses. The pinnacles are decorated with slender shafts and richly ornamented gables. The windows of the chapter-house contain five lights. They will be further described in the account of the interior of the building. Above them is a plain battlement, with two rows of ornament below it, and three figures in each bay above it. There is a very curious buttress at the point of junction of the vestibule and the chapter-house. It is joined to the wall of the chapter-house up to the battlement, and consists of an irregular mass of masonry ornamented as far as possible in the same manner as the other buttresses with gables and panelling. The two bays of the vestibule nearest to the chapter-house have nothing unusual about them except their buttresses. One of these is set close to the wall up to the spire of the pinnacle. All the other buttresses of the vestibule, except the one built against the buttress of the transept end, have pinnacles joined to the wall by a pierced arch of curious and ingenious design. The vestibule is crowned by plain battlements like that of the chapter-house, with small square-headed windows of two lights each. The windows of the two bays nearest the transept end are of most unusual design, which will be explained in the account of the interior; these bays are narrower than the others, that nearest to the transept being the narrowest of all.