Such were the modifications of plan voluntarily made by the architect; others were rendered necessary by circumstances. Some additional residences were introduced, refreshment rooms and offices were re-arranged, provision was necessary to meet the immense extension of the business of Parliamentary Committees, alterations made in order to provide for the whole of the public records, and, above all, changes in plan and elevation were necessitated on every side by the enormous claims, both upon the space and arrangements of the building, made by Dr. Reid for his schemes of ventilation. The central tower was wholly due to these requirements; many other parts of the building were carried up, and many smaller turrets were introduced, to meet the requirements of his system. The spaces under the Houses, intended for the horses and carriages of members, were surrendered to him, and the want of them is severely felt. On the whole it has been already noticed that he absorbed one-third of the cubical contents of the building. All these things involved frequent changes, constant thought and labour, and no slight increase of expenditure. These alterations of plan were naturally followed by considerable alterations of design; some, in fact, necessitated by them, others dependent on certain changes of idea in the mind of the architect himself, and in the general feeling as to Gothic architecture. Both these kinds of alteration were manifested in [Illustration: NEW PALACE AT WESTMINSTER. GENERAL VIEW, FROM LAMBETH PALACE.]