So much for the beautiful in architecture: in construction there is less to be learned in travelling, but the student must not be ignorant of it. He should know the elements of geometry and the mathematics, and of their application to mechanics. He must be acquainted with the usual method of forming roofs, and floors, and the principles which determine the magnitudes of the different parts; and will have learned the general rules which regulate the thickness of piers and walls, which have to support the action of vaults and arches. It is not necessary that he should be a profound mathematician, or able on every occasion to calculate the value of active and opposing forces. Calculations have been made by much better mathematicians than he is likely to be, and besides, such results are subject to so many exceptions and modifications, arising from the imperfect nature of the materials, that experience at last is found to be the principal guide. Convenience is principally studied in plans, but the manners of different countries vary so widely, that what would be perfectly satisfactory in one place, would be considered as very defective in another: nevertheless, it is useful to observe the different distribution of the apartments in different places, and to understand their merits as connected with the manners of the inhabitants. The study of economy, that is, of the best employment of a given quantity of materials and labour, or what amounts to the same thing, the performance of any given work with the least possible quantity of materials and labour, must accompany that of construction and solidity. The habit of noticing in every case how far it has been observed, and where it has failed, will greatly strengthen the judgment on this subject; but we must always remember, that the formation of a less beautiful or less durable building by smaller means, is not economy, but parsimony. An architect should not be a mere artist; he ought to have some tincture both of literature and science, and also some knowledge of history. Not to draw from it irrelevant fables, as Vitruvius tells us, but to enrich the mind and strengthen the understanding. In every work of art, and I may be forgiven for repeating the sentiment, the highest value is in the impression of the mind of the artist; and how can that deserve admiration which is the product of feebleness or fatuity?