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lies before him. To enable him to perform his multifarious functions with honour to himself and satisfaction to his country is the great object of this Encyclopædia : and, without further preface, we shall proceed to lay before the reader an outline of its contents, and the plan we have adopted in its compilation.

The first portion of the work is devoted to the history of the past ; for it has been thought that a knowledge of the manner in which others have accomplished works similar to those we are called upon to execute at once facilitates our labour and inspires us with confidence in what we are about to undertake.

In treating of Geology, Mineralogy, and Chemistry, the only aim has been to point out the nature of these subjects, and give a general idea of the properties of the materials which form the earth's crust, with an account of their composition, as far as might be generally serviceable to those who employ them in the arts of construction, or operate upon them mechanically,

Geometry, as the very foundation of the acquirements of the Civil Engineer, embracing, as it does, levelling, surveying, the mensuration of planes and solids ; trigonometry in all its practical applications ; drawing, perspective, mapping, laying down charts, and all the preliminary steps to great undertakings, as well as their execution, --should be made the first study of all who are desirous of becoming acquainted with the other sciences; for without it, in fact, no portion of them can be rightly comprehended.

Mechanics are also a most important subject. The ancients, indeed, knew the principles of the inclined plane, the wedge, the screw, the lever, and the pulley, and by their application were enabled to move the vast weights accounts of which are transmitted to us; but the improvements made in machinery in modern times have undoubtedly enabled us to execute works of vast magnitude with a great saving of manual labour. From experiments upon the strength and properties of the metals, and the application of geometry to mechanics, we can construct machines, which from their variety of movement, and the useful purposes to which they are applied, are inventions and novelties which belong to the present age. The tools and engines employed by the Civil Engineer are instances of the advancement in this branch of physics.

Hydrostatics, with the theory of the motion of fluids, and the various hydraulic machines that have been invented, facilitate the operations the Engineer in raising water, directing its course usefully and efficiently, whether for sanatory, domestic, or agricultural purposes; and without an almost complete command over this element, he can scarcely be considered worthy of his high vocation.

The nature of the Atmosphere, and its properties as a moving power, has greatly occupied the attention of mechanics in all ages, and its services cannot be too highly appreciated. For the construction of windmills and similar contrivances, numerous experiments have been made, replete with benefit to the millwright.

Warming and Lighting are daily becoming matters of public attention, and must therefore occupy the consideration of every man of science; but the Civil Engineer must beware of fanciful theories : whatever may be bis system, it must be based on a thorough knowledge of the elements which he is to direct, and he must never lose sight of the requisite balance to be maintained between the heat generated and the ventilation. Lighting our coasts has occupied the attention of such philosophers as Professor Faraday, whose interesting discoveries have greatly improved our lighthouses, and elevated this subject into an important science.

Gas Lighting has its engineers, who have improved the methods of distilling coal, and laid down principles to direct the proportions of every part of the establishment where such works are conducted.

Steum, considered as a moving power, is the most extraordinary discovery of this or any other age. By its application manual and horse labour have been greatly economised; machinery of every kind is set in motion; and millions of human beings are transported in a short space of time from one end of the empire to the other. This branch of our subject, it is unnecessary to add, particularly deserves our study.

Carpentry, which embraces the construction of timber roofs, bridges, centres, scaffolding, gc., with a thorough knowledge of the use and properties of timber, has been treated at considerable length; though not more so than the importance of the subject demands. Although iron has in this country superseded the employment of timber in many instances, there are occasions in which the carpenter's art

cannot be dispensed with ; moreover, the principles embraced by it are also those practised by other artificers, and deserve to be understood, if on that account alone.

Masonry is another branch of artificer's work necessary to be thoroughly understood by the Civil Engineer. The construction of every variety of arch and dome occupies several pages: while the mathematical calculations upon the strength of stone, the effects of thrust and pressure, are dilated upon in several parts of the work. The examination of the qualities of the various stones used in construction, together with an analysis of them, has been also fully detailed from parliamentary and other documents that may be relied upon. As a science the mason's art has not in this country been made sufficiently prominent, nor excited sufficient interest to call forth a treatise on the subject; but a volume would be necessary to exhibit the varieties of construction, the skill displayed in overcoming the many difficulties that arise, and the gradual progress of this highly important branch of the profession.

Stone Bridges, and the principles upon which they are constructed, should be thoroughly studied by the Hydraulic Engineer, as they embrace all the knowledge required for the formation of docks, harbours, piers, jetties, quays, &c. which are among the most triumphant efforts of the engineer. Of the machinery invented to aid these works, and for which we are indebted to the bridge-builders of the last century, ample accounts have been given in that portion of the work devoted to machinery. The stone bridges over the Thames at London are highly deserving of attention ; they may be considered as the result of great study, and the best examples of the application of science to such structures.

Canals, though now superseded by Railways, ought not on that account to be entirely neglected : for should steam navigation be still further improved, it is not improbable that the data which have occasioned their disuse may prove more favourable for their future construction, and hence the principles which belong to their formation should be thoroughly understood by the civil engineer, as there are many localities where canals would have a decided preference over railways.

Draining and Embanking have from a very early period occupied the attention of the government as well as individuals. To confine rivers within their banks, and draw off the surplus waters from the surface of the land, are not only benefits conferred on agriculture, but on its cultivators, by rendering the atmosphere more salubrious and agreeable. Towns and cities also require attention to their sewerage, and the cleansing of the streets; and several local acts of parliament have been passed to enable these objects to be carried into effect; but one grand comprehensive view is still wanting for this to be thoroughly accomplished, and it will never be attained until the united efforts of a number of engineers, well-instructed in Geology, shall suggest for every district the best means of attaining it.

Railroads have given an extraordinary impetus to the profession; but it is time that the principles of their construction should be better comprehended: the public, at whose expense these highly important works have been executed, having hitherto generally preferred the mechanic to the artificer, as the director of the chief lines that have been completed. The construction of a railroad requires a great combination of talent before it can be brought to perfection. The selection of the country through which it is to pass, the building of bridges and viaducts, laying down rails, &c., are even more important considerations than the locomotive engine, which draws vast loads along the line. We have already had numerous failures, where the arts of construction have been employed, and it is to be desired that the engineers entrusted with the expenditure of such vast sums as are embarked in these speculations would qualify themselves, at once to comprehend these arts, and to practise them beneficially.

The Principles of Proportion which regulate the quantity of material to be employed in the arts of construction should be diligently studied both by the Architect and the Civil Engineer. To this subject the author has devoted the most careful consideration, having measured a vast number of buildings of all ages, for the purpose of forming an opinion upon the difference of character expressed in the Doric, Ionic, Byzantine, and Mediæval styles. For economic purposes this enquiry is worthy of great attention, it being apparent that if an entire building or a portion in the Byzantine style be cubed, one part out of twelve only is devoted to material; in St. George's Chapel, Windsor, two parts; in the Chapter-House at Wells four; in the Ionic porticoes six ; in the Doric eight; a variation between a twelfth, a sixth, a third, a half, and two thirds of the entire cube being employed for supports, and the remainder for space.

One of the great features of the age is the division of labour, and as the population increases, and the influence of knowledge spreads, it seems likely to be still further carried out. The province of the Civil Engineer at present extends over the works performed by the artificer, miner, and mechanic; he is entrusted with the direction of all that is difficult and scientific in construction, whether upon land or water, as well as with designing the machinery necessary for these important purposes. This knowledge was formerly demanded of the architect, who in addition was required to be acquainted with the fine arts. His qualifications, according to Vitruvius, were to embrace all that could be known; and many illustrious names could be adduced to prove that the requirements of the great Roman architect were fulfilled to the letter.

To design an edifice that shall have “ Commodity, Firmness, and Delight,” or to render it both serviceable and expressive of its purpose, requires a variety of talent ; and it is to be feared that the architect who confines his attention solely to that portion embraced by the fine arts will eventually lose his power : for without studying the principles of construction, he cannot give character to his design, and is not qualified to be entrusted with the execution of a work. On the other hand, should the Civil Engineer be required to act as architect, he must pursue the course adopted by Sir Christopher Wren,-set out upon his travels, and examine and study those buildings which have received the approbation of the most competent judges; and he will find that Egyptian, Grecian, Roman, and Mediæval architecture, have each its peculiar principles and character of expression. Equal application is required for a perfect initiation into the knowledge of architecture as a fine art as for that of the science of construction. St. Paul's, London, which is a masterpiece of construction, gives but too strong evidence that the genius of the mathematician had not profited sufficiently from his journey in search of what was consistent and perfect in architecture; he did not even advance so far in that study as his predecessor Inigo Jones. We admire this splendid edifice, not for its architecture, but for the principles developed in its construction. Those who pass judgment on a design should be in possession of all the elements necessary for such a task. They should be acquainted with construction generally and in detail

, and should understand the proper relative proportions of every part of the edifice. The public are enabled to pronounce the Menai Bridge to be both beautiful and useful: but before the architect can decide that it is a perfect work of its kind, he must be satisfied, not only that every tie rod and strut is rightly proportioned, but that all of them in their respective characters express their functions, producing a whole combining security, solidity, and utility.

It is impossible to dismiss this portion of our subject without expressing feelings of the most painful regret at the position which Architecture now appears to hold in this country. In France, Germany, and throughout Europe, it occupies its rightful place, as the chief and most important of the arts of design : there the architect is prepared for the exercise of his profession by a long course of study, tested by strict examinations in elementary mathematics and the sciences of construction, while all the student's talents and energies are called forth by the spirit of emulation produced by contests for medals and academic honours

. Foreign governments powerfully contribute to the encouragement of successful merit by bestowing thereon their patronage and protection, by conferring civil orders and decorations, and by endowing academies and professorships, which enable the man of science to devote his leisure to the cultivation and advancement of his art.

The Engineers, estimating at its true value the power acquired by combination, have wisely united “ for the general advancement of mechanical science, and more particularly for promoting the acquisition of that species of knowledge which constitutes the profession of a Civil Engineer.". They have defined the nature and objects of their Institution; they encourage the student to cultivate the sciences ancillary to his profession, and, by the distribution of medals and prizes for the most able memoirs, incite him to the study and description of engineering works at home and abroad. Nor has the means of furnishing the aspirant with opportunities for acquiring theoretical knowledge been neglected: the College of Civil Engineers, the engineering classes at King's and University Colleges, and at the University of Durham, communicate much valuable information, which would have been inaccessible in the office or workshop. For the architect no such means are provided, nor has the Institute defined the art in a manner to make the public feel its value or necessity. Let the architects follow the wise example of the engineer, and they will have done much to acquire for their art the respect and encouragement of their countrymen, and to place it in the elevated position which elsewhere it so deservedly occupies.

For the information contained in this Encyclopædia, the author is indebted to several eminent writers, and to numerous tours which he made for the express purpose of observing the engineering works both of this country, and on the continent. The practical observations are the result of thirty years' employment in his profession ; but he has freely borrowed the opinions suitable to his undertaking from every trustworthy source to which he has had access, and more especially from the following foreign authors, a more extended perusal of which he earnestly recommends to every student.

Gauthey, “ Traité de la Construction des Ponts, &c. ;” M. Belidor, “ Architecture Hydraulique;" M. Rondelet, “ L'Art de Bâtir ;"M. Bruyere, “E'tudes relatives à l'Art des Constructions ; " M. Perronet's “ Description des Ponts, &c.;”. M. Prony's “Nouveau Architecture Hydraulique," and " Description Hydrographique et Historique des Marais Pontins;" M. Boistard's “ Observations faites sur différens Travaux ; " M. Berard's “Statique des Voutes ;” M. Hachette's “ Traité des Machines ;" MM. Lanz et Bétancourt,“ Sur la Composition des Machines ;” M. Borgnis, “Traité complet de Mécanique appliquée aux Arts ; " M. Mallet, “Géométrie pratique, &c. &c;"

the several Essays comprised in the “Raccoltà d'Autori Italiani, che trattano del Moto dell' Acque," whose names are frequently introduced where this subject is discussed ; Alberti, “ l'Architectura;” and above all, the “Opera M. Vitruvii Pollionis,” edited by Poleni and Stratico, 4 volumes. He has also to acknowledge assistance received from his eldest son, Edward Cresy, whom it has been his wish to qualify for the exercise of the important duties both of architect and civil engineer, and who, whilst studying his profession, executed nearly the whole of the drawings, so ably cut on wood by Mr. R. Branston, of St. Andrew's Hill Doctors' Commons, to whom he offers his best thanks for his care and attention during the progress of the work.

To conclude: the author's great desire has been to embody in one volume all the leading principles and multifarious details on which the science of Civil Engineering is based; and to produce a work that might at once instruct the pupil, and prove a useful guide to him in his professional career. The work, he believes, is the first on the subject which has been published in this country. The labour bestowed upon its compilation has been of no ordinary kind; and he terminates it with regret, feeling assured that one individual could not do justice to a subject involving so many considerations of public importance. Should he, however, be so fortunate as to awaken in the mind of the young engineer a love for his profession per se, and a sense of the honourable position in which he may place himself by careful study and an undeviating course of integrity, he will not think that he bas laboured in vain.

E. CRESY. South Darenth, near Dartford, Kent.

January, 1847.

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