144 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[Mat, 



for want of it« We have monthly to record in this journal lamentable 

 instances of time and money wasted on patents which the slightest 

 scientific knowledge would prove \'alueless. Not long ago a person 

 took out a patent of which the principle was based on the idea that 

 the pressure of fluids arose from the elasticity of the air contained in 

 them! A thoroughly practical engineer told the present writer not 

 long ago, that a bullet did not acquire its full velocity till some time 

 after it left the mouth of the gun ! And we have been gravely assured 

 that the strength of the Thames Tunnel must be very great indeed, 

 for it had to support not only the superincumbent water, but also the 

 enormous weight of the vessels floating in it,— as if the weight of the 

 vessels were not the same as that of the water displaced by them ! 



The scientific knowledge which would render these preposterous 

 mistakes impossible cannot be acquired by the engineer while engaged 

 in the busy occupations of his profession. The knowledge, if acquired 

 at all, must be a part of his preparatory education. Of that we are 

 certain : — The crude philosophy which he may form by his own ob- 

 servations in the workshop or engine-room can never compete with 

 the systematic certainty of theoretical knowledge. Such philosophy 

 it is the object of the College of Civil Engineers to impart; and we 

 have the more readiness to applaud the object, because we find that 

 the Institution no longer adopts the opposite, equally fatal, error of 

 imagining that theoretical knowledge will supersede practical. 

 Neither suffices without the other. The students are instructed in 

 pure science, but they are f.imiliarized also with the working tools of 

 the engineer. The operations of turning and casting of metal, the 

 details of the management of steam-engines, actual experiments on 

 the strength of roofs and arches, the practice of surveying and level- 

 ling, all these are actually carried into effect by their own hands. It 

 is not pretended that by these studies the student at onco become 

 qualified for the practice of his profession ; but when he takes his 

 next step, and enters the workshop of the engineer, he brings with 

 him a large amount of knowledge, which infinitely increases the value 

 of the instruction received under the working engineer, and which 

 guides his efforts for the remainder of his life. 



In conclusion — the College of Civil Engineers is under the principal 

 guidance of one on whom the rery highest academical honours have 

 been bestowed, the Rev. W. Cowie, of whose attainments it would be 

 presumption to speak here, and who to his scientific knowledge joins 

 the practical information which can only be acquired by actual obser- 

 vation, and an ardent desire to advance the science of engineering. 



*HE GEOLOGY AKD ARCHITECTURE OF IRELAKD. 



Practical Geology and Architecture of Ireland. By George Wil- 

 kinson, Architect. Illustrated with Seventeen Plates and Seventy- 

 two Wood-cuts. London : John Murray, Albemarle Street, 1845. 

 pp. 400, royal 8vo. 



No science has in modern times made such rapid advances as Geo- 

 logy. Born but yesterday, it has asserted its claims at once so con- 

 vincingly as to be recognized as second in importance to no branch of 

 human knowledge by which the arts and operations of practical in- 

 dustry are facilitated : and to scarcely any branch of human skill is 

 geology likely to afford more direct aid than to architecture. Mr. 

 Wilkinson, the author of the work before us, is already favourably 

 known to our readers by two lectures, delivered before the Geological 

 Society of Dublin, one on Geology connected with Architecture, 

 reported in this Journal, Vol. VI. p. 5ti, and the other on the Mar- 

 bles of Ireland, reported at p. S3 of the present volume. It is the 

 object of the present woik to illustrate the importance of directing 

 the choice of materials for building in Ireland by a due knowledge 

 of the geological character of that country. The subject is considered 

 under lour distinct heads : the first is a general description of the dif- 

 ferent kinds of rocks found in Ireland, their arrangement and composi- 

 tion, and the purposes for which they are severally applicable. The 

 next head is a review of the ancient architecture of Ireland, from the 

 earliest specimens of cromlechs, cairns, and raonolithal structures, to 

 the debasement of Christian Architecture. Under this head consider- 

 able space is devoted to the subject of the Round Towers of Irelaud, 

 the distinctions between the Norman architecture of that country and 

 our own, and to ancient domestic architecture. This part of the book 

 is the largest, but it is not of a purely architectural nature : continual 

 allusions are made to the durability and geological character of the 

 materials of ancient buildings. The third part is a digest of the 

 geology of each county of Ireland considered separately, aud the work 

 concludes with a large collection of tables recording the results of 

 experiments on the strength of the principal building stones. 



Having thus given a general view of Mr. Wilkinson's work, we will 

 proceed to consider it more particularly, and will first take the liberty 

 of extracting some of the remarks in which he points out the interest 

 which architects have in the progress of geological knowledge. After 

 showing the facilities which this knowledge affords for determining 

 the suitability of different stones for various architectural purposes, 

 he adds — 



"Yet the architect, who is by his profession most interested, and 

 whose first study should be directed to the acquirement of such in- 

 formation as would make him familiar with this portion of the opera- 

 tions of nature, the contemplation of which must imbue him with ele- 

 vated ideas, is generally most neglectful of such a study, and contents 

 himself with the possession of information with regard to the mer- 

 chantable prices and qualities of the different stones which he finds in 

 the stonecutter's yard, or which he sees others in the habit of using: 

 it is then not surprising if with equal ignorance he perpetuate what 

 is bad, or practises, by accident, what is good. 



"In large cities this is particularly the case: specifications for con- 

 structive arrangements are often prepared almost by rote ; and when 

 a design has to be carried out in a country locality where the features 

 are new, as well as the mode of using the materials, the architect is 

 either too often the blind dupe of tiiose in whose hands he has to 

 entruct himself, or he commits some egregious error, or both." P. 3. 



"Who can contemplate the imperishable and solid structures of the 

 ancient Egyptians without entertaining impressions of those people 

 which language would not produce ? These connecting links in the 

 history of the past and the present cannot fail to stimulate, in the most 

 forcible manner, admiration of those whose minds conceived, and 

 whose efforts raised the enduring monuments of a vigorous race .' The 

 present inhabitant of Egypt, Greece, and Rome, are greatly indebted 

 for the sympathy of other nations, and for their wealth, to the gran- 

 deur of their architectural remains : in these, good and durable mate- 

 rials have been employed, without which we should have had but a 

 mass of crumbled ruins, or indistinct piles of decomposed matter ; the 

 memorial of the valuable models of antiquity presenting beauty of 

 design, a fit adaptation of construction, and elegant forms, perfected 

 by a skilful people in the course of ages, would have been lost to us." 

 P. 4. 



We may here observe in passing that while geology is illustrating 

 architecture, the art may, perhaps, in turn throw back a little light on 

 the science. The present appearance of ancient structures, formed 

 as they are of almost every kind of materials, is in effect a record of 

 vast series of experiments, which the alchemist Time has been pro- 

 secuting on the nature of various stones, and a minute examination of 

 the changes actually produced by time, might probably do much for 

 the confirmation of geological truths. The following passages are 

 introduced to give the reader an idea of the nature of the first part of 

 Mr. Wilkinson's work. 



"Granite is a compound of quartz, felspar, and mica. In its ordi- 

 nary state these ingredients are in nearly equal proportions, the mica 

 being less in amount than the other two. When hornblende replaces 

 the mica, the rock is called syenite. Of these ingredients, the quartz 

 is much the hardest and most durable, and is generally of a whitish 

 colour, occasionally black or brown (Mourne Mouutains) ; the felspar 

 is not so hard, generally whitish also, but frequently of a red, green, 

 or yellow tinge, as well as of other colours. The mica is a scaly, 

 shining, and metallic looking mineral, varying in colour from greyish 

 white to black, dark brown, or dark green. The two latter principally 

 determine the durability of the stone, which commonly varies with its 

 working quality, the most easily converted being also those rocks in 

 which the felspar js soft or the mica abundant ; the larger the grain 

 also, the greater is the facility of conversion for common work, and the 

 greater the disposition to decay." P. 13. 



" Ireland at the present lime derives the greater part of her supply 

 of slates from Wales; but she possesses valuable quarries which, if 

 rightly worked, and if duly encouraged, would speedily diminish the 

 necessity for resorting to Wales, and many thousands of pounds which 

 now flow out of the country in a direction from which no reciprocal 

 trade arises, might be advantageously employed in the improvement 

 and enrichment of the country." P. 28. 



"The various marbles may be next considered under this division, 

 although, in mineral character and chemical composition, several 

 varieties contain much less of lime than of other earths. A great 

 variety of marbles is met with in different parts of Ireland. Colour 

 and facility of conversion are the two most important properties, and 

 determine their value. The great partiality for the marbles of Italy, 

 and the long-established trade in them, operate much against the use 

 of the Irish marbles ; and there are, doubtless, many varieties posses- 

 sing great beauty, which will probably hereafter, as they become 



