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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Feb. 3, 



GEOLOGY IN CONNEXION 'WITII ARCHITECTURE. 



On the importance qfffcological studies in connexion with the practice of archi- 

 tecture, teith notice of rxperimentx on tin- resistance' to crushing and fracture, and 

 on the ahsorbent quaiities of the principal hnitding stones of Ireland. By Geoegk 

 Wilkinson, Esu. Read at the Geological SociETr of Dublin, lOUi of 

 January, 1844. 



In bringing before the Geologicnl Society the resulis of some experiments 

 made on the principal building stones of Ireland, it is, I conceive, necessary 

 to ofler some general remarks on the atlvantagcs to be derived tlierefrom ; ad- 

 vantages, in my opinion, so very general, that to look at the result of expe- 

 riments in a merely mechanical and professional point of view, would be con- 

 fining the subject wilhin too narrow limits. It ouglit to be a just matter of 

 sur[irise that, at Ibis advanced age of scientific investigation, the subject 

 of practical geology in all its important bearings should have occupied so 

 little attention ; and that where there appears a desire for ameliorating the 

 condition of the people of this country, particularly by promoting employ- 

 ment in ways calculated to develop its natural resources, persons sliould over- 

 look what is capable of being accomplished through the medium of well 

 directed e.Nperiments in this interesting and valuable science. To present the 

 importance of practical geology in a familiar way, I would call your atten- 

 tion to the large proportion of people ivho are daily engaged in operations 

 on the rocks in the country, either in dislodging or separating from their 

 native beds those portions required fur the varied purposes of building opera- 

 tions, or in conveying to the localities where they are required, and in shap- 

 ing them for the diflerent purposes to which they are to be applied, and thus 

 calling to aid all the useful arts of the country, giving extensive employment 

 to labourers, mechanics, and tradesmen, as well as to the scientific and learned 

 professions of engineers, architects, artists, and others. 



Must persons are more or less interested in the construction of their habi- 

 tations, and I may say, all see the advantages of public structures, and ap- 

 preciate the importance of bridges, canals, and other public and private 

 buildings, and probably see in them the progress of civilization, and the 

 benefit and dignity they confer on a country ; but few, and very few, know 

 anything of the materials employed in their construction, which too often 

 present themselves to their minds only as a heap of stones and mortar. If 

 we look to the early history of the most ancient nations, we find that the art 

 of building has attended the first advance of civilization; and the use of 

 worked stone has succeeded to caves in rocks, and the rude wicker or earth 

 work of their common and early structures ; but tlie conversion of stone to 

 the increasing artificial wants of society was necessarily consequent on the 

 advance of the mechniiical arts before it could be shaped and applied. How 

 interesting are the first though rude efforts displaying practical geology , 

 The bold and noble monuments of the early ages show the natural vigour of 

 the human mind, untutored in the mechanical skill and art of later times. 

 The stupendous monolilhal structures, and those early sepulchral monuments, 

 known as cromlechs, cairns, and moats, which abound throughout Western 

 Europe, were doubtless the work of a people, who, taking nature for their 

 guide, by prodigious labour, raised and put together, and frequently con- 

 veyed to great distances, for the erection of their monuments, the immense 

 stones which, detached from their native beds, were distributed over the sur- 

 face of the country. Most of those stones are of the primary and crystalline 

 class of rocks, which, from their liardness, have resisted the violence of that 

 (listurl)ing power which removed them from their mass, and all'ord us a good 

 knowledge of their enduring quality. Moreover, the originality and boldness 

 of their application, resulted from minds familiar with nature's \vorks and 

 untaught in the arts, which in after ages, accomplished by skill and the use 

 of smaller sized materials, what the eaily ages, unskilled in building, could 

 alone express by the magnitude of the stones. 



Let us ccnsider the more advanced history of the principal nations of the 

 earth, and we shall find that geology, which term I may here use to express 

 the converted rocks, has received great consideration. The architects and 

 sculptors of Greece and Rome knew the qualities of their materials, and if we 

 may judge from ancient writers and existing remains, gave consider.able at- 

 tention to them, abounding as those countries did in good materials. In the 

 writings of Vitruvius on Roman architecture, the most particular rules are 

 laid down «ith regard to the selection and use of building stones, and the 

 cements employed with them. How important are the results of their inliu- 

 ence on society ! If Egypt, Greece, and Rome, had had their principal struc- 

 tures of a perishable material, what would we not have lost ? What interest 

 would we now feel in those countries ; or how coultl we have derived the 

 great advantages which have ilowed from them ? Good materials, and a 

 right knowledge in using them, have, however, produced a diflerent result ; 

 and again, what do not those countries owe to the durability of their struc- 

 tures, conceived, as they have been, in a noble spirit. M'ithout them, Rome 

 of the present day would be unvisitcd by the countless thous,ands whose 

 wealth noiv enriches her; without her buildings the classic shores of Greece 

 would less of European sympathy j nor would the dusky inhabitants of Egypt 



occupy such interesting ground hut from the remains of the stupendous and 

 imperishable monuments of her past history. Our own kingdom also pos- 

 sesses proud memoiials in the enduring monuments of the middle ages. Those 

 connecting links with the past and present, afford us noble examples of the 

 religious zeal and skill of our I'orefathers ; whilst the perseverance which has 

 been displayed in accomplishing their erection, is much calculated to stimu- 

 late us to bold designs. These indelible landmarks of his early home, the 

 traveller finds deeply implanted in his mind, and it is difficult for us to esti- 

 mate their eftect on society, in the attachment they cause to our laws and 

 institutions. Nor do those venerated and bold structures fail to excite a 

 (loiverful feeling in the inhabitants of the new world, who, though born in a 

 distant land, contemplate with pride and fervent admiration the works of 

 their progenitors. But the edifices of centuries past, many of which, even 

 in their dismantled state, have withstood the destructive violence of the ele- 

 ments, will yet outlive very many of the most costly structures of the present 

 day ; and until a very recent period, so comparatively few were the buildings 

 calculated to endure to any distant period, that future ages, judging by our 

 public structures, will look upon the people of the present time as a dege- 

 nerated race, and in the erections of centuries back will contemplate the 

 finest and most durable monuments of architectural skill. 



Many persons may say that a durability sufficient for the age is all that 

 is necessary, and that posterity, which has done nothing for them, may act 

 for itself. This, however, even in a narrow practical and economic point of 

 view is most erroiieous, for the constructive arrangement of the ancient 

 buildings is less costly than in those of the modern period, and from their 

 simplicity and the right use of the materials employed, they are more sound 

 and durable edifices. In the buildings of the present day the simplicity of 

 early structures has been lost sight of; a laboured mass of cut stone being 

 more appreciated by the public than outline of design, and harmony of effect. 

 We see in the ancient structures a homogeneous construction — the u.se of 

 timber as supports under masonry is avoided ; where openings or projections 

 occur stone arches or other stone supports are employed, and a much more 

 general use of stone, for various purposes, prevails, than at the present day ; 

 and in them we have models of constructive arrangement which we may pro- 

 fitably imitate. Many of the old buildings are so constructed that when 

 dismantled of their roofs and their floors, they return almost to the state of 

 the original rock , perhaps as a mass of limestone, for the stones may be lime, 

 the sand may be that of limestone, and the lime burnt from the same rock. 

 Such is frequently the case ; thus, the mortar being good, becomes hardened 

 by age. and more approaches the nature of stone ; for it is said by an intelli- 

 gent and scientific Frenchman who has given much attention to cements, 

 that it requires 1,000 years to make mortar really good. Without doubting 

 that a few years are sufficient to produce good mortar, it might be stated 

 that the mortar of the Egyptian Pyramids, now supposed to be nearly 4,000 

 years old. is still in a good state of preservation. Structures so constructed 

 become like a solid mass of rock ; and that this is the case, the explosions 

 made by Cromwell, in the I7th century, have very well shown, for the re- 

 mains of some of the old castles, of which portions have been disturbed, ap- 

 pear almost imperishable. The sound and enduring stale of some of the 

 rnins, the original forms of which are still perfect, enable us (airly to state 

 that a right use of the rocks of the earth has been capable of jiroducing such 

 a solid mass, that many may now, in their skeleton shapes, fairly be called 

 architectural fossils ; and they afford to the practical, as organic remains do 

 to the scientific geologist, valuable studies in determining the character of 

 the rocks to v\ hich they belong. 



To the antiquarian, also, the study of geology affords much information, 

 for the use of certain rocks, and the mode of working them, determine, to a 

 considerable extent, the chronological date of the building in which they 

 occur. It was a peculiar custom of the Normans and Anglo-Normans, to 

 make use of none but the sandstones or oolites, similar to those with which 

 they had become familiar in their own country, and in the round towers, and 

 early ecclesiastical structures, erected under the inffuence of the Christians 

 familiar with the Norman or Lombardic architecture, we rarely find anything 

 but sandstones employed in the dressed masonry. With the Normans or 

 Lombards (under which name I may include the northern nations who estab- 

 lished themselves on the decline of the Roman power, and perfected from the 

 last and woist models of the eastern and western Roman empires that pecu- 

 liar architecture known to us as Norman, in which circular arches are the 

 peculiar characteristic,) it was the practice to make their doorways the most 

 enriched portions of their structures, and from being more elaborated or 

 worked than any otiier part, they are commonly executed in a different kind 

 of material, sandstones of variable quality having been generally used ; and 

 it is a peculiar fact, that an instance in which limestone occurs for dressed 

 work or for doorways is very rare. Being familiar with the kind of mate- 

 rials employed in must of these structures, I do not recollect one in which 

 the ordinary limestone rock has been so used. 



It is not until a late period of the Norman architecture in Ireland that 

 limestone has been employed. In the large limestone tract of the west of 

 Galway and Mayo, where are the ruins of Cong and EaUintubber.in the later 



