us 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Apri;., 



use of angular stones was introduced, and newroad-materials were furnished 

 from the trap. rocks of Leicestershire. 



On the profession, before wliicli this lecture was delivered geology has a 

 particular claim ; for is it not from a neglect of its precepts that buildings 

 erected only two centuries ago are severely injured by the weather ! This 

 arises from using a calcareous sand-stone, which, imbibing moisture, is decom- 

 posed by the agency of the carbonic acid in rain water ; while the use of 

 granite is not free from the same defects, the felspar, one of its ingredients, 

 being an eq^ually perishable material : in fact, it is only such stones as siliceous 

 sandstone, which are capable of resisting that insinuating desti'oyer. The 

 legislature has indeed recognised this connexion of geology witli architecture, 

 by sending Mr. de la Beche on a mission through the stone-producing dis- 

 tricts of England, to ascertain which possesses the best stone, for the construe- 

 tion of the new Houses of Parliament. The sculptor is also interested in the 

 qualities and durability of his material, and many are both the modern and 

 ancient statues polluted by the iron stain, which spots some of the 

 finest works. The painter cannot disregard this science with impunity ; for 

 what can be more improper, than in the representation of some historical event 

 in the undulating scenery of the south of England, as the signing of Magna 

 Chai'ta, or the imprisonment of Charles I., to see it accompanied with the 

 shai'p peaks and straggling rocks of the primary or transition strata! A 

 literary friend, a lady of some celebrity, had committed this error; she had 

 described in one of her works the Isle of Sheppey, with the fanciful attributes 

 of chalky clift's and whitened walls; but, having occasion subsequently to 

 visit it, what was her astonishment to see none of the things she had represented, 

 but only shores bordered with mud ! Nor, in its general relations, is geology 

 less attractive than in its physical utility, for most truly does it show us the 

 omnipotence of the Creator, and teaches us to find sermons in stones, and 

 good in every thing. To the architect the whole world offers the contemplation 

 of a kindred work, one mighty temple, reared by Nature to her great Creator : 

 its details beautiful as they are regular ; its grandeur towering to the clouds, 

 and its chambers replete with all that can be useful to the favoured people 

 who inhabit it; in truth, a worthy monument of the Great Architect. 



In giving a limited sketch of geology, it is impossible to embrace the 

 whole science, and indeed lectures may more truly he regarded as incentives 

 to study, tlian as supplying the place of study its'elf. A geologist is indeed 

 called upon to narrate, in the naiTow space of an hour, revolutions of centu- 

 ries, and the history of a million years. He is, in truth, like a traveller carried 

 at railway speed through a delightful country, and has only time to enumerate 

 the objects which he cannot describe. 



In nature, as in revelation, all is regular, all is systematic, and every 

 apparent divergence serves only to confirm the wonderful provisions of the 

 whole. The dislocations which occur in strata, so far from being produced 

 by confusion or blind chance, are purposely placed, like magazines, to supply 

 us with the riches of the mineral world ; and here we have stored up resources 

 which othenvise would have been sunk far beneath our means of search. The 

 terms used in geology, however diificult they may appear in name, are per- 

 fectly simple in their explanation ; as, when we use the term anlidinal strata, 

 we only express that formation which resembles the ridge made by the roof 

 of a house. Many of these terms have no existence in nature, but are 

 employed, as in other sciences, to assist the imperfection of our mental powers ; 

 thus — we say primary, transitive, secoudaiy strata, as in music we use bars 

 to mai-k the time, without any reference to the existence of such in the execu- 

 tion of the piece. Geology, however, is a science in which, hke astionomy ,we 

 must doubt tho evidence of our senses, and perpetually expect results for 

 which on fij-st impressions wo are unprepared ; like as in that we are taught 

 that the smi, apparently ever moving, is yet a stationary globe, so here 

 we are fold that what was once land is now sea, and that the" firm ground on 

 which we stand was floated over by the monsters of the deep ; that the hard 

 and ponderous rock was once as soft and yielding as the quicksaud ; and that 

 the very stones before us in former days waUicd the wind as things of life. The 

 inquirer into geology finds himself like .\laddin in the care ; at first the rocks 

 seem to close around him and shut out all hope, hut no sooner has he gained 

 the talisman of science, than a fairyland of wonder breaks upon his view. 

 To the man of the world no science can be more practically useful, to the 

 philosopher nothing more agreeable, and to the Christian nothing more satis- 

 factory ; for here he finds tho fleeting existence of man chronicled as sm'ely 

 as in holy writ, and here he sees the eternity of the Great Creator, when he 

 witnesses the successive destruction of rocks" that almost seem to outvie lime, 

 and powers that seem as they could conquer it. 



Monday, March 25tli — H. J. RoBiNSON, Esq., V.P., in the chair. 



Mr. Richardson gave his second lecture on Geology, in which he con- 

 sidered the rocks with reference to their zoological relations, and their adapta- 

 tion to the necessities of mankind. The lecturer commenced by recapitulating 

 the topics of his introductory discourse, and enforcing the definition of geology 

 as a science which requires the investigation of every branch of organic and 

 inorganic nature, which in the extent of its disquisitions is occupied witli 

 the past, the present, and the future. He again recalled its moral tendency, 

 the manner in which it proves the perishability of matter, by showing the 

 successive decay of every substance on the surface of the earth, and the 

 powerful lesson which it teaches us of veferi ing everything to its first cause, 

 and looking to the great Creator as alone immutable, eternal, imperii^hable. 



The greater portion of the crust of the earth, and the secondary and tertiary 

 portions in particular, Mr. Richardson showed not only to be derived from 

 the destruction of previous bodies, but absolutely from living beings. These 

 remains are not confined to the gigantic relics which strike every eye, but 

 they are to be traced in those minute organizations which uie scarcely icj 



cognizable even by the microscope. Piles of rocks, beyond calculation and 

 imagination, are formed by the infusorial insects and the coral tribes, and, as 

 if to show the vastness of his power, it is by means of these tiny labourers 

 that the Almighty has called into existence his most magnificent works. The 

 pebble that we hold in our hands may once have lived in a thousand breath- 

 ing forms, and seen the history of centuries ; and, as Young says, — 



'■ Where is ftie dust that was not once alive '.' ' 

 The very rocks that now upheave their crests to heaven, once crawled in 

 earliest forms upon the earth, and from insects which we should crush in the 

 height of our fancied power, a greater Being has devoted to fabricate his 

 nobler monuments. Even the primary rocks themselves have not been 

 supposed to be exempt from the alloy of animal remains ; and the observations 

 of the Rev. Mr. Reade, of Clapham, have induced him to suspect their pre- 

 sence in mica and opal of porphyry. In mica he has perceived, by his micro- 

 scope, annular or ringlike impressions, which he cannot but refer to the re- 

 mains of infusoria, although, from the constitution of primary rocks, 

 crystalized by heat to their minutest molecules, this result has beeu doubted 

 by many. To the microscope, however, we must look for the elucidation of 

 this subject, and even when we are far from having availed ourselves of its 

 present powers, we may look forward to a period when it will have attained 

 a greater perfection, while only recently its powers have been augmented 

 50 per cent. 



In the primary rocks no well-defined organic rernaiDs appear, and it is not 

 until we came to trilobitic schist that we obtain satisfactory testimony of their 

 presence. This stone derives its name from the trilobite, an animal of the 

 crustaceous tribe, most nearly allied to the king-crab, and which is chiefly 

 remarkable for the beautiful structure of its eye. This organ, which has 3 

 or 400 lenses, Dr. Buckland, in his " Bridgewaler Treatise," has adduced to 

 prove the similarity of constitution between the atmosphere and ocean of the 

 ancient world and that which now exists, proving that it has remained un- 

 altered in its properties in all the immensity of time. The secondary rocks 

 are indeed most important in their zoological character, and here it is that 

 we meet those anomalous animals, the ichthyosaur, or fish-lizard, and its ally 

 the plesiosaur. In the oolite, which is most important for its constructive 

 uses, we find the megalosaur, or great lizard, shells, ammonites and other ves- 

 tiges of its luarine formation. It is from this class of rocks that we obtain 

 Freestone, Bathstoiie, and Portlandstone. In the Wealden formation which 

 succeeds it we find many interesting features. The Sussex marble is formed 

 almost exclusively of snail shells, such as lived in the great river of which 

 the Weald district was once the bed. This marble afibrds some most 

 beautiful columns to Chichester Cathedral, and it is the material of which the 

 archbishop's throne at Canterbury is formed. To the same class also belongs 

 Purbeckstoue. We now come to the chalk which is the boundary of the 

 secondary formation, and is distinguished by the presence of the spirolimite, 

 a microscopic shell, allied to the nautilus and the argonaut, for the discovery 

 of which we are indebted to that eminent philosopher and amiable man the 

 Marquis of Northampton, President of the Royal Society, who was present at 

 the previous lecture. In the tertiary strata we find vestiges of the marine and 

 freshwater animals which formerly inhabited the site of these deposits, and no 

 district is more interesting than the London clay. In this and in the fresh- 

 water rocks of the Isle of Wight we find the uummulite, so called from its 

 resemblance to a Roman coin, and it is of stone formed of this shell that the 

 great Pyramid of Gizeh is constructed. Strabo noticed the appeaiance of 

 this shell, and he attributed it to the remains of the lentils on which the 

 workmen fed, and which he supposed, having been thrown on the spot, bad 

 been petrified. This nummulitic rock is one of the latest formations, and yet, 

 as if to stamp man a parvenu on the earth of which he boasts himself master, 

 the earliest of his works are but nature's last. 



Having thus exhibited the manner in which the zoology of a rock demon- 

 strates its character, the lecturer proceeded to illustrate the application of 

 geology to the practice of conslruction. He truly observed, that this science, 

 by showing the advantages and defects of strata, became of the highest im- 

 portance to the architect and the engineer. It would be absurd, he said, for 

 him, to teach architecture to architects ; but, while on this subject, he might 

 perhaps be permitted to make one cursory allusion bearing on this subject. 

 In the i4tli chapter of Leviticus, from the middle to the end of the chapter, 

 there are soniecurious provisions, notgenerally observed, with regard to the 

 leprosy of a house, as derived from defects in its position or construction, and 

 showing the attention which the inspired legislator devoted even to this sub- 

 ject. 'With regard to the influence of strata upon foundations, be supposed 

 those points to be well known ; and as time did not admit a longer detail, he 

 must run cursorily over some few points which he should have wished to have 

 given at greater length. Rocks, he remarked, are divided into two great 

 classes from their origin — the igneous from fire, and the aqueous from water 

 or slate ; and the difterent kinds of useful stone range from the primary strata 

 upwards through every gradation— from primary limestone to slate, sand- 

 stone, maguesian limestone, and oolite. The main qualities for a good build- 

 ing stone are firmness and consistency, and one of the best empirical rules by 

 which an architect can judge of the .stone of a district is by observing its oldest 

 buildings, which, if aft'ected by the weather, are principally injured on its 

 north aud west sides. The best way to ensure the greatest degree of resistance in 

 a stone is to place it in the same way as it is in the quarry, that is, horizon- 

 tally ; and this is particularly necessary in laminated strata and those of the 

 tertiary formation, of which most of the buildings in Paris are constructed. 

 Argillaceous limestong also, which comes soft from the quarry, and hardens 

 afterwards, requites reat care and attention. Stones of tinequal colour, 

 spotted, or veined, areuot so strong as those of uniform colour, aud should be 



