The Pamphlet Collection of Sir Robert Stout: Volume 68
Earthquakes and Architecture
Earthquakes and Architecture.
I Trust I shall be excused for having the temerity to address a paper to you by way of rejoinder to Mr. Haskell's, entitled: "The Earthquakes in Canterbury, and its effects on the Architecture of Wellington;" but as he had in that paper, with only one exception, criticised buildings of which I had been the architect, I felt it to be my bounden duty to those who had employed me, to vindicate the faith I had in the stability of brick buildings, and to show, as far as in me lay, those gentlemen, as well as others, that their confidence in the foundations of our city is not misplaced; and also to prove to you, if I could, that modern science has in architecture acquired sufficient knowledge of construction as to be able to erect buildings capable of withstanding earthquakes, even of a severer nature than we are ever likely to experience here.
The subject is an important one, as without sufficient confidence in the stability of the buildings, those who make our cities would never attempt to erect any of a permanent character. Thus the progress of architecture would be checked, and the best index of our civilization impaired. From this point of view, as I have said, the subject is not only an important but an interesting one. If I cannot make it so to you, the fault must be mine.
As Mr. Maskell has quoted Professor Milne, of Japan, as probably the best living authority, and whom from the tenor of his paper he evidently believes in, I would ask you to bear with me while I take a glance through the two chapters he devotes in his book to the effects of earthquakes produced upon buildings, just to see if he is so infallible as Mr. Maskell would have us believe.
Any one reading these two chapters for the first time might come to the conclusion that the Professor, with all his learning, knew little or nothing of architectural construction, as he uses words and phrases that are unknown in its practice; and nowhere does he give us any specific information as to the mode of construction, or to the qualities of the materials used in the buildings injured, but contents himself with stating whether of brick or stone, and often not so much.page 8
The reader will after a little study modify this conclusion, and say that he has studied theory more than practice. At page 100 he gives us an illustration of the effects of an earthquake in Belluno, and on the next page, of one of the brick buildings in Tokio. You observe, brick for the one, anything for the other. Throughout he has a great deal to say about the arches curving into the abutments. Everyone knows that an arch must curve into its abutments, if it curve anywhere. His meaning is, I think, that all arches should either be semicircular or elliptic. But really it is a matter of taste whether the openings should be trabeated or arcuated; if arcuated, then the architect has only to see that the arches of whatever form have no thrust, and this is always a primary condition, whether in earthquake countries or elsewhere, and is usually provided for by introducing wood, wrought, or cast-iron safe lintels, with butts to wood and skew-backs to iron.
On page 101, the Professor says that he, "with Mr. Josiah Conder, visited a large number of foreign-built houses in the district of Ginza." (The foreign houses he refers to are mostly built by English or American architects and builders.) Their chief reason for choosing this was because it was the only district where a large number of similar buildings could be found. By examining houses or buildings of different construction, the effects produced upon them by earth-quakes are very often likely to show so many differences that it becomes almost an impossibility to determine what the general effect has been. "Unsymmetrical construction, involving unsymmetrical ruin." These are his words, and seem applicable to the suggestion made to him by his colleague, Mr. Perry, as illustrated on page 112. The one is square and symmetrical, and possesses the elements that no artist could beautify. The only inference to be drawn from these two illustrations is, to use the Professor's own words: "In the one you have square and symmetrical durability, in the other angular and unsymmetrical ruin." At page 114 is shown the Webber House, San Francisco, as shattered by the earthquake of 1868. This house was built in the early fifties, when the Anglo-American had only been a few years in California, and at a time when the effect of earthquakes on buildings was little understood. (The Professor takes care not to tell us this.) On page 116 he illustrates a mill at Hayward's, also in California. This was a temporary clapboard erection, as you can see, and was insufficiently fastened to the under-pinning; it was shaken off, and hence came to the ground.
At page 128 he quotes a Mr. Ronaldson, who says that in 1868, at San Francisco, the ornamental stonework in stone and cement buildings was thrown from its position. At that time there were no cement buildings in that city at all; and only one stone building was injured, and that one the Bank of California, on the corner of Sansom and California Streets. The whole of the injury consisted in the balustrade round the top being displaced, and was subsequently taken down to prevent further trouble. He admits that the brick buildings with similar ornaments all stood. But the wonder to me is how Mr. Ronaldson missed taking note of those buildings erected on what is considered earthquake-proof principles, for at that time there were hundreds, only one of which was injured. This exception was the Livingstone block, the architect of which was Mr. Farquharson. The block stands on the corner of Battery and California Streets: it is 187 feet 6 inches square, and three stories high. The ground at the page 9 rear corner, facing California Street, sunk about four feet. This part of the city is all reclaimed land from the bay. The reason then given for the subsidence was that there had been a quicksand under, and that the weight of the superincumbent earth, the weight of the building and its contents, and the shaking of the earthquake, had expelled the water and sunk it to a solid substance. The block is built on floating foundations, and did not follow the ground altogether; it followed it far enough, however, to cause fissures in the brickwork. The earthquake occurred in the morning; and before sunset of next day the settlement was raised by hydraulic power, and in ten days or a fortnight the earthwork was filled in, the street made good, the fissures in the brickwork stopped, the floors straightened, and the roof rendered watertight, and no one would have suspected that anything extraordinary had occurred to the building. I tell you this to show that here was a building that would have been a total wreck, had the scientific principles of construction been neglected. He (Mr. Ronaldson) says that most injury was done to those buildings erected before our Institute had studied the effects of earthquakes upon buildings; this so far is true, but the damage was chiefly to fire-walls, or as they are termed here parapets. There were a great many chimney stacks nipped off at the roofs of the wooden buildings. In fact, there was more damage done to wooden buildings than brick ones. I do not know who this Mr. Ronaldson is, but I do know that in 1868 he did not practise as an architect in San Francisco. Quoting Mr. Mallet, he says (page 125) that "the ordinary buildings in Italy, though built of stone and mortar, are poorly put together and are in no way adapted to withstand the frightful shakings they are subjected to from time to time." Now this may be said of all the older buildings in Italy; and many of the ordinary buildings now being erected are put together on the self-same principles as they have been doing for two thousand years. At the same time, the construction of some of their public buildings is more in harmony with modern scientific principles.
The Professor gives some rather amusing illustrations. For instance, on page 108, he says: "It may be interesting to call attention to the fact that in the formula showing three relationships, it was the shape, rather than the weight of a body, which determined it should be overturned or projected by a motion at its base." He states, as an interesting proof that light bodies may be overturned as easily as heavy ones, that Mr. Mallet refers to the overturning of several large haystacks as one of the results of the Neapolitan earthquake. This seems directly opposed to one of Mr. Maskell's positions. I would like to ask him where we are to sleep in earthquake times; as for safety we are neither to do so under heavy nor light buildings? No; nor even under a haystack.
On page 118, (fig. 26,) the Professor illustrates with three flat springs, made out of bamboo, and loaded at the top with pieces of lead. He explains the results of nine experiments, with his deductions therefrom. To architects in the practice of their profession in regions subject to earthquakes, a study of these experiments will be invaluable, and is to my thinking the best part of the two chapters devoted to this subject.
On page 133 is a sentence that most of our citizens will read with wonder; it is this: The Professor says: "For instance, a Civil page 10 Engineer, writing about the New Zealand earthquakes of 1855, when all the brick buildings in Wellington were overthrown, says that it was more violent on the sides of the hills at those places, and least so in the centre of the plains." He (the Professor) quotes this from the "Report of the British Association" of 1858, page 106. Now we of Wellington know this sweeping assertion to be wide of the truth. Here we may well ask: How about all the Professor's quotations? Is it possible that he can be led astray with all the others, as he has been by this nameless engineer? And here I hope you will pardon me for taking a short retrospect of the earthquakes in this much abused Wellington of ours. Seeing this sweeping assertion from such a source, and repeated in a book of such influence as this of Professor Milne's, I felt constrained to make searching inquiries among the surviving old settlers, and particularly of Mr. Thomas Mackenzie, who landed here in 1840, and was afterwards proprietor of the Independent newspaper; and of Mr. J. Plimmer, a distinguished builder, who has been here since 1843. All I can gather from these gentlemen, and many others, prove that there have only been three earthquakes in Wellington since 1840 of any memorability. This is the one in 1840; another in October, 1848; and this one of the nameless engineer, in 1855.
In 1840 the first settlers landed at Petone beach. Having no tents, they at once built themselves whares, composed of toi-toi and flax. They found the toi-toi answer the purpose very well; but after dry weather the flax, as a roofing material, was a failure. One night there was an earthquake "happened" around, The agitated occupants, thinking the Maoris were shaking their buildings down, rushed out in the most primitive of costumes, but saw no one, and at last concluded that old mother earth had been seized with one of her tremors. I have not been able to get any further particulars of this earthquake, excepting that the toi-toi and flax whares were earthquake proof.
The earthquake of October, 1848, seems to have been of a more severe character. There were three distinct shocks of about equal force, the last doing the most injury. Many of the brick buildings were shattered. Mr. Fitzherbert's free and bonded stores, on Farish Street, collapsed, as you see, but were afterwards restored by Mr. Plimmer. One end of the ordnance store was thrown out; afterwards it was all taken down. The front wall of the Colonial Hospital on Pipitea Street was partly thrown out, and so injured that it was thought advisable to take it down. A new hospital was being built of brick on Mount Cook, but was now stopped. Hickson's store is yet standing, on the corner of Old Custom-house and Cornhill Streets. The sketch, as you may see, is somewhat exaggerated. The Wesley Church, on Manners Street, was thrown down, and a wooden one afterwards built. These are all the brick buildings injured or destroyed at that time. It is worthy of note that no wooden buildings were injured, though many chimneys were thrown down. It was customary at this time to build chimneys on the outside, so that they had an opportunity of falling easily. These brick buildings, and all the chimneys, were built with a mortar composed of shell-lime, and clay from Barrett's Point. This composition was said to make a beautiful rich-looking mortar; with age, however, the lime reduced the composition to a powder. What page 11 wonder, then, that with such a cement so much damage was done. Old intelligent pioneers assure me that if the buildings had been constructed then as now, they are sure that little or no damage would have been done. Sir George Grey was then Governor, residing in Auckland; and Mr. Eyre (afterwards of Jamaica notoriety,) was Lieutenant-Governor, residing in Wellington. Mr. Eyre drew up a most sensational report of the earthquake, which had a most alarming effect on the colonists, and retarded colonization for a long time. (Verily, Wellington seems never to have been without such friends.)
I have seen a pamphlet published in Sydney by D. Hall, 76 York Street, purporting to give an account of the earthquake in New Zealand in 1848. After an introductory clause, it proceeds to give an elaborate account of an earthquake which occurred in Italy in 1834, by which the city of Spoleto in the then Pontificial States was almost destroyed. The pamphlet neglects to point out the connection between this Italian earthquake of 1834 and the New Zealand shakes of 1848. It then proceeds to lay before its readers an account of the recent earthquakes in Wellington, "as witnessed by Mr. William Fitzherbert, a gentleman who had resided for many years in Wellington, and to whom we [i.e. the publishers who write,] are indebted for the following interesting details." It is needless going into the particulars, but I assure you they are fully up to the usual sensational style of newspaper writers. The interesting part of the pamphlet to me was the illustrated page it contained, of which here is an enlarged copy. It was lithographed for the publishers by J. Allan, 2 Bridge Street, Sydney, from a sketch by Mr. Robert Park, of Wellington, engineer and surveyor. The buildings are said to be very closely represented, only Hickson's store being somewhat exaggerated.
And now in respect to the earthquake of 1855, when, as quoted by Professor Milne, all the brick buildings in Wellington were overthrown. I have said it is directly contrary to facts; old settlers thoroughly to be relied on, and who remember all the special circumstances connected with this earthquake, assure me that there were no brick buildings totally wrecked, though some few were injured. The fact is, most of those built before that time are standing yet. I have taken the trouble to go and see them, since Mr. Maskell read his paper, and found all of them in good order, answering all the purposes for which they were built. There is Mr. Hickson's store, that stood the earthquakes of 1848 and 1855, still used as a store by Mr. McCarthy, brewer. Messrs. Bethune and Hunter use another of the same class as a bonded store. There are two shops in Willis Street, between Dixon and Ghuznee Streets. There is a residence in Ingestre Street, where the late Mr. Hickson lived, and which the late Captain Kreeft occupied for many years. There is another in Abel Smith Street, that was erected for Mr. Holt, and now occupied by Mr. Hickson; and there is another on Adelaide Road that was built for Mr. Braithwaite, solicitor, afterwards occupied by John Jonson, Esq., and family, Mr. John Minifie and family, &c. These buildings are all in good repair, but may be said to have reached that point which in human life is called middle age, when, though robust and healthy, they have lost the vigour of youth, while the end may yet be far off.
There were other brick buildings that successfully withstood the shakes of 1855, as for instance the offices of the Independent newspaper, but which have since been taken down to make way for page 12 larger premises, and for other improvements, but I will not weary you with the enumeration. I hope, however, that I have proved to you that this sweeping assertion—made by a nameless engineer to the British Association, and copied into Professor Milne's book—is without foundation, and that Mr. Maskell's greatest living authority is not infallible after all.
In saying this, it is not to be understood that I do not appreciate Professor Milne's talents, or wish to depreciate his great learning, or his professional knowledge of Siesmology; but I do protest against his being quoted by implication as being the best living authority on the construction of buildings called earthquake-proof. For I am bold enough to say that I think he is not. I freely acknowledge that he has started many new, valuable, and interesting theories, and given expression to thoughts that the architect would do well to ponder over. With this explanation, I may now say that I have gathered many stray thoughts from him. For instance, I have a letter of his contributed to the London Times about nine or ten years ago, respecting the destruction occasioned by an earthquake in Panama, regarding the construction and maintenance of the inter-oceanic canal at that place. In one part he says, "Although we cannot prevent the terrible disturbances which in earthquake shaken countries are from time to time inevitable, yet by studying the effects of previous disturbances we are enabled to do something to guard ourselves against any disturbances of the future." (!!) The Professor finishes up his letter by saying: "Although we cannot avert the calamities consequent upon earthquakes, very much indeed may be done to mitigate them. Patents have been granted for earthquake-proof houses; and I can answer for the fact that such houses have withstood moderate disturbances better than their neighbours." (!) These two quotations contain sound reasoning, and are valuable to us here. This way: we have the evidence of our oldest and most intelligent settlers for forty-eight years, that all the earthquakes that have occurred here in that time have had a forward oscillating movement, ending more or less with a severe backward jerk, and that hitherto it has been this ending that has been the cause of the damage done. For this period, then, of nearly 50 years, we have abundant proof that all our earthquakes have had pretty much the same character of movement, and that for that time they have been of a mild type. I think, moreover, that our primeval forests, on examination, will go far to prove that this period may be extended to hundreds of years (always excepting the small area round the Hot Lakes). These giants of the forest are of slow growth, and many of them must have stood for thousands of years, and which, with the slight hold they have of the ground—that is, comparatively speaking—they could not have done had these islands been subjected to the violent convulsions they have in Japan, Java, and elsewhere. With this evidence I think we may be satisfied that we shall continue to have earthquakes of a mild type; and we may well hope that carefully constructed brick buildings will easily withstand them.
For all this, I believe there are some of our early settlers who still have nervous feelings on the subject of brick buildings, so difficult is it to eradicate impressions, however wrong, and how difficult, too, to change an established repute. I was in the Ovens District, in Victoria, in 1855, when the news came that Wellington, New page 13 Zealand, was destroyed by an earthquake. The other day a similar rumour spread over that colony, when we had no earthquake at all; our old reputation had evidently been smouldering all these years. Much of this reputation is no doubt due to the startling reports by Mr. Eyre in 1848, and the nameless engineer in 1855.
And this brings me to the question of the possibility of erecting brick buildings in New Zealand, and in Wellington in particular, capable of resisting earthquake shocks, even of a severer nature than any we have had experience of here. I have no hesitation in saying that it is; and more, that buildings of such a quality are erected. Just reflect: Have we not buildings and chimneys yet standing in our city that withstood the shocks of 1848 and 1855; in the construction of which no scientific principles were followed, wherein bricks of the commonest quality were used, and laid too many of them in a composition worse, if possible, than no mortar at all? Need I say that these, for quality and workmanship, are not to be compared in any way to those now being built; and yet they stood.
As Mr. Maskell referred to some of the buildings erected under my care, I may here be permitted to say something concerning them. When Messrs. W. and G. Turnbull first proposed building on the reclaimed land, they told me they would do so in brick, if, with the foundations, it would not be too costly. (Unfortunately the cost is always an exigency, and has apparently been lost sight of by Mr. Maskell.) I suggested floating foundations, as they were not costly, and had stood the earthquakes well in San Francisco; that, in the position their buildings were to be, the filled-in earth between the rock below and the buildings would deaden the stroke of an earthquake, should one come. This foundation consists, first, of a double layer of angular planking, and over these a double row of beams, side by side, and then all strapped and bolted together. This system was adopted for the free store. For the bonded store, piles were adopted instead of the angular planking, with the double row of beams on top, all strapped and bolted together. The motive for these beams is that when a shake takes place, they will carry the superstructure along with the oscillations of the earthquake. Both these buildings were nearly ready for the roofs when a shake came round. This was at a time when our Solons were in session. Many of them rushed down to the Reclaimed Land expecting to see them in ruins, and, I suppose, were somewhat disgusted to see the mechanics at work as if nothing had happened; so little notion had they of the strength of brick buildings, or the tenacity with which they hold together. I mention this to show that even the siftings of the New Zealand population had little faith at that time in the stability of brick structures in Wellington. For the building on Lambton Quay, built for Jacob Joseph, Esq., 11 years ago, it has, as Mr. Maskell says, "the openings arranged in the usual way "—that is, the openings are over one another, and simply means, if Mr. Maskell will look at it rightly, that all the weight of the walls from the top down, all the floors and roof, and the weight of all the merchandise within, is conducted down to the foundations on straight perpendicular supports. For, even in earthquake countries, there is such a thing as specific gravity, a factor seemingly overlooked by Professor Milne and his colleague, Mr. Perry, who recommended the openings to be scattered over the face of the building, thereby rendering perpendicular support impossible. Mr. Maskell thinks this page 14 building too high. It is exactly as the proprietor required it; and I submit he had a right to build it the height it is if he was willing to pay for it. It is this very height that gives it an elasticity or a pliability that enables it to follow, or, we may say, accompany, the oscillations of the earthquakes—a quality that one-or two-storey buildings cannot possess. For in despite of Professor Milne, and all the authorities he has quoted, I assert and can prove that the high buildings in San Francisco suffered the least. The walls of this building, with the brick, mortar, bond and hoop iron, would in 10 or 12 months from the time of its erection be thoroughly incorporated. The floors and roofs, too, are powerful auxiliaries in binding the building into one compact mass. This is true of any building: a quality which the Professor, and those he quotes from, singularly enough overlooks. That this building is united together into one compact mass, Mr Walter Nathan assures me; that with the two or three earthquakes we have had since it was erected, it moved with their oscillations, and when these ceased there were no cracks to be seen anywhere, not even in the plaster. Mr Maskell says that the National Mutual building has a heavy cornice, and other projections, and that the arches do not curve into the abutments. He says the same of the Post Office. Now in each of these buildings the cornices project 6 in. less than according to the best authorities, they should do in order to produce true architectural beauty. I note this to show that I have erred on his side, if error it is. In my opinion, however, the line of 6 in. more could have been touched with perfect safety, as the roof behind is infinitely more than a counterbalancing weight; this is further shown by the cornice projecting over the baked walls of the Post Office for the past 18 months, without floors or roof, and after being exposed to such a heat. So far as the arches are concerned, they all curve to the abutments, for the reason there is nowhere else to butt them to. I am really sorry that the number of the windows in the Post Office do not please Mr. Maskell. In that building it is now too late to try. I may explain, however, that the officers, who at the time it was being designed had competent authority, wanted all the light they could get, and I never heard any of them complain of having too much. For its safety as a building I cannot now answer, and am not responsible; but before it was destroyed by fire I would have stood in any part of it during the severest shake I have felt, either here or on the west coast of America, and had perfect confidence in its safety. So much for egoism, but which, from the remarks in Mr. Maskell's paper, I could not avoid.
In another part of his paper he says that his only object for reading it was to call attention to the fact, that the buildings of Wellington were not put up with a view to resist earthquakes. Now this is not a fact, as he could easily have ascertained by applying to the proper quarters. Here, as elsewhere, money enters largely into the quality of a building, and, speaking personally, I use to the utmost every precaution that the money at my disposal will allow; and I am sure, for their own sakes, my contemporaries in their wisdom are doing the same thing. Therefore, it is neither just nor fair to an honourable profession to make such an invidious assertion—not even by a gentleman who confesses he knows nothing about it.
I am not prepared to speak of the construction of buildings in Christchurch, only that I took a cursory look at Morton's block, and page 15 the Cathedra], when last there. The Cathedral spire, and Morton's block facing the street, are faced with stone and backed with brick. So far as I could see, there were no precautionary measures against the action of earthquakes, though there might have been. The mortar appeared to me soft, and only composed of lime and sand.
I agree with Mr. Maskell in saying that the Corporation By-laws ought to be more explicit than they are. There is not one word about the quality of the brick, or of the mortar, (a more important factor,) or how they are to be laid together; and not one word of the floors and roofs, nor of the sizes of their respective timbers in relation to the space. The parapets are too high, and are dangerous. Clearly, our City Fathers have paid more attention to the Fire Insurance agents than to earthquake agitators. When on this subject, I must note that I think the time has come that this city should have a Building Inspector that knows something about building construction, one who has sense enough not to make the Building Regulations a continual source of irritation to all concerned; and one, too, who, under differing conditions could take and give, while securing the public safety.
Of some suggestions for foundations in Professor Milne's book, one is to place a building upon two sets of rollers, one set resting upon the other, at right angles; another is cannon balls, carried on plates resting on foundations; and yet another is described in a design for a house, the upper part of which was to rest on balls, which roll in inverted cups fixed on the lower part of the building; but all this must refer to bamboo and paper architecture, and for isolated buildings, where there is room to roll, and would, therefore, be of no use to us here. In a paper that was published a year or two ago, he (the Professor) suggests a method which he thinks applicable for heavy structures of stone or brick. It is to allow them to rest on foundations on hard ground, rising from a deep pit or series of trenches; that is, to provide a soft cushion for the building, or just such a foundation as we have on our reclaimed land, and exactly as I explained to Messrs. W. and G. Turnbull and Co., twelve years ago.
I have mentioned floating foundations as being largely used for buildings on the city front, San Francisco, and that answered the purpose perfectly there, and were not costly. I adopted them two or three times here; but as many of our citizens thought it ridiculous to build brick on wood, I had to abandon them, they not knowing, or forgetting, that but for such foundations, cities like New Orleans never would have been built. For an earthquake-proof building I still think that on our reclaimed land it is the best method that could be adopted, as the heavy frame-work all bolted together will prevent the building from spreading at the bottom. For foundations anywhere, off the reclaimed land, they are easily and cheaply found and require no remark.
In erecting the superstructure the following system may be adopted in a general way. It was a system that was in universal practice in California in my time, and may with advantage be practised here, as we are building under very similar circumstances. There, as here, there are no seasoned bricks to be had, none that have been exposed to wind and weather for at least twelve months before being used—the rule being, out of the kiln into the building. There, as here, there are no buildings to slake the cement, that is, a building with a large floor page 16 surface, whereon the cement could be spread out and kept dry, (for it must not be wetted until it is to be used,) and turned over now and again for two or three weeks. This process is to slake, as far as possible, any particles of free lime that may exist in the best cement. There, as here, we have to admit our heavy timbers into the buildings fresh from the forests.
The bricks used should be hard and sound, not too finely moulded, but square; and if new, water to be continually poured on them, as without the water the mortar will not adhere. Further, there should not be more than three courses of stretchers to one of headers.
In respect to the cement to be used, in brick or stone buildings in earthquake regions, too much attention cannot be given, as upon it the stability of the building entirely depends. It ought to be composed of such a mixture as that, when it is hardened, it will have a density as nearly as possible analogous to the stone or brick to be used, and so that the walls may be as nearly as possible one homogeneous mass.
This question of cement has in all ages been a vital question with architects. We cannot forget the words of Pliny, when he said "The cause from which at Rome so many buildings fall is the bad cement." In latter times we have examples of mortar without any adhesive quality. For instance, M. Fruesart having to re-construct in Strasburg, in 1822, the foundations of a bastion built in 1666, found there the mortar as fresh as if the masons had laid it out some few hours be-fore. A similar circumstance was observed at Berlin, by the architects who took down one of the towers of St. Peter's, which was built about eighty years before. Happily, with lessons such as these, and others, and with our greater knowledge of chemistry, we now know the nature of most of our limes and cements, and so are able to compound a mortar in the present day that in ten or twelve months will in hardness equal, if not be superior to, the best mortar extracted from Roman monuments that have an antiquity of two thousand years.
In California the limes are none of the best, and we substituted Rosendale or Portland cements, as we could get them. The former is a natural product of America, of which Mr. Henry Reid gives the analysis in his book on cement. After some experience we found that not only this but Portland cement set too quickly; that in some buildings where alterations had to be made the cement only formed a cake between the bricks, without the slightest adhesion thereto. Two French architects told us of a custom they had in France of mixing cement with the lime and sand; that by this process the setting was slowed long enough to allow the brick and mortar to adhere together. After trial we found not only this to be true, but that it was easier worked, and that the bricklayers could lay a greater number of bricks per day. These two architects, at the time this discussion was going on, told us of an aqueduct built in Paris, 87 miles long, having nearly three miles of arches, some of them 50 feet high, and of 40 feet span, that had been built with a concrete of this mixture, and that the work was eminently satisfactory. It is called in France "beton agglomere," and was invented by Monsieur F. Congiet. Curiously enough, this very aqueduct is spoken of in "The Building Materials of Otago," by Mr. Blair, and by him highly commended. After this there was no other mortar used in San Francisco. The specification is something to this effect: To three measures of clean sharp sand (this sand is the foundation of a great part of San Francisco) add one page 17 measure of rock lime and one measure of Portland cement. If it was Rosendale cement: To four measures of clean sharp sand add two measures of rock lime and one measure of Rosendale cement. The mortar was mixed in the usual way. These are only the proportions. You will note that there is a greater portion of lime to the Rosendale cement, the reason being that it set so much quicker than the Portland. With well-soaked bricks, and such mortar as the above, all the joints fully filled, we found that in less than twelve months brickwork became one tough solid mass.
Mixing lime with cement has sometimes been condemned, as, for instance, by Mr. Henry Reid; but he knew nothing whatever of the conditions we had to struggle against, or the aims with which we were actuated, and was therefore unfit to be our judge. There were both architects and builders here who condemned it, because they saw it in Mr. Reid's book. But, as has often been said: "To the young or inexperienced all things are mere theories," and most of the builders now admit its utility.
To render the building still more durable, we continued the use of building in the walls the usual complement of hoop-iron, and added bond-irons to girt the buildings at the beds of all the joists and roofs, instead of the usual wall-plates. The ends of all these bond-irons are clipped and bolted together. The ends of all floors or roofing beams, and the ends of the joists at short intervals, are anchored to the walls with wrought-iron cross-anchors; and wherever framed joists or the butt end of joists meet they are strapped together with straps and bolts.
The timbers in California are much better for building purposes than those we have here. The fibre is tougher and more pronounced, and when overloaded will give warning before breaking; and, above all, they are capable of being seasoned, and do not shrink the end way. Here our timbers have little or no fibre; when overloaded they break without warning. Some of the varieties never season, and the most useful and best shrink the end way, to the disgust of both the architect and the builder. For these reasons largo allowance should be made for our timbers. The thickness of the joists should be one-fifth of their depth—certainly never less than one-sixth; and they should be bridged not more than six or seven feet apart. Of course, I am speaking of brick or stone buildings. It can easily be seen that by such a method of construction no fractures could have happened in the walls, as illustrated in Professor Milne's book. In addition to this mode of construction, further security has been sought by building inside the walls strong timber framework, strongly anchored into the masonry, furred angularly, and then lined with strong matched lining, the opposite way of the furring. Colonel Elliott, of the United States Engineers, advocated a system of triangular rods to be built within the walls, begun on the solid masonry in the foundations, and so to the top. Something like this was adopted in the erection of the University of California, by Mr. Farquharson. There have been patents granted in America for various methods of earthquake-proof construction, but, so far as my information goes, the benefit has not been compensated for by the extra cost.
Mr. Maskell tells us that he has taken opportunities of looking at some of the brick buildings in this city, and finds the greater part of the theories of Professor Milne neglected. I hope he will now admit page 18 that in those peregrinations his looking was only superficial: that he only saw regular openings, one over the other, instead of scattered ones; that the arches were not curved into the abutments, and that there were some projections that did not please him. Also that he will, after hearing the foregoing general description of the construction of the buildings under consideration, see that the wrought-iron within the walls, and the iron bond connection that the floors and roof have with them, form such a tower of strength as even Professor Milne never dreamt of. The above is the system that has been followed in the buildings Mr. Maskell has criticised; and I await with perfect confidence the result of any test they may be subjected to, though I trust that time may be far off. It is a mode of construction that has been eminently efficient in San Francisco, and along that coast, and is in use with the San Francisco architects, a body of gentlemen who represent almost every nation in Europe, as well as America, and who began the study of earthquake-proof construction long years before the name of John Milne was known to the scientific world, who are still continuing the study, and, on this subject, are in my opinion the best authorities on the face of the earth, Professor Milne and all his hearsay evidences notwithstanding.
In conclusion, I hope there is nothing contained in Mr. Maskell's paper, nor in Professor Milne's book, that will alienate the faith we have in our adopted country;—that we inhabitants of the Great Britain of the South will continue to believe that we shall have no more severe tremors of Mother Earth in the future than we have had in the past. That with this faith in ourselves and in our new home, we may continue to cultivate the arts and sciences, and in civilisation march on abreast of the other great families of the Anglo-Saxon race that are to be found in every quarter of the globe. That we may even have the courage to rival in progress our illustrious mother, the Great Britain of the North, who, in the face of the 255 recorded earthquakes, has built a city of such a magnitude, of such excellence, and who governs it with a perfection such as the world has never seen. That we may feel in our souls that these islands are as safe and secure as the land which has sustained the Pyramids for thousands of years: more steady than the foundations on which the ancient Greeks erected their matchless temples : as enduring as the sunny plains of Italy, on which the ancient Romans originated the glories of arcuated architecture, and rendered possible the production of the sublime cathedrals of the middle ages: that we may have such a faith in this our abode as the citizens of that young great city of the Occident have in theirs, and wherein originated the mammoth hotels of our own time.
"True," those may say who are habitually foreboding evil; "but our fate may, one of these days, be as was those of Japan, Java, and Central America of late years." Aye; and so, too, may come the time spoken of in Holy Writ, when "the heavens shall pass away with a great noise, and the elements shall melt with fervent heat; the earth also and the works that are therein shall be burned up."page 19
Mr. W. M. Maskell regretted that Mr. Turnbull had made the question a personal one. He (Mr. Maskell) had carefully avoided that; and his only object in presenting the paper was to draw public attention to an important matter. He did not desire to defend Professor Milne—he could stand up for himself; but if he was allowed he would differ from Mr. Turnbull's opinion of that gentleman. As far as his (Mr. Maskell's) reading went—and it was not that of a few days—no name stood so high as that of Professor Milne upon such matters. He combated Mr. Turnbull's arguments at some length, and pointed out that the effects and results of earthquakes were incomprehensible. Earthquakes seemed to knock buildings down, or leave them alone, just as they liked. A number of buildings on one side of a street might be knocked down, while others on the opposite side would be uninjured, He considered that Mr. Turnbull had given up the whole question, just as an architect who had written to a newspaper in reply to his (Mr. Maskell's) paper had done, by making a statement that we were not likely to again experience destructive earthquakes. Those who thought that were perfectly welcome to their opinions. He did not believe that we were not going to have destructive earthquakes in New Zealand, and he explained that the whole of his paper was based on the supposition that what had happened before would probably happen again. He quoted some notes on the shock of 1848, written by Mr. W. Fitzherbert, who stated that "the earth in some parts was moved in waves averaging about 12 inches in height." He would like to know how their brick buildings would fare under those circumstances. Mr. Fitzherbert had further stated that several brick buildings were thrown down, and that a subsequent shock completed the destruction of most of the brick buildings. Mr. Maskell also quoted from some notes on the same earthquake given by Mr. H. S. Chapman (afterward Judge Chapman) in an article in the Westminster Review, detailing the damage done. Mr. Maskell expressed his belief that if the recent shock experienced in Canterbury had occurred here that half the large buildings of brick and stone in the city would have been very much injured, if they had not fallen down.
Mr. Turnbull said that Mr. Maskell regretted his "making the matter a personal one." He denied this, and pointed out that Mr. Maskell, by selecting his (Mr. Turnbull's) buildings for criticism, had put him on his defence; and hoped that in his paper he had succeeded in dispelling many of the fears in the stability of our buildings which might have arisen from the startling tone of Mr. Maskell's paper. Mr. Turnbull denied that he had given up the whole question. He had taken in hand to read a paper on "Earthquakes and Architecture." The paper from beginning to end had never left the subject. With regard to the earth waves one foot high, described by Mr. Fitzherbert in 1848, reliable old settlers allow there was nothing of the kind, though there might have been atmospheric illusion that produced something approaching to their appearance. Mr. Turnbull did not envy the feelings of those who were always living in dread of something terrible that was going to happen. He said he intended to pursue the subject at some future date.
The meeting then terminated.