The Cathedral of Noto still dominates its city withgrace and majesty despite its gutted interior and

broken dome. The collapse of S. Nicolo on 13 March1996 was just the latest misfortune in a longsuccession.] From shortly after the inception of thecity of Noto on its present site in 1693 until the late20th century collapses and closures caused by

earthquakes plagued the church. The foundations ofthe original Chiesa Madre of S. Nicolo can be still beseen seven kilometers northwest of the present cityamong the ruins of old Noto (Noto Antica), destroyed

in the earthquake of 1693. The Baroque city of Notoand its Chiesa Madre of S. Nicolo are products of amassive earthquake reconstruction effort which

Figure 1S. Nicolü. Fa~adc overlooking the main piazza of Noto with

a fragment of the dome stillstanding in 1998 (phata: authar)

Building the cathedral of Noto

Stephen Tobriner

continued into the late 18th century. Whenearthquakes rumbled through the new city of Noto in1727, 1780, 1818 and 1848 each damaged orcollapsed S. Nicolo. The last earthquake to strike thecity in 1990 opened cracks in the church whichdirectly contributed to its failure in the rainstorm of

1996 (Gavarini 2000).Since S. Nicolo experienced multiple earthquakes

it is fair to ask whether the architects andstonemasons chosen to build or repair it attemptcd tomake the church seismically resistan!. Onlyconstruction documents corroborated by the mins of

the building itself can definitively answer thisquestion. The challenge is to try to understand the

architect' s or builder' s intention. The methods 18th-century Sicilians used to insure stability inearthquakes might differ markedly from our own. Forexample, one commonly held principie of antiseismicdesign derived from Classical authors and advised by

architectural theorists like Antonio Averlino (11Filarete), Andrea Palladio, and Francesco Milizia(Laner and Barbisan 1986, 13-27, 30-35, 56) was

that buildings should be constructed over caverns orincorporate vertical shafts and hollow walls to avoidinhibiting vapors expelled from the earth during anearthquake (Guidoboni 1989). This idea is socounterintuitive we might miss it even if we saw abuilding intentionally built over a void. Other

intuitive ideas about how to stabilize a building arecloser to our own. The Mannerist architect, Pirro

Ligorio, after examining the mins of Ferrara after the

Proceedings of the First International Congress on Construction History, Madrid, 20th-24th January 2003, ed. S. Huerta, Madrid: I. Juan de Herrera, SEdHC, ETSAM, A. E. Benvenuto, COAM, F. Dragados, 2003.

1980

earthquake of 1570, offered his own observationsabout building safety (Guidoboni 1997). He criticizedbuildings that were simply too old, built with thinwalls, lacking in reinforcement, bonded with inferior

mortar. He blamed the craftsman guilds workingwithout the guidance of a trained architect (likehimself, of course) for the poor design and execution

of the buildings that failed. His remedy was first tobuild well' with the best of materials and to use ironties where necessary to bond walls together. He saw

evidence of heavy exterior walls oscillating atdifferent frequencies and striking one another. Hesuggested heavier than usual interna] partitions tohelp stabi]ize these walls. He proposed uniform wal!

thickness as a way of insuring that buildings movedtogether in earthquakes and hypothesized that regularground plans were far more resistant to shaking thanirregular ones. Ligorio's intuitive reasoning seemsconsidered, and generally in accord with present-day

ideas of seismically resistant designo He, andcountless architects who followed him, had to facethe problematic behavior of brittle masonry wal!swhich lack resilience when subjected to lateral forcesgenerated by earthquakes.

The temporary church of S. Nicolo built in 1693was certainly influenced by the fear of earthquakes.Because citizens feared the return of the deadlyearthquakes which leveled not only Noto, but morethan forty cities in Southeastern Sicily, they builtsmall low structures throughout the 1690s (Tobriner1982). The baracca of S. Nicolo, like others in thecity, was modest. But within a decade, al! over Noto,

the temporary buiJdings were being replaced bylarger ones in stone. Among these permanent building

was S. Nicolo, begun in 1696. Like other building s inthe new Noto, S. Nicolo, was a patchwork of newlyquarried and previously cut stonework. As

stonemasons established quarries on the slopes of thenew site of Noto, they sent mule train after mule train

to Noto Antica to excavate stone from the ruins. Themarble portal of the main doorway of S. Nicolo, Iyingin ruin s in Noto Antica, was transported to the newcity in 1696 and incorporated in the new fa~ade. In1718 the insignia ofthe city found in Noto Antica wassolemnly affixed to the fa~ade of the new Chiesa

Madre clearly underscoring the transfer of the city.In the midst of reconstruction a major earthquake

struck Noto in 1727, badly damaging the new stone S.Nicolo for the first time (Boschi et al. 1993). So badly

S. Tobriner

damaged was the marb]e main porta] in theearthquake of 1727 that it was at risk of tota] ruin.

This decorative feature and the stone around it whichhad previously collapsed with the old church in 1693,nearly faiJed after it was installed in the new. The

interior of the church must have been at risk as wellbecause authorities removed the precious Arch of S.Corrado (the patron saint of Noto) and installed it forsafe keeping in the church of S. Domenico. The 1727earthquake not on]y damaged S. NicoJo. The facade

of the church of S. Francesco broke apart, the vault ofS. Agata fell, the cross of the church of SS. Trinitatumbled off, S. Maria di Gesu was damaged, and aportion of the facade of the Jesuit seminary facing thepresent Piazza XVI Maggio collapsed (Canale 1976,58,363,288-89; Boschi et al. 1995; Gallo 1964).

The 1727 earthquake should have proven to thepeople of Noto that seismic events recurred and thatthey were extremely dangerous to masonry structures.

Yet no evidence of antiseismic constructiontechniques appears in the first church of S. Nicolo,badly damaged in the earthquake of 1727, eventhough this first church was built within memory of

the great earthquake of 1693. Just the year before, in1726, a major earthquake destroyed scores of

buildings in Sicily's capital city of PaJermo, only afew days ride from Noto. Palermo had initiated somesurprisingly avant-garde antiseismic construction

methods (La Duca 1995). For example, after the 1726Palermo earthquake we know that antiseismicso]utions for domes made of stucco and wood instead

of stone were discussed and implemented.Strengthening of damaged structures through thecopious use of iron was introduced. Even a lawprohibiting the use of heavy balconies waspromulgated.

What effect did the lessons of the Palermoearthquake of 1726 and the earthquake of ] 727 ha veon reconstruction in Noto? An aristocrat writing

Noto's early history states that after the earthquake«the walls of convents, pa]aces and churches were insuch poor condition, so full of fissures, that they hadto be repaired either with buttresses or iron chains.»Variations on these techniques are used afterearthquakes in present day Sicily. Rosario Gagliardi,

the most famous architect working in 18th centuryNoto, must have known about how to builtantiseismical1y. For example, Gagliardi wasemployed as the architect of the new church of S.

Building the cathedral.ofNoto 1981

Maria la Rotonda in 1730 in whieh the walls werestrengthened with iron rods. Twenty years later in

1750 in an assessment of the ehureh of S. Miehele inthe Sicilian town of Scicli he proposed two solutionsto roofing in relationship to earthquakes (Nifosi 1988,32, 37). He advised that light vaults of wood and eane

and plaster would resist earthquakes more effectivelythan stone arches. Gagliardi's diseussion of vaults inSeicli proves he was cognizant of seismie hazards andunderstood antiseismic strategies. Yet no seismicstrengthening is recorded at S. Nicolb. While workersseem to have been repairing the «pietra d'intaglio»[ashlar masonry] of the «arehes, pilasters, andwindows», Gagliardi was employed to take down and

to remount the bells of the ehurch. It seems thatGagliardi was adding a single belfry to the facade,perhaps a miniature or full-scale tower fa<;:ade. What

is not described are the antiseismie iron rods or chainshe used in S. Maria la Rotonda. Instead, the upperpart of the facade, probably ruined in the earthquake,

is remade. lt is diffieult to judge this work in relationto seismic safety.

Between October 8, 1745 and August 21, 1746, forreasons still unclear, the campaign to finish the first

church was abandoned and an entirely new churchbegun. Perhaps the earthquake of 1727 had dealt the

first church a fatal blow, the extent of which expertsonly realized over time. lt is possible that the initial

damage caused further failures much later just as thedamage from the 1990 earthquake contributed to the

failure of S. Nicolb in 1996. Social and aestheticreasons eould also aecount for the abandoning the1696 designo Perhaps the first church, stillincomplete, was insufficiently large or grand inrelation to new mother churches being erected inother eities of southeastern Sicily. The new secondchurch begun in the 1740s was designed encapsulate

the nave of the first church. Documents record thatstone is delivered to the site as early as 1746. Theshipments of stone are presumably for the new waJls

for the apse and chapels being built at the northernend of the church. which could be built while thefacade and nave of the first ehurch remainedundisturbed.

1IYJX'I~ic,,1 CoostruClÍoOn Ph.u-c~

17# -1.(,4 ~Mj~..,m: «o óc I«.;.M d.mil - t 7éft.. I ~(,.x",~",,'" ,1 ~ fin! ,b,¡rth, "'.,.. fac...x ",d

"""'~0(,1><11«><0<1 cturm- 1?f1$-1.~9 e«uUwu"" <>1'1"",*",1 d('>~i_. ~ liSO. 181? «4'~ md ,«<c.!r.K1>on oft~ <10m<,. d~ 10.as;¡jJd P'''''''\«Y iiIiiiIIIi4S.I8(,¡ «>1~oftho~ é'.om:"'''!CI>~''''''''I<>!",,*,''-''Y

1M 11» C\."<1tINctio!> 0(. t1<"Ndo*,Figure 2

S. Nicolb. Plan i11ustrating successive building campaigns (drawing: Emanuele Fidone)

--

1982

Figure 3S. Nieolo. Detail of lateral elevation (photo: author)

Authorities caJled in Gagliardi in 1753 to render anexpert' s opinion as to the condition of the first church.The question was whether to reutilize the nave andfacade 01'the first church or finance new construction.Gagliardi strongly condemns the construction andaesthetics of the entire first church in order forcechurch authorities to finance a new building. Gagliardiwrites «internal1y and external1y 1 declare the buildingto be false to architecture without the possibility 01'being able to be brought to any approximation 01'proportion 01' architectural perfection. Second, you

can't vault it because the walls are very weak and fuJl01' holes .. In my view the church should bedemolished and so the new church, which one can seeis already underway, and rises with afine and regularsense 01' architecture can be built.» Gagliardi'scondemnation 01' the structUre and the architectUraldesign ofthe first church is a legal document and must

been taken extremely seriously. That he did notexclude his own work on the facade is surprising,since his condemnation could be legaJly binding,inferring that the architects who had directed the

works (himself included!) would have beenfinancial1y responsiblc for the shortcomings 01' thebuilding. A second document 01' Ocl. 1, 1753complained that the wal1s were improper1y

constructed 01'«pietra mol1e» (soft stones).After initial reluctance the church officials

endorsed the new second church. From 1764 to 1769work began on the chapel 01'S. Corrado, the chapel 01'

the SS. Sacramento, the left campanile and the rightlateral elevation of the second church.

S. Tobriner

Figure 4

S. Nicolo. Interior as seen frol11 rel11ains of roof al crossing(photo: author)

The lateral right wal1 was laid outside the perimeter01' the nave 01' the first church, which was still intact,Figure 3. Both the right and 1eft lateral elevations

with their dynamic rhythms, expressive decorativefeatures, and quality 01' surface and depth are in thestyle 01' Rosario Gagliardi. Between 1769 and 1776

the old church in the interior 01' the new walls wasdemolished, and the new interior with piers to supportthe c1erestory, the fa<;ade, and dome wereeonstructed.

Although his name is never mentioned in thedocuments, the author 01' the plan and original

elevation for the second church of S. Nicolo isprobably Rosario Gagliardi. The plan of the church isvery close to a number 01' variants of a basilica planattributed to Gagliardi as well as to other buildings hedesigned like SS. Croei1'isso in Noto. Only in 1767 is

the «architetto» named, and he is Gagliardi' sassociate, Vincenzo Sinatra (Di Blasi 1990, 18).Be1'ore Gagliardi died in 1762 Sinatra had established

a close professional relationship with him which wasfurther strengthened when Sinatra marriedGagliardi's niece. Working 1'or Vincenzo Sinatra ashis capomastro was Giuseppe Sinatra, Vincenzo's sonby a previous marriage. By the time construction of

the facade had begun Gagl1ardi's full Baroque stylehad waned in popularity and Sinatra toned down thefacade, as his patrons, the aristocrats of Noto, would

have wished. The second church was opened 1'01'services in 1776.

Several features of the second church of S. Nicolo(Figure 4) could have been attempts to make it

Building lhe cathedral 01'Noto 1983

seismically resistant. The 1'irst possibility is that the

lateral elevation n1' Gag]iardi' s prniect called 1'or abuilding with excessive mass and a low height tn

width ratin which Inwered the center 01 gravity. Themassive lateral walls and deep chapels 0.1'the navemight aid the stability nf S. NieolÓ In an earthquake.

The depth 01' the wall itself and its cnntinuity withmini mal apertures, combined with the interinr walls,

which link it the internal piers, provide resislance intwo directinns. Further, the buttresses above thelateral facades help stabilize the clerestory walls. Thesecond possibility is that Gagliardi may haveattempted to lessen mass bearing on walls. 11' theinterior were vaulted in cane and plaster. exertingnegligible thrust on the clerestory walls, the seismic

threat to the structure would have been lessened.Gagliardi designed domes in Noto like lhe one atopthe Jesuit church of S. Carlo. as «Lombard domes>"with 1'ramed till1ber rno1's and interiors 01' wond,ball1boo and stucco instead of heavy rnasonry. Theinterior 01' S, Chiara has an intricately designed lightstucco and wnoden vault. In his work throughoutNoto there is a lack of large domes, tower racades, 01'high towers. An acknnwledgment 01' seismic

problell1s might explain why Gagliardi's church 01' S.Dornenico is unusually squat and why he adopted thernethod 01' miniaturization in his tower 1'acadechurches which reduced how far the last storyprojected above the rooí'. Because S. Nicolo was the

Chiesa Madre, it required a dome. The kind 01' dome

1'avored by Gagliardi is illustrated in his design ror S.

Figure 5S. Giorgio, Ragusa. Elevation. Rosario Gagliarcli (Archivesof S. Giorgio, Ragusa)

figure 6

S. NicolÓ. Plan illustrating discrepancy between buttresses

and lransvcrse arches (drawing: Emanuele Fidonc)

Giorgio in Ragusa Ibla 01' 1738 ( Figure 5). This dome

with its modest cupola, low drul11, and heavy walls isext1'emely conservative. Un1'ortunately, like all domeswhether they be l11asonry or steel, this one wouldhave been at risk in earthquakes.

Severa] puzzling changes, perhaps rclated to

earthquake damage, occurred in the nave during theconstruction of this second church (Figures 6 and 7).

The internal transverse arches are not aligned with theexterior buttrcsses. Hov" can this strangeinconsistency be explained'!

One cnuld hypothesize the presence 01'a truss roo1'which was huilt in relation to the external buttresses,perhaps designed 1'or a lower stone vault in a 1'irstcampaign, around 1770. This solution was then

changed to the one we see today. They decided on ahigher vault in cane and plaster with the transverse

arches in stone which are o1'1'-axis in relation to thebuttresses. The builders could have decided 10 altertheir original deslgn 1'or acsthetic or structuralreasons. lt is pnssible that thc building may have beendamaged by the earthquakes 01' 1666 and 1667 which

struck Noto. lt is aiso possiblc that cracks appeared inthe piers 01' the building, causing builders to rcthinkthe design for lhe clerestory, roo1' and vault. If thishypothetical change did occur, the diminishing 01' theweight of the vaults could be scen as an antiseismicstrategy, but thc off-axis arches introduce torsion into

the structure because 01' the irregularity of the loadpath.

The ruins 01'the second church 01'S. NicolÓ (Figure8), and the documents related lo its construction are in

accord: This was a masonry building built in the

tradition of Noto (Fianchino and Sciuto 1999,71-82,

1984

Figure 7S. Nicolo. Exterior buttresses (photo: author)

lOO-124). Like other Noto buildings S. Nicolo isentirely stone, without a single brick. The stonescalled out in the documents are the stones which wereused in other buildings (Fianchino 1983, 74-75).Some are quarried from the site of the city and othersare brought from quarries nearby. They includevarious grades of sandstone and limestone (Emmi andRealini 1996, 111- 120). The construction techniquesare similar to those described by Giovanni BiagioAmico (1684-1754) in his treatise L'Architetto

Prattico (1726/1750) and detailed by modernscholars of 18thcentury Sicilian architecture (Cottone1987, 81-86). Amico writes that among the various

kinds of walls «There is al so another way of makingencased walls . . . in which the exterior is constructedof squared stones and linked together with othersquared stones keyed are right angles, and filled with

stones and earth, or mortar. In Sicily they use mostlyuncut and roughly cut stone, filling the remainingvoids with small stones and mortar with finelyhammered lime (Amico 1726/1750, 1, 63).» Thisstone masonry technique, described by Vitruvius, waswell known in Antiquity. The ruins of the exteriorwalls of S. Nicolo clearly illustrate the use ofirregular stones placed in rough rows inside an outerring of cut stone, » pietra d'intaglio.» This technique

was common throughout southeastern Sicily as acomparison between S. Nicolo and the Monastero dei

Bcnedettini of Catania demonstrates (Barbera andLombardo 1989,20-25). The ultimate stability of themass of stones depends upon the strength of themortar and if all else fails on the ashlar masonry skinof the wall.

In the last campaign to finish the nave of S. Nicolostonemasons made a major miscalculation in the

S. Tobriner

construction of the nave piers which nullified anyattempt to make the building safe in earthquakes. The

static loads of the clerestory, side vaults, nave vaults,and dome are all carried by the piers, so theirconstruction is particularly important. But in S.Nicolo the nave piers are the weakest part of theentire building because of one mistake, the use ofround river stones in their construction (Figure 9).While river stones are excellent in compression they

are smooth and round making it difficult for mortar toadhere to them. As architectural treatise writersuniforrnly advise, they must be broken up if used inwalls. To do otherwise is to build a structure thatviolates the rules of good architectural practice(Alberti 1988, book 3, 8, I 1). After the Calabrian

earthquakes of 1783 authorities condemned the use ofround river stones in walls as being one of the causes

Figure 8S. Nico10. Intcrior with broken piers on Icft (photo: author)

Building the cathedral of Noto 19R5

Figure 9s. Nicolo. A broken picr illustrating rivcr stones in core andcut stone facing (photo: author)

for building failures in earthquakes (Tobriner 1983,135). The Bourbon government of Naples prohibited

the use of uncut river stünes in all new construction inCalabria.

The mistake of using round river stones in the piersis compounded by the use of poor rubble limestoneand weak mortar and an even weaker external ashlarrevetment (Binda et al. 2000a, Binda et al. 2000b).The mortar in the piers is not particular1y strong andwas not viscous enough to penetrate between therubble. As a result there are unfilled ho]es in the coresof the piers. The stones in the core are of poor qualityas well. In fact, except for the river stones,Gagliardi's description of the construction weaknessof the first church, and his accompanyingcondemnation of the same year, fit the description ofthe construction of these piers and the stones of whichthey are composed. The exterior «pietra di intaglia»

had the potential of confining the problems of thecoreo But only one thin width of cut stones was laid.Unlike designs advised by Vitruvius, which weresupposed to be made of chains of stones, here there is

but one width of poor1y bonded stone. To makematters worse, the design of the piers hadindentations for niches which induced the masons tolay stones which in some cases touched only at the

corners. The miracle is that S. Nicolü stood as long asit did.

How can the poor construction of the piers beexplained? It should be noted that the piers, nave ruof,

and dome were the last part of the building campaign,

coinciding with the demolition of the old church. Theupper parts of the church are better crafted with

material superior to the lower. The demolition of the

old church would have produced a great deal ofmaterial which would have had to have been cartedaway. Gagliardi's condemnation of the first church

was long forgotten. Perhaps materia] from the firstchurch was reused in the piers to simply use it up. The

river stones, too, were probably on the site. Perhapsthere had been an overrun and these stones wereextras. So to use up unwanted material the bases of

the piers were begun with river stones and soft limestones. There also could have been unsupervisedfilling of the carefully cut exterior perimeters of thepiers. Master masons set the cut stone (pietra

d'intaglio) while day workers may have beenresponsible for filling the interiors. Hence themistake.

Another possibility exists which is linked to thereluctance of the aristocrats to fund the project andthe anxiety of the populace regarding their unfinishedChiesa Madre. After the initial ardor to complete thebuilding, enthusiasm waned. In the l 740s and l750s

aristocrats appear to have been reluctant to fund theproject. lnstead they concentrated on their own

churches and chapels. But by 1770 the fundingoutlook brightened. A document of 1770 enumeratesan aristocratic bequest of funds to the Chiesa Madrethat so inspired the populace that they donated notonly their own money but their own labor, motivatedby «un Santo Zelo.» What effect did this «zeai»

combined with faith and impatience have on theconstruction of the church? Is it possible that thecitizens of Noto were moved, like the aristocrats andcommoners of the Miracle of the Carts in MedievalChartres, to carrying stones to the construction site of

the Chiesa Madre. Could these stones have comefrom the Asinaro River which flows near the site ofNoto? Faced with the pious donation of mounds ofinappropriate material, and the further donation of

free unskilled labor, perhaps the capomastri headedby Giuseppe Sinatra made disastrous misjudgments.

Yet another possibility is that seeing the poor qualityof the rubble limestone available for the filling of thepiers the capmastro decided that stronger limestone,

even in the shape of smooth river stones, was betterthan nothing. Understanding the problem heinterspersed the river stones with the other fill in the

plers.

1986

The piers may have begun to show signs ofweakness during construction. The vertical cracksdiscovered in the piers by Luigia Binda and her groupof researchers indicate they were spreading andbuckling under vertical gravity ]oads at least as early

as the re-plastering of the church around 1950 andmost likely before (Binda et al. 2000b). Could thecracks have alarmed the capomastri sufficiently for

them to attempt to diminish the ]oad by lightening theroor! Could this explain the puzzling change in thevau1t design? We will never know.

S. Nicola' s construction history is complicated stillfurther by the fai]ure and reconstruction of its dome.While a detailed history of the domes of S. Nicola is

not germane to this essay an assessment of theirpossible antiseismic qualities is. The dome of the

second church, the first dome, was badly damaged inan earthquake on June 5, 1780. The dome collapsedand the remains of both it and the apse weredemolished by late June. In 1789 the French travelerLéon Dufourny describes work under way to build asecond dome. According to Dufourny, the architectStefano Ittar was in charge of the works. Dufournyexplains that Ittar was diminishing the dimensions of

the windows of the erossing and reshaping them asovals in an attempt to provide better support for thedome. Dufourny is dubious that this strategy issufficient to correct the problem. Since rttar is nevermentioned in the documents, it is possible he left theproject which was then executed by Bernardo Labisi,

the son of Paolo Labisi, who appears in the cantiere ofS. Nicola as an architcct in ]809 and an engineer in

1809 and 1813. By 18 l 6 windows were installed andby 1817 the dome was plastered. In 18 l 8 another

earthquake damaged the new second dome. lt wasevaluated for possible repairs in 1839, only to beshaken to ruins in 1848. The third dome was begun byLuigi Cassone in 1857 and completed in 186 l.

Unfortunately, information about the first two

domes is extremely limiled, and even lhe designprocess of the third is unclear. Still the question can

be posed whelher there is any evidence of anliseismicconstruclion features. In other words are there anyspeeial design features or reinforcement strategiesparticular to antiseismic design? Several possibilitiesemerge. The first involves the partial filling of thenave windows (Figure 10) at the crossing before theinslallation of the second dome that Dufournyascribes to Stefano rttar. This tried and true method

S. Tobriner

was used many times before. For example, after theseeond dome of Hagia Sophia partially collapsed inan earthquake in 984 four windows were closed toconsolidate it (Mainstone 1997, 89-99). rttar mayhave also designed the buttresses of the crossingbelow the dome, which are bui1t of inclined cut stoneto effectively counter the thrust of the weight of thedrum. The beautiful stonework thoughtfully laid tocounter the lateral thrust contrasts markedly with thework in the rest of the building. Another example ofantiseismic considerations was the unsuceessfulattempt by Cassone to limit the weight of the third

dome by using pomice stone. Unfortunately the stonecould not be obtained. Professor Maddam of the

Figure 10

S. Nicolü. Oval window and buttresses at crossing. [n the

late 18'" century the original aperture was diminished and a

smaller oval window inserted to add strength to the crossing(photo: author)

Building the cathedral of Noto 1987

University of Catania advised Cassone to use brick

and strong pozzolana mortar for the dome, whichwould have yielded a stronger structure than Noto'stypical mortar and stone construction but this

suggestion was not taken.

What could have been done to improve theperformance of S. Nicolo? Masonry is extremelyrigid and brittle and therefore vulnerable seismicdamage. A masonry structure is composed ofthousands of pieces bound together by mortar. Thechallenge is how to aid a masonry structure to move

as a unit without breaking apart. In relation to domes,the famous treatise of Giovanni Poieni, Memorieistoriche della Gran Dome del Tempio Vaticano. e

de' danni di essa, e de' ristoramenti loro (Parma1748), would have been a useful source for the

builders of S. NicolÓ. Poleni explains the mechanicsof dome failure and discusses counter measures likethe use of iron chains to control the thrusts of domes.Poleni's analysis the effectiveness ofthe iron bars andchains used in Sto Peter's dome in relation toearthquakes is extensive. Iron rods had be en used byBrunelleschi in his Ospedale degli Innocenti inFlorence to control the splaying of arches (Saalman1993,40-48). In the Wh century Giacomo della Porta

used iron rods to control hoop forces when he wascompleting the dome of St. Peter' s (Robison 1988,257). Later in the 17th century Francesco Borromini

used iron chains to counter the thrust of hiscomplicated dome of S. Ivo alla Sapienza (Connors1996, 680). Iron was used by the Perrault in the 17thcentury in the eastern facade of the Louvre (Berger1993, 65-67). It was iron that was recommended as

an anti-seismic measure after the earthquake of 1751in Gualdo Tadino, Umbria (Tobriner 1997). GiovannBattista Mori recommended iron reinforcement afterthe Calabrian earthquake of 1783. When the churchof S.Maria degli Angeli in Umbria was badlydamaged in an earthquake in 1832 its dome wasrepaired with bands of iron and the entirereconstruction was tied together by iron straps(Mancini and Scotti 1989). But there is no such

reinforcement in S. Nicolo.It is important to remember that S. Nico10 was

being reconstructed during a period in whichearthquake resistant construction was known, even inNoto. In a treatise of Christian Wo1ff's ElementaMatheseos Universae (1715-17) translated for Paolo

Labisi in 1746 as Elementi dell'Architettura Civile

there is a discussion of lateral bracing in roof systemsand a depiction of the «craticola» used in foundationswhich served «ad impedire ne' tremuoti loscompaginamento delle parti» (Tobriner 1997,34-37). Books and artic\es on antiseismic design (Di

Pasquale 1986; Lanier and Barbisan 1996; Barbisan

and Lanier, 1995) like Eusebio Sguario's Specimenphysico-geometricum de terraemotu ad architecturae(\ 756) were in circulation and because of the

earthquakes of Lisbon in 1755 and Calabria in 1783discussion of seismic problems became morecommon in the 18th century (Placanica 1985).Francesco Milizia in his Principii di Architettura

Civile (\ 781) discussed antiseismic constructionstrategies (Di Pasquaie 1986). Common sensesolutions for limiting a building's exposure toearthquake damage like building its dome in cane andplaster, reducing the dome's height, or e1iminating itentirely seem never to have been discussed in Noto.

Such changes in traditional practice are not withoutprecedent: After the earthquake of 1783 the Bourbongovernment of Naples limited the height of building s

because of seismic danger. Yet we can wellunderstand the problem the people of Noto faced. lt isunthinkab1e that the Chiesa Madre, much less theCathedral not have a dome.

Instead of improving the performance of S. Nicolo,19thand 20th century alterations may have accentuated

the inherent weakness of the structure. With theelevation of S. Nicolo to the status of Cathedral carnethe neeessity to create an even more exaltedarehitectural statement. The chancel and apse wereextended and the stone arches of the transept added.Of course the status of a Cathedral called for a highdome so when the last reconstruction occurred theengineer in charge, Luigi Cassone, complied.Twentieth century alterations followed the pattern ofthe 19th century. Church officials attempted tostabilize the Cathedral by adding a flat concrete roofwhich prejudiced the structure in two ways. Theweight of the roof was added lo the structure amI thetops of the former transverse arches were cut (Figure11). Rather than improving the performance of the

structure by providing a stiff diaphragm to distributethe loads, the roof may have aggravated the situation.When one side pier failed instead of a localizedfailure, the roof spread the damage by transferringload to the rest of the nave, and thereby collapsing the

entire interior.

--~-

1988

Figure II

S. Nicolü. Collapsed mof showing 20'h century alterations.

In Ihe 1950s transversc arches were cut, clcrestory wallsheightencd and concrete and steel roof with parapets added(photo: author)

The Cathedral of S. Nicolo is an important andparadoxical symbol for the city of Noto. It represents

the Noto that aspired tu be a center of culture duringthe waning years of the Baroque style in the 18thcentury. [t record s Noto's last transformation in the

19th century into an aspiring ecclesiastical power.

Noto's citizens as well as the Church attempted to usethe new Cathedral to capitalize on re]igion to bringprosperity to the city. The Cathedral in the 19th

century embodied a memory of past importance of the

18th century as well as Noto Antica. On the positiveside, the reconstructions symbolize Noto's resolve toexist and continue as a city. Technically, there seemsto have been pride and faith in traditionalunadulterated stone masonry that was repJaced againand again after earthquakes with little change intechnology. One wonders whether the architects took

failure for granted, realizing that it was likeJy that theexterior walls, side ais]e domes, and nave arcadewould survive while the dome and part of the crossingwould likely faiJ. Perhaps they felt they could do no

S. Tobriner

Figure 12

better. Less positively, the reconstructions could beseen as repetitions of failure without significantinnovation or care taken to find a more appropriatesolution. These reconstructions seem to indicate alack of interest in the challenges that must be metwhen building in earthquake-prone Sicily. Thehistory of the CathedraJ of S. Nicolo is a story oftenacity and enduring tradition, but al so of disregard

for the lessons of the past.

NOTES

1. This paper represents a summary of the studies in

Tobriner et al. 1998. All cited dates and documentsrelating to the Cathedral of Noto are fmm this reference.

The entire study is scheduled to appear as the first issue

of a series to be published by the ArchitectureDepartment of the University of Palermo. An earlier

version of this paper was submitted to Construction and

Building Materials.