Publisher’s version / Version de l'éditeur: APT Bulletin, 10, 1, pp. 20-34, 1978
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Roman stone and other decorative artificial stones
Ritchie, T.
https://publications-cnrc.canada.ca/fra/droits
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Ser
TH1
N21d
no. 785 National Research Conseil national
C . 2
1
#
Council Canada de recherchesCanada
AN
ALYROMAN STONE AND OTHER DECORATIVE
ARTWICIAL ST*ONES
by T. Ritchie 5
Reprinted, with permission, from
The Association for Preservation Technology Bulletin VoL X, No. 1, 1978
p. 20 34
DBR Paper No. 785
Division of Building Research
SOMMA I R E Au Canada, l a f a b r i c a t i o n d e p i e r r e a r t i f i c i e l l e 3 p a r t i r de b 6 t o n d a t e du d g b u t du s i s c l e . L'un d e s t y p e s , l a p i e r r e romaine, 6 t a i t beaucoup employ6 e t on l u i d o n n a i t d e s formes e t d e s t e x t u r e s
trss
d 6 c o r a t i v e s . L ' a r t i c l e d 6 c r i t l a t e c h n i q u e d e f a b r i c a t i o n p a r c o u l a g e d u b 6 t o n dans un moule e n s a b l e e t f o u m i t d e s exemples d e son u t i l i s a t i o n e n c o n s t r u c t i o n .ROMAN STONE AND OTHER DECORATIVE ART1 FICI AL STONES by
T. R i t c h i e
*
The p o r t l a n d cement and concrete i n d u s t r i e s t h a t became such an important p a r t o f construction and b u i l d i n g i n the e a r l y years of t h i s century had t h e i r beginning i n t h e experimental work o f Joseph Aspdin, t h e English b r i c k l a y e r , i n making a r t i f i c i a l stone. I n 1824 a p a t e n t was issued t o him f o r h i s i n e n t i o n o f "an improvement i n the modes of producing an
'8
Y
a r t i f i c i a l stone
.
The m a t e r i a l Aspdin made he c a l l e d p o r t l a n d cement, a f t e r the n a t u r a l Portland stone i t resembled. It was, i n h i s words,". .
.a cement o r a r t i f i c i a l stone f o r stuccoing bui 1 dings, waterworks, c i s terns o r any o t h e r purpose t o whi ch i t may be appl i cable.. . .
"
A r t i f i c i a l Stone i n CanadaA decade a f t e r Aspdin's patent was granted, a Canadian p a t e n t was issued f o r a h y d r a u l i c cement developed by Frederick ~addely,2 an o f f i c e r o f the Royal Engineers s t a t i o n e d a t Quebec. Subsequently i n Canada, t h e r e was s u f f i c i e n t i n t e r e s t i n t h e manufacture of h y d r a u l i c cements and i n t h e products made from them t h a t when the Universal E x h i b i t i o n was he1 d i n Paris i n 1855 several displays o f cement and cement products were included i n the Canadian e x h i b i t . 3 For example, P i e r r e Gauvreau, a r e s i d e n t o f Quebec who had patented i n 1854 h i s
".
..
new and useful cement, t o be c a l l e d by him Gauvreau's Canadian h y d r a u l i c cement,"4 sent samples o f t h e stone from which he made h i s cement, some a r t i f i c i a l stone formed from i t , as w e l l asa pipe made from the cement. Other samples o f hardened h y d r a u l i c cement were displayed by Thomas C. Keefer, the prominent engineer.
I n s p i t e o f t h i s e a r l y Canadian i n t e r e s t i n a r t i f i c i a l stone, i t s extensive manufacture and use d i d n o t come about f o r another ha1 f-century, when i n the l a s t decade o f t h e 19th century a Canadian p o r t l a n d cement
i n d u s t r y was established. Engineers began t o employ concrete i n l a r g e q u a n t i t i e s , t o the e x t e n t t h a t i n 1896 t h e Canadian Engineer noted t h a t
"Of l a t e , m o n o l i t h i c works o f g r e a t importance have been c a r r i e d o u t and every day concrete as b u i l d i n g m a t e r i a l i s creeping t o a foremost place."5
Concrete's impact on t r a d i t i o n a l masonry c o n s t r u c t i o n was a1 so noted i n a r e p o r t by the Ontario Bureau o f Mines prepared i n 1904; "The use o f limestone i n the form o f blocks f o r b u i l d i n g and s t r u c t u r a l purposes has been considerably a f f e c t e d during the l a s t ten years o r so by the
*
M r . R i t c h i e i s a Research Officer, D i v i s i o n o f B u i l d i n g Research, National Research Counci 1 o f Canada.s u b s t i t u t i o n o f concrete
-
crushed stone and cement. Formerly, f o rinstance, dimension stone was used exclusively i n bridge work and for locks and other canal structures
. .
.
(but). . .
concrete i s being used i n place o f stone... .
"
The new materi a1 was also being appl i e d t o bui 1 dingconstruction ; "some 1 arge bui 1 dings i n the Province are bui 1 t of concrete..
.
(and).
.
.
concrete blocks, whi ch resemble those o f stone, are a1 so coming i n t o use."6
I n summary, by the t u r n o f the century, a r t i f i c i a l stone had been introduced t o the Csnadian b u i l d i n g industry and had been accepted by it;
". .
.cement i s proving a formidable competitor t o stone f o r uses i n which the l a t t e r was f o r long employed almost exclusively. Quarrymen lookaskance a t the new material which i s rep1 acing t h e i r product i n bridge work, foundations and construction work o f various kinds, contending t h a t i t w i l l prove less durable and more 1 ia b l e t o destruction by f r o s t when exposed t o the action o f water. Time only w i l l show whether these imputations are warranted, but i n the meantime there i s l i t t l e doubt t h a t cement f o r many
uses i s pressing hard on stone.
"7
The Roman Stone Company
As a r e s u l t o f the demand f o r concrete, by the f i r s t decade o f t h i s century a l l l a r g e Canadian communities, and many small ones, were served by a concrete block factory. There were also a few manufacturers o f orna- mental a r t i f i c i a l stone, the l a r g e s t the Roman Stone Company of Toronto. This firm, established i n 1903, produced a decorative stone c a l l e d "Roman
Stone" by a process developed and patented i n the United States by C.W. Stevens j u s t before the t u r n o f the century.8
The Stevens Process
I n the Stevens process, the f o l l o w i n g f atures o f which were recorded by the c h i e f engineer o f the Roman Stone Co.8, a r t i f i c i a l stone was manu- factured by casting concrete i n a sand mould, j u s t as molten i r o n i s cast i n such a mould. The absorptiveness o f the mould was an important factor i n the qua1 i t y o f the product obtained from the Stevens process. As soon as the wet concrete was poured i n t o i t , water from the concrete was drawn i n t o the sand. The concrete, accordingly, was compacted, but there re- mained s u f f i c i e n t water i n i t t o hydrate the cement, and the moist sand surrounding the concrete provided i t w i t h i d e a l curing conditions
.
The process, therefore, appl i e d t o concrete manufacture two conditions t h a t only much l a t e r became generally recognized as essential f o r the production o f good q u a l i t y concrete: a low water cement r a t i o and moist curing.A1 though sand moul ds were more expensive than the usual wooden o r i r o n moulds, because a separate one was required f o r each piece cast, the Stevens process y i e l d e d a much f i n e r product than could be obtained from other moulds. It was denser, more uniform i n colour, and i t possessed a
more n a t u r a l t e x t u r e than t h e a r t i f i c i a l stone formed i n o t h e r moulds. The c a s t a r t i c l e was sometimes l e f t w i t h i t s as-moulded f i n i s h , s i n c e a n a t u r a l stone t e x t u r e c o u l d be o b t a i n e d by veneering t h e p a t t e r n w i t h t h i n s t r i p s o f wood, b u t i t was f r e q u e n t l y f u r t h e r f i n i s h e d by hand c a r v i n g t o enhance t h e d e t a i l i n g .
Qua1 i t y Control
I n making Roman Stone, t h e qua1 i t y o f t h e aggregate was c a r e f u l l y
c o n t r o l l e d , as was i t s p r o p o r t i o n i n g w i t h cement and water. Various
n a t u r a l stones provided a v a r i e t y o f colours. Thus, f o r w h i t e stone, Niagara limestone and a w h i t e marble from Tweed were used; whereas t o
produce stones o f o t h e r colours, gray, brown, r e d and 01 i ve sandstones
were selected. Each type o f stone was d r i e d , crushed and s i e v e d i n t o t h r e e p a r t i c l e - s i ze f r a c t i o n s , t h e l a r g e s t p a r t i c l e s b e i n g about corn- kernel s i z e . These f r a c t i o n s were recombined i n t h e concrete mix i n pro- p o r t i o n s t h a t produced a dense m a t e r i a l .
The p r o p o r t i o n i n g of t h e cement and aggregate was c l o s e l y c o n t r o l l e d , as w e l l as t h e gauging of t h e amount o f water, which was drawn from a tank maintained a t constant temperature. The m a t e r i a l s were mixed i n a mechanical mixer, a f t e r which t h e concrete was run o f f i n t o l a r g e tubs
c a r r i e d by a t r a v e l l i n g crane t o t r a n s p o r t i t t o t h e c a s t i n g shop. The tubs
were f i t t e d w i t h s p i r a l paddles t o a g i t a t e t h e concrete, thus m a i n t a i n i n g
a uniform mix u n t i l i t was poured i n t o t h e moulds. The concrete was k e p t
i n t h e moulds f o r t h r e e o r f o u r days b e f o r e t h e y were opened, and t h e casts were then s t o r e d i n a temperature-constant room f o r seasoning u n t i l shipped.
One-piece stones as l o n g as 20 f e e t were manufactured, and stones were c a s t w i t h s e t t i n g hooks i n place. Those t h a t would be s u b j e c t e d t o t e n s i l e s t r e s s i n use were r e i n f o r c e d w i t h s t e e l . The products of t h e Roman Stone Company were nevertheless considered t o be re1 a t i v e l y cheap,
since i t was claimed t h a t a column i n Roman Stone c o s t o n l y s l i g h t l y more
than one o f wood.
The crushing s t r e n g t h o f Roman Stone, depending on t h e aggregate and t h e mix p r o p o r t i o n s , was between 2000 and 4000 pounds p e r square i n c h a t
s i x months, and i n excess of 7000 pounds a t two years. I t s s t r e n g t h was
s l i g h t l y g r e a t e r than t h a t o f Ohio sandstone and was much g r e a t e r than
t h a t o f Indiana limestone. I t s s t r e n g t h a l s o g r e a t l y exceeded t h a t of
concrete made by the d r y process, used i n t h e manufacture of c e r t a i n concrete blocks. The water a b s o r p t i o n o f Roman Stone, l e s s than 1 p e r cent, was exceeded by t h a t o f Ohio sandstone and I n d i a n a limestone, a t 5 p e r c e n t each, and was g r e a t l y exceeded by t h a t o f d r y process concrete, i n excess of 12 p e r cent.
A p p l i c a t i o n o f Roman Stone
D e t a i l s o f t h e a p p l i c a t i o n o f Roman Stone t o a p a r t i c u l a r b u i l d i n g p r o j e c t have been recorded i n an account o f t h e I m p e r i a l Trusts Company
B u i l d i n g on Richmond S t r e e t i n ~ o r o n t o . 1 0 This s t r u c t u r e , designed by the a r c h i t e c t s Chadwick and Beckett and constructed i n 1909, now houses the Premier T r u s t Company (Figure 1 )
.
I t s e n t i r e f r o n t was made of Roman Stone, i n c l u d i n g t a l l columns, a r c h i t r a v e , f r i e z e , cornice and parapet. The moulding o f i t s p a r t s was entrusted t o the f i r m o f Adamson and Wicks, who prepared wooden patterns from c l a y models o f t h e various p a r t s . A l lt h e stones of t h e b u i l d i n g were carved a f t e r c a s t i n g t o sharpen the a r r i s e s and t o expose t h e marble aggregate.
The columns o f t h e b u i l d i n g , 4 f e e t i n diameter a t t h e base and over 33 feet high, were formed i n 3-foot-high hollow sections w i t h an 18-inch diameter hole t o reduce t h e weight f o r handling; even so, each o f the 1 ower col umn sections wei ghed 23 tons. But the end pieces o f the corni ce were even heavier, weighing over 3 tons each. The stone o f the main architrave, spanning about 20 f e e t between the two middle columns, was r e i n f o r c e d w i t h a s t e e l I-beam c a s t w i t h i n it.
The Roman Stone o f t h i s b u i l d i n g was made from Tweed marble and Dyckerhoff cement i n proportions of about 33:l. The cement, o f German manufacture, c o s t twice as much as l o c a l cement, b u t was used because o f the excel l e n t and uniform product i t y i e l d e d .
The present b u i l d i n g d i f f e r s i n several respects fkom the o r i g i n a l . For example, a parapet, p a r t l y w a l l and balustrade, has been removed from over t h e c o m i ce. The o r i g i n a l entrance, framed i n massive and ornate Roman Stone, has a l s o been removed, w i t h e n t r y now gained through a
modern a d d i t i o n b u i l t alongside t h e o r i g i n a l b u i l d i n g . A t h i r d change i s the rep1 acement o f t h e o r i g i n a l windows
,
whi ch had been topped w i t h semi-
c i r c u l a r stone arches.Other Exam~les o f Roman Stone
Many b u i l d i n g s o f Roman Stone have been mentioned i n accounts o f Canadian b u i l d i n g . The Ivey Warehouse on We1 1 in g t o n Street, Toronto, i n s u r v i v i n g the great f i r e o f 1904 though surrounded by b u i l d i n g s t h a t
perished, was c i t e d as an example o f Roman Stone's f i r e p r o o f qua1 i t i e s . ll A good example o f Roman Stone c a s t i n t o h i g h l y decorative c l a s s i c a l
a r c h i t e c t u r a l forms was the Carnegie P u b l i c L i b r a r y i n St. Catharines (Figure 2), described as having been b u i l t e n t i r e l y o f Roman stone9. Constructed i n 1903, i t was demo1 ished i n 1965. Demolition was the fate a l s o o f t h e Canada Permanent Mortgage Corporation b u i l d i n g (Figure 3)
constructed i n 1905 i n Regina, Saskatchewan; an e a r l y example o f r e i n f o r c e d concrete frame construction, i t was faced w i t h Roman Stone, w i t h a backing o f t e r r a c o t t a l z .
Other a p p l i c a t i o n s o f Roman Stone i n c l u d e the Screen House o f the Ontario Power Company p l a n t a t Niagara F a l l s and t h e Canadian Bank o f Comnerce b u i l d i n g i n ~ o n d o n l 2 . I t was employed by a r c h i t e c t G.M. M i l l e r t o t r i m the brickwork o f t h e Central Methodist Church, Bloor Street,
Fig. 1 ( a ) Imperial
Trusts
Company B u i l d i n g (now Premier T r u s t Company), c o n s t r u c t e d i n 1909; l a t e r a d d i t i o n on r i g h t .,'< k . 3 % * * * a v * > e * s * 0 8 8 a r 8 1 , . " .' . . * V Y W V * r 9 f 8 V $ 2 ' 8 l d l l U ~ ~ I ~ 8 - I I I W W B ' ~ + % Y ~ , ~ * % >, $+>? <,,<, , ,,& > , , A . * * . * ? I > $ ? ' . ""..: :*::, ", "*"A ,, . " , * , ' I , , - , " , , , , * . I , , , , , $ , , , ,,, ,,, , , : ,,,, I * , , + A I * , , I , , l i i l < > . * * ,, < , A ",* *w-wm-" 8% x
-
, . . ",," ", -- ~ A d > - , , I I rl&r.Trs> 8 8 8 8 8 8 T 8 8 8 B r 6 r T<alls:~i'aihilp 8 4 8 8 B 8 a 8 4 r W2 a l I I,ll<i&Za.&b $ 8 s B L $ 8 8 % 88 I*'Ik"aC**S%P81HHYHH# " M m % * a % % * % * ~ ? " - * * < * 8 L \ % * % ? 5 % % , > + ? & > + ? > + + ? ? * A , 8 *' I IF i g . l ( b ) D e t a i l o f column cap, I m p e r i a l T r u s t s Company B u i l d i n g .
0 w
rta
~ o r o n t o l 3 , and was used i n two o t h e r b u i l d i n g s constructed i n 1903, a branch bank o f t h e Canadian Bank of Commerce i n Parkdale, Toronto,
designed by D a r l i n g and Pearson, and i n the Westmount, Montreal, Branch o f t h e Royal Bank, designed by H.C. ~ t o n e l 4 .
Three n o t a b l e examples o f t h e use o f Roman Stone i n Toronto,
described and p i c t u r e d i n a 1916 issue of C O ~ C ~ - e t e magazine14, i n c l u d e the Graphic A r t s B u i l d i n g (Figure 4) a t Richmond and Sheppard Streets, housing t h e pub1 is h e r s o f Saturday f i g h t and G r i p magazines. The balustrade over t h e cornice now lacks i t s balusters, probably f a i l e d from weathering; t h i s has a l s o cracked b a l u s t e r s e l sewhere i n t h e b u i l d i n g . A second example,
S t . Paul ' s Church (Figure 5 ) on Bl o o r S t . E., designed by E. J. Lennox and opened i n 1913, has Roman Stone as a t r i m f o r t h e e x t e r i o r stone masonry as we1 1 as f o r i n t e r i o r use. An a r c h i t e c t u r a l feature o f the b u i l d i n g i s a rose window 27 f e e t i n diameter o f Roman Stone t r a c e r y . The t h i r d example, t h e ten-storey s t e e l -frame Lumsden Bui l d i n g (Figure 6) a t Yonge and Adel aide Streets, designed by J.A. Mackenzie and constructed i n 190916, ill u s t r a t e s t h e use of Roman Stone i n e a r l y h i g h - r i s e construction. Except f o r t h e ground f l o o r where g r a n i t e was used, i t s s t r e e t - f a c i n g w a l l s were f i n i s h e d w i t h Roman Stone c a r r i e d on the s t e e l frame a t each f l o o r and backed w i t h hard b r i c k , which was i t s e l f 1 in e d w i t h porous hollow b r i c k . The o t h e r w a l l s were faced i n b r i c k .
A1 though no c o n f i r m a t i o n has been obtained on the matter, i t appears probable t h a t s t i 11 another appl i c a t i o n o f Roman Stone was contempl ated when t h e p r e s i d e n t o f t h e Roman Stone Company, m i l l i o n a i r e (and l a t e r , S i r ) Henry M. P e l l a t t , had plans drawn by E. J. ~ e n n o x fo r h i s famous residence, t h e 98-room "Casa Loma," a p r o j e c t t h a t was completed i n 1913. Decl i ne o f Roman Stone
The extensive use o f Roman Stone i n the decade f o l l o w i n g the s t a r t o f i t s manufacture apparently d i d n o t continue a f t e r t h e F i r s t World War, perhaps as a r e s u l t o f t h e economic e f f e c t s o f t h e war. Changes i n a r c h i t e c t u r a l s t y l e , which reduced t h e demand f o r h i g h l y decorative and e l a b o r a t e ornamentation, probably affected t h e market f o r t h e products o f the Roman Stone Company, as would have t h e competition from o t h e r firms, n o t a b l y the Canadian Benedict Stone Ltd. o f Montre 1, manufacturers of Benedi c t Stone, a product a l s o c a s t i n sand moulds77. Many examples o f t h e use o f t h i s m a t e r i a l d u r i n g the 1920's are given i n The Contractor; they i n c l u d e T r i n i t y College School, P o r t Hope, t h e Caron and Keefer B u i l d i n g s i n Montreal, and Acadia U n i v e r s i t y , W o l f v i l l e , Nova ~ c o t i a l 8 . Concl us i on
Roman Stone provided Canadian a r c h i t e c t s and b u i 1 ders w i t h a h i g h l y decorative a r t i f i c i a l stone t h a t was e x t e n s i v e l y used i n t h e f i r s t decade o f t h i s century. O f t h e many b u i l d i n g s i n which Roman Stone was employed, a t l e a s t two have been demolished, whether from obsolescence, "redevelop- ment," o r advanced weathering decay o f t h e m a t e r i a l
.
Another has beenI
I
I
I
Fig. 6 Lumsden B u i l d i n g , Toronto, c o n s t r u c t e d i n 1909. The s t r u c t u r e on
t h e r i g h t i s t h e B i rkbeck B u i l d i n g , c o n s t r u c t e d from a r t i f i c i a 1
a l t e r e d from i t s o r i g i n a l design as a r e s u l t o f enlargement and p o s s i b l y a l s o because of t h e decay o f p a r t s t h a t were f r e e l y exposed t o t h e
weather.
The b u i l d i n g s o f Roman Stone t h a t stand, whether i n t h e o r i g i n a l o r a1 t e r e d c o n d i t i o n , provide examples n o t o n l y o f t h e e a r l y a p p l i c a t i o n 3f
decorative a r t i f i c i a l stone t o Canadian b u i l d i n g , b u t a l s o o f an i m p o r t a n t t e c h n i c a l i n n o v a t i o n i n the manufacture o f concrete. I n a d d i t i o n , they provide a g l impse o f t h e a r c h i t e c t u r a l s t y l e s important t o Canadian b u i 1 ders and a r c h i t e c t s o f a ha1 f - c e n t u r y ago.
I
I
Footnotes1 H.C. Badder, "The i n v e n t i o n and e a r l y development of P o r t l a n d Cement,"
Concrete, Vol
,
25, NO. 4, Oct. 1924.I
2 Patents of Canada from 1824 t o 1849, Love1 1 and Gibson, Toronto, 1860.3 Canada a t the U n i v e r s a l E x h i b i t i o n of 1855, Toronto, John Love1 1,
1856.
4 Patent No. 449, 1854; Patents of Canada from 1849 t o 1855, Love1 1 and Gibson
,
Toronto, 1865.5 "Experiments on concrete made a t McGill University," Cmadian
Engineer, Vo1. I V , NO. 8, Dec. 1896, p'. 221.
6 W i l l e t G. M i l l e r , ~ i m e s t o n e s of Ontario, Report of t h e Bureau of Mines (Ontario), Vol. X I I I , P a r t 11, 1904.
7 I b i d , P a r t 1 of k p o r t , S t a t i s t i c a l Review, p . 14.
8 H.P. G i l l e t t e and C.S. H i l l , Concrete constructionmethods and cost,
New York, Clark P u b l i s h i n g Co., 1908, pp. 644-646.
9 Char1 es D. Watson, "Decorative cement products,
"
Canadian A r c h i t e c t and B u i l d e r ,V Q ~
.
X V I I , No. 193, Jan. 1904, pp. 19-21.10 " O f f i c e b u i l d i n g of t h e Imperial Trusts Co," Canadian Cement and Concrete R e v i m , Vo1
.
3, No. 2, Feb.
1909.11 "The Toronto fire," Canadiun A r c h i t e c t and B u i l d e r , Val
.
X V I I,No. 197, May 1904.
12 Charles D. Watson, "Report o f t h e Comni t t e e on A r t and Architecture," National Association o f Cement Users, Proceedings, Vo1. I I I, 1907. 13 Canadian A r c h i t e c t and B u i l d e r , June 1906.
14 Canadian Architect and Builder, Feb
.
1906.15 Concrete, Vol. 9, No. 6 , December 1916, p p . 186-188.
16 "The Lumsden Bui 1 di ng
,
Toront o ,
"
Canadian Cement and Concrete Review, Vol. 3, No. 12, Dec. 1909.17 J . C1
