The Washington herald., 1912-03-20

completely replaced lime and plaster and
become exclusively the cement OF the
present Is to be found in the fact that
by reason of the lack of plasticity. or
woTkability, TO coin a word. OF its NOR
tars. IL is not adapted for use under con-
ditions where mortars are TO be apphed
by hand with the trowel. or similar tool,
sCch as In he case OF stuccoing the
inside and outside OF buildings and the
laying of brick. While Portland cement,
owing TO its low cost, great strength de-
veloped at short Periods, and convenience
OF use, is the best fitted of all cements
yet deveIoped to meet the requirement OF
modern practice for structural. not dec
Orative or covering purposes, ! am by by
present rate OF increase in consumption
and rank as high among the cements
Of the future as Il does among the ee-
n:ents Of to-day. Gypsum plasters. as
Indicated. are used almost entirely under
present conditions in the building trade
for the plastering or stuccotng OF in
, for this Is that exposure to moisture and
ordinary atmospheric conditions preva-
lent in the United States is destructive
Of this material There Is considerable
discussion among architects and builders
even as to the durability Of gypsum plas-
tiers when sheltered from the direct &C
tion of the weather, some maintaining
that gypsum plasters or stuecoos. gain
tkeir maximum strength at short periods,
and from then on deteriorate; others
maintain their durability. using as an
argument the condition OF the remains
OF early plastering and stucco found IN
Egypt and other southern countries: they
overlook, however, that the dry. equablt
climate Of these semi-desert regions Is
exceedingly favorable for the endurance
Of gypsum plasteTs. They also oyerlook
the fact that among the Egyptians, gyp,
| sum was not used for the main body oi
| the plaster. but simply in gauging the
white or finish coat: the Egyptian plas-
ter consisted OF three-coat work. the firsl
two being a mixture OF lime, sand. AND
hair. and the third being gypsum or lime
gauged with gypsum This Is evidenced
| BY the plaster pavement at Tel Amarna
\ which Is elabor3tely painted; the floor oi
this work Is laid on brick, the first coai
Is OF rough lime stucco about one Incl
thick. and the finishing coat Is well haired
/ inch thick very smooth and fine. and
( Showing evidence OF troweling. Their or
dinary partitions were laid on reeds lacet
| together with cord for lathing; over TIM
was placed a rough coat OF lime stuccf
4 about three-fo1rth OF an inch thick. ant
a finishing coat OF gypsum plaster. III
gypsum for interior wall coverings dur
| ing the past fifteen years is due no
to any superiority of the finished wal
/ over walls plastered with lime, but Il
/ the fact that the rapid hardening Of gyp
sum plasters and their early develop
ment of strength lent themselves to tn
i rapidity required in modern construction
and also to the fact that the ntaterta
| for immediate use without the necessit,
of any extended preparation prior 4
gauging II and applying II on the wall
Lime Consumption shown.
The line on the chart showing the us
OF lime Is deceptive. in that IL show
the total production and consumption o
lime in the United States and fails &
ldifferentiate the lime used for fertilizins
chemical. and Industrial purposes from
IaN-- E.,F1 -N- Nfr1rl
and while the general use of lime show
a continuous gain up until 1906, this gaii
has been largely due to its increased US
/ for purposes other than building con
struction- The gypsum lime fails to shoy
the amount Of gypsum imported an
made into building material The actua
comparison OF the use OF these two ma
terials In the building trade b more clear
ly shown in the small chart at the uppe
portion. The use of natural cement a
in 1sse; since then there has been rapi
and constant decline In its production
and use.
ate amount OF lime and gypsum use
directly in the building trade for tn
years 1904 to 1910. II will be noted tha
the use of gypsum slightly exceeds tina
Of lime for $50. and when en- y h Is considers % ere
In the laying Of brick and stone wall
&c. the extent OF the inroads made b
gypsum products on the market Tor Inn
as wall plaster is plain.
No man. II asked in 1895 to predict IN
relative consumption OF these material
to-day. would have anticipated the rapi
growth in use OF Portland cement an
gypsum plasters or the marked deciin
In use of natural cements that has pras
ltically obliterated a hourishing industr
in which large amounts Of capital WEI
? invested, and II Is with some hesitado
that / undertake to forecast the futuI
OF these materials. especially as n
|, probabilities are still further compiicate
! BY the advent OF a new factor-Alca limt
and cements. These are 30 emtnently
! the present as TO have almost escape
, notice in the Geological Surveys revie
of cementitious materials for the ye;
, l1ef0. In order 70 demonstrate that Ale
4 lines are, OF the present. ] VIII show {
, 1.-THE screen a series Of pictures inustra
} ing the classes OF construction in whlc
! tthey have been used. Alca lines We
: first offered commercially for sale IN SCI
! tember, 1910, although they had been yei
: thoroughly tried out In practical col
l struetion for some years previously.
: | in speaking OF Alca lines L appear
: he laying greater stress ON their prebab
5 position among the cements OF the futu
: than you think Is justified by the actu
I showing 10 date. must plead guilty
o. being hrmly astride OF hobby. Whi