6. A discussion with Gary Arseneau and Dr David Schaff (10)
The Accuracy Of
Technical Dating Methods
The following answer expressed my doubts about the
accuracy of the dating method the conservation report might offer:
I would be interested indeed to see the conservation report. Your
assessment "...that the stains that appear on our plasters did not
happen overnight and must have taken many many years to occur" gives
us an additional part of the puzzle. Still, we do not know for how
long a period of time the plaster were in a humid environment, and we do
not know if the humidity level was 40% or 70%.
David wrote me, in your opinion the plasters should be
80-100 years old, judging from the corrosion, stains, cracks, dirt and
grime. That would be a very important assessment.
Of course, it will not be possible to determine exactly
if a certain plaster was produced in 1915 or in 1920. The difference
would be only ca. 5% in relation to the 86 years that have passed since
1915. But it would be a very important step in countering the critique by
Arseneau and Antoinette Romain.
Please allow me to play the devilīs advocate once again and ask you if
you think its is really possible to narrow (down) the age of the plasters
within a 20 yearīs period?
I am no technical expert on humidity absorption and rusting rates
either. But I know how plaster walls and iron tools look like in a
humid basement. From this most rudimentariy and pre-scientific
knowledge, I guess only 20 or 30 years in a humid environment would be
long enough to make those plaster armatures corrode pretty ugly. Please
correct me when I am wrong. For obvious anatomical reasons, the genital
area of a standing figure is very near to the plasterīs central vertical
axis, so here the bleeding comes through first.
Also grime and dirt and dust build up much quicker than we like them to.
(...) Do not clean a porous plaster sculpture standing in a humid foundry
storeroom for 50 years and it will look pretty old, I guess.
[From: Letter to Mary Reid, 6 Dec. 2001]
I my reply to David Schaff, I utterered the same concern
and insisted once more that the outer dimensions of the Maclaren plasters
might very well prove their origin from the bon creux moulds but
not their age of production:
Mary also wrote me on the possibility to date the
plasters by examining the effects of humidity and corrosion of the
armatures. If it would be possible indeed to narrow the production date of
these plasters to a period 80 till 100 years back from now, we would have
1901 till 1921 as a time range, which means 85% probability for a lifetime
Judging from everyday household experience, I was not so sure if this
method would allow for such exact dating. Are you sure the same
corrosion and stains could not build up over, letīs say, 50 years
instead of 80-100 years? (...)
Maybe I just do not know enough about plaster casting, but in my eyes, the
fact a plaster positive shape corresponds exactly to a certain mould or to
a sister positive plaster shape does not prove how old it is. If moulds
and positive plasters do not change their shape over time spontaneously
(I never heard they would do so), then a positive plaster pulled from the
original mould yesterday would have exactly the same dimensions as a
sister positive plaster pulled from that mould one hundred years ago.
And a duplicate foundry plaster reproduced only yesterday from an original
100-year old original foundry plaster would match exactly both with this
lifetime original foundry plaster and with the mould this original foundry
plaster was pulled from and with other lifetime studio and representation
plasters pulled from the same mould.(...)
What about the signatures? In Toronto, I did not check the plasters in
detail in this respect. Do they have ink/pencil signatures or incised
inscriptions, or foundry signatures and cachets? I saw the incised
dedication "a mon ami D." in Barrie and the incised inscription
at the back of the Balzac Head, but I did not check the rest. The Status
Reports of June 2000 just say: "Signed: A. Rodin".
[From: Letter to Dr David Schaff, 6 Dec. 2001]