After 1824 : As I’ve never had a chance to get a look at any
Erard grands
made before the invention of the double repetition action, I’
ll only consider for the moment these later instruments.

The documents : Although the double repetition action was
patented in 1821, the first pianos appear to have been built
around 1824. Adam Liszt wrote to Czerny that year : « The
new invention of the very able technician Erard is
remarkable [….] With one touch, you can without lifting the
hand play a chord, loud or soft, as many times as you like,
it’s absolutely astonishing. There are only three
instruments of this type finished, the fourth is under
construction for my son ».
At the end of the Spring of that year, Franz Liszt left for
London with Pierre Erard, on a concert tour whose purpose
was at the same time to promote the prodigy and the new
piano he had adopted. They were accompanied by a
barless double repetition piano, and a second prototype,
with bars, was sent to them at the end of May. One can
say that this second piano was the first piano in history in
which all the elements that make up a modern piano were
established (one could also argue that the full iron frame
and overstringing are basic defining elements of the
modern piano, in which case you have to wait till Steinway
brought these together in the 1860’s).
It is interesting to note that Broadwood had already built a
piano with iron bars before Erard and Liszt got to London,
and there was is a historical debate about which firm was
the inventor.
Another novelty in some of the Erard grands of this period
is the 7 octave span, that was only taken up in the average
production in the late 1840’s.
As we have already mentioned, the revolutionary double
repetition instrument took a while to be accepted : in 1828,
according to the archives, Erard was making both « new
action » and « old type escapement » pianos.

Surviving pianos :  The investment costs to set up the
production of this new instrument and it’s complex action,
must have been enormous, and in 1828 the archives only
mention eight pianos made with the new action : it is no
surprise that so few of these early pianos are known of
from this crucial period of piano history. In 1832, the
London factory had only made 177 pianos.
*Pianos on stands : The four earliest grand pianos known
have in common a very unusual case type : the three legs
are held together at their base by a stand that echoes the
shape of the piano. Three of these pianos are London
models (n°7x, Hummel’s piano; n° 16x, modified in the
Paris factory in 1843;  n° 177, in superb original condition),
the other one is a Paris model. Is this ratio a coincidence,
or did the London factory have a bigger production of
grands while Paris also made squares and uprights? This
could make sense, if as I believe the London factory was
set up from the start to make the new double repetition
model.
The action of these pianos, « mécanique à échelle », is the
same as the one published by Erard in 1834 : hammer
shanks made up from strips of wood glued together,
wooden checks, under dampers worked by counterweights
(not springs as on later models).
From a structural point of view, it is obvious that Erard was
going through an experimental stage : on n° 7x, the hitch
plate is wood covered in brass, whereas on n° 177 the
bars stops are fitted straight into the wood.
These pianos, obviously built in small numbers, all have
exceptionally beautiful and ornate cases, as if Erard were
trying their very best to promote these instruments : choice
veneers, a lot of sculpted detail, elaborate inlay….
*Pianos with round legs : For a short period after the
models on stands, Erard Paris appears to have made
pianos with round (n°13415) or godrooned legs.
The London factory made a model with large godroons
(see the legs on n° 16x, non-original, from a c.1835 London
grand).
*Pianos with facetted legs : This type of legs, that was to
remain characteristic of Erard until the end of the XIX th
century, were probably first made c.1835. At about the
same date, Erard fitted a metal hitch plate to their pianos,
that prevented the bars from pushing away their stops, that
were only until then held by wood.
Several surviving Paris models have similar cases : flame
mahogany panels, separated by boxwood inlay, that create
lozenge shapes  on the lyre and top of the legs.
In about 1838, Erard replaced the « ladder » action by a
more modern type, with metal catches, spring-loaded
dampers, and fork type hammer shanks (these first fork
shaped hammer shanks were much more delicate than on
the slightly later models, see n° 14404).
*Pianos with S shaped fallboard : All the earlier Erards had
quarter circle profile fallboards, with spandrels of the same
shape either side of the keyboard. The new model
integrates the S shape of the fallboard into the sides of the
case. Whereas n° 14404 follows the old type, n° 14731
adopts the new case type : presumably the change over
took place in 1838.
Several pianos of this period have very attractive cases,
with brass inlay forming intricate patterns (first seen on n°
14404, boxwood and mahogany) setting off rosewood
veneers (see n° 14731).

*Other characteristics : Several other changes occur in the
pianos over this period, that don’t fit into the chronological
evolution of the casework discussed above.
For example, most of the early pianos have a keyslip fitted
on hinges that rotates down to access the action, that was
later replaced by a screwed keyslip like on modern pianos.
Some early Paris Erards have round bars that the London
factory never seems to have used :  the Paris factory gave
up this idea from about 1834.
The address on the fallboard evolved quite a bit : on the
very early pianos this was elaborately written in ink and the
long text seems to differ from piano to piano. From the
early 1830’s, the address follows a more standard form : «
Par brevet d’invention Erard Paris » in brass lettering
surrounded by ornate scroll work. This didn’t change until
the mid-1840’s, when it was replaced by a more simple «
Par brevet Erard à Paris » in linear sloped script.
The music stand didn’t evolve at all over this whole period.
Dust covers appear to have been used until the late 1840’s.
At some point of the evolution of the Erard action, the wood
hammer flanges were replaced by brass, with a screw
adjustment of the play.
London n° 177
London n° 7x
14 731
14 404