A) THE ORIGIN
Since the second century mills were
on the side of the Gianicolo that from St Peter in
Montorio steeply slopes down to the Tiber; they were
activated by the fall of the water that the emperor
Traiano had derived from the area of the Sabatini
mountains (pict. A1).
During the Goth siege of Rome in 537 AD, Vitige ordered
the aqueducts cut in order to prevent the arrival of
drinkable water to the city; this lack of water also
stopped the operation of the Gianicolo mills. These were
reactivated, in a new position, only in the XVII century
when Pope Paul V Borghese (1607-1612) built the aqueduct
that still has his name (Acqua Paola) conveying water
from the lake of Bracciano (pict. A2).
The forced inactivity of
the Gianicolo mills gave birth to the Tiber floating
mills: in fact, as Procopio of Cesarea testifies, the
Byzantine general Belisario, sent by the emperor
Giustiniano to garrison the city, used the river's
current to move the first floating mills. He anchored to
the banks two boats with a wheel between them; the
wheel, activated by the current, drove the millstones
located in the boats themselves.
The mills had been first located just downstream from
Ponte Sisto, the bridge across the only part of the
Tiber enclosed by walls on both sides and therefore
protected from the military point of view; moreover this
location is near the Gianicolo and this made the
transport of the millstones easier.
From there
the mills grew around the Tiber Island, thus becoming
part of the Tiber landscape for more than 1300 years
until the construction of the embankments.
From some remnants recovered near the piers of the Ponte
Neroniano, near Castel S.Angelo, (one millstone, a chain
and some planks of the raft) it has been possible to
reconstruct a scale model of the mill (pict. A3).
Page top
B)
THE LEFT BRANCH
The oldest traces of the Tiber mills are found on the
left branch of the river; it was, however, less used
than the right one due to its reduced water flow.
The first
textual references to the mills are found in texts of
the 1300s, but the first graphic evidence is a drawing
by "Anonymous Escurialensis" (after a drawing by
Giuliano da Sangallo), dated between 1485 and 1514
(pict. B1), that shows three mills on the Tiber's left
branch just upstream from the Ponte Fabricio, and an
engraving by Hieronymus Cock dated 1530-34 (pict. B2)
that shows two mills, also just upstream from the
Fabricio bridge, one anchored to the left bank and the
other to the island.
All later images show a single mill, or two placed side
by side, but located upstream, on the Regola bank.
In
particular two mills are shown by Silvestro Peruzzi
(1564-65) and by Giovanni Maggi (1625) (pict. B3); Maggi
drew them not to scale and located in front of
S.Vincenzo and Anastasio at the Regola, further upstream
than where they probably really were.  
A single mill is indicated in the maps of Antonio
Tempesta (1593), Matteo Greuter (1618), G.B.Falda (1676)
(pict. B4) and G.B.Nolli (1748) (pict. B5).
This mill is known (1620) as "mola di S.Andrea al
Portone delli Hebrei" [mill of S.Andrea at the
Door of the Jews], as it was located near one of the 5
doors, clearly visible in the Falda and Nolli maps, that
enclosed the Jewish Ghetto constituted by Papal Bull in
1555. The doors were definitively unhinged only in 1848.
Andrea Chiesa, engineer from Bologna, appointed together
with Gambarini to study the Tiber, also reported in 1745
that in the left branch of the river near the island
there was only one mill, known as "Mola di Ghetto"
[mill of the Ghetto], located in correspondence with the
north end of the island and therefore near Monte Cenci
as shown in the 1746 map (pict. B6).
The last citation of this mill is dated 1810; the mill,
therefore, completely disappeared in the beginning of
the 1800s.
The last known mill on the Tiber's
left branch is the so-called "mola terragna" [mill with
foundations] located on the island (not floating). In a
census it was numbered as 43 and 44 of "Via delle
mole di S.Bartolomeo" [Street of the Mills of St
Bartolomeo]. Starting in 1826 it is found, under the
name of the "Giuditta" mill, in the records of the "Specchi
Dimostrativi" [Demonstrative Reports] of grinding
(see also para. D). Its location is shown on the
Lanciani map (end of XIX century - pict. B7) together
with the long wall of pilings which directs the flow of
the water to the mill.
Page
top
C) THE RIGHT BRANCH
Many more mills have always been in the right
branch of the river, due to the river's larger size and
greater flow on that side; there the last mills were
removed only during the construction of the embankments
after the big flood of 1870. The Ponte Cestio was also
known as "Ponte Ferrato" [bridge-with-iron] (see
pict. E6) for the many mooring chains of the mills
around it.
Often the
mills' moorings were broken by the strength of the
current, so it is not unusual to find in the old maps
only the masonry ramp without the mill. In the Tempesta
map (1593) 4 mills are visible (two mills and a ramp at
the island and one moored to the Trastevere bank); in
the Maggi map (1625) (pict. C1) three ramps without
mills, all of them moored to the island, are shown. Falda (1676)
(pict. C2) shows six mills, two moored to the island and
four to the right Trastevere bank; in the Falda map one
can also find two facing mills just downstream from
Ponte Rotto. Nolli (1748)
(pict. C3) also shows six mills, three moored to the
island and two plus a ramp moored to the Trastevere
bank. These locations perfectly match those indicated,
two years before (1746), by Chiesa.
In the picture C4, an elaboration on the Lanciani map
(1893-1901) are indicated the locations of the various
mills obtained from the available documents.
The mills had names, often those of saints; a partial
analysis of their locations, limited to the most recent
ones, has been possible with the use of existing
documents: the "brogliardi", the maps of the Pio
Gregoriano land register, the daily "Specchi
Dimostrativi" [Demonstrative Reports] (SD - see
also para D) of the Supervision of Grinding and the
works of Cialdi and Moroni. The mills were classified
according to their administration: those moored to the
island were in the administrative Custody of the Island,
while those moored to the Trastevere bank were in the
Custody of S.Bonosa.
In the "brogliardi"
and in the maps of the Pio Gregoriano land register
only the urban blocks are recorded; however, as the sentence:
"...in front of the mill of..." is often indicated in
the records, it is possible to identify the mills of
S.Francesco, SS.Annunziata and S.Maria located
respectively "in front of" blocks II, III and IV of
the island (see pict.C5 from the 1748 G.B.Nolli map).
Finally, as the Acquaroni engraving that represents a
mill downstream from Ponte Cestio moored at Trastevere
(see picture E4) may be dated around 1820, this mill
can be identified as the S.Agostino mill, given that,
at that time, the S.Nicola mill was still moored to
the island.
Page
top
D) DESCRIPTION
The mills consisted of two floating rafts: on the
main one, nearest to the bank, were located the
millstones inside the characteristic small house,
often with a cross on the top. Between the two rafts
was supported the bladed wheel. The working
principle is shown in the animation carried out
at the Technical College Meucci in Rome. The rafts
were moored to the banks by long chains; a masonry
ramp and a wooden footbridge allowed access to the
bank (pict. E1 e A3).
In every mill four workers were normally employed: two
"loaders" that brought the grain and the flour with
beasts of burden, a "servant" that worked at the
millstone and was assigned to repairs and a generic
"boy" for various services.
In a mill about 4500 kg of grain per day were ground
and the production was daily recorded by the food
administration; we have this data from 1823 to
1845 (pict. D1).
The Roman millers located the religious see of their
corporation, "Romana Molendinariorum", in the
S. Bartolomeo church on the Tiber Island, building a
chapel decorated with images of their activity (pict.
E9); a plaque still commemorates one of the many
restorations of the chapel (pict. D2).
The mills obstructed the normal water flow of the
river and often the strength of the current broke the
moorings and dragged the mill downstream with
disastrous results. As early as the middle of the
1700s it was proposed that they be moved downstream
from the town and in 1870 the Public Works Ministerial
Commission included the floating mills among the
causes of the Tiber floods in Rome. After the big
flood of December 1870 and the successive construction
of the embankment the Tiber mills definitively
disappeared.
Page
top
E) THE IMAGES

E1 |

E2 |

E3 |

E4 |
E1
- This picture probably shows the SS
Annunziata mill moored to the Tiber's right
branch upstream from Ponte Cestio. On the left
is shown the main raft connected to the bank
by a masonry ramp and a wooden footbridge. In
the foreground is the mooring turret of
another mill (probably the San Francesco mill)
located downstream (Chaffourier 1870)
E2 - This picture was taken from Ponte
Rotto; the island is on the right. Upstream
from Ponte Cestio one sees the San Francesco
mill in the middle of the arch, the SS
Annunziata mill just behind; a third mill in
the background obstructs almost completely the
right branch of the river (Chaffourier 1870)
E3 - Upstream from Ponte Cestio are
visible, moored to the island, the SS
Annunziata mill and, in the middle of the
picture, the San Francesco mill (Chaffourier
1870)
E4 -The mill downstream from Ponte
Cestio moored to the Trastevere bank; at the
left are visible the beasts of burden passing
on the footbridge. Behind the bridge we see
part of the San Francesco mill (Antonio
Acquaroni ~1820)
|
E5 |

E6 |

E7 |

E8 |
E5
- "Isola Tiberina verso occidente" [Tiber
Island's west side]. On the left branch,
upstream from Ponte Fabricio, is shown the
ramp of the Sant'Andrea mill also known as
"Ghetto mill"; on the right branch in the
foreground the Santa Maria mill, the partially
hidden SS Annunziata and San Francesco mills
moored to the island and two more moored to
the Trastevere bank (Giuseppe Vasi 1754)
E6 - "Veduta di Ponte Ferrato degli
Antiquarj detto Cestio" [View of
bridge-with-iron of the "antique dealers",
called Cestio]; fantasy view from the island
upstream from the bridge (G.B. Piranesi,
middle of XVIII century)
E7 - The Tiber Island and the Tiber's
left branch with Ponte Fabricio and two mills;
the left one is probably the mill "Sant'Andrea
al portone delli Hebrei" [mill of S.Andrea at
the Door of the Jews]. (Hieronymus Cock
1530-34; see also B2)
E8 - Fantasy view showing several mills
downstream from Ponte Sisto (Hieronymus
Francken, inc. M.Sadler - copy from a Du Perac
1574 dwg.)
|

E9 |

E10 |

E11 |

E12 |
E9
- Images of the mills painted on the ceiling
of the Chapel in the San Bartolomeo church, on
the Tiber Island, where the corporation of
milled established their religious see
E10 - In this painting from the end of
the XIX century is visible, behind the arch of
Ponte Cestio, the ramp of the old Ghetto mill
(St Andrea)
E11 - This painting represents a view
seen from the east end of the island which
shows a mill and its relevant access ramp
behind Ponte Rotto (anonymous - end of the
XVIII century)
E12 - A
millstone dug out from the river bed and
exposed at the Ripa Grande port. It is
possible to see the characteristic "guzzatura"
i.e. the grooves carved by skilled craftsman
in order to permit the proper grinding of
grain. As soon as it was carved a millstone
tended to become packed with grain and
required a preparatory period of grinding
before it produced in a satisfactory manner
|
Page
top
F) BIBLIOGRAPHY AND CREDITS
[1]
Cesare D'Onofrio "Il Tevere" - Romana
Società Editrice - 1980
[2] AAVV "La nave di Pietra" - exibition
catalogue - Electa - 1983
[3] Gaetano Moroni "Dizionario di erudizione
storico - ecclesiastica da S. Pietro sino ai
nostri giorni" - Tipografia Emiliana -
Venezia, 1855
- Pictures A1 and A2 courtesy of Katherine Rinne
- Pictures E10 and E11 courtesy of Kalervo Koskimiehen
Page top |
The realization of this section was made
possible thanks to the essential contribution of
the book:
Umberto Mariotti Bianchi
Roma Sparita: I molini del Tevere
Ediz. Babuino - Roma 1976
English translation check by Karen Bermann
|
|