mariuscomper.ukRomână
The basalt slabs of the Via Appia road, near Rome

Dacia, AD 108

How long is a step?

Five Roman feet laid end to end: about 1.48 m. The body named the measure, but Rome's roads were never surveyed with a soldier's stride — Rome had standards, rods, and mile-counting machines. The mile is gone; the words stayed.

One Roman pace: ≈1.48 m.

The Via Appia, near Rome: basalt slabs of a consular road. The stones were laid to standard measures, checked against the rod. Photo: Flavia Verona, Wikimedia Commons, CC BY-SA 4.0

The body gave the name. The standard gave the length.

Five feet make a passus

Two and a half feet made the single step, the gradus (≈74 cm), and the double pace, the passus, gathered five feet: ≈1.48 m. Five standard feet — the measure no longer depended on any marching sole.

The rod lifts the measure out of the body

Isidore of Seville summed the system up in a sentence: every measure sits in the body — palmus, pes, passus — and only the rod is carried. The ten-foot rod (the pertica, the surveyors' decempeda) lifted measurement out of the body and into the state's hand.

Yet the name comes from the body

Body origin, not surveying method: two single steps make one double pace. The length was fixed by the standard — five standard feet — and checked against the ten-foot rod.

The mile counted itself

Surveyors worked with the graduated rod and the groma, and Vitruvius describes a road odometer: a four-foot wheel turned toothed wheels, and every mile — 5,000 feet — dropped a pebble into a vessel. The mile counted itself.

Modern schematic after Vitruvius, On Architecture 10.9: one turn of the wheel covers 12.5 feet, and every 400 turns the upper drum revolves once and a pebble announces the mile — 5,000 feet.

Three footprints, the ten-foot rod, and the Roman measures Three prints: the single step gradus of about 74 cm between the first two, the double pace passus of about 1.48 m between the first and third, the pes length of about 29.6 cm, and below, the decempeda rod of ten feet. gradus · ≈74 cmpassus · ≈1.48 mpes · ≈29.6 cm decempeda · 10 feet = 2 passus
Body origin, not surveying method: two single steps make one double pace. The length was fixed by the standard — five standard feet — and checked against the ten-foot rod.
Schematic of the odometer described by Vitruvius The carriage wheel, four feet across, turns two toothed drums; at every mile, a pebble announces the distance. wheel · Ø 4 feetupper drum · 400 teeth mile drumone mile pebble
Modern schematic after Vitruvius, On Architecture 10.9: every 400 turns of the wheel revolve the upper drum once, and a pebble announces the mile — 5,000 feet.

Pace out your mile

Pick the length of your ordinary step — one step, not a passus — and see how many fit in a mile of ≈1,480 m.

At 75 cm a step, the Roman mile of ≈1,480 m takes ≈1,973 steps.

Ten thousand paces, set in stone

The Aiton milestone

  1. Imp · Caesar · Nerva · Traianus · Aug · Ger · DacicusImp(erator) Caesar Nerva Traianus Aug(ustus) Ger(manicus) Dacicus
  2. Pontif · Maxim · Pot · XII · Cos · Vpontif(ex) maxim(us), [tribunicia?] pot(estate) XII, co(n)s(ul) V
  3. Imp · VI · P · P · Fecitimp(erator) VI, p(ater) p(atriae), fecit
  4. Per · Coh · I · Fl · Ulpper coh(ortem) I Fl(aviam) Ulp(iam)
  5. Hisp · Mil · C · R · EqHispan(orum) mil(liariam) c(ivium) R(omanorum) eq(uitatam)
  6. A · Potaissa · Napocaea Potaissa Napocae
  7. M · P · Xm(ilia) p(assuum) X

the original stone, lost

The 1758 drawing of the Aiton milestone
The 1758 drawing associated with M. P. Szathmári: the principal early visual record of the lost monument (after Winkler 1982, in Fodorean 2015).Via Wikimedia Commons, public domain
The modern copy of the milestone, at Turda
The Turda copy, in front of the post office, erected in 1993: a modern replica after the 1758 drawing.Photo: CristianChirita, Wikimedia Commons, public domain

Ten miles from Potaissa

At Aiton, near Cluj, a stone marker once counted distance in thousands of paces. The milestone, found in 1758, had been raised in AD 108 on Trajan's orders, on the road between Potaissa and Napoca. Its last letters say everything: M·P·X — m(ilia) p(assuum) X, ten thousand paces, ten miles: ≈14.8 km.

The whole road: 24 miles

Ten miles give the stone's position: the milestone stood ten Roman miles north of Potaissa, toward Napoca. The whole road measured 24 miles — the Peutinger map gives XXIIII (≈35.5 km), and Fodorean's 3D model ≈31.7 km.

A road built by a cohort

The road had been built by cohors I Flavia Ulpia Hispanorum milliaria civium Romanorum equitata — an auxiliary cohort of “thousand” class, mixing infantry and cavalry. The inscription is the oldest epigraphic record of the names Potaissa and Napoca, today's Turda and Cluj. Mommsen entered the text into the Corpus Inscriptionum Latinarum, III, 1627.

Expanded, line by line

The Emperor Trajan, with the titulature of AD 108, built the road through the first cohort of Spaniards — from Potaissa toward Napoca: ten thousand paces. The year 108 comes from the imperial titulature.

The Aiton milestone, CIL III 1627, after EDH HD049451.

The original is lost

The original is lost, with no detailed description; it survives in a 1758 drawing associated with M. P. Szathmári, rediscovered by Iudita Winkler in a Cluj manuscript. Johann Seivert first read and published the text in 1773, at Vienna. Today one copy of the stone stands at the Aiton school, and another — since 1993 — in front of the Turda post office.

The Potaissa–Napoca road and the position of the Aiton stone Potaissa at zero miles, the Aiton stone at ten miles (about 14.8 km), Napoca at the end of the 24-mile road. POTAISSA0 miles AITONX miles · ≈14.8 km NAPOCAXXIIII miles · ≈35.5 km (Turda)(Cluj)
The stone's position on the Potaissa–Napoca road: ten miles from Potaissa; the whole road, 24 miles (after Fodorean 2015).

The Aiton milestone, CIL III 1627, after EDH HD049451: Trajan built the road through the first cohort of Spaniards, from Potaissa toward Napoca — ten thousand paces. The year 108 comes from the imperial titulature.

Expanded + translated

Imp(erator) Caesar Nerva Traianus Aug(ustus) Ger(manicus) Dacicus, pontif(ex) maxim(us), [tribunicia?] pot(estate) XII, co(n)s(ul) V, imp(erator) VI, p(ater) p(atriae), fecit per coh(ortem) I Fl(aviam) Ulp(iam) Hispan(orum) mil(liariam) c(ivium) R(omanorum) eq(uitatam), a Potaissa Napocae, m(ilia) p(assuum) X.

The Emperor Trajan, with the titulature of AD 108, built the road through the first cohort of Spaniards — from Potaissa toward Napoca: ten thousand paces.

Where
Aiton, Cluj county; copies at the Aiton school and at Turda
When
AD 108, dated by the imperial titulature
Number
CIL III 1627; EDH HD049451
Distance
M·P·X — ten miles from Potaissa (≈14.8 km); the Potaissa–Napoca road: 24 miles

The metric law was signed on 15 September 1864 — Mihail Kogălniceanu defended it in parliament — and it replaced the measures of its day, the stânjen and the palmă, over decades. The comparative tables the law required set the metre against the old units:

  1. 1864 The law. Cuza signs; Kogălniceanu defends.
  2. 1875 Application. Metre–against–old-measures tables.
  3. 1879 Compulsory in transactions.
  4. 1881 Imposed across the whole territory.
  5. 1883 The Metre Convention. Romania, 19th member.

What stayed in the language

Three letters on the stone — M·P·X — open three histories: an inherited word, a word that came home, and a number that never left.

Mmilă

came back

M for milia, through Mod. Gk. μίλι (DER, 16th c.). The word returned; the measure was no longer the same: today's mile is 1.609 km, the Roman one ≈1.48.

Ppas

inherited

P for passuum, from passus (DER). The word stayed; the fixed value of five feet did not.

Xzece

inherited

On the stone, X reads decem; Romanian zece comes from Lat. decem (DEXI). Three signs, three ages of the language.

Further down from pas

From pas came a verb, a departure, and a return — and one old measure happened, by chance, to land near the passus.

  1. pasa păși

    inherited

    A verb born from pas (DER): to step, to walk.

  2. passarepăsa

    old, inherited

    Păsa meant “to go”, probably straight from Lat. passare (DER). It survives in Alecsandri's line: “Pasă, ceată călătoare”.

  3. passera pasa

    returned through French

    From Fr. passer (DEX), heir of the same Lat. passare: the family entered Romanian twice.

  4. pas mare≈1.47 m

    close numbers, separate histories

    The old measures knew the small pas (4 palme) and the great pas (6 palme). Six palms of Șerban Vodă's stânjen (1.962 m) make ≈1.47 m — within a centimetre of the passus. But in Moldavia, with the 2.23 m stânjen, the same great pas gave ≈1.67 m. Similar bodies make similar measures; continuity is not proven.

    passus · 1.48 m
    great pas, 1.962 m stânjen · 1.47 m
    great pas, 2.23 m stânjen · 1.67 m

Sources

The Roman measures are the standard ones — pes ≈29.6 cm, passus five feet, the mile a thousand paces. The etymologies come from dictionaries; the milestone, from epigraphers.

Ancient texts

Dictionaries

Studies and documents

Images