το βάρο και το μετρήματο
Weights & Measures

This page illustrates many of the problems involved in designing an isolating version of an ancient language to express modern concepts. In the case of ΤΑΚΕ one can have regard to the modern form of Greek; but this is not always possible as, of course, modern Greek has not retained ancient forms. Many of the metric units below are derived from names of persons (cf. the 'Proper Names' page).

This has not been an easy task and several compromises have necessarily had to be made.

1. SI Prefixes

We have already seen from the 'Numerals' that for million, billion, trillion (short scale, i.e. 10⁶, 10⁹, 10¹²) etc., ΤΑΚΕ uses the SI prefixes. It, therefore. also uses them as prefixes for SI weights and measurements. The SI prefix for a thousand (10³) is kilo- which is a mangled form of Greek χιλιο-. Indeed, modern Greek uses χιλιο- as its equivalent of SI kilo-. However, on the 'Numerals' page we saw that ΤΑΚΕ uses χιλια- as a prefix for 1000 and it, therefore, uses it as its equivalent for the SI prefix (The ancient language used both χιλια- and χιλιο- as a prefix).

SI also allows prefixes for 10 and 100 from the French metric system, namely deca- and hecto-. While deca- is properly derived from Greek, hecto- is an arbitrary mangling of Greek ἑκατόν. The modern Greeks use εκατο- but that is not found in the ancient language and, therefore, will not do in ΤΑΚΕ. In the ancient language, the prefix was either ἑκατογ-/ ἑκατομ-/ ἑκατον-, the nasal depending upon the initial sound of the word the prefix was attached to, or ἑκατοντα-; the latter, for reasons explained on the 'Numerals' page, is the ΤΑΚΕ form of the prefix and is what it uses instead of the SI hecto-. Both ΤΑΚΕ and modern Greek use δεκα- for SI deca-.

It will be seen that all the ΤΑΚΕ forms of prefixes for multiples of 10 end in -α-.

As equivalents for deci-, centi- and mili-, I had considered following the modern Greeks and use Greek prefixes for tenth, hundredth and thousandth respectively (i.e. δεκατο-, ἑκατοστο-, χιλιοστο-). But it would logically follow that in ΤΑΚΕ micro- would become μεγοστο-, nano- would become γιγοστο- etc. This would be all very logical but probably not satisfactory in use.

In the end, it seemed preferable simply to write the various SI prefixes for divisions of 10 in Greek letters, even though it means that in ΤΑΚΕ μικρο- will mean both "small" and "millionth" - but context will surely make it clear. The only question was the rendering of deci- and centi-; does ΤΑΚΕ render Latin c as Greek κ, reflecting the ancient pronunciation, or as Greek σ, reflecting the various modern "soft-c" pronunciations? The words κεντηνάριος (← Latin: centēnarius "an official drawing a salary of 100 thousand sesterces") and κεντορίων/ κεντουρίων/ κεντυρίων (← Latin: centuriō "centurion") are attested in the ancient language. Apart from one example of a verb δεκυρεύειν "to be a decurion", there are no ancient words from Latin decem, decim-. However, although the whole SI system has, of course, no ancient precedent, it is perhaps more in keeping with the "spirit of ΤΑΚΕ" to reflect the ancient pronunciation and render the prefixes as δεκι- and κεντι- respectively.

The complete set of prefixes are:

SI prefix	SI symbol	ΤΑΚΕ prefix	10n	Short scale	Long scale	Example
yotta	Y	ἰοττα	1024	septillion	quadrillion	ἰοττάμετρο
zetta	Ζ	ζεττα	1021	sextillion	trilliard	ζεττάμετρο
exa	E	ἐξα	1018	quintillion	trillion	ἐξάμετρο
peta	P	πετα	1015	quadrillion	billiard	πετάμετρο
tera	T	τερα	1012	trillion	billion	τεράμετρο
giga	G	γιγα	109	billion	milliard	γιγάμετρο
mega	M	μεγα	106	million		μεγάμετρο
kilo	k	χιλια	103	thousand		χιλιάμετρο
hecto	h	ἑκατοντα	102	hundred		ἑκατοντάμετρο
deca	da	δεκα	101	ten		δεκάμετρο
–	–	–	100	unit		μέτρο
deci	d	δεκι	10-1	tenth		δεκίμετρο
centi	c	κεντι	10-2	hundredth		κεντίμετρο
milli	m	μιλλι	10-3	thousandth		μιλλίμετρο
micro	μ	μικρο	10-6	millionth		μικρόμετρο
nano	n	νανο	10-9	billionth	milliardth	νανόμετρο
pico	p	πικο	10-12	trillionth	billionth	πικόμετρο
femto	f	φεμτο	10-15	quadrillionth	billiardth	φεμτόμετρο
atto	a	ἀττο	10-18	quintillionth	trillionth	ἀττόμετρο
zepto	z	ζεπτο	10-21	sextillionth	trilliardth	ζεπτόμετρο
yocto	y	ἰοκτο	10-24	septillionth	quadrillionth	ἰοκτόμετρο

Thus it will be seen that, apart from the two mangled Greek prefixes of the French metric system, ΤΑΚΕ simply uses the SI prefixes; it replaces only the mangled Greek prefixes with actual Greek derived ones.

It can be argued, of course, that some of the other prefixes are also mangled Greek, e.e. giga- ← γίγας (gen. γίγαντος) "giant"; but γίγας did not (and does not) mean "billion/ milliard" and the common, though by no means universal, English pronunciation of the prefix as [ɡɪɡə] does not suggest it is readily connected in the public mind with "giant" or "gigantic"; nor have the modern Greeks have not seen fit to use γιγαντο- as the prefix. Besides, what would we do with tera- which is a hybrid mangling of τέρας (gen. τέρως or τέρατος) "monster" and τετρα- "four"? And we could hardly 'unmangle' peta-, exa- and -yotta- as πεντα-, ἑξα- and ὀκτα- - they would give entirely the wrong meanings!

Indeed, the coining of exa- to denote 10¹⁸ times is not, in view of the prefix hexa- (six [times]), one of the most brilliant of SI prefixes! However, unlike modern Greek where εξάμετρο may mean either an "hexameter" (a metrical line of verse consisting of six feet) or an "exametre" (a distance of 10¹⁸ metres), ΤΑΚΕ does (just) distinguish between ἑξάμετρο and ἐξάμετρο.  

2. SI Base Units

The International System of Units (SI) defines seven basic units of measure from which all other SI units are derived. One of those seven we met in the table above, i.e. μέτρο = metre (← ancient Greek μέτρον "measure, metre/meter [of verse]"). There was also an ancient word for second (i.e. 1/60 of a minute), namely δευτερόλεπτον, from which we derive ΤΑΚΕ δευτερόλεπτο.

Both ampere and kelvin are named after person, so ΤΑΚΕ just puts those names into Greek letters.

Two other units have Latin derived names: candela is simply the Latin candēla (candle) which appears in ancient Greek as κανδήλη and thus remains the same in ΤΑΚΕ; mole is derived from molecule (or more strictly the German Molekül, as the German Mol had been coined by Wilhelm Ostwald in 1893) ← modern Latin molecule, coined in the 17th century as a diminutive of the classical Latin feminine noun mōles (genitive: mōlis) "mass".

The modern Greek for molecule is μόριο which is derived from ancient μόριον "piece, portion, constituent part"; ΤΑΚΕ will likewise use μόριο with the more precise meaning of molecule. Strictly, the ancient μόριον was a diminutive of μόρος "fate, destiny, doom, death" (i.e. one's allotted portion); that is too far removed from the meaning we want.

In modern Greek mole is γραμμομόριο or simply μολ. The latter is just a transcription of the SI unit symbol mol; the former is a calque of the term gram-molecule which has sometimes been used in the same sense as mole. However, it just will not do in ΤΑΚΕ. In ancient Greek and in ΤΑΚΕ γραμμο- is the compositional form of γραμμή "stroke [of a pen], line, row"; it has nothing to do with the SI unit of mass known as the gram(mme) (we shall discuss this further below). There was no ancient borrowing from Latin mōles; so we cannot really do much better than the modern μολ, though in view of the long vowel of the Latin original, μῶλ would surely be better for ΤΑΚΕ.

That just leaves kilogram to consider. Although SI lists this as a basic unit, it does, of course have an SI prefix. However, as far as SI is concerned a definition is given for kilogram, and a gram is just one thousandth of that. We have seen above that ΤΑΚΕ replaces the mangled Greek kilo- with χιλια-; so what we have to think about is the ΤΑΚΕ word for gram.

In modern Greek, kilogram is χιλιόγραμμο while a gram is γραμμάριο! I have already commented that the morpheme γραμμο cannot be a valid ΤΑΚΕ derivation from ancient Greek in this context. The word gramme of the French metric system was derived from a late Latin gramma (genitive: grammatis) which a certain Rhemmius Fannininus gave as a weight of two obols in a book on weights and measures that he published sometime around 400 CE. As an obol weighed about half a gram, I guess this was appropriate, but the reference is, to say the least, somewhat obscure. The late Latin word was without doubt borrowed from ancient Greek γράμμα (gen. γράμματος) which is found in a few obscure references referring to weight of about 1g, but whose overwhelming meaning is: "letter [in both senses of the English word], a written character, a set of characters etc.". That is the meaning of ΤΑΚΕ γράμματο. The modern Greek γραμμάριο, however, is from an ancient Greek γραμμάριον = a weight of two obols. ΤΑΚΕ, therefore, also renders gram[me] as γραμμάριο but, unlike the modern language, keeps the same form in compounds; thus a kilogram is χιλιαγραμμάριο.

The seven base units are:

Measure of …	English word	SI symbol	ΤΑΚΕ word	For the SI definitions of these units, see   en.wikipedia.org/wiki/SI_base_units
length	metre	m	μέτρο
mass	kilogram	kg	χιλιαγραμμάριο
time	second	s	δευτερόλεπτο
electric current	ampere	A	ἀμπήρ
thermodynamic temperature	kelvin	K	κέλβιν
amount of substance	mole	mol	μῶλ
luminous intensity	candela	cd	κανδήλη

Note:

• The SI prefixes may be used with all seven basic units, except χιλιαγραμμάριο (kilogram) since that already has a prefix and SI prefixes must not be doubled up. In the case of units of mass, prefixes are added to γραμμάριο (gram[me]). As for δευτερόλεπτο (second), while prefixes denoting fractions of the unit are common enough, e.g. μιλλιδευτερόλεπτο (millisecond), νανοδευτερόλεπτο (nanosecond) etc., the multiplicatives are not normally used as higher units of time are commonly measured in λεπτό (minute = 60 s), ὥρα (hour = 3600 s) and ἡμέρα (day = 86400 s) - see "4. Some non-SI units associated with SI" below.
  For the use of the prefixes with κέλβιν (kelvin), see en.wikipedia.org/wiki/Thermodynamic_temperature.
• In many languages, kilogram is simply abbreviated to kilo which becomes used as an independent word. Indeed, we find κιλό used this way in modern Greek (I've head pronounced [ʧi'lo] in Crete). Clearly χιλιαγραμμάριο is a bit of a mouthful for everyday use and ΤΑΚΕ also allows κιλό. Also SI officially accepts that ton[ne] may be used as an equivalent of megagram and ΤΑΚΕ likewise accepts τόννη (the hellenized form of Latin tonna) as an alternative for μεγαγραμμάριο. See "4. Some non-SI units associated with SI" below.

 

3. SI Derived Units

1. Named units derived from SI base units

These are given in the table below. For formulae showing showing both expressions in terms of other units and expressions in terms of SI base units, see en.wikipedia.org/wiki/SI_derived_units; and for more information about individual units, click on the English name of the unit.

Most of the unit names are, in fact, names of people or, in the case of farad and volt, shortened forms of surnames. In the ancient language, foreign names were often just respelled in Greek, as far as the phonotactics of the language allowed, and left indeclinable. That is what I have done with the names below, with the sole exception of Celsius. This name is a latinized from the Swedish Högen. The Latin name would have been hellenized by the ancients as Κέλσιος which, indeed, is also the modern Greek for Celsius, -ος being the nominative singular ending. Nouns of the 2nd declension, ending in -ος are adopted in ΤΑΚΕ without the final -ς. Hence ΤΑΚΕ for Celsius is Κέλσιο.

As for the five units not named after people:

• radian is derived from radius. The ΤΑΚΕ word for radius is ἀκτῖνο (← ancient Greek: ἀκτίς, gen. ἀκτῖνο. Cf. modern Greek ακτίνα); from this we derive ἀκτίνιο = radian (cf. modern Greek ακτίνιο).
• steradian is derived from ancient Greek στερεός (stereos "solid") + radian which, however, would have been expected to give *stereoradian, of which steradian is a contraction. ΤΑΚΕ likewise uses a compound of στερεό- and ἀκτίνιο which gives us στερεακτίνιο (ΤΑΚΕ, however, does not contract this form).
• lumen is merely the Latin nominative singular of a word meaning [source of] light, brilliance, clearness. In the ancient language we find φλαμήν (nominative) used for Latin flāmen (gen. flāminis a type of priest); we also find Latin lūmenārium rendered as λουμενάριον (window, window shutter). Therefore, I assume a hellenized *λουμήν (gen. *λουμένος) from which is derived ΤΑΚΕ λουμένο.
• lux is merely the Latin nominative singular of a word meaning light [of the sun or other heavenly bodies], [day]light. On the basis of the attested δούξ (gen. δουκός ← Latin: dūx, dūcis) we assume a hellenized *λούξ (gen. *λουκός ← Latin: lūx, lūcis) which gives ΤΑΚΕ λουκό.
• Katal is derived catalytic, catalysis etc.; similarly, ΤΑΚΕ derives κατάλ from καταλυτικό, κατάλυσι etc.

 

Name in English	Symbol	Name in ΤΑΚΕ	Quantity
hertz	Hz	ἕρς	frequency
radian	rad	ἀκτίνιο	angle
steradian	sr	στερεακτίνιο	solid angle
newton	N	νεῦτον	force, weight
pascal	Pa	πασκάλ	pressure, stress
joule	J	ζοῦλ	energy, work, heat
watt	W	οὐάτ	power, radiant flux
coulomb	C	κουλόμ	electric charge or quantity of electricity
volt	V	βόλτ	voltage, electrical potential difference, electromotive force
farad	F	φάραδ	electric capacitance
ohm	Ω	ὦμ	electric resistance, impedance, reactance
siemens	S	σεῖμενς	electrical conductance
weber	Wb	βῆβερ	magnetic flux
tesla	T	τέσλα	magnetic field strength, magnetic flux density
henry	H	ἕνρι	inductance
Celsius	°C	Κέλσιο	Celsius temperature
lumen	lm	λουμένο	luminous flux
lux	lx	λουκό	illuminance
becquerel	Bq	βεκκερέλ	radioactivity (decays per unit time)
gray	Gy	γρῆι	absorbed dose (of ionizing radiation)
sievert	Sv	σεῖβερτ	equivalent dose (of ionizing radiation)
katal	kat	κατάλ	catalytic activity

 

4. Some non-SI units associated with SI

4.1 Widely used units officially accepted for use with the SI and expected to be used indefinitely

The three units of time - minute, hour, day - are ancient and were used long before the Greeks. The day must be as old as language itself. The hours of daylight had been divided into 12 hours at least since the time of the Sumerians in the 4th millennium BCE. The Babylonians divided hours and degrees into sexagesimal fractions; therefore, it is not surprising that we find ancient Greek words for 'hour', 'minute' and 'second'. Indeed, all the ΤΑΚΕ words for the first six units below are derived from the ancient language.

The metric system of 1795 had a unit called the are, defined as 100 m². When the metric system was rationalized in 1960 with the of SI Units, recognition of the are was withdrawn, but the hectare (i.e. 100 ares = 10 000 m²) continued to be recognized as a "unit of measure that may be used with SI". Modern Greek simply hellenizes the French hectare as εκτάριο, treating it as a single morpheme and not as a compound. After some hesitation, I have decided to adopt a similar solution in ΤΑΚΕ, namely ἑκτάριο (this cannot, of course, be regarded as a compound as the prefix for 100x is ἑκατοντα-).

In SI units, capacity is measured in cubic metres, cubic centimetres etc. However, the pre-SI measure litre, defined as a cubic decimetre, is retained as a measure that may be used with SI units (for historic reasons, two symbols are officially allowed: lower case l or upper case L). The name is derived from ancient Greek λίτρον, a fairly rare and late variant of the Classical λίτρα. The latter was used both to denote a weight of about a Troy pound and of a unit of capacity, otherwise known as ἡμίνα or κοτύλη, of slightly less a third of a litre. Despite the difference in measurement, I have decided to use the ancient λίτρα. The ΤΑΚΕ form τόννη is discussed at the end of Section 1 above.
 

Name		Symbol	Quantity	Equivalent SI unit
English	ΤΑΚΕ
minute	λεπτό	min	time (SI unit multiple)	1 min = 60 s
hour	ὥρα	h		1 h = 60 min = 3600 s
day	ἡμέρα	d		1 d = 24 h = 1440 min = 86400 s
degree of arc	μοῖρα ἐκ τόξο	°	angle (dimensionless unit)	1° = (π/180) rad
minute of arc	λεπτό ἐκ τόξο	′		1′ = (1/60)° = (π/10800) rad
second of arc	δευτερόλεπτο ἐκ τόξο	″		1″ = (1/60)′ = (1/3600)° = (π/648000) rad
hectare	ἑκτάριο	ha	area (decimal unit multiple)	1 ha = 100 a = 10000 m2 = 1 hm2
litre	λίτρα	l or L	volume (decimal unit multiple)	1 l = 1 dm3 = 0.001 m3
tonne	τόννη	t	mass (decimal unit multiple)	1 t = 103 kg = 1 Mg

The time and angle units predate the metric systems by many centuries; they are not used with SI prefixes. For the other permitted units, see below.

Also ἑκτάριο should not be used with SI prefixes . Both λίτρα and τόννη, however, may have SI prefixes; see below.

4.2 Tables of area, volume and mass with standard SI units and allowable alternatives.

The officially accepted units λίτρα and τόννη may be used with SI prefixes. However, while λίτρα may be used with any SI prefix, τόννη will not, for fairly obvious reasons, be used with prefixes denoting fractions but only with multiplicative prefixes. As for ἑκτάριο, this is never used with SI prefixes but be treated as an non-compoundable word just like κιλό. See the tables below.

Note: in the ancient language, both λίτρα and τόννη ended in long vowels; so both words retain the accent on the penultimate syllable and do not 'throw it back' onto the prefix as, for example, μέτρο does.

 
Table 1 - Area.

Multiple of square metres	Symbol	Name		Equivalent area
		English	ΤΑΚΕ	Symbol	English	ΤΑΚΕ
104	ha	hectare	ἑκτάριο	hm2	1 square hectometre	1 τετραγωνικό ἑκατοντάμετρο

Other measurements of area are expressed as square metres (τετραγωνικό μέτρο), square millimetres (τετραγωνικό μιλλίμετρο), square kilometres (τετραγωνικό χιλιάμετρο) etc.
 
Table 2 - Volume (the most commonly used forms are shown in bold).

Multiple/ submultiple of litres	Symbols		Name		Equivalent volume
			English	ΤΑΚΕ	Symbol	English	ΤΑΚΕ
1024 L	Yl	YL	yottalitre	ἰοτταλίτρα	103 Mm3	1000 cubic megametres	1000 κυβικό μεγάμετρο
1021 L	Zl	ZL	zettalitre	ζετταλίτρα	Mm3	1 cubic megametre	1 κυβικό μεγάμετρο
1018 L	El	EL	exalitre	ἐξαλίτρα	106 km3	million cubic kilometres	μέγα κυβικό χιλιάμετρο
1015 L	Pl	PL	petalitre	πεταλίτρα	103 km3	1000 cubic kilometres	1000 κυβικό χιλιάμετρο
1012 L	Tl	TL	teralitre	τεραλίτρα	km3	1 cubic kilometre	1 κυβικό χιλιάμετρο
109 L	Gl	GL	gigalitre	γιγαλίτρα	hm3	1 cubic hectometre	1 κυβικό ἑκατοντάμετρο
106 L	Ml	ML	megalitre	μεγαλίτρα	dam3	1 cubic decametre	1 κυβικό δεκάμετρο
103 L	kl	kL	kilolitre	χιλιαλίτρα	m3	1 cubic metre	1 κυβικό μέτρο
102 L	hl	hL	hectolitre	ἑκατονταλίτρα	102 dm3	100 cubic decimetres	100 κυβικό δεκίμετρο
101 L	dal	daL	decalitre	δεκαλίτρα	101 dm3	10 cubic decimetres	10 κυβικό δεκίμετρο
100 L	l	L	litre	λίτρα	dm3	1 cubic decimetre	1 κυβικό δεκίμετρο
10−1 L	dl	dL	decilitre	δεκιλίτρα	102 cm3	100 cubic centimetres	100 κυβικό κεντίμετρο
10−2 L	cl	cL	centilitre	κεντιλίτρα	101 cm3	ten cubic centimetres	10 κυβικό κεντίμετρο
10−3 L	ml	mL	millilitre	μιλλιλίτρα	cm3	1 cubic centimetre	1 κυβικό κεντίμετρο
10−6 L	µl	µL	microlitre	μικρολίτρα	mm3	1 cubic millimetre	1 κυβικό μιλλίμετρο
10−9 L	nl	nL	nanolitre	νανολίτρα	106 µm3	million cubic micrometres	μέγα κυβικό μικρόμετρο
10−12 L	pl	pL	picolitre	πικολίτρα	103 µm3	1000 cubic micrometres	1000 κυβικό μικρόμετρο
10−15 L	fl	fL	femtolitre	φεμτολίτρα	µm3	1 cubic micrometre	1 κυβικό μικρόμετρο
10−18 L	al	aL	attolitre	ἀττολίτρα	106 nm3	million cubic nanometres	μέγα κυβικό νανόμετρο
10−21 L	zl	zL	zeptolitre	ζεπτολίτρα	103 nm3	1000 cubic nanometres	1000 κυβικό νανόμετρο
10−24 L	yl	yL	yoctolitre	ἰοκτολίτρα	nm3	1 cubic nanometre	1 κυβικό νανόμετρο

 
Table 3 - Mass (also includes κιλό which ΤΑΚΕ allows as an alternative to χιλιαγραμμάριο).

Multiple of grams	Symbol	Name		Equivalent mass
		English	ΤΑΚΕ	Symbol	English	ΤΑΚΕ
103	kg	kilo	κιλό	kg	kilogram	χιλιαγραμμάριο
106	t	tonne	τόννη	Mg	megagram	μεγαγραμμάριο
109	kt	kilotonne	χιλιατόννη	Gg	gigagram	γιγαγραμμάριο
1012	Mt	megatonne	μεγατόννη	Tg	teragram	τεραγραμμάριο
1015	Gt	gigatonne	γιγατόννη	Pg	petagram	πεταγραμμάριο
1018	Tt	teratonne	τερατόννη	Eg	exagram	ἐξαγραμμάριο
1021	Pt	petatonne	πετατόννη	Zg	zettagram	ζετταγραμμάριο
1024	Et	exatonne	ἐξατόννη	Yg	yottagram	ἰοτταγραμμάριο
1027	Zt	zettatonne	ζεττατόννη	103 Yg	1000 yottagrams	1000 ἰοτταγραμμάριο
1030	Yt	yottatonne	ἰοττατόννη	106 Yg	million yottagrams	μέγα ἰοτταγραμμάριο

 

5. Some other units accepted in ΤΑΚΕ

Length

Commonly accepted units of length are the Ångström (which is equal to 0.1 nanometre and is often used to express the sizes of atoms, lengths of chemical bonds, the wavelengths of electromagnetic radiation and the dimensions of parts of integrated circuits) and the nautical mile (which corresponds approximately to one minute of arc of latitude along any meridian and remains in use by sea and air navigators worldwide because of its convenience when working with charts).

The Roman mile was known to the Greeks and was called μίλιον; it was about 1.48 km. In modern times a metric mile of 1.5 km is used in athletics; this is given in the table below. I had been tempted to resurrect the ancient στάδιον but decided not to do so, partly as ancient standards varied so much (anything from 100 m to 190 m) and also because στάδιο will be used in to mean "stadium".

Speed

The knot is a speed of one nautical mile per hour; it is widely used in meteorology, and in maritime and air navigation. The term is derived from counting the number of knots that unspooled from the reel of a wooden board, known as a chip log, in a specific time. In modern Greek the knot is known as κόμβος, which in the ancient language meant "roll, band, girth." ΤΑΚΕ similarly uses this word in the form κόμβο.

Area

The barn is approximately the cross sectional area of a uranium nucleus and is defined as 10⁻²⁸ m² (= 100 fm²) and is used in particle physics. ΤΑΚΕ also uses the ancient plethron with a metric value of 1000 square metres, i.e. a tenth of a hectare. This is the same as the modern Greek στρέμμα. In the ancient language στρέμμα meant "twisted thread; wrench, strain, sprain; conspiracy, band of conspirators." Its use as a term of measurement is not attested before the Byzantine period.

Pressure

Although the SI unit for measuring pressure is, as we saw above, the pascal (πασκάλ), the deprecated measure bar is still commonly used by engineers as using pascals would involve using very large numbers, the bar being equal to 100 kilopascals (100 χιλιάπασκαλ); also the millibar is often used in meteorology instead of the SI hectopascal. The word was introduced by Sir Napier Shaw in 1909 and is derived from the ancient Greek βάρος "weight." In ΤΑΚΕ βάρο, therefore, means "weight", so we simply adopt βάρ for the measurement.

These units are shown in the table below:

Quantity	Symbol	Name		Equivalent mass
		English	ΤΑΚΕ	Symbol	English	ΤΑΚΕ
length	Å	ångström	ἄγγστρεμ	0.1 nm	0.1 nanometre	0.1 νανόμετρο
length	(mi)	metric mile	μετρικό μίλιο	1.5 km	1.5 kilometres	1.5 χιλιάμετρο
length	nm	nautical mile	ναυτικό μίλιο	1852 m	1852 metres	1852 μέτρο
speed	kt	knot	κόμβο	(1852/3600) m/s	1 nautical mile per hour	1 ναυτικό μίλιο καθ᾽ὥρα
area	b	barn	βάρνο	100 fm2	100 square femtometres	100 τετραγωνικό φεμτόμετρο
area	(pl)	plethron	πλέθρο	1000 m2	1000 square metres	1000 τετραγωνικό μέτρο
pressure	bar	bar	βάρ	100 kPa	100 kilopascals	100 χιλιάπασκαλ

As we saw above, the form millibar (μίλλιβαρ) is often used; indeed, ångström (ἄγγστρεμ), barn (βάρνο) and bar (βάρ) may be used with SI prefixes (the ΤΑΚΕ compounds being accented on the third from last syllable). The other measures, i.e. mile (μίλιο), knot (κόμβο) and plethora (πλέθρο) should not be used with SI prefixes.