Two hundred and eighty quinariæ

That’s what Attilius gets to hear from his “overseer” Gavius Corax when he asks on page 49 of Robert Harris’s “Pompeii”:
 ‘What’s the capacity of the Piscina?’
 ‘Two hundred and eighty Quinariæ.’ 
   Now the Piscina was not a swimming pool, as modern Italian would lead us to believe, and not (just) a basin or fishes, as the name would suggest (pisces = fishes). This was the Piscina Mirabilis. It was a well closed water tank, a cistern of 12600 or 10700¹) m³ – sources differ – for potable water at the North end of the bay of Naples, back in A.D. 79 (v.Chr.), at the end of the Roman aquæduct Aqua Augusta.
   And then he tells us “that one quinaria was roughly the daily requirement of two hundred people.”
   Stragely enough for such a precise author as Harris, he does not tell us more – or modern details. The Roman Empire (like Austria) entered the Metre Convention only in 1875, the US in 1878. But that would not have helped us. Tubes all over the world are measured in inches, still today.
   As mimilar measure was the quirinaria. If you google quirinaria, you don’t even find a sensible translation. 

   But you find money: a not too pupular coin, worth half a dinar, also called Victorinatus, named from Quini and Æs, quini is five and æs stands for Asses. A Quinarius was worth 5 asses. The value imprinted was either a Q or a V, apparently even then the sign of Victorianus (Source). But let’s not follow this route.
   Quirinaria today are stories from the Italian parliament, the Quirinale. No good either.

The Aqua Augusta today, « Ponti Rossi », lit. red bridges) crossing via Nicola Nicolini ca. number 55 in Naples at   40.87262,14.265361, near the airport · Foto Baku, Wilipedia, part

So? Back in 1820 they still knew what at least Carl Friedrich Quednow, here: “Frontin thinks that Quirinaria must have been tubes, made from four individual tubes together”, 

Carl Friedrich Quednow, Beschreibung der Alterthümer in Trier … 1820.

Plinius had specified that a Quirinaria was a tube from sheet measuring five inch in width. Frontin said Quirinaria were tubes out of five quarter tubes. Read yourself. Quednow continues i telling us that the Romans had altogether 25 types of tubes, Quirinariæ were the smallest and the Centinovicenæ the largest.

Here, 1842: “The quinaria is equivalent to about 2000 cubic feet, of about 7 gallons each.” – Anyone understands that? Source must be:
De aquaeductu urbis Romae by Sextus Iulius Frontinus, named “Curator Aquarum” in 97 after Christ, by Imperator Nerva. Here, 2017: « Roma era servita da 9 acquedotti (poi 11) e che la portata era stimata in 24.360 “Quirinarie” al secondo, pari a 1.010.623 metri cubi al giorno: una disponibilità pro-capite doppia di quella attuale! ». 1,010,623 m³/day ÷ 24,360 quirinariæ = 41.5 m³/quirinaria. Or: 1 quirinaria = 41.5 m³, if applied for a day. During a second that would be 0.48 litres. See below.

« Il Triomfo dell’acqua », the triuph of water, an exhibition catalog of 1987, here scecifies quirinaliæ as water flow: 0.47 to 0.48 litres/second. However here: “ … no unanimity exists for the value of the quinaria.” – “ … the Romans were not capable of calculating exactly the volume of flowing water.”

(From here.) 5000 to 6000 gallons = 19 to over 20 m³

Iside a Roman Cisterne, like the Piscina Mirabilis.
Panorama picture. Istanbul, June 2014. Foto Jörn

   Links: 
Pompeii by Harris
Quinaria in Wikipedia
Aqua Augusta: 
   https://en.wikipedia.org/wiki/Aqua_Augusta_(Naples)
(1) Aqua Augusta – Serino (Italy)    
   http://www.romanaqueducts.info/aquasite/serino2/index.html  
   with this map of the piscina mirablis, explained there:

The Piscina Mirabilis at Misenum, “well preserved”:
   https://en.wikipedia.org/wiki/Piscina_Mirabilis 
List of Roman Aquæducts:
   https://en.wikipedia.org/wiki/List_of_aqueducts_in_the_Roman_Empire 
Aqeducts
   https://en.wikipedia.org/wiki/Roman_engineering#Aqueducts

Tullia Ritti, Klaus Grewe, Paul Kessener: "A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications", Journal of Roman Archaeology, Vol. 20 (2007), pp. 138–163 (148, fig. 10) · Wikipedia · “Dating to the second half of the 3rd century AD,^[5] the sawmill is the earliest known machine to combine a crank with a connecting rod.^[6]”

I found a critical article on Fontinus and those who tried to make sense of quinariæ by Harward Professor M. H. Morgan of 1902, here. Prof. Morgan could not have known that Americans, messing up metric and non-metric measurements, would loose a 125 Million Dollar Mars probe in 1999, or else he might have approached the issue more carefully.

Permalink to here: http://j.mp/2thHVFw =
   https://blogabissl.blogspot.com/2018/03/two-hundred-and-eighty-quirinari.html

Nasa’s view into the eye of Vesuvius. (Source)

One of the most concise studies on Fontninus you find here:

Marcus Agrippa

http://penelope.uchicago.edu/~grout/encyclopaedia_romana/romanforum/quinaria.html
   On a single stylish page with brown background “The Quinaria and Fontinus” are subject of thoughts and calculations, based on Fontinus. Worth a thorough look.
   This is part of the fine
 “Encyclopædia Romana” by James Grout, see here.