This 1839 description of a 'Vaso cilindrico di piombo' found in Pompei gives its dimensions asAlto palmo uno ed once nove, per palmo uno e once otto di diametro. It seems that at some point the palmo was standardized in Naples at 26,4 cm (http://es.wikipedia.org/wiki/Palmo). Anybody knows what once nove and once otto would be? Thanks very much in advance.
Hi, I cannot say for sure but one "oncia", when directly referred to a prime unit (as "palmo" in your excerpt) should be intended as 1/12 part of that prime misure. So, in your example "palmo uno ed once nove" should be "1.75 palmi" that is 1 palmo + 9/12 palmo. "palmo uno ed once otto" should be approx "1.67 palmi" that's 1 palmo + 8/12 palmo. Anyway these are pretty old standards and are now completely substituted by the MKS system.
TheChabon, see this Wiki article, I quote: Ancient Roman units of length Name Latin name Equivalent Roman value Metric equivalent Digit Inch Palm Foot Digit digitus 1 3⁄4 1⁄4 1⁄16 18.5 mm Inch uncia orpollex 11⁄3 1 1⁄3 1⁄12 24.6 mm Palm palmus minor 4 3 1 1⁄4 74 mm Great palm palmus major 12 9 3 3⁄4 222 mm Foot pes 16 12 4 1 296 mm Foot + palm palmipes 20 15 5 11⁄4 370 mm Cubit cubitus 24 18 6 1 1⁄2 444 mm Metric equivalents are based on the estimated value 1 pes = 296 mm[4]
Thanks very much for both replies. I discovered a whole world I was not remotely aware of. With nine inch 'great palms' he would not have said palmo uno ed once nove but two palms. Soperhaps '1/12 palmo' is what the author was meaning here --or alternatively, the 26,4 cm palm is a 10 inch palm --sometimes engineers and technicians went decimal. If I ever get to any certainty I'll post back.
