Chapter IV: Volume – More Than Just Space
In the realm of volumes, our story begins in the kitchens and markets of the ancient world. Whether it’s the baker kneading dough for bread, a merchant selling oil, or a winemaker storing his new vintage, volume plays a vital role. Each, in their way, a cook’s scoop, a potter’s jar, or a farmer’s basket held the seeds of the concept of volume.
Ancient Times and the Middle Ages
Tracing back to 3000 BCE, the Sumerians in ancient Mesopotamia used “gur”, “bariga”, and ‘ban’ as volume units. Meanwhile, in ancient Rome, volumes were measured in “amphorae” and “sextarii”. An amphora was a two-handled pot with a narrow neck, typically used for storing wine, oil, or grains. A sextarius, on the other hand, was a small unit, equivalent to about one pint in the modern-day UK system.
As with length and weight, the Middle Ages saw a variety of volume measures. Ale was sold in “firkins” and “kilderkins”, butter in “firkins”, and wine, oil, and honey in “tuns”. In many cases, these measurements were linked to weight. A firkin of butter, for instance, weighed 56 pounds, which is approximately 25.4 kg. The term “tun” shares an etymological connection with the unit of mass “ton”. Interestingly, the mass of a tun of wine aligns closely with a long ton, which is quantified as 2240 pounds or approximately 1016 kilograms. Yet, these measurements were anything but universal and varied from one commodity, region, or period to another.
The French Revolution
The French Revolution overhauled the political landscape, bringing sweeping changes to the world of measurement. It gave birth to the “liter”, defined as one cubic decimeter and later redefined as the volume of one kilogram of water, continuing the French quest for standardization and simplicity.
The Fluid Ounce Story
The term “fluid ounce” originates from measurements used in the British Imperial and American customary systems. The term’s etymology can be broken down into two components: “fluid” and “ounce.”
- “Fluid” comes from the Latin word “fluidus”, which means flowing or liquid. In the context of measurements, “fluid” refers to a measurement of volume, not weight. This distinguishes fluid ounces from ounces as units of weight.
- “Ounce”: The term “ounce” is derived from the Latin word “uncia, which was a unit that was one-twelfth of the Roman pound (“libra”). The word came into English through Anglo-Norman French, where “once” was a unit of weight.
A “fluid ounce” is a unit of volume that is approximately equivalent to the volume of one avoirdupois ounce of water at standard temperature and pressure, depending on the system used (US customary vs. Imperial). This volume-weight connection is not precise and varies with temperature, but it’s the origin of why the term “ounce” is used in both contexts.
The precise definition of a fluid ounce varies:
- In the British Imperial System, one fluid ounce equals 1/160th of an imperial gallon, 1/20th of an imperial pint, or exactly 28.4130625 milliliters (ml).
- In the American customary system, one fluid ounce equals 1/128th of a U.S. gallon, 1/16th of a U.S. pint, or approximately 29.5735297 milliliters (ml).
The Pint Story
A pint is a unit of volume or capacity used in the United States, the United Kingdom, and other countries. It’s worth noting that the exact value of a pint varies between these two measurement systems:
- In the U.S. customary system, one pint equals 1/8th of a U.S. gallon, 2 U.S. cups, or 16 U.S. fluid ounces, approximately 473.176 milliliters.
- In the British Imperial system, one pint equals 1/8th of an Imperial gallon, or 20 Imperial fluid ounces, precisely 568.26125 milliliters.
The term “pint” originates from the Old French word “pinte”, which in turn came from Latin “pincta” meaning “painted,” for marks painted on the side of a container to denote capacity.
These systems originated from traditional measurement systems that were used before the widespread adoption of the metric system. Even though the metric system is now used in most countries, the pint and other non-metric units are still commonly used in specific contexts, such as serving beer in the UK (Imperial pint) and measuring ingredients in U.S. recipes (U.S. pint).
Ah, the british imperial system! it was a bit of a shock when I, a german used to the metric system, walked into an english pub and asked for a half-liter of ale. the barman’s bemused “Don’t you mean a pint, mate?” still makes me chuckle. a pint, you see, isn’t a neat 500 milliliters but about 568. It’s an amusing puzzle and part of the charm when in britain. ultimately, it’s not about the exact measure but the universal cheer a good beer brings. so, Prosi! To the joy of shared differences and a well-poured pint!
Lukas
Nowadays
Today, the liter, along with its derivatives such as milliliters and cubic meters, is used universally in science and is standard in most countries. However, the United States still holds onto its customary system, where liquid volume is measured in fluid ounces, cups, pints, quarts, and gallons. Interestingly, a U.S. gallon is smaller than a U.K. gallon, reminding us of the inherent charm and idiosyncrasy of the world of measurement.
Volume measurement, whether in amphorae, firkins, or liters, goes beyond practical purposes. It tells the story of human civilization, our relationship with commodities, and our quest for standardization. From the ancient potter crafting his jars to the modern scientist calibrating her lab equipment, the volume measure is a testament to human ingenuity and our desire to shape and understand the world.
