Seeking to preserve compatibility with other countries, the units of mass are based on the troy grain. 1 pound equals 7680 troy grains, or around 497•65632 grammes, making it heavier than the Imperial pound. One avoirdupois pound is around 91% of a Hambrian pound, weighing 7000 grains. 1 ounce equals 480 grains, or around 31•10352 grammes. The troy pound is the same as normal, being 5670 grains. 16 drachms make 1 ounce. 30 grains make 1 drachm. 16 ounces make a Hambrian pound. 14 pounds make a stone. 2 stones make a quarter. 4 quarters make a hundredweight. 20 hundredweight make a ton. 2240 pounds make a ton.
The units of length are officially derived from a standard pound, the New Royal Catherine Standard Pound, manufactured in 1937 in response to the danger posed by WW2. It replaced the Royal Catherine Standard Pound manufactured in 1783. It can also be checked from mass. 1¼ inches cubed of pure water weighs one ounce at 60°F, upon the pedestal at Woolhill Square at atmospheric pressure. This is approximately 1•95 cubic inches. Therefore, 2 and 61 cubic ganes and cubic poppyseeds respectively (7/64 cubic inches) of water weigh exactly one drachm at 60°F at the place above. One yard is the base unit of length. It equals approximately around 90•5723566718 centimetres. It is divided into three feet, which are around 30•1907855573 centimetres long each. One feet equals twelve inches, which is around 2•51589879644 centimetres. One inch is equal to three barleycorns. One barleycorn is equal to four poppyseeds. One barleyseed equals 16 ganes. Four ganes equal one poppyseed. 80 thrippings make one gane. There are 3840 thrippings in an inch. Smaller sizes are denoted via fractions of the thripping or sometimes, in decimals. On the other end of the spectrum, 1760 yards make a standard mile, around 1.59407 kilometres. One eighth of a mile is a furlong, which is divided into ten chains. One chain is 22 yards, 66 feet and 4 perches. One perch is 5½ yards. There are also other rarely used measurements such as the league (3 miles) or a pace (30 inches). The Catherinian lengths are therefore slightly shorter than those of the Imperial or US Customary system though not by a lot.
The unit of force is equal to the unit of mass at Woolhill Square. Pound-force is defined as the force needed to accelerate a mass of one pound at the speed of gravity. Similarly, ounce-force is the force needed to accelerate a mass of one ounce at the speed of gravity. Therefore, 1 pound-force is around 4•88399912448 newtons. One ounce-force is around 0.30524994528 N.
The units of volume are based on the units of mass and length. One fluid ounce is the volume occupied by one ounce mass or 1¼ inches cubed of pure water. One gill is five fluid ounces. One pint is four gills, and one quart two pints. I gallon is four quarts. 1 gallon of pure water weighs 10 lb, and occupies around 6•786 inches cubed, or exactly 312½ cubic inches.
The unit of cycles per second is known as a cycond, a portmanteau of 'cycle per second'. One cycle per second is known as one cycond. 20 cyconds make 1 drone. 800 drones make 1 lepson. 1 lepson is exactly 1600 Hz. An average person's hearing range is 1 drone to 1 lepson.
Electric units
Electric units were adopted in the late 19th century with the discovery of the principles of electricity. Electric units are named according to the apothecary’s system with apothecary divisions, though is based upon the Hambrian pound.
The unit of current is the power pound, which is the energy required to create a force of 1 Hambrian pound-force per foot in two parallel wires 1 inch apart. This is approximately 1426•5341339063 ampere. Evidently, this is far too large to be useful for most applications. Therefore, it is divided into the power ounce, power drachm and power grain. 12 power ounces make a power pound, therefore being approximately 118•877844492 A. One power drachm is one eighth of a power ounce, and is approximately 14•8597305615 A. A power scruple is a third of a power drachm, and is around 4•95324352051 A. Finally, 1 power grain is a twentieth of a power scruple, and is approximately 0•247662176025 A. The power grain, scruple and drachm are probably the most widely used units, as the power pound and all units above it, such as the power stone, power quarter or power hundredweight are far too large to consider. Current smaller than a power grain are expressed in fractions of, or sometimes, in decimals. The symbols for power is ‘u-‘, which stands for the Latin, ‘vis’, meaning power. Thus, ‘u℔’, ‘u℥’, ‘uʒ’, ‘u℈’ and ‘ugr’.
Other derived electric units are not mentioned here.
Other units include the caldorpound, the light produced from a standard pure beeswax candle weighing 1 pound , 8 inches high with a radius of 1 inch, burning at a rate of 2½ ounces per hour.
