is not only a traditional, predecimal, British currency denomination but also an old-style, uniquely Scottish measure for a beer’s strength. In the 19th century, it referred to the pretax price of a British barrel (36 UK gal, about 43.2 US gal or 164 l) or a hogshead (54 UK gal, about 64.8 US gal) of ale. In those days, Scottish ales were brewed to a wide range of differing strengths, from a very weak gravity of perhaps 7.5 P (OG 1.030) to a whopping gravity of perhaps 32.5 P (OG 1.130). The stronger the brew, the more it cost, from roughly 60 to 160 shillings. The classic way of making Scottish ales is by the parti-gyle method, which involves boiling and fermenting the early, heavier runnings and the later, weaker runnings of the same mash separately. See parti-gyle. Parti-gyle beers are often blended from two consecutive batches and sometimes from different-strength runnings. The strongest finished ales were often called Scotch ales or Wee Heavy ales; the mid-range brews were called Export ales and the weaker ones Scottish ales or Two-Penny ales. This nomenclature, however, was never applied consistently, and the technical dividing lines that separate the various shillings ratings have always been somewhat fluid. A typical 60-shilling Two-Penny may have a gravity of 7.5°Plato–8.75°Plato (1.030–1.035); a 70-shilling Export 8.75°P–10°P (1.035–1.040); an 80-shilling Export 10°P–13.75°P (1.040–1.055); a 90-shilling Wee Heavy 13.75°P–19.25°P (1.055–1.075); and a 140-shilling outlier 23.75°P–32.5°P (1.095–1.130). Shilling ratings are sometimes denoted by the old currency symbol “/-,” with “80-shilling” becoming “80/-.” The modern drinker, when these antiquated terms are used, simply knows to expect a beer of “normal” strength (4.5% to 5.5% alcohol by volume) to be designated “80 shillings” and something lighter below this number and something heavier above it.