British currency prior to the 1970sfarthing – the smallest coinage = 1/4 penny
halfpenny (pronounced “hay-pinee”.) = 1/2 penny
penny – (in conjunction with other denominations is called “pence”.)
threepenny (thruh-pence) = three pennies
sixpence = six pennies
shilling 12 pence (1/20 pound sterling) in slang a “bob.”
two shillings = 24 pence (1/10 pound sterling)
two and six. — two shillings plus sixpence = 30 pence
five shillings – 60 pence (called a Crown)
one pound = 240 pence = 20 shillings (called a “sovereign”; a slang expression was “quid) = £
guinea = 1 pound plus one shilling
All of prices in Thank Goodness You’re Here are in bob (bob is the plural of bob). 1/20th of a pound is not as awkward as I thought. Guineas, which are mentioned throughout Jonathan Strange and Mr. Norrell, are 21/20ths of a pound.