27¹¹/₃₂ _grains_ are 1 _dram_ 1 dr. 6 _drams_, or _drachms_ 1 _ounce_[41] 1 oz. 16 _ounces_ 1 _pound_ 1 lb. 28 _pounds_ 1 _quarter_ 1 qr. 4 _quarters_ 1 _hundred-weight_ 1 cwt. 20 _hundred-weight_ 1 _ton_ 1 ton. [41] It is more common to divide the ounce into four quarters than into sixteen drams. The pound averdupois contains 7000 grains. A cubic foot of water weighs 62·3210606 pounds averdupois, or 997·1369691 ounces. For the precious metals and for medicines, the pound troy, containing 5760 grains, is used, but is differently divided in the two cases. The measures are as follow: TROY WEIGHT. 24 _grains_ are 1 _pennyweight_ 1 dwt. 20 _pennyweights_ 1 _ounce_ 1 oz. 12 _ounces_ 1 _pound_ 1 lb. The pound troy contains 5760 grains. A cubic foot of water weighs 75·7374 pounds troy, or 908·8488 ounces. APOTHECARIES’ WEIGHT. 20 _grains_ are 1 _scruple_ ℈ 3 _scruples_ 1 _dram_ ʒ 8 _drams_ 1 _ounce_ ℥ 12 _ounces_ 1 _pound_ lb 218. The standard coins of copper, silver, and gold, are,--the penny, which is 10⅔ drams of copper; the shilling, which weighs 3 pennyweights 15 grains, of which 3 parts out of 40 are alloy, and the rest pure silver; and the sovereign, weighing 5 pennyweights and 3¼ grains, of which 1 part out of 12 is copper, and the rest pure gold. MEASURES OF MONEY. The lowest coin is a farthing, which is marked thus, ¼, being one fourth of a penny. 2 _farthings_ are 1 _halfpenny_ ½_d_. 2 _halfpence_ 1 _penny_ 1_d_. 12 _pence_ 1 _shilling_ 1_s_. 20 _shillings_ 1 _pound_[42] or _sovereign_ £1 21 _shillings_ 1 _guinea_.[43] 219. When any quantity is made up of several others, expressed in different units, such as £1. 14. 6, or 2cwt. 1qr. 3lbs., it is called a _compound quantity_. From these tables it is evident that any compound quantity of any substance can be measured in several different ways. For example, the sum of money which we call five pounds four shillings is also 104 shillings, or 1248 pence, or 4992 farthings. It is easy to reduce any quantity from one of these measurements to another; and the following examples will be sufficient to shew how to apply the same process, usually called REDUCTION, to all sorts of quantities. I. How many farthings are there in £18. 12. 6¾?[44] [42] The English pound is generally called a _pound sterling_, which distinguishes it from the weight called a pound, and also from foreign coins.