Ounces and Pounds

 

There's an old riddle that goes "Which weighs more, an ounce of feathers or an ounce of gold?" and the accepted answer is that they both weigh the same.

Except that they don't.

An ounce of feathers weighs the same as an ounce of bread or an ounce of balsa wood, but an ounce of gold is heavier.  The reason is that feathers and bread and balsa wood are weighed using the Avoirdupois scale, and gold is measured on the Troy scale.

An Avoirdupois ounce is 437.5 grains (28.35g), but a Troy ounce is 480 grains (31.10g).  An ounce of any precious metal is 42.5 grains heavier than any non-metal because the two things are measured on different scales.

Pounds are something else.  An Avoirdupois pound is 16 Avoirdupois ounces, 7,000 grains, 453.6 grams, but a Troy pound is only 12 Troy ounces, 5,760 grains, 373.24 grams.

Oddly, while an ounce of gold may be heavier than an ounce of feathers, a pound of feathers is heavier (by 80g) than a pound of gold.

—==+++==—

Update:   Thanks to Jim Pruitt for the correction.  This originally said 'lead', but Jim points out that the Troy scale is used only for precious metals and like substances such as gems, so I changed 'lead' into 'gold'.  Hot dog, I'm an alchemist!