The gramophone sat in your parlor and certainly couldn't be carried along with you and your earbobs. When 78 rpm records first appeared on the market, they were very rare.When they became popularly available, you could find them everywhere; but then the technology changed and they became rare again. Archaeologists investigate trash, not shop window displays, so we measure things when they are discarded; in this example, we're going to use junkyards.We don't have historical information about the junkyards--they were illegal dumping areas and no county records have been kept on them.For a study we're doing on, say, the availability of music in rural locations during the 20th century, we'd like to know more about the deposits in these illicit junkyards.
Petrie was a scientific archaeologist, probably close to our first example.
It isn't possible to investigate all of a junkyard, so we'll pick a representative sample of the deposit.