Petrie knew that styles of pottery seemed to come and go over time--in his case, he noted that some ceramic urns from the graves had handles and others had just stylized ridges in the same location on similarly shaped urns.He assumed that the change in styles was an evolutionary one, and, if you could quantify that change, he surmised it might be used to indicate which cemeteries were older than others.But nowadays we normally use who: This is George, who you met at our house last year.This is George’s brother, who I went to school with.There might be a small number of them (or fragments of them) in the junkyard which stopped taking junk during the first years 78s were invented.You would expect a large number in one closed when 78s were popular and a small number again after 78s were replaced by a different technology.
We don't have historical information about the junkyards--they were illegal dumping areas and no county records have been kept on them.
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.
Archaeologically, you would expect no 78s to be found in a junkyard that was closed before 78s were invented.
Warm air can hold more water vapor than cool air, so a particular amount of water vapor will yield a lower relative humidity in warm air than it does in cool air.
Seriation, also called artifact sequencing, is an early scientific method of relative dating, invented (most likely) by the Egyptologist Sir William Flinders Petrie in the late 19th century.
Petrie was a scientific archaeologist, probably close to our first example.