Dating Clay Pipes by Stem Bore

In the 1950s J. C. Harrington studied thousands of pipe stems excavated at Jamestown and other colonial Virginia sites. He noted a definite relationship between the diameter of the bore (the hole through the stem) and the age of the pipe it came from. Essentially, the diameter decreased as the pipes became more recent – possibly because the stem length was gradually increasing.

Louis Binford later devised a mathematical formula to refine Harrington's dating method and this gives the following table:

9/64 inch bore dates to 1590-1620
8/64 inch bore dates to 1620-1650
7/64 inch bore dates to 1650-1680
6/64 inch bore dates to 1680-1720
5/64 inch bore dates to 1720-1750
4/64 inch bore dates to 1750-1800

This approximate dating technique only definitively applies to pipe stems manufactured in England between about 1590 and 1800 but it might also be a guide for other European pipes.