These later disappeared and the bowls tended to become straighter and more or less cylindrical in shape, getting longer and narrower as time went on.
As the century drew to a close a major change occurred in the shape of the howls.
Oswald in The Evolution and Chronology of English Clay Tobacco Pipes in the Archaeological News Letter (September 1961, Volume 7, Number 3) gives a well illustrated series of dated types.
All of these publications have been freely drawn upon to compile these very brief notes.
Held with the bowl pointing away from the body the initial of his Christian name is often found on the left and that of his surname on the right.
Varieties of this shape lasted throughout most of the 18th century, the later ones being smaller and thinner walled than those made at the beginning of the century.
From about 1650 records become better and for the 18th century most of the manufacturers are known.
As tobacco became cheaper towards the middle of the 17th century, larger and more bulbous bowls came into favour.
He had never found a clay pipe bowl in the debris of a robbed Roman wall (it happened at Springhead) or in the filling of a pit cut into a prehistoric earthwork and wondered when the dark deed had been done.
Over the last twenty years the study and dating of clay pipes has become of increasing value as an aid to the dating of post-medieval sites and later intrusions into earlier sites.
Some useful publications on the dating of clay pipes have appeared in recent years.
The easiest to obtain is that by Adrian Oswald, The Archaeology and Economic History of English Clay Tobacco Pipes, Journal of the British Archaeological Association, (1969), also issued as a reprint.
These had a stepped or spurred foot and were often pinched in and rouletted below the lip.