To give an example, Ben Wade was a British manufacturer of pipes since the late 1800s. Obviously there are exceptions and large pipes appear, however many of the older Ben Wade pipes tended to be smaller in comparison to today's pipes. Add to that the shortages of briar caused by back-to-back wars. Many bowls tended to be smaller, and they're useful for someone who has little leisure time and must budget their tobacco.
My guess is that the trend toward increased bowl sizes began in the 50s and was further reinforced by the adoption of styles from abroad, including extravagant Italian and Danish styles. Somehow I can't picture a 19th Century Leeds factory worker smoking a flamboyant Danish Ben Wade "freehand." This is something suggestive of the burgeoning post-war middle class that had a little more time to sit around and a little more money to spend on tobacco. But obviously there were and will always be pipes of every size to suit any purpose or lifestyle.
My guess is that the trend toward increased bowl sizes began in the 50s and was further reinforced by the adoption of styles from abroad, including extravagant Italian and Danish styles. Somehow I can't picture a 19th Century Leeds factory worker smoking a flamboyant Danish Ben Wade "freehand." This is something suggestive of the burgeoning post-war middle class that had a little more time to sit around and a little more money to spend on tobacco. But obviously there were and will always be pipes of every size to suit any purpose or lifestyle.