"The most noteworthy development of the open fireplace took place in 1796, when... Count Rumford published... "Chimney Fireplaces." His main contribution was the alleviation of the smoking chimney. One fault... he... asserted, was due to the large chimney throat. Rumford also introduced the inclined fireback, which increased fireplace effeciency by providing... greater . For the purpose of breaking up the current of smoke in the... downdraft, the back smoke shelf of Rumford's improved fireplace ended abruptly—a practice strictly adhered to... to this day."