Water Resources and Environment. The jurisdiction of the Subcommittee on Water Resources and Environment consists generally of matters relating to water resources development, conservation and management, water pollution control and water infrastructure, and hazardous waste cleanup.
A pennyweight (abbreviated dwt) is a unit of mass that is equal to 24 grains, 1â20 of a troy ounce, 1â240 of a troy pound, approximately 0.054857 avoirdupois ounce and exactly 1.55517384 grams.
In the Middle Ages, a British penny 's weight was literally, as well as monetarily, 1â20 of an ounce and 1â240 of a pound of sterling silver. At that time, the pound in use was the Tower pound (5,400 troy grains).The medieval English pennyweight was thus equal to 32 Tower grains (also known as wheat grains).hat name is derived from the price for a hundred nails in 15th century England: the larger the nail, the higher the cost per hundred. The pennyweight also bears no relation to the weight of the American  penny  (1 cent) coin, which weighs 2.5 g (for those minted after 1982).