"Some of the important results obtained in investigations of capacities of plumbing stacks in test systems at the National Bureau of Standards and elsewhere are discussed. Data are shown from experiments on the flow of water and air in such systems, and analyses of certain flow phenomena are given. Methods are shown for applying the results of research in hydraulics and pneumatics to the preparation of loading tables (for drainage and vent stacks) suitable for use in plumbing codes" (p. 1).