Boyd's directory of the District of Columbia (1876)
Washington, D.C. : W.H. Boyd · leaf 55
ent the backing in of smoke. In school houses mischievous and thoughtless boys cause much trouble and annoyance by throwing insoluble substances down the hoppers, thereby clogging the traps. To avoid this trouble, water- trough or range closets have been used from w^hich obstructing mat- ters maybe… … The ventilating pipe extends along behind the water trough and communicates therewith by openings equal in number to the number of hoppers. These openings are graded in size by choking, so as to equalize the draft. A movable partition near one end holds the water when closed, and w^hen raised it…
Washington (D.C.) -- Directories
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
