at figs. 66 and 67. The former acts partly asa filter, and the latter is merely an adaptation of the trapdrawn at fig. 59. They might prevent the influx of coldair into the cistern. No cistern overflow, even withtraps affixed, should be soldered into a soil-pipe or waste-pipe of any description,… … ^W ? El H a an air-supply post for the drains, and I figure it here,because it will sometimes be found useful. Passing from the interior to the exterior of a houseor public building, we enter upon the necessaryquestion of yard and of road-traps. A good trap for aback-yard is the large-sized trap…
