The Christmas tree...

It was a contradiction in plumbing that water supply pipes and heating systems (systems that convey clean water) were provided with centralised pipe manifolds that could be inspected whilst drainage systems had no manifold and in addition the different pipes intersected in series by means of the branches arranged behind one another. It’s as if an electrician were to connect the lamps of an apartment in series one behind the other, like the lights on a Christmas tree, in such a way that when one fuses all the ones downstream of it would fuse (when one branch gets blocked the entire system upstream gets blocked).

In addition, it was as if the electric cables were buried under the masonry without sheaths so that future maintenance was impossible. That is exactly how very many drainage systems are made today: the advent of plastics has replaced the old lead pipes with the ubiquitous gully trap that distinguished them and served as a manifold and inspection point for the entire system.

Branches, which are invisible, took the place of the gully trap but that way the drainage pipes became “Christmas trees” without inspection points and were serially connected. And then all types of things were invented for aerating the abomination.