If it's a one way system, ie, gas, wherein the material is piped in and then burned, there will be only one hole in the wall. If it's a circulating system, then there will be two, these being for hot water radiator, baseboard or steam heat in order of decreasing probability. But for combustable materials, there has to be a flue, or rather, there should be a flue. Perhaps the adjacent vent cover was the older venting system adapted for the current system? The gas light systems put carbon monoxide directly into the room, seldom with any kind of venting apart from around loose fitting doors and windows as it dispersed.

Lyle Browning


On Dec 11, 2012, at 3:42 PM, Stacy Kozakavich wrote:

> Hi all,
> 
> This is a bit tangential to archaeology as it deals with the old operating systems of an extant house, but I'm sure there will be many people on this list with the experience and expertise to answer this question:
> 
> I'm trying to figure out what a couple of old utility/service connections are in the second-floor bedrooms of a 1911 house in the San Francisco Bay area. 
> 
> Pictures here: https://picasaweb.google.com/105553509479038352556/Utilities?authuser=0&authkey=Gv1sRgCK6Nzfby4rTl0QE&feat=directlink
> 
> I know I *should*  know what these are, but am drawing a blank - they don't quite look like water/steam heat system pipes as they're narrow diameter and there aren't any other traces of past radiators on the walls or floor. They seem too close to the floor to be connections for gas lighting. 
> 
> Anyone recognize these?
> 
> Thanks in advance,
> Stacy Kozakavich
> Oakland, CA