Michael Kuznetsov has left a new comment on your post "The Determinism of Air Conditioning <http://www.lawrencehelm.com/2009/11/determinism-of-air-conditioning.html> ": Lawrence: I find your story to be most fascinating. It manifests how different our worlds are! A story like this would be impossible or even unimaginable in Russia for obvious reasons. Your words: "cut a hole through the wall" have aroused my special interest. Could you tell me what exactly the stuff your walls are made of? What is their thickness? And with what exactly tool your son managed to make a hole in the wall to install the air-conditioner through your study wall. Please satisfy my curiosity! Michael Michael, Good to hear from you again. You write that this couldn’t possibly happen in Russia “for obvious reasons.” Do you mean there are no single-family dwellings in Russia? That would surprise me. Perhaps we have some places like that in the U.S. – where one must live in “flats,” but if one looks away from the cities, then single-family units are going to be common. There will be apartment buildings (for those who must rent) and also condos (that people like to live in for various reasons), also single-family dwellings. Here in the San Jacinto Valley, Single-family dwellings predominate. Older houses might be lath and plaster. Newer construction however, must meet more stringent earthquake standards. California is earthquake prone, so our houses are built to sway rather than break. My house was built in 1998 and has several safety features, my son tells me, that older houses don’t have – a sprinkler system throughout the house, for example, and metal “bands” here and there to reinforce the underlying wooden structure. We have experienced a few earthquakes since we moved here. Typically the dogs will hop up and look about in excitement. I’ve rushed out back with them a time our two and they look about as though looking for whatever it was slammed against the house. But the worst thing that happened was that some books feel off some shelves. I’m guessing that my walls are about six or seven inches thick. In regard to the walls, they are framed with two-by-fours, that is pine that has been cut into 2 inches by 4 inches and then of lengths necessary to the task. The frame goes up according to a pattern to leave openings for windows and doors. A stairwell goes up to the second floor which has pine planking installed on top of a framework. The inside is covered with sheets of “dry wall.” This is a fibrous material that isn’t as strong as wood but can be painted or replaced without too much difficulty. Early construction used “lath and plaster” for the inside. My condo in Garden Grover (where I lived before moving to San Jacinto) had lath and plaster walls. The outside of the walls are covered in, if memory serves me, something like chicken wire and then colored cement is sprayed onto the wire. My son cut this material loose in two segments. They are perhaps an inch thick and very solid. As to the tools my son used, he used a drill to create a hole large enough for a saw blade, and then used a Sawzall to cut through everything. Don’t you have Sawzalls in Russia? http://www.milwaukeetool.com/Sawzall/intro.aspx Lawrence Helm