Paradise ponders... Starting with our last session, my neighbor's kids (Abby and Nicholas) are actually writing programs. I created a little “sandbox” in a browser page for them to play around in. Their first homework assignment was to modify a program I wrote that paints a hollow rectangle to paint a solid rectangle instead. It will be very interesting to see (a) if they managed to do this at all, and (b) how they went about it. We'll be talking about various approaches to this today, and then I'm going to give them a program that paints a solid circle – and their homework will be to paint a hollow one.
Yesterday and the day before at Tim's house, we dug the entire trench with the backhoe without hurting anything. No broken gas lines, especially :) However, there was one short stretch (about five feet) where we knew a power line ran. We knew this because the first time we dug a trench here (last fall) we broke it with the backhoe, making a nice big spark and even some smoke. So this time, we “skinned” the first foot off the top with the backhoe, then dug down carefully by hand, with shovels. Somehow we managed to nick the wire anyway! We were surprised how shallow the wire was, only about an inch under the trench we'd dug with the backhoe. I hit the wire with the tip of my shovel and made a nice spark, and one of us (we're not sure who) scraped a piece of insulation off. The conductor, though, wasn't harmed at all.
Tim knows a local electrician (Curt) who was able to come out later in the day to fix the problem. He cut the wire, threaded a piece of thick heat-shrink tubing over one end, stripped the insulation off an inch of each new end, then crimped on the biggest butt connector I've ever seen. He had an enormous crimping tool that looked like it would crush 1" diameter steel bolts (and maybe it could!). After that, he just pushed the heat-shrink tubing into the right place to cover all the damage we did, then used a torch to shrink it down to size. In no time at all, the entire thing was patched. When you know what you're doing, and have the right parts and tools, seemingly difficult problems can made into tiny ones.
Speaking of which, one of the things Tim needed to do to install his new pump wiring was to drill a 1.5" diameter hole through his foundation, about 18" below ground level. We'd dug the dirt away from his foundation to expose the right place for the hole, but to do the drilling time hired a fellow (Ed) he knows. Ed had the right tools: a small but very powerful electric drill motor with a water inlet, and a collection of industrial diamond-tipped drill bits. The water inlet on the drill dribbled a constant flow of water into the inside of the drill bit, cooling it down (especially at the biting end). It took him about 15 minutes to set up, then about 4 minutes to actually drill a perfect, smooth hole through 12" of concrete. I have an impact drill that can make such holes, but I know from hard experience that it would have taken me much longer, I had a good chance of being stopped by a rock (the diamond blade goes right through them), and the hole would have been only very roughly round. Also the noise of the impact drill is awful, while Ed's diamond bit was no noisier than an ordinary wood drill bit. The nice hole it produced made it trivial to insert a piece of PVC pipe (to protect the cable from rubbing on the concrete).
Later today, after I've finished the kids' lesson for the week, I'm heading over to my neighbor Alan L.'s house to do some backhoe work. He's got some big shrubs that need to come out, and the idea of hand-digging them he found intimidating for some reason :)