• Category Archives looking back

  • As in “looking back in time,” things which have a historical connection.

  • CADOP5

    Posted on by Don

    Happy Ides of March! Watch your backs, and remember: the day ain’t over ’til it’s over…

    I took a graduate-level computer-aided design course in college — way back when CAD/CAM/CAE was really not a consumer-grade product — and a good part of the course was about optimization. I happened to think about that the other day when I was idly browsing through various Python modules (the way one does), and I ran across a genetic algorithm package.

    Genetic algorithms had their own vogue a few decades back, but that long-ago was long after I left college. Still, playing with it got me to reminiscing about the the things we did way back in school, and about the program we used and our professor (Dr Michael Pappas, who was its author), so I Googled him and the program.

    Dr Pappas passed away in 2015 — I found his obituary. He was a major player in the computer-aided and biomedical engineering worlds, and was the co-inventor of the artificial knee, among other things. I knew he was a big deal back in the day, but I guess I never realized how big a deal he was. (He had a pronounced limp and a seriously deformed back/hip, so I suspect he had some skin in the artificial joint game.) He was fairly intense, and was one of those guys who always seemed on the edge of blowing his stack, though in fact he was always decent and patient with us students. That was one of my all-time favorite classes…

    The optimization program itself was called CADOP5; it was written in FORTRAN and it was a bear to use. (I remember him telling us, at the start of the course, that we needed to start working now on our optimization project, because it couldn’t be finished in a day, or a week, or even two weeks… I was probably the only one in the class to get an A on the project, and I wasn’t even able to find the optimum solution — though I was able to say why.) When I searched for CADOP5, I didn’t find much except this thesis at NJIT. The program given in that paper was a refinement called CADOP8; I might have met the student working on it at some point, but he had his PhD by the time I took the course with Dr Pappas.

    I really did like that class a lot, and its professor, and in fact tried to get Dr Pappas as my thesis advisor, but I got some behind-the-scenes stonewalling from one of his other students/assistants (it took naive me about a year to realize that maybe I’d been undermined), so did my thesis on linkages under Dr Sodhi, and the rest is history — or at least, water under the bridge.

    Back to the Python genetic algorithm: I downloaded it and wrote a little program to test it. It was amazingly easy to use, like all things Python, but it seemed pretty slow to me. (High computation cost? Slow convergence? No idea.) There are many other optimization critters out there in the Python ecosystem, I wonder how they would stack up against that one particular genetic algorithm module, or against those ancient CADOP programs for that matter.

    Anyway, something from the Wayback Machine: this and this are what I was writing fifteen years ago, maybe a month or so before I met Anne.


    looking back tech talk

  • The Corliss Comes Alive

    Posted on by Don

    Happy Pi Day! Here is that post about the steam engines.

    The National Museum of Industrial History has a few gigantic, spectacularly beautiful old restored steam engines, some of them even in operating order. I’ve seen the steam exhibit before, but I have been meaning to go back to the museum to see it again, because my friend Donna’s father just helped restore a new one they got. (George is a retired woodworker and very handy.)

    That new, and newly restored, addition to their collection is a Colt-Baxter “portable steam engine,” patented by a guy named Baxter and manufactured by Colt Firearms as a way to diversify after the Civil War. The Baxter was “portable” in the sense that it was only as big as a big barrel rather than building-sized; it ran at about 15 psi steam pressure and put out about 10 horsepower, was built to run a belt drive, and was ideal for powering small factories, machine shops etc — they sold maybe 300,000 of them over the years. (I learned all this at the Museum on Sunday, and on the Internet yesterday…)

    The museum had a demo day Sunday, where they would power up their Corliss engine — the biggest steam engine they have, and beautifully restored — using compressed air. I figured I’d kill three birds with one stone by riding the Iguana over for a test ride, watching the Corliss in action, and seeing the new Baxter engine on display.

    Here’s a video I made of the Corliss:

    At about 19 seconds into the video you can see what makes a Corliss engine a Corliss: the spider-web of levers running off a central rotating plate are what control the steam valves that feed the pistons. This engine was used to run a water pump; I’m pretty sure that the black part (the front) is the steam engine end, and the green part at the back is the water pump.

    And, here are a few photos I took of the Baxter:

    Colt-Baxter Steam Engine

    (Along the wall in the background, you can see some belt-driven machines on loan from the Smithsonian, drills and lathes and such, that the Baxter would have powered.) The Baxter had its own furnace/boiler built into the lower section, with the piston inside the top of the “barrel” and the bulk of the machinery on top.

    Baxter Engine Top Front
    Baxter Engine Top Rear

    The museum had a few other exhibits, including a few small model engines running, as part of the demo, and one final surprise for me: the Baxter engine was operational! They didn’t have a fire running inside it, it was all compressed air like the Corliss, but here is a video of the operator starting it up:

    In all, a banner day!


    looking back tech talk 📎and tagged

  • Sandy, Ten Years On

    Posted on by Don

    Here’s a link to what I wrote on this date, ten years ago. Emmi was visiting that week; here’s a photo of her with her nemesis: Alanthus.

    Emmi Triumphant

    We were without power for about a week after Sandy, maybe even a little longer, and there was a lot of tree damage in the area, but we personally had no tree, or roof, or any other property damage — we got off lucky.

    Here in the present it’s a bit cloudy and drizzly, and we just got back from a morning of routine doctor visits.

    Meantime, we’ve had an ant infestation over the past few days, probably as a response to the changing weather. I tried using a commercial anti-ant product on them but no luck, so yesterday I put together some internet/DIY ant bait (sugar water with borax on strategically-placed cotton balls), and it wiped them out in a day.

    And one final bit of news: I am temporarily without a cello — it’s in the shop getting some bridge work done, and while it’s there I’m also getting both my bows re-haired. (Everything should be done by tomorrow.)

    It’s a quiet autumn day, but things are moving along…


    day by day looking back

  • Meniolagomeka

    Posted on by Don
    Meniolagomeka Memorial Stone

    Meniolagomeka (“fat land in the midst of scarcity”) was a small Lenape village near what is now Kunkletown, on the banks of the Aquashikola Creek just north of Blue Mountain at Smith’s Gap. The Moravians had converted many in the village, and eventually founded a mission station there, but some time after the Walking Purchase the natives were evicted by the colonial authorities, and the Moravians relocated them to Gnadenhuetten (Lehighton). The actual location was pretty much forgotten for a century, until the Moravian Historical Society rediscovered it and put up this memorial marker.

    The village is not far off the route of one of the more iconic local bike rides — among my crowd anyway; it’s part of the old Gap Gallop century ride, crossing Blue Mountain at Little Gap and returning via Wind Gap a dozen or so miles further down the ridge — but I had no idea anything like this was here until recently. After the week of kitchen disasters we just had, Anne and I both needed a big ride, so even though the Blue Mountain route doesn’t really follow many native paths, and the Meniolagomeka site does not figure prominently in my Native Paths project, I thought it would be neat to do the ride, and make an effort to find the old memorial stone.

    So that was the ride we did on Friday, with our friend Dwight H.

    Our ride took us up Township Line Road, through Bath and Moore Township, and out to Danielsville via the little roads that run south of the mountain. Blue Mountain Drive was being repaved and was down to one lane the whole way to the top, but the construction guys gave us some traffic assistance (and an audience) for the climb. We regrouped at the top, then bombed down the hill, past the ski resort and made the right onto Smith Gap Road.

    The memorial is on a road called Chestnut Ridge Road, a turn off Smith Gap Road (and pretty much at Smith Gap). We turned off our route, spent some time admiring Aquashikola Creek, and then rode a few hundred yards up the hill and found the stone — it was at the edge of a field, on what looked like private property but close to and easily visible from the road. We stopped, took some pictures and paid our respects, and then continued on our way. (We heard thunder so we weren’t sticking around.)

    The rest of the ride was pretty uneventful, though we did get caught in a storm cell (a little cold rain actually felt good), and we also stopped at the “Snoopy Barn,” where Dwight took a few selfies. All told, we got in about 67 miles in just over seven hours. (I took about a mile off the beginning and end of the ride on my map, to preserve some privacy.)


    looking back the sporting life 📎and tagged

  • Indian Paths Update

    Posted on by Don

    I’m still cruising along on this project: I’ve got just over 110 paths in the database (of maybe 150 total), about 130 towns or other path endpoints, and 92 motorway routes. I have added no actual paths yet, but the motor routes are starting to look like a real network.

    My current plan is to parse the book three times: once (this time around) to capture the paths, path endpoints, and motor routes; once (the final, and probably most difficult, round) to try and develop the original foot paths; and in between these rounds I will go through the paths/chapters and try to capture all the cross-references between them.

    I noticed early on that there were a lot of things like “this is an extension of that other path,” “so-and-so path also goes by this name,” “this path intersects with these others,” and such like throughout the text; the path descriptions are festooned with these kinds of cross-references.

    (I also finally picked up on the fact that paths without a path/chapter number are not actually part of the previous chapter, but are basically “chapterless,” just the next path name in alphabetical order. They act sort of as placeholders, the alternate names of other, more fully fleshed-out paths — that is, more cross-references.)

    I want to hold on to all this cross-reference information in my database, so I set up a bridge table to work something like a resource description framework, with the referring path as the subject, the referenced path as the object, and for the predicate I would use a description of the relationship type, such as “[subject path] is a continuation of [object path],” “[object path’s name] is an alternate name for [subject path],” “for more info see [object],” and so on. I now have all of this set up and ready to go, but before filling it in with information I want to have all the paths already in the database. Soon…

    Meanwhile, the details, of each path or town I add, have all been real eye-openers. I often do a little internet research on each town, or village, or Native name I come across, and each bit of info, each piece of the puzzle is another portal into that era.


    looking back tech talk 📎and tagged

  • Native Paths Update

    Posted on by Don

    I kept at it, and am now about a quarter of the way through the trails — the motorway parts, at least — in my Indian Paths of Pennsylvania project. I have a pretty good idea of how the book is organized now, and came up with a pretty decent workflow that gets me through a single path in just under an hour. I do one or two a day. It’s pretty easy to get absorbed, trying to find the tiny old roads and landmarks based on their descriptions in the book, and I’ve been totally sucked into the history of that Colonial-Revolutionary era. (I picked up Mason & Dixon again, since it goes right through the middle of that time and place.)

    I also think there will be some epic rides this summer, based on these routes — I’ve been drooling over some of the scenes I see in Google Street View.


    day by day looking back tech talk 📎and tagged

  • Foiled Again!

    Posted on by Don

    I have a love-hate relationship with Paul A. W. Wallace’s Indian Paths of Pennsylvania. I love reading the individual chapters on each path — their descriptions, and the accounts of them in the letters and diary entries of early Colonial explorers, but any hard look at the specifics and the trails themselves become frustratingly vague. This is all the more frustrating because the information looks specific and authoritative enough, until you take that close look…

    Some of this is because the original information is vague — nobody was tracking their steps with a GPS back then — so the actual trail location is not perfectly known, and partly it’s because the trails themselves are long gone (though some are at least partly followed by modern roads), so it’s hard to search them out without trespassing, but there also just seems to be some missing ingredient needed to define a trail network.

    A few years ago I thought that this last part could be solved with a little bit of GIS detective work, so I started a QGIS project to define the trails and see about building a network, but I sort of ran out of steam — I basically foundered on the vagueness of the trail descriptions. I did one or two in the Lehigh Valley, and realized that the sleuthing needed was a lot more laborious than simple data entry, and the project languished after those first few paths.

    I was thinking about all this again recently, and realized that there is a critical first step I ignored: the book serves primarily as an automotive guide, with detailed instructions for driving in the vicinity of each path. I also thought that if I broke the task down to a set of database tables, I could link these auto routes to their various paths and book chapters . (Some trail chapters actually describe multiple trails and subtrails, while some motorway descriptions continue across multiple chapters, so many-to-many relationships abound but that’s what databases are for. Furthermore, most of the trail chapters have a start and an endpoint, yet more data I can use to cross reference.)

    This scheme fell apart within the first few trails. The very first trail, the “Allegheny Path,” has Philadelphia as the start point and “Pittsburg and Kittanning” as the endpoint — so which is the endpoint? Apparently neither, because the trail is only described as far as Harrisburg; the “Allegheny Path” chapter ends with references to several other trails (different chapters, in other words) heading West from Harrisburg as possible continuations. So OK, I can deal with this: my endpoints are really Philadelphia and Harrisburg, and I’ll stuff the rest of the info into my “description” column. (There is a second path listed in that first chapter, but it is little more than a historical aside and a reference to another path/chapter. This is going to get tricky.)

    Luckily the motorway for the Allegheny Path is easy to follow. I used an open routing plugin to follow along a bunch of control points, and voilá I had my linestring. This ain’t so bad!

    The very next chapter, I ran into motorway difficulties: the route description made no sense. Either the routes were not prepared with adequate ground-truthing (unlikely, though I was starting to feel uncharitable), or the roads (and their designations) had changed at some point in the 55 years since the book came out. This seems the more likely explanation, since I-80 goes right through the area in question, was only finished in 1970, and probably changed a lot of things in its wake. I actually found the Wikipedia article on the Bald Eagle Creek Path more useful.

    So I’m back to deciphering and making judgement calls rather than strictly converting the information from one format to another, even for these road descriptions. I didn’t expect this project to be done in an afternoon, or even a week or so, but “going to take forever because I’m not really working on it” is now closer to my expectation.

    (Note: I found that someone already took these paths and put them into a GIS, but it’s on PA-Share and that’s proved difficult to work with — and deliberately limited, unless you pay — so far. We’ll see…)


    looking back tech talk 📎and tagged

  • Another Milestone

    Posted on by Don

    I ran across this entry the other day on my old blog: it was ten years ago today that we had our first (non-test) firing of the wood-fired oven. The oven is in pretty rough shape right now, we haven’t used it more than a year — it’s something we usually do for parties (the same is true for brewing beer) and we haven’t had a party in, well…


    looking back pioneer arts

  • This Old Video

    Posted on by Don

    Here’s the video I did of our memorial ride for Brian. I made this about eleven years ago and put it on Facebook, where it sort of languished ever since — FB “memories” just brought up some of that trip’s photos, and so I went rummaging for it. I just added it to my Youtube channel, where it will have a home — maybe a more accessible/discoverable one — with my other videos, if I ever actually make any.

    So anyway, there it is. I can’t say “enjoy;” it was a pretty somber moment but I sometimes like to look back at that day. I would love to know what happened to some of Brian’s own ride and vacation videos, he was a master at that sort of thing, and his videos were almost as much fun as the trips themselves.


    looking back the sporting life 📎and tagged