This is probably slightly irrational, but it pains me to see how many slide rules go unsold at auction sites, and probably end up being thrown away. Admittedly, most of these are school rules of which there are thirteen in a dozen, but I see a fair number of nice ones as well. The collector in me wants to buy them all, but the rational Pinus says that I already have a few, and unlike the gentleman in the article, I do not wish to fill my home with slide rules...
To put a programming angle on things: Using a slide rule feels a bit like assembly-language programming on something like the Z80. Since operations can only take their input from certain places, and only leave their output at certain places, you need to try to arrange things so that any intermediate results are in a place where they can be used as input for the next step.
You're lucky, you have that with slide rules. I have it with musical instruments, specifically pianos. It's been the subject of some domestic friction ;) I'm pretty sure if I would switch to slide rules that the reaction would be one of great relief.
You've just given me an idea for a slide rule that takes a key and provides easy visuals for the chords around that key and how to translate to another key. Eg "oh if you started on c maj bit you wanna play that in F? You're gonna need these sharps and flats my man". Might be a fun educational tool for learners.
Now you've done it :) I have been thinking about this and an email exchange with another HN'er about a super interesting project pretty much non-stop! Thank you though, what an outstanding idea.
some subplot to this mystery could be that a collector buys them all up to artificially create the scarcity to inflate the value of the collection. kind of like the housing inventory after the '08 collapse
Coincidentally I'm making one right now. I never knew about Walter and his passion but I totally get it, sliderules have a magic all their own. Ostensibly just a couple of passive pieces of material but the power of logarithms turns them into universal calculators. A radio amateur that I knew was faster with his slide rule than I ever was with a calculator! The calculator produced more digits but most of those were useless.
HP calculators will only display the number of digits you specify and there is an RND function which will round the number to that number of digits.
While it doesn't fulfill the criteria of "managing significant digits" (you still have to know at each point how many significant digits you have, which isn't obvious with calculations like logarithms), it does make things significantly (ahem) easier in most common cases.
No, it depends on the significant digits of the input number. And more often than not there are very few of those, even though it may look like there are a lot. And your average calculator has no idea about how to deal with this properly. A typical measurement (say, temperature) has two significant digits at best, three if you're very precise and have a calibrated thermometer operating in the sweet spot of its scale. A measurement of time is hard to achieve to better than 10/th of a second without special preparation and as the interval you are measuring gets longer so will the error (because they tend to accumulate). A measurement of weight is so tricky that even three or four successive measurements are going to give you different results. Modern personal weight scales fake this by freezing the digital output at some arbitrary value and if you get off the scale and back on again it doesn't do another measurement but it simply displays the stored value to give you the illusion of precision where there really isn't any, another measurement might be off by a few hundred grams.
So for most problems that do not involve money but real world data the number of significant digits is very low. Two, three, maybe. Four in very rare cases. And when you start combining them you're quickly into 'order of magnitude' territory rather than anything precise.
Right, that's what I was saying. Which is why I was wondering about the claim that I'm replying to saying that a calculator itself has a specific number of significant digits independent of the input numbers
I always wondered how they made the markings on the high quality slide rules of yore. Were they engraved? Were there machines that would scribe them? Now we might laser engrave, but that feels too recent. Maybe some sort of acid etching? I don't know!
For now out of wood, it will be 'oversized' so I get enough accuracy because I can only inscribe 0.4 mm lines, though I have an idea on how to improve on that for just this job.
The ones that I used to have were plastic and the lettering seemed to have been superimposed on top of the base material, Pickett's were definitely printed, not engraved. But older ones were engraved and I'm super curious about the process they used, I'm imagining a reversed pantograph or something like that.
The famous real estate developer Gerald D Hines used a slide rule constantly - it gave him time to think of answers to questions while clients watched him go through the motions of some calculation. It also helped him quickly do actual sums to scope out the major dimensions and costs of a project, further impressing clients. This was before pocket calculators, of course, but slide rules were probably more mesmerising to watch in action anyway.
One of my favorite scenes is from Apollo 13 where Jim asks Houston to confirm his numbers he calculated by hand, then it cuts to all of mission control using their slide rules to confirm his results.
I still have my old slide rule (aluminum) and my Dad's (wood). I love the things, but had no idea somebody had built a web site and a company around them. After the zombie apocalypse, there will be no batteries and calculators won't work. But we'll be able to rebuild society with slide rules. If we can find any.
Walter was also a fixture in a small but active community of devotees of old-school HP and Tektronix test equipment, and I think he was active in 80s-era HP computer user groups as well. His storefront is still maintained by his wife: https://www.sphere.bc.ca/ .
That website is a gem. I have a 2235 here that I just can't part with, it has long since been replaced by a digital one but I'd feel like a complete traitor if I sold it.
That's true, but consider: there is a difference between someone selling a pile of stuff amongst which there happens to be an old slide rule versus someone specializing in slide rules. The device itself may be next to free but you're going to have to keep it in stock pretty much forever and working on the classical ones is going to be pretty time consuming. I'd see it as buying an item from a museum subsidizing the curator rather than as a purely commercial transaction. After all, even $10 is a lot of money for a piece of 30 year old plastic so there has to be something else that makes it tick. And slide rule collectors are a thing. If you just need one to use then $10 is fine, if you're looking for that one special issue with the weird scales then suddenly $200 may be acceptable, especially if you know it will sustain the world of slide rules for a couple of days longer. In dutch there is this word called 'gunnen' which I have not yet found a good English translation for, it denotes the act of allowing someone to have your business even if you know the price isn't as low as it could go because you like the person. This is a clear case of that concept.
I'll be ready to go for the apocalypse too. I recently scored an abacus at an antique shop -- a Japanese soroban that looks like it was made in the 50s or 60s. I call it the most retro piece of computing equipment I own.
I love the fancy Japanese abacus I bought at a thrift shop, it's very nice and simply elegant.
I also really enjoyed learning to use it, it was surprisingly easy. I also really have enjoyed learning more about "abacus culture". There are students so good with them that they don't even need abacus' anymore. They just use "air abacus'"
The brain will really never cease to amaze me, that's a very interesting story. So they have internalized the abacus to the point that it's entire state is present in their head. I wonder how long they can maintain that state and if they are able to mentally put it aside for a while, perform another calculation and then recall the stored one.
I've seen a similar thing with a really good chess player friend of mine, he could play without actually looking at the board.
In a post-catastrophe society that totally destroys our networks, knowledge is so dispersed and so many computers and electricity generation mechanisms exist, that I find it impossible to believe Wikipedia and a library of ebooks won’t be preserved in some fashion. From that point it’s a land rush to establish new companies and factories to get us back to prior glory.
That's sad and unfortunate. Experts and dealers of such equipment are a dissapearing breed. I have 2 slide rules; a super cheap plastic unit from high school days, and a full-sized Dietzgen I bought for a dollar (leather case and all). It was in a junked car at a pick'nPull yard. My skills have gotten very rusty, so now I prefer my HP-15c handheld or my HP-42c emulators on my iPhone.
Yeah, I occasionally have that problem -- I don't want to be the custodian of these items with minor collect-ability, they aren't particularly valuable (to have an easy market to get them into the hands of someone who does), but I also don't want to be the person to just discard little bits of history.
That it wasn't used daily by an engineer in anger, you want one that isn't worn to the point where the accuracy suffers. A slide rule is a precision instrument, the cursor and the scales should be free of scratches, the cursor should slide freely but without play across the outside ways and the slides themselves should slide with some friction but never so much that you need to apply force. Low quality ones may have discolored to the point that using them is harder, the better quality ones came in a cover and should have been stored there. I'd probably avoid wood as the base material, it's too unpredictable.
Dirt is fine, damage is not and slop is to be avoided.
In Europe Aristo made nice and affordable ones that sold in a hard plastic casing, if you can find one of those in the original sleeve it should be fine even if it has been sitting for three decades or more. Other good brands: Faber-Castell, Ahrend, Hemmi. You can find them for $10 or less if you look around for a bit. In the USA 'Pickett sliderule' on ebay, from $5 to $300 for NIB...
I am no damn expert, but I've used them. If you're actually going to use it:
Choose a size that you can read and fits in your hands
Choose a smooth sliding Indicator (some have magnifiers) and Slider without slop
Choose scales you'll use (typ 2 linear and 2 log, some have trig roots etc)
Choose one with the precision you think you'll need
I think most of them are plastic, but some feel better in the hands. There are of course metal, wood, and I think ivory. There are cylindrical ones, and all sorts of historical examples. If you're going to carry it around you'll want a case (or a pocket protector) to put it in.
Sad to hear this. I bought quite a few slide rules from the years from him. I even had an outstanding wish-list (of one) for a particular circular slide rule I had been dreaming to own.
I'm so sorry Walter Shawlee is no longer with us, we need advocates and enthusiasts like him to carry on historical knowledge of practices and traditions especially so when they were so deeply embedded in engineering culture as was the slide rule.
As I type this my Faber Castell Novo-Duplex 2/83N slide rule is sitting on my lap—it's same model as shown in the article and prised by Walter Shawlee. I still use it regularly as it's often quicker than using a calculator. Also, it has one great advantage over a calculator in that its scales are visual and often I can look along them to read off multiple solutions to a problem without even having to reposition the slide. That is, it has properties that not even calculators have.
This 2/83N is also a prised possession of mine, it used to belong to my mechanical engineer father who bought it in the 1960s. It's a wonderful tool and it's in still perfect condition along with its case, instructions and its quick reference table (shame I can't post a photo of it here).
I believe tools of this quality have historical value and I—as its temporary custodian—have a duty to look after it carefully.
Some lines from 'The Dark Tower' spring to mind, your dad would no doubt be very proud of you. I hope my kids will value my tool collection in the way you do. I have very few hard connections to the past of my family, and those I keep close to me. Now the challenge will be to convince your children if you have any to keep that slide-rule in honor, I really like your view of tools. Too often they are seen as 'wear items' rather than as things to last for much longer than a single life time.
In a similar vein, my father came from a generation a little after the commenters to where he used HP calculators in college and later got an HP15c when he graduated. I bought one of the re-released ones and learned to use it just to have a better understanding of the engineering culture he came from. Those old calculators were stack based (RPN) and programmable in a day when practically nobody had a personal computer, so you could often do your assignments on it, instead of waiting in line to do it in Fortran. I think he lucked out and fully missed the punch card era to where they had terminals by that point. The manuals on the HP15c were also fantastic and had lots of example problems like a mini textbook.
They're a fun branch on the programming tree. I've tried to nibble a bit from all of them to see what's available and there were a couple that really altered my way of thinking, the lambda calculus inspired minimal programming languages, the Prolog/Erlang branch and the FORTH derived branch. All of those offer fascinating insights into what it means to compute.
Agreed. The APL branch has been my favorite so far. I've looked at a bunch of weird ones like Forth, Lisp, APL, prolog, Haskell, Smalltalk, and many others. I keep going back to Python though. It's overall environment of language, libraries, free, open source...etc seem to firm a nice optimal point despite several drawbacks.
Yes, Python is the Swiss army knife of programming now. It's in many ways unfortunate but you can't beat the fact that just about any algorithm you can think of is probably available in an optimized form if you need it, with HW acceleration to boot.
I use Anaconda to keep the gremlins at bay, without that everything turns messy very quickly but somehow they've managed to keep it all organized and functional. Especially notebooks are a very powerful exploratory programming tool.
Thanks for your comment. My philosophy is that if it's functionally efficient and still works then continue to use it. Throwing something away just because it's old is not paying due respect for the human effort and ingenuity that went into both designing and making it. Also, it's ecologically wasteful to do so, similarly so is planned obsolescence (a pet hate of mine).
This applies to many things we own, but it's especially so for well-crafted objects such as musical instruments and many hand tools, which have long evolved to the point of near perfection, thus replacing serviceable tools with new ones serves no useful point other than perhaps they look somewhat more 'pretty' or current.
For example, I have a large collection of woodworking tools that are much older than I am by many decades, yet they still remain perfectly serviceable and very reliable (I'm aware of their history but I treat them as functional tools that I actually use—not simply collector's items). I have near several dozen hand planes of different sizes most of which easily predate WWII, the oldest was manufactured in 1907 and some of the highest quality ones date from the mid 1930s (Stanley planes and ilk are very easy to date accurately).
The traditional bench plane as used by woodworkers is a quintessential example of a well evolved tool; its near perfect ergonomic design together with its intrinsically very robust construction has meant that its design has changed only marginally since Leonard Bailey patented the first modern plane design in 1867¹. And after some further perfecting by Justus Traut in 1885² and a few later manufacturing tweaks its design has essentially remained static since at least the end of 19th Century to the extent that many of its parts are often fully interchangeable despite the fact that a plane could have been built at anytime over the past century—in fact, Stanley continues to sell screw sets and parts that fit any plane built over this period whether it's for their own product or that of their competition—for instance the Record Planes company³. Moreover, all modern manufacturers of hand planes use the same naming and size nomenclature as did (and does) Stanley, the design was such a success that the moment the patents ran out other manufacturers followed original designs to the letter.
Like the famous/classic Darmstadt slide rule design and that of my Faber Castell Novo-Duplex 2/83N, the Bailey plane is design classic, it's not only very functional and rugged but it has remained so over many generations. As mentioned, with its now-timeless design one shouldn't consider possession of a Bailey-style plane simply as just ownership but rather as its temporary custodian. That millions of planes are still in existence and functional after having outlived multiple owners is testament to the fact.
I see no conflict or clash between using and or paying due homage to old technology when it is relevant and makes sense to do so and yet still being up to speed with modern tech. No doubt, in many instances newer technologies bring many advances and efficiencies over their older counterparts but as we've seen from the Bailey plane example we shouldn't simply abandon a technology just because it is old. Whilst the Bailey plane is a clear-cut instance of older tech winning out over much newer designs, my point is that we often abandon older technologies and processes either out of prejudice or because they've fallen out of fashion rather than because of demonstrable reasons such safety or that they have become impractical considering newer technology, and or they are now too costly to maintain.
True, whilst the latter points are often very valid reasons for abandoning old technologies all too frequently we use the former excuses to kill them off and often this results in negative consequences (for instance we regularly delete great swathes of information about older tech from modern textbooks, so the younger generation remains ignorant of them despite their intrinsic importance). Fact is older technologies are frequently much more functional than our prejudices are prepared to allow us to admit and we dismiss them to our disadvantage. Often older tech possesses certain properties and features that cannot be easily replicated by its replacement, or that various aspects of it can be used in new ways not previously thought of.
That said, I do not want others to misconstrue what I have said about the value older technologies or for some to consider my words as that of a Neo-Luddite, so below I provide an example of technology that many in my own profession of electronics have long deemed obsolete and long dead—specifically that of vacuum tube electronics, which I would maintain is definitely far from being dead!
Electronics is a broad and rapidly evolving field that has required my constant attention to keep abreast of ongoing developments such as semiconductor design, imaging, electro-optics and recently quantum dot tech has been increasingly competing for my attention, so it's very tempting to dismiss parts of the field that one perceives as no longer useful.
The trouble is things are never that simple. If one examines textbooks on electronics one will find that many never mention vacuum tube electronics, and those that do usually give it very scant attention, so why do I claim it's important? Well, whilst vacuum electronics is now essentially nonexistent in much of our modern tech including home appliances, computers and many other devices—even in TV sets and monitors the cathode ray tube has given way to solid state replacements, but that doesn't mean the tech is dead. In fact, it's still very much alive in many industrial processes. Microwave ovens continue to use vacuum tube magnetrons, so does RADAR along with klystrons. Our famous and truly remarkable Voyager spacecraft use TWTs (Traveling Wave Tubes), high-powered radio and television transmitters use vacuum tetrodes and electron microscopes and many other scientific instruments use vacuum technology some of which can never be replaced with solid-state electronics due their intrinsic characteristics—an electron microscope for instance.
Excluding vacuum tube technology from electronic courses has another serious negative effect in that a whole branch of physics is being neglected, and it goes without saying that if one doesn't understand it then neither does one fully understand solid-state (and more broadly condensed matter) physics. The vacuum and vacuum physics is a crucially important aspect of physics, and particle physics would be nonexistent if physicists didn't understand how particles move in a vacuum.
This brings me back to the importance and necessity of having a good understanding of the historical background/developments of any tech one is working with as there's always a cross-fertilization between the old and the new that not only contextualizes the technology but also leads to a much better understanding of it. Whilst many would disagree with this assessment, I would claim that many others and I have gained much useful knowledge from these historical concepts, so it's little wonder that I am rather annoyed that teaching them is not considered relevant and or a compulsory part of electronics training. I have lost track of the many times I have had to inform my younger staff about relevant connections between certain concepts that to them are seemingly unrelated, had their syllabuses included historical information about their subjects then said connections would have been obvious.
Have you ever noticed how physicists have an unusually rich to excellent knowledge of say the historical background and development of quantum mechanics? This is not without good reason as they've found that in that working through the thinking processes of their forefathers greatly improves their understanding of this complex field. Unfortunately, as mentioned, that so little attention is paid to historical aspects in many engineering courses is clearly demonstrable as a quick glance at many a modern engineering textbook will attest.
My apologies for such a long rave but experience has forced me into developing such strong views.
Software 'engineering' is unique in that we can't seem to wait to burn up the previous generation of tools while re-inventing them in ever more broken ways. There is hardly any institutional knowledge passed down from one generation of programmers to the next, they all go through the same re-invention. The amount of effort that is burned up like that is insane.
You remind me of something that I've been meaning to do for a long time, which is to pull out all of my oldest tools and give them the best possible treatment. My most prized tool is probably a 1960's Estwing hammer that I found in an abandoned shed. It's hands down the best hammer I've ever owned and I hope I'm doing the long deceased first owner proper honor by keeping his hammer in use and in good shape.
As for vacuum tubes: I got into electronics just as the world was turning to solid state and so I've seen both sides, the idea that you can just follow the physical path of the electrons helped so much in understanding how it all worked. Without that foundation I would have had a much harder time understanding how solid state electronics worked.
A related tool ( to slide rules - a way to make multiplication and division easier ) I recall using logs to do calculatios.
I recall using the lookup table booklet of logs
Log tables for multiplying and dividing
ie From Google of phrase "....using log tables ..."
1900s.org
https://www.1900s.org.uk › logarithms
Logarithms provide an easy means of multiplying and dividing using just simple addition and subtraction together with lookup tables.
My older sibling and I spanned the boundary between lookup tables and calculators. Her math exams came with booklets of sin and cos and log tables. Mine didnt because I was expected to use a calculator. I think the tables all evaporated in under two years around 1984 (or maybe thats just as far back as I can recall)
Once the Great Flood was over, Noah let all the animals off the Ark, and told them to go forth and procreate. And so they did, except the snake couple. So Noah made some wooden furniture for them, and thus the snakes were able to procreate.
You know, because the snakes were adders. They needed log tables to multiply.
To put a programming angle on things: Using a slide rule feels a bit like assembly-language programming on something like the Z80. Since operations can only take their input from certain places, and only leave their output at certain places, you need to try to arrange things so that any intermediate results are in a place where they can be used as input for the next step.