I guess the recent purchase of an old instrument has awakened an interest in older technology. I've been tinkering with a slide rule for a couple of weeks, learning how to use it. Amazing devices. Seem to be accurate to about 3-4 significant digits. Not really enough to calculate a traverse, but still pretty cool. Unfortunately the two I have on hand are decimal instead of DMS. Anyone have an old DMS slide rule they'd be willing to part with for a little remuneration? Were the 20" models more precise or just easier to read versions of the 10-12" models?
I did not know there was such a thing as a DMS slide rule.
Interesting.
I have some brand new ones still in box with instructions, etc. Give me a call later and I can go over what I have with you.
The 20" helped with accuracy some - generally at the lower end of scales or for some of the speciaty rules like stadia and hour angle.
Dave
540 828 2778
Both Ipod and Android devices have an app for that. Just go to your appstore and search for "sliderule".
That's pretty cool, Andy. Sounds excellent for learning how to operate one. But I'm really leaning toward holding the actual thing... I also don't want all the other kids to laugh at me when the batteries get low on my slide rule. 😉
I'll definitely holler soon. Thanks.
All of my information is gleaned from brief descriptions I've found on the web. But I do believe there were DMS scales. Perhaps the pinnacle of surveying slide rules (which is probably beyond this surveyor's reach) was the K&E that reduced sunshots and stadia (I believe using cos^2).
Still have mine in the desk, doing anything more than multiplication and division would require a peek in the book that came with it, it's on the shelf. Keeping track of the decimal location also would need review. Have a circular slide rule that I took to the field until I got the HP35 in 74 or 75, circular slide rule is still around here someplace. Slide rules work as log tables and like modern calculators use decimal degrees, you enter or read DMS because there is built in software to make the conversions. Used the stack on the HP 35 to convert degrees back and fourth.
jud
I usually have 1-2 for sale on eBay, great selling items.
However, I'm currently out....
I'm also interested if anyone has any they wish to part with....
I can explain it to you, but I can't understand it for you...
This is a link to a scanned manual of the K&E 4102 sliderule designed for surveyors. Pretty cool!
http://www.mccoys-kecatalogs.com/KEManuals/4102/4102_man.htm
> when the batteries get low on my slide rule. 😉
Now that made me laugh.
What is a slide rule? 🙂
> What is a slide rule? 🙂
I can think of a couple:
Wait 'til the last kid gets out of the way before going down.
Please don't go 'up' the slide.
No pushing
😛
I have a 4102 on indefinite loan. It has special scales for computing an altitude solar, as you can tell from the manual. That manual only surfaced a few years ago, before that a few of us were scratching our heads on how to use it, and until I try it out, I am still not sure. At least now we have a guide.
Just did an altitude this morning in preparation for doing some testing with it in the coming months.
I've been thinking of doing some youtube videos on old techniques such as red-book and curta or monroe handcrank, and slide rule. Not sure about the slide rule as every few years I get mine out and compute a traverse with it, and am reminded it is not very good. You just are not quite accurate enough to make it worth while. It doesn't take that long to look up the functions in the tables.
It could be useful for meanders, and some simple area (A x B) computations, stadia and slope staking, but not very good for traversing.
As previously posted accurate to about 3 places for a normal rule, 4 places almost for a 20" rule.
- jlw
that's quite a prize, Jerry. I hope you'll share your results.
You'll find my 4102 pictured on Clark's site. If you do your observations correctly and at the right time of day, the 4102 will return answers correct to a minute or two.
As to precision, I was thinking the same thing. Just outside of practicality for traverse calculations. 5 places might have really made it a game changer.
From what I understand the Curta and Monroe mechanical calculators could do basic add, subtract, multiply and divide (which is pretty cool). Were there any common use mechanical calculators that performed trig operations, and square roots, or did one have to revert to the trig/log tables for that?
I used to be able to extract square roots on a Monroe hand crank and a Curta.
That was forty years ago!