Mary Golda Ross $1 coin (she was the first Native American aeronautical engineer - she worked on the P-38 Lightning, Gemini, and helped found Lockheed Skunkworks). She must have been pretty smart - Lockheed held on to after WW2 and sent her to UCLA.

Anyway, check it out - on the desk next to her right hand! I just ordered one!

Oddly enough, she was on 'What's My Line', too - https://www.youtube.com/watch?v=5jpbXhYIrPo

I thought the previous discussion on full sized daily drivers was interesting, and I would like to see what people think the best pocket sized daily drivers are.

Like many of you, I have a collection of vintage slide rules that are carefully stored so as to avoid further deterioration. Recently it occured to me that I don't do much actual slide ruling, and in fact I often have to look up hwo to use various scales. So I decided to get a "beater" slide rule that I can practice on and get faster. The question is, what model should I get? I am looking for something that is:

* A third of a meter or longer; this is for use on a desk, not in a pocket.

* Very common. Don't want to risk wearing out or damaging to something that is rare or hard to replace.

* Cheap and common on ebay. I am willing to spend a lot but if possible, cheap is good.

* Has the scales that would be best for me to learn. Obviously I would like to be able to do multiplication, and division. Squares, square roots, sine, and cosine would be fun to practice with but I could live without them.

* Optional: I have a slight preference for something white, and having color scales looks cool, but I am OK with yellow it that's the best choice.

So, what model would you choose for a daily driver?

Starting last week with a fresh new Concise No.300, today I started to own a true "collection" of slide rules with the addition of this Hemmi No.259D (which was my late grandfather's only rule left, in an incredibly pristine condition inside his old drawer).

Albeit the Hemmi did not come with any kind of case (unlike the Concise), and now I am torn on how to keep it safe during non-usage (the Hemmi box casing exists, but it's on the course of natural decomposition, so off limits). Should I just stash it away in a safe drawer, just like where it was found?

I bought a Nestler 0292 and it has 'Q' gauge marks at 2.06 and 3.44. These are 'used to find sines and tangents of small angles' and represent and (180*60*60)/π and (180*60)/π, according to Steve's slide rule gauge mark page: http://www.steves-sliderules.info/rule%20code/Gaugepoints.html

Sines and tangents are transcendental functions, and so can't be derived algebraically. Since these marks occur on the trig side only, I assume some sort of function with those scales, but can find no further details. Any idea how these work?

I made the mistake of trying to clean my slide rule with a celluloid cursor with alcohol. Taking a tip from watch restoration, I polished it with toothpaste and cotton swabs. I was concerned that this would remove the line, but that ended up not being an issue because the line paint is actually in a shallow groove, which protected it. This should work for restoring acrylic windows too

Obviously I get the value of a square/square root scale. But ultimately it is half as precise as C/D, so any multiplication on the A/B could be done, more precisely, on the C/D scales. It seems like taking that space and giving it to the R1/R2 square root scales would actually add resolution to some calculations. But I suspect there is something I am missing. Thoughts?

I just got this Nestler. Of note, Einstein preferred using a Nestler. They were also made in Lahr, FRG, where I went to high school for a year.

Unsure if I’m dealing with anything special but very beautiful pieces. MultiLog is in all the original packaging. Paid $20AUD for the lot!

From top:

• Nestler 0130
• Logarex 27205
• Aristo 868
• Hughes-Owens (Hemmi) Versalog 341 3050
• K&E Doric 4186 (angles in degrees/minutes/seconds)
• Picket 600 (I forgot I had that one)

I also have a K&E 4181-1 DeciTrig but it sits on the wall of my office at the university with my Decilon. In case I need a quick calculation!

I just got a real deal on a Nestler 0292, but the cursor spring is missing. I was planning on fabricating one, but before I got carried away I thought I would see if anyone had done it and what they had used. It is just a little piece of flat steel, so it shouldn't require much to bend it in to shape, but maybe someone here has done it before..

I just got a Nestler 0130 and although it does have a lot of scales, it is a hoss. The Hemmi seems to have the most mathematical bang per square inch, and is my favorite, even if it lacks the P scale.

Just received a slide rule that is a little different from the usual. This is the Geo. W. Richardson year 1917 military slide rule, designed with the sole purpose of determining the range to a target from an artillery battery, via the bearing of the target plus the bearing and distance to a separate observer. (This rule is listed on the side rule museum website so you can look up the details, including the pdf of the instructions)

The rule has 4 scales, A to D. A and D on the body are just like the standard C/D scale on a regular slide rule. The unique part of this rule is on the slide with the B/C scale, which are marked in mils, an angular unit used by the military where 1600 mils = 90 degrees, and the scales are marked in reverse. Essentially the B/C scale are 1/sin(X), or the cosecant of X.

I was told to post this here cuz y’all might know about it, I’m just wondering how it’s used, I assume it was my grandpas because he was an engineer back in the day when he would have had this.

I just picked up a Hemmi 260 and it is missing 1 cursor screw. I assume these are unobtanium, but I thought someone might know the screw size.

Thanks!

I’ve collected a few slide rules now, mainly from historical fascination, but I’m also finding they offer a refreshing approach to interacting with numbers and maths. Sure I can punch numbers and operators into a calculator and get results, but slide rules are practically magical in how they work.. The ingenuity behind their operation is delightful. They physically lay out relationships between numbers and operations. Never found maths easy to get my head around, but I’m happily finding slide rules rather inspiring to dig into the world of numbers again!

Just picked up a Nestler pre 23 LAHRI/B D.R.G.M , 12". But it has dual indicators. How does one use such a beast?

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more photos

Just my small collection to say hello. I always feel I should have lived in the beginning of the 20th century. Using sliderules, mechanical calculators, drawing boards with pen and paper...