The Hunt for a Curta and Discovery of a Treasure

I had decided that I wanted a Curta calculator for my collection of antique mechanical calculators. It was going to represent the last of my mechanical calculators, chronologically speaking.  I should preface this with the comment that I could have easily gone out and purchased a Curta, but that takes half the fun out of it. Curtas are fairly expensive little gadgets, it would not be hard to spend $600 on a good one.  I like to find my computing collectibles at more affordable prices. I figure, if it costs less, then I can have some money left over to buy something else for my collection.

I know that most engineers who went to school when slide rules were de rigeuer ended up keeping their slide rules even though they never used them after they got weaned onto electronic calculators and computers.  They just feel that after all that time together, you don't just throw one away. You have to have more respect for it.  So, it gets tucked away in some drawer somewhere, and every once in while they run across it and it brings back all those fond memories of years past.  The damn thing has no monetary value, so they don't sell it either.  I have found, when telling people that I collect these devices that they are all to often willing to part with theirs because they know it is going to a good home and it will be treated right and won't be destroyed.

Back to the Curta. I figured that someone who used to enter rally races would be in pretty much the same situation as an engineer and his slide rule.  So, I started tracking down rally car enthusiasts.  It isn't very hard. You find one, if he doesn't have one to spare, then ask for the names of others that he know and their phone numbers. It went fairly fast. I had been looking off and on in my spare time for about two weeks, when this one fellow referred me to another.  I called the individual.

No, he had sold his last year. He had no use for it anymore. He couldn't just throw it out and someone offered to give him $100 for it, so he took it.  I, of course, had explained that I was looking for one for my collection of computing devices.  So, then, out of the blue, he says to me, "Maybe you would be interested in these slide rules we have."  My ears went up. "Oh, slide rules! What kind of slide rules?" He replied, "My wife's grandfather, or great grandfather designed them and she might want to get rid of them. I don't know much about them. You would have to talk to her about them."

His wife eventually got on the phone after I had gotten the names of a few more potential Curta owners. When his wife got on the phone she explained that her great grandfather, Edwin Thacher, had designed these slide rules and she had the original production runs for one of them and a prototype for another.  The former was the cylindrical slide rule that I have already written about, the latter was a Scofield-Thacher Engineer's slide rule. 

I asked her if she would be interested in selling the devices. She indicated that she would. We made arrangements for me to come out to visit her.  

Two weeks later I found myself on the road again.  It was about a 4 hour trip in rural New York.  

A little historical insert is due here. Edwin Thacher (1840-1920) was born in DeKalb, Lawrence County, New York and died in New York City. He grew up as a youth in Herman, NY not too far from DeKalb. He was trained as Civil Engineer at Rensselaer Polytechnic Institute in Troy, New York in 1863 and was employed at first on the Cedar Rapids & Missouri River Railroad, and subsequently with the US Military Railroad during the Civil War. Thereafter, he worked for the Louisville, Cincinnati & Lexington Railroad, Louisville Bridge & Iron Co., and as Chief Engineer of the Keystone Bridge Co. He was most noted for his concrete compression bridges and the slide rules he designed to engineer his bridges. He was always plagued by the lack of accuracy in the calculations he performed in designing bridges.  His most substantial engineering project was the design of the Walnut Street Bridge in Chattanooga, Hamilton County, TN. It was a six-span through truss bridge over the Tennessee River built from 1889 to 1891. It has a total length of approximately 2,370 feet with the longest single span being 320 feet. It is in the National Register of Historic Places.  The Walnut Street Bridge was converted to a pedestrian bridge some time in the latter part of the 20th century and may be the longest pedestrian bridge in the world.  Among the various slide rules he designed, was the cylindrical slide rule that carries his name (in reality, Thatcher[sic] due to a typo) to solve the accuracy problems he was encountering in his bridge engineering design work.

Now, back to the rest of the story. I arrived at the home of the great granddaughter of Edwin Thacher and had a cordial meeting with them.  They produced the various Thacher devices. The K&E 4012 was serial number 1050, indicating that it was the 50th production number produced.  the Scofield-Thacher Engineer's rule was clearly a prototype. They started disclosing what information they knew about him which wasn't all that much, but then they produced their Thacher family Bible.  You should know that way back when it was very common for families to record all the births, deaths, marriages, etc. in the family Bible.  Well, there it was: Edwin Thacher, born October 12, 1839 to Seymour Thacher and Elizabeth (Smith) Thacher.  From there she showed me the family tree, showing her direct descendancy from Edwin. Wow! Was this the Holy Grail squared, or what?  Most of the biographies on Edwin were wrong on the date of his birth. He was not born in 1840 as noted!

We got down to business and discussed the sale of the items.  Their concern was that these were large devices and no one in the family had expressed interest in them and they wanted to make sure that they ended up being taken care of. Yes, yes. I'm real good at taking care of my slide rules.  We talked about the price.  We did not conclude anything at that meeting.  They wanted to think about the whole matter. I did not want to pressure them. I told them I would send them some biographical information on their great grandfather, which I did as soon as I got back home.

We had a number of conversations after that and the conclusion was that they thought they would, at least for the time being, hold onto these family mementos. DARN!!!

So close, but so far from completing the purchase.

By the way, this whole story started out looking for a Curta. Well, I got my Curta a number of months later, but not from the plan I had set out to get it. An acquaintance of mine had a friend who was an engineer who had some slide rules who wanted to give them to me, and while talking to him I learned that he used to participate in rally races. Yes, he still had his Curta, and yes, if I gave him $50 he would sell it to me.

I now have that Curta.