Curta Type 1 CalculatorLarry & Carole Meeker
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                   Antique Dealers & Brokers

Purveyors and Dealers of Americana  /  Patented & Mechanical Antiques

Antique & Vintage
Calculation Devices / Slide Rules & Related

We can help you sell your Scientific and Calculation Related Antiques &  Collectibles!!

We deal in and sell early and unusual slide rules and early patented calculation devices.  We also deal in many other Antique French Calculatoroffice related antiques and collectibles.   We specialize in tools and technology related antiques from the home, shop, farm, or office.

We are full time antique dealers of early scientific and technology related antiques and actively deal in a broad range of related antiques and related advertising.

This site, is our informational and past sales results website. There are links on the left to informational pages, and on the right are links to past sales results for many scientific related antiques we have sold.

Our antique sales site for these and other types of antiques and collectibles is  Please visit it that site if you are looking to buy these types of antiques and collectibles.

Please contact us by email at if you have any interesting technological or scientific related antiques you want to sell, or want to cosign to us to sell for you.

Below are some pictures of the types of scientific antiques and vintage calculation devices and slide rules that we deal in and are seeking, along with some basic information to help you determine what you have.

Curta Calculators

The picture below is of the ever-popular Curta calculator.  The example pictured is known as a Type 1.  This step drum calculator that was also produced as a Type 2 during the curta calculatorsame time frame.  The main differences in the two calculators are that the type 2 Curta calculator has a larger capacity.  These calculating devices were first designed during WWII and were introduced shortly after the Second World War to the commercial market.  They were still being made right up to the time the hand-held electronic calculator caused their popularity to wane and production to end in the 70's  They originally retailed for about $150.00.  For most of the 70's and into the 80's examples sat on shelves and in back storerooms of drafting supply shops as dead stock for years.  Before the internet it was oftentimes hard to even get original retail for them.  Prices climbed and held steady for a number of years at around 200.  After word got out that they were being collected and a constant supply and demand became available on the internet, prices skyrocketed. 

curta calculator Not too many years ago these devices could be had for a couple hundred dollars and there were more than enough to go around.  The supply seemed endless, and the demand scant.  The Internet auctions came and the market changed with a new group of collectors entering the market.  Prices initially went up to new unheard of levels and then back down after that initial demand was fulfilled and the tech bubble blew up.  They are still a popular collectible and demand is pretty constant with prices for them ranging anywhere from $500-1500.00 or so depending on a few variables including the serial # and condition.

Calculator Values

The prices of most later or more modern electronic calculators also took off  for a while and reached new and unheard of values when demand rose right after the internet came into vogue.  Many of those values dropped considerably after the tech bubble burst.  The value of these calculators seems to be tied to the amount of money folks of the proper age group have to spend as disposable income at any given time.  High when the stock market was doing well, and not so well after the bubble burst.  That scenario has repeated itself during this latest recession as well and I am willing to bet the same is true in relation to what happens in the Real Estate market.  Prices and interest rise in good markets and fall in bad.   I expect that things are going to be soft for a while.  It seems the only modern calculator to buck this trend are the examples of early Apple computers bringing 6 figures at auction. 

A market was also created by the internet for electronic hand-held calculators from our school Antique Adding Machinedays and evolved during this period also.  Another new collectible was born.  It seems that this category bubble went the same way as the last NASDAQ bubble as well.   I would bet a chart comparing the two price levels would look very swimilar.  The difference being that this may have been more fad than real.  Think Beannie Babies here.   I think it will be years, if ever, before some of the lofty heights that some of these later electronic calculation devices and other collectibles once brought is met again.   The one caveat being the rare of the rare still do well with the prime example being the Apple 1 computers selling for half a million or so.  Results like that are explained by some folks simply having too much money.

I like, and still look for these handheld electronic calculators, but rarely do I want the larger later and more typically seen  modern 10-key model calculators or adders, like those from the 30's or 40's or later.   Including large Victors, Burroughs, and a host of the other later 10-key heavyweight adding machines that seem to be in every garage and in every antique booth and even at the end of some ropes in the bottom of people's boats acting as ballast or anchors.  There are people who do collect and are looking for these later machines, but I do not know them and have no market to sell them.  Check eBay to see what most of these later 20's - 60's era calculators / adders actually sell for and you will see what I mean.

Early Calculation Devices

Antique and vintage calculating devices have had an interesting and varied period of development through the years.  Every one is familiar with the abacus, one of the earliest of all calculating devices. 

Another early form of a calculator first developed antique double wheel calculator for Western civilizations was known as Napier's Bones.  These were cubes or dice-like in shape, and were made  from bones or ivory and real examples are extremely rare and collectible.  They are being reproduced today and sold at various internet sites and auctions, at times with no indication of their true vintage.  Be aware.

Logarithmic scales found on slide rules were first introduced by Routledge in the early 1800's and were incorporated into the various forms of rules and other devices that were the forerunner to the slide rule as we know it today.  These scales were typically found on rules during the early to mid 1800's primarily for use by merchants and trades people who needed a viable way to run larger calculations for their lines of work or business.

One of the first types of mass produced calculating devices that still survive in numbers today are paper tables with  wheels and dials similar to the adder that is pictured above on the right.  The Palmer's Computing Scale (not shown) is the best known and most commonly seen of these types of early paper calculators.  Other variations do exist and are good pieces.

Early Dial type calculators / adders were around pretty much during the same period.  The best known of this style machine is the well known Webb Adder which was  patented in webb-adder the late 1800's..  These were produced in a few different configurations throughout the years, with the earliest versions having a wooden back  On the right is the later version, this one being marked with the maker's name and patent date. There are early knockoffs of this calculator / adder that are not marked that can found as well.  They were produced to compete with the real things, much as the pirated tapes and CDs that abound in today's markets.

hart_caluculaterOn the left  is a pretty rare and earlier model adder / calculator with this same basic configuration as those above.  It is known as the Hart Patent Adder.

I am interested in any of these kinds of early dial calculators,  sliding style calculators, or circular calculators like the one in the top left corner.

Please note that there is little market for newer sliding adders like those by the German firm Castell and the Japanese ones from the 1950's that were marketed after World  War II and sold from novelty catalogs and the back of magazines for a $1.00 or so.

I am an active antique dealer in early or antique calculation devices and looking to add nice examples to the sale pages on our sales website located at  I have a good selection of slide rules, calculators, adders and other early office and scientific antiques listed for sale there. Please take a look if interested in buying or selling.

Key Type Calculation Devices

Near the turn of the century dials began to give way to key type adders and calculators, or those with stepped drum and pinwheel style mechanisms, and when these stepped drum and pin-wheel models became more economically feasible to manufacture, even though they were invented years earlier they soon dominated the market.

This style calculating machine,  which quickly and easily performed four functions, became the standard.  Shortly thereafter calculators became electrified and all of these old style calculators were pretty much relegated to the status of obsolete but not necessarily collectible.  Millions had been produced and they are still readily available.

The story of the electronic calculator, and the design changes that they went through in a very short period of time until arriving at today's wonders of technological advances is a dramatic and interesting story. There is a very informative and well done site that is primarily focused on the history of the Hewlett Packard line of calculators, but they also have a very nice and well done history of earlier calculation devices leading up to the HP line. A more detailed history of this period can be found at The Museum of HP Calculators.  It is interesting reading and should be looked into if you are trying to identify your calculator, or if this is the sort of thing that interests you. 1st model wood comptometer

The most famous, and most commonly found early key style calculating machines is the Comptometer. It was a very popular machine in its day, as attested to by the sheer number that have survived and are still available. The most common versions are found in a tan metal case and sell for under 100 in most cases, but the earliest version came housed in a wooden case like the one pictured on the right and is much harder to find. These have been known to sell for several thousand depending on condition, serial number, and other factors.

Most 10 key machines by other makers that look similar to this with metal cases (like the Burroughs) are  considered very common and of little interest to me or to most other collectors of early calculating technology with limited storage space.

Other non electric calculators considered collectible operated with the calcumter / adding machine stepped drum or pin-wheel mechanism. Some of the names of these style machines are the Marchant, Odhner, Time is Money (TIM), The Millionaire Calculator, The Peerless Reckoning Machine which was sold by K & E, as well as a host of others that were being produced early on.  In general the earlier the better, with some selling for 1000.00 or more and others 100 or less. 

The above adders / calculators are an example of the caliber, condition and quality of these types of devices that we are primarily interested in.  To see examples of calculation devices we have sold in the past please look at the sales archive pages listed on the right.

Click the appropriate links on the right side if you would like to see past sales results for antique calculators & Slide Rules we have sold. 

If you have or know of one of these earlier and interesting adders / calculators that you want to sell please contact me at

To see examples of similar antiques that we currently have for sale please go to our sister site at and visit the numerous sale pages you will find there. 

Thank you!!
Larry & Carole

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Larry & Carole Meeker