Kyle Rankin @kyle@librem.one

The Burroughs adding machines aren't my favorite to use, but they are my favorite to look at. Check out the lines on this 100-year-old Class 3. It reminds me of sedans from that era.

There are few things as satisfying as fixing something you are unfamiliar with by researching how it works and applying basic troubleshooting skills. In other news, the furnace works again (insufficent pilot light flame around the thermocouple).

Adding to my collection...

Due to the size and the case design, I suspect Addometers were mostly stored on or in desks and pulled out for quick arithmetic and they work well for that. The Imperial model I have was probably thrown in a toolbox and has lots of wear and even initials carved in it.

As I mentioned the Model C was designed for Imperial measurements and had a dial that went up to 11 so inches could carry over into feet. Here I'm calculating 2' 9 3/4" + 1' 6 7/8". Doing math with Imperial measurements really makes you appreciate the Metric system.

You can also perform division using the repeated subtraction method but you have to keep track of the number of subtractions in your head. To clear the registers, just pull on the lever on the right side. This also ejects the stylus for you if it's in storage.

To multiply, perform repeated addition and shift left for each term in the multiplier. Here is 12 x 12.

To subtract, use the smaller digits on the outside of the dial to enter the subtrahend and rotate anti-clockwise. The mechanism also will decrement from the left side automatically. Here I'm subtracting 50 from 31341.

To add, put the stylus in the dial for the corresponding digit using the larger numbers, and turn clockwise until the dial stops. The mechanism automatically carries the one without having to move in different directions like with a "shepherd's hook" design. Here is 31337 + 4.

My Model A came with the original case, which was designed with a notch cut in the side so you can access the stylus storage and the clearing lever without removing it from the case. It also came with the original instructions!

From a distance they look similar but the Model C was designed for adding Imperial measurements and has a dial that goes up to 11 for adding inches. Both models feature a dial for fractions on the far right, where Model Bs only have decimal dials. All models have a ruler on top.

This is a pair of Addometers made by Reliable Typewriter & Adding Machine company. They were made from 1930-1960s. The top one is a Model A I think from the early 1930s due to "patent pending" text on the front. The bottom one is a Model C I think from the 1950s.

My favorite part of touring the U.S.S Midway was probably seeing the comms, sensor and radar stations.

"A new technology can inconspicuously scan the same surface [a blank wall] for shadows and reflections imperceptible to the human eye, then analyze them to determine details, including how many people are in the room—and what they are doing." #privacy https://www.scientificamerican.com/article/a-blank-wall-can-show-how-many-people-are-in-a-room-and-what-theyre-doing/

I can see why when this machine came out it seemed advanced compared to a Comptometer, but the quirks make it tricky to use. I had to record multiple videos because I would crank past the stop and lock the carriage. Later models fixed these quirks and are much nicer to use.

Clearing this machine is also quirky, you can clear the counting register with a clockwise turn of the top crank, but to clear the main register you must lift the carriage up manually before you turn the top crank anti-clockwise. Later models automatically lifted the carriage.