Twitter Telegraph

Here’s an image of a recent project:


It’s an old telegraph sounder seated in a wooden resonator. Underneath it, I’ve added a small board with electronics so that the telegraph can tap out messages from Twitter.

Electrical telegraphs were invented in the 1800s to communicate quickly across long distances. Devices were physically connected by wires between stations, and operators tapped out messages in Morse code on a small, paddle-like device called a key.

The sounders tapped out those messages, so one could hear the code spaced between the taps of the sounder. The small black cans in the image are covering coils of wires. When a current goes through the coils, they act as electromagnets, and pull down the black tab above them. That movement brings down the armature, a clacking noise is heard. When the current stops, the black tab is released, the arm raises, and another contact is hit to make another noise.

Locally, a historic roundhouse is being renovated. As part of that process, those behind the renovations have also been exploring the expansive history of railways, roundhouses and the related technologies and effects of those spaces in general. The telegraph played a role, as railway lines afforded the establishment of distant telegraph cables, connecting networks of stations and, eventually, facilitated improved train routing.

This project was an attempt to connect technology rooted in the 19th- and early 20th-centuries with 21st-century networks. How could we make that telegraph sounder tap out Twitter messages?

The results bridge those time periods through the technologies used. The telegraph sounder was used as the starting point and is the output of the device. To operate the sounder, an Arduino microcontroller board was connected to it. The Arduino can control the sounder by activating the coils — turning them on and off via one of the Arduino’s digital I/O ports. Mark Fickett’s Arduinomorse library was used to translate messages into Morse code and activate the sounder, and a few components (a resistor, diode, and transistor) were added to protect the digital pin of the Arduino by separating the activation signals from the powering of the coils.

The other main component is a FONA board from Adafruit. This device, using a SIM card, can connect to cellular phone networks, and with it, you can add many of the functions of a cell phone to your project. The FONA connects via 2G networks, which allows for SMS messages to be sent to and from the device. I connected a FONA to the Arduino, and programmed the Arduino to check periodically for new SMS messages. If it has messages, translate them to Morse code and tap them out on the sounder. The code I used is available on GitHub.


The final results are a standalone telegraph sounder that is connected to cellular phone networks. It receives SMS messages and can tap those messages out in Morse code. It can operate off batteries if necessary, so it should work anywhere it can connect to a cell phone signal.

The SMS messages for this come from Twitter. The device’s cell phone number is associated with a Twitter account, and that account is set up to send an SMS to that number whenever the account is mentioned. If you’d like to activate the telegraph with a Twitter message, mention @ldntelegraphco and your tweet will be tapped out for those near it to hear.

To package it up, I mounted the electronics onto a piece of black acrylic. The resonator for the sounder already had four holes in the bottom of it that I used to attach the electronics to the telegraph. This was convenient as nothing had to be permanently altered to the historic device. Wires were attached to it via the provided screw terminals, so those can be detached and the base unscrewed to remove the electronics.


If you’d like to see it in action, check out Shawn Adamsson’s Vine recording.

Image Averaging

I taught an undergraduate course on digital history methods at Huron University College in the fall of 2013. We focused on topics from American popular culture as source materials to experiment with those digital tools. Students had a great deal of freedom in the topics they chose for their larger independent projects in that class. Quite a few students chose to work with sports-related topics.

In particular, one student was interested in the Super Bowl and its marketing over time. I helped her find digital source materials for that component of her work, and one small set we found quite interesting were the Super Bowl program covers over at the NFL website. But in what ways could a series of images be analyzed beyond just laying them out one-by-one for examination?

Image averaging is a useful technique where individual pixel values are averaged across images and the results constructed into a new image. An excellent introduction to the technique and its uses can be found in Form+Code, by Casey Reas, Chandler McWilliams and LUST. They describe that, “By repeatedly combining related images, one can expose behaviorial norms, reveal expectations, and find connections that were less obvious when the images were viewed as a series separated in space,” (p. 83) and they point out some excellent examples by artists Jason Salavon and Michael Najjar.

We decided to try the technique across the Super Bowl program covers by just grouping them into 10-year spans. The results are below. In her work, the student chose to focus on the apparent shifts towards the imagery of the trophy from the images of players and places. The trophy took central prominence, with a more uniform focus in the final series.

superbowlcoveraverage1-9 superbowlcoveraverage10-19superbowlcoveraverage20-29 superbowlcoveraverage30-39 superbowlcoveraverage40-47

To accomplish this averaging, we used ImageMagick. There’s an “evaluate-sequence” function with a “mean” option that will allow you to take a group of images, average them, and create a file of the results.

Imagery can be a very useful source for analysis by historians, and as more collections of digitized imagery become available to historians, I’m looking forward to seeing what we can do with those collections.


Sense of Depth

Computational tools afford us the opportunity to revisit historical collections, exploring and experimenting with sources in new ways. Stereoscopic images are ripe for this sort of engagement. Once popular pastimes that were viewed through binocular stereoscopes, they recorded scenes from two positions, to capture a scene as a pair of eyes would see it. The viewer was able to see the depth of the scene through the stereoscope, as each eye saw it’s own unique view of the scene.

The stereoscopic images that remain offer not only the visual record of those scenes, but retain that depth information captured by those two viewpoints. Although stereoscopes are less likely to be at hand today in order to view those images, we can still explore the depth they provide using image processing software to get a sense of the depth information recorded among them.

My research of magicians has often led me into the topic of mediums and seances, and in particular, I’ve found the Thomas Glendenning Hamilton collection at the University of Manitoba a rich and visually compelling archival source. Hamilton was a physician in Winnipeg in the early twentieth century. He recorded seances in a variety of formats, from taking notes to capturing images during seances with remotely controlled banks of cameras. In particular, stereoscopic cameras were included among the apparatus he used to record moments of those events.

I wondered how much more, if anything, I could see of those images — could I get a better sense of being in one of those seances? In what ways could the stereoscopic images be used without the original image at hand, and without a stereoscope?

A couple of stereoscopic images from the collection stood out to me for the action they portrayed. It looks like some seances were dangerous places to be in the 1920s.


Image courtesy of the University of Manitoba’s Hamilton Family Fonds


Telekinesis #26f – Levitating table

Image courtesy of the University of Manitoba’s Hamilton Family Fonds

Wobble images were my first attempt to view these. This process takes each stereoscopic image — the left and right views of the same scene — and uses them as frames of a very small movie. The images alternate, each viewable for just under a second. This flickering image, though, gives a sense of the depth in the scene as objects within it are situated in slightly different positions due to the two vantage points.



These two images should look like they’re wobbling or flickering. If not, open them in a new tab or window to see the full effect.

To make these, I used GIMP — a free image manipulation program. I imported the original stereoscopic image, and cut each image out of it. I saved each of these so I’d have a left and right image on its own. I then opened the left and right images as layers, and used the Animate filter in order to generate a animated GIF of the scene. When exporting the results as a GIF file, there’s an option to specify the duration of each frame. For these, I used 800 milliseconds. When viewed, an image is shown for just under a second, then it switches to the next image that is shown for 800 ms, and then back to the first. The cycle just loops continuously.

Viewing these, our brains create a sense of some of the depth in the images from the changes of position between the two scenes. In particular, we can sense the inside of the box, the flying table, and where people are situated. In the first image, I was drawn to the medium’s raised foot. Is she dodging the table, or could she have kicked the table? The expressions of the observers stand in contrast to the action of those within the seance circle.

In the second image, the observer’s facial expression is very puzzling, especially when combined with the position of his hands. Is he holding back the table, throwing it, or removing it from where it landed?

The flickering of the second image seems more harsh because the one image is brighter than the other. The jerky motion of this simple animation is also at odds with the original production of the stereoscope — a static photographic capture of the scene.

I still don’t have a stereoscope, but I do have red/blue 3D glasses from various sources. GIMP can also be used to create anaglyph renderings of the scenes. These can be viewed with any red/blue or red/cyan 3D glasses, and the depth effect is dramatic and much easier to explore than in the wobbling images above.



To make these, I imported each view into GIMP as a separate layer. Above each, I put a coloured layer transformed into a screen. Above the right view, I placed a red screen. I made a copy of the red screen and inverted the colour of this duplicate. This left a cyan layer that was transformed into a screen. The red screen was merged with the right view, and the cyan screen was merged with the left view. Those two resulting layers were then combined to produce the results above.

These translations of the digitized stereoscopic images make the views they offered via the original stereoscopes accessible through contemporary media, and allow us another opportunity to explore the depth information recorded nearly 100 years ago.

Talk at University of Waterloo

Recently visited the University of Waterloo to give a talk on The 3D Historian: Technologies for Experimenting with Form, Matter, and Interaction.

Thanks Ian Milligan and the History Department at the University of Waterloo for inviting me, and being great hosts. Also thanks to all those who attended — it was nice meeting you all, and I enjoyed the great, cross-disciplinary discussions.

For more information on the talk, you can see the description at the Speaker Series website.