Mexico's National Museum of Art is housed in one of the intimidating buildings erected during the presidency of Porfirio Díaz. It contains a small but exquisite collection of paintings and sculptures by Mexican artists. I've enjoyed viewing it twice and I'm convinced it merits a third visit.
Originally the building was built to contain the Ministry of Communications: in fact the name is El Palacio de Comunicaciones, carved into the stone above the main entrance.
On a recent visit I was distracted by a phone call. While waiting for me to finish, Laura went exploring in the nether regions of the ground floor, where she discovered this—a museum dedicated to the telegraph.
Ye Gods! What a treat for a retired electrical engineer! And totally unexpected. In one moment I was appreciating José María Velasco landscapes; the next I was swimming in techie gear.
Albeit tech stuff from long ago—like telegraph sending and receiving sets. This one might have been used for practice. You operate it by sitting behind it (in this view), tapping out messages on the red-knobbed key, and receiving the return message by listening to the clicks and clacks of the sounder (the complicated thingy on the far right).
As a boy, I learned Morse code practicing on a set similar to this one, except mine was about a hundred years newer.
Imagine you are working in the telegraph office in Mexico City in 1870. Telegraph lines come to the city from all over the country. Suppose an operator in San Luis Potosi wants to send a message to the station in Veracruz. To connect these two particular lines out of all the dozens of lines coming into your office you need a crossbar switch. That is what this is.
You make connections by pushing tapered brass pins into holes between the lines you want to connect. It's crude, it's primitive, it's effective. This board contains somewhat fewer than a thousand individual switches. The computer you're using to read this post contains more than a billion, and they operate about a billion times faster than push pins. The principles are the same; the technology has just become a million billion times more efficient.
If you don't use wires to transmit signals, you don't need a crossbar switch. Guglielmo Marconi developed the first practical wireless telegraph, using a spark gap transmitter of which this is an example. Marconi is a rare case of an engineer winning a Nobel Prize.
This machine may not do much for you, but to me it's beautiful: all that hand-worked brass, copper, wood and iron. They don't make 'em like this anymore.
Thank God.
Transmitting with one of these machines is like throwing rocks into a pond with someone on the opposite shore counting waves to decipher the message. In effect there's only one channel: whoever throws the biggest rocks is the one that gets heard. Because of this kind of interference, it's illegal to operate a spark gap transmitter today.
This set is similar in many ways to the spark gap radios aboard the Titanic. The ship's wireless operators were too busy sending passengers' personal messages to pay attention to warnings of icebergs sent from other ships. It's the Dilbert story: engineers provided a solution, management screwed it up.
None of the technology on display in the Telegraph Museum was developed or manufactured in Mexico, but it's relevant nonetheless. Wires connected the country so that the government could react quickly to events. The telegraph set Mexico on the path to becoming a modern nation. I'm gratified that someone in the Ministry of Communications took steps to see that it wasn't forgotten.
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