I don't remember seeing one "in the flesh". Hint....it's been around for more than a century, it still works. Looking at interesting stuff and guessing, is fun. Similar to the way we SEEM to do presidential elections in the USA. UPDATE: Readers here are so well informed. This device was made in 1916 and yes indeed, it is a telegraph machine for sending & receiving Morse Code. Coincidentally or not, the most recent Season III episode of "Star Trek Discovery" contains a scene where good guy crew members are held hostage by proverbial bad guys from The Emerald Exchange (dark green skinned folks who engage in galactic trade & capitalism [more subtle media brainwashing, by the way]) plot a successful escape right under their captors' noses by feigning boredom, tapping out their attack plans with their fingers, using......MorseCode. Turns out it's a requirement for 1st year Star Fleet Academy cadets.
This device is a symbol of communication; at the time telegraphs and Morse Code were widely used a century and more ago, who imagined >100 years ago the e-mail, texting and live streaming video of year 2020? Who imagined in year 1816 this device of a century later? We will all be here in spirit but not flesh, to see communication methods year 2130 considers normal, including what's used to bring what shows up on this website. The Committee has displayed this scenario to me; I like it, mostly because it feels natural & normal in ways I often do not.