Get your gramophone running at its best with this Columbia speed tester! Simply place the indicator and a record on the turntable beneath a 50-cycle electric bulb, and watch the magic unfold. When it's spinning at 78 RPM, the lines stay perfectly still. If they zoom forward, it’s too fast. If they drift back, it’s too slow. All you have to do is adjust the speed lever, and voila! Your turntable is dialled in, giving you the smooth, crisp sound you crave. This gadget from c. 1950 was a must-have for any gramophone lover who wanted flawless, precise performance every time. Today's vinyl aficionados are probably unfamiliar with speed testers like this one, making it an important reminder of some long-outdated tech. Nowadays, you can test turntable speed with a smartphone app.