MEGGER

Sydney Evershed and Ernest Vignoles started an instrument company in 1895. Most famous would become their megger, an instrument for measuring resistances in the megohm range. This required a hand dynamo to generate high voltages. They invented a novel galvanometer that did not require zero adjustment and that was virtually independent of the generator output voltage.

I have a "Major Megger" and a small "Wee Megger" in my collection.