GALVONOMETER
This type of instrument was used in the 1900's to measure very low currents by sending a beam of light to the mirror shown in picture 1 and reflecting this back onto a wall using the miiror as an amplifier small currents in u/A can display a displacement of a few inches on the wall... This is how years ago without Modern Electronics they did get very accurate results and must have been a while setting things up.... This instrument has to be balanced and if you look at picture 2 there is an air buble in the middle and you can see the three adjustable feet.. The meter is scaled in degree's...... I was lucky to find this in a cellar at a junk shop in Bideford in Devon........ It was not working but soon repaired it....... Inside it is still in good condition all made of brass........... G3RFL
