ClipArt ETC
"The coil is of flat, rectangular shape, with a narrow central opening just large enough to allow one of the magnets of the astatic system to swing freely. The other magnet swings over a graduated circle placed on the top of the coil, and serves also as an index. Sometimes a mirror and scale are substituted for the index and graduated circle. The sole on which the coil stands is movable on a fixed piece which can be levelled by means of three screws." &mdash Encyclopedia Britannica, 1893

Astatic Multiplier

"The coil is of flat, rectangular shape, with a narrow central opening just large enough to allow one…

An illustration of Macedonio Melloni's thermomultiplier, a combination of thermopile and galvanometer.

Thermomultiplier

An illustration of Macedonio Melloni's thermomultiplier, a combination of thermopile and galvanometer.