Electroscope
From Tardis Wiki, the free Doctor Who reference
The electroscope was a type of device used by the Thals of Skaro to map their own star system as well as others up to the range the device allowed. (TV: "The Ambush" [+]Part of The Daleks, Loading...{"namedep":"The Ambush (4)","1":"The Daleks (TV story)"})
