This bridge and testing set consists of an instrument with brass fittings in a wooden case with a lid. Marked: "Queen & Co. / Makers / Phila."; and "Queen & Co. / The Queen Acme Portable Testing Set. #1560." This is a bridge and testing set incorporating a self-contained galvanometer and plug connections. The resistors are not arranged in decades, but in series somewhat like the weights of a balance, namely. 1, 2, 5, 10, etc., ohms to 5,000 ohms. It would seem strange that at this period (1903). when the set was designed, it was not provided with a decade arrangement of resistors, which idea was a great improvement and was old at that time. Adjusted completed 30 October 1903.
This bridge consists of an instrument with brass external components mounted in a wooden case with a hard rubber top; marked “Elliot Bros, London, No. 1652". It 'is a dial plug type bridge having five decades adjustable from 0.1 ohm to 10,000 ohms. The original resistors in this bridge were probably made of platenoid which is an alloy of tungsten, nickel, copper and zinc. Manganin, which is not affected by temperature, subsequently replaced platenoid and all other alloys for this purpose.
This bridge and testing set consists of an instrument with brass blocks end terminals in a wooden case with a lid. Marked: "Whitney Testing Set / Catalog No. 755 Serial #19888 / Whitney Electrical Inst. Co , Penacook, N.H., U.S.A." The instrument has four decades, is adjustable from 1 ohm to 10,000 ohms., uses plug connections and incorporates a self-contained galvanometer. This type of set is used for general circuit and fault testing arid for general resistance measurement. Adjusted 10 February 1904.
