No. 86. Two ounces of copper sulphate, commonly called bluestone. The crystals may be kept in a large wooden pill box.
No. 87. One dozen copper washers.
No. 88. One combination rule, 1 ft. long, marked with English and metric systems.
No. 89. A hollow coil of No. 24 insulated copper wire ([Fig. 130]). The spool, on which the wire is wound, has a hole for a five-sixteenths inch core. It is turned down thin, so that the wire is near the core. The coil is about 1⅛ in. long and 1 in. in diameter. Spring connectors are joined to the ends of the coil.
No. 90. A hollow coil of No. 25 insulated copper wire, similar to No. 89, with spring connectors attached to its ends.
No. 91. Carbon rod for electroplating.
No. 92, 93. Two soft iron cores, with screws (I C, [Fig. 130]). These cores are 5/16 in. in diameter, and have a threaded hole in one end for fastening them to No. 94.
No. 94. A tin box with three holes punched in its top ([Fig. 132]). This serves as a base, as well as a yoke, for the two electromagnets, A, B, shown in plan.
No. 95. Combination connecting plates ([Fig. 132]). Three aluminum straps are fastened to a wooden base. They are turned up at their ends so that spring connectors can be easily pushed upon them.
No. 96. One long iron core (L I C, [Fig. 140]). This is of soft iron, 5/16 in. in diameter, and long enough to pass through both coils (No. 89, 90).