No. 17. A small box of iron filings from soft iron.
No. 18. A compass ([Fig. 5]). The needle swings very freely; it is enclosed in a wooden pill box, the cover of which forms the support.
No. 19, 20. Two soft steel wire nails, 2 in. long.
No. 21, 22. Two pieces of spring steel, about 3 in. long and ⅜ in. wide, to be magnetized by the student and used as bar magnets.
No. 23. An iron ring, or washer, about ⅞ in. in diameter.
No. 24. A sifter for iron filings. This consists of a pasteboard pill box: Prick holes through the bottom with a pin.
No. 25. A thin, flexible piece of spring steel, about 3 in. long and ⅛ in. wide.
No. 26, 27. Two ebonite sheets (E S, [Fig. 34]), each 4 in. square. These are made with a special surface. They are very much better than the ordinary smooth ebonite.
No. 28. One ebonite rod (E R, [Fig. 34]), 3½ in. long, with special surface.