A text-book of physics, largely experimentalOn the Harvard college "Descriptive list of elementary physical experiments." . d the compass upon it is small.(See Fig. 250.) No. 101. The solid parts of a small Daniellcell, the copper and zinc plates provided withwires, about No. 20, some 30 cm long. No. 102. A simple commutator for electriccurrents. (See Fig. 256.) No. 103a. Six wooden spools (Fig. 303, halfsize) each wound with uncovered No. 30 Ger-man-silver wire, two of them carrying 200 , one carrying 100 cm., one 120 cm., one80 cm., one 40 cm. * No. 103 b. A similar spool with 200 cm.
A text-book of physics, largely experimentalOn the Harvard college "Descriptive list of elementary physical experiments." . d the compass upon it is small.(See Fig. 250.) No. 101. The solid parts of a small Daniellcell, the copper and zinc plates provided withwires, about No. 20, some 30 cm long. No. 102. A simple commutator for electriccurrents. (See Fig. 256.) No. 103a. Six wooden spools (Fig. 303, halfsize) each wound with uncovered No. 30 Ger-man-silver wire, two of them carrying 200 , one carrying 100 cm., one 120 cm., one80 cm., one 40 cm. * No. 103 b. A similar spool with 200 cm. ofNo. 28 German-silver wire. No. 103c. A similar spool with 2000 cm. ofNo. 30 covered copper of the wires of Nos. 103a and 103b should be of the samequality, all of the No. 30 being, if possible, from the same piece. Every spool should be soaked in melted paraffin before the wireis laid on it. Every wire should be wound in such a way as to haveno magnetic effect. Every spool should be dipped, not soaked,in melted paraffin after it is wound. At some point on each spool the wire should be left so exposed. Fig. 303. APPENDIX I. 547 that its diameter can be measured b}r means of screw calipers. Forthis purpose a bit may be left projecting beyond the point of solder-ing to the heavy copper terminals. No. 104. A pair of double binding-posts for use with, the spoolsof No. 103. No. 105. A pair of triple binding-posts for introducing two ofthe spools of No. 103a into the circuit in parallel. (Not necessary.) No. 106. A simple form of Wheatstones bridge, shown in , with thick connecting strips of brass or copper of very smallresistance in comparison with the thin German-silver wire, hi, onemeter long, which is stretched along a meter-rod (not shown), andis neatly soldered to the strips at each end. At a, b, d, e, f, g, and mare binding-posts. The post a has two nuts, and under the lowernut is a washer, the edge of which comes just over the inner edgeof the metal st
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectphysics
