Figure (. Schweigger madi rms peculiar construction of 

 wire coils, wound endwise on .1 shorl vertical section of 

 glass tubing with .1 compass needle inside, merel; to 

 startle his Halle audience w it!> the fact thai the compass 

 needle could rest in any ol several stable positions. 

 1 rom Journal fti) Chemit und Physik.) 



11 k 1 111 R WORDS \i»OUT 



I III \l \Y \1 U,\l I It I'HI \()MI \ \" 



I 1 lii— w.i- presumably written between November I. 

 d thi I " I, 1821, publii ation date ol 

 In- Journal.] 



[Tiese wonderful new electrical effects are 1 1 n .■- 1 

 easil) rendered perceptible with the help ol the pre- 

 \ i(iu-l\ described wire loops. I focus .me] nidi, on jus) 

 one ol the windings ol I igure 3, we sketch .i new draw- 

 ing, Figure -,.... Since ii i- ol majoi importance 

 that these loops be made of silk-covered wire lying 

 evenl) on one another, ii is convenient to wind the 

 loops on two small slotted -ti< k- of wood, although ii 

 i- also possible in hold the wires together with w.i\ 01 

 shellac, 01 to tie them togethei in an orderly mannei 



with -ilk tine. id .... 



In Figure 5, Aa and C< represeni litde slotted rods 

 of wood on which the silk-covered wire i- wound. Only 

 three windings are shown in the figure, but I generally 

 adopl three times th<u many. Now 1 i- connected with 



ii ppei and d with the zinc, and the compass 15 set 



between the rod- \.i and O w iih the coil perpendii ulai to 

 die magnetic meridian and the terminals <l. 1 al the east. 



I he instant / and K are dipped in the ammonium 

 chloride solution, the needle nun- around and stays with 

 the north pole point south .... 



[f now the compass is taken out of the coil and put in 

 position b. all effects are reversed, and are considerably 

 weakei . for ol>\ ious 1 easons .... 



•''The reference here is to the Oersted-type experiments 

 described in two papers l>\ authors other than Schw 

 es 19 to 14 ol the volume. 



Figure 5. s > uu 1 toci r's suggesi i< in 

 of one possible design foi an ampli- 

 i\ ing electromagnetic indii at u 

 I In- components are wooden rods 

 and insulated wire. Position l> 

 referred to in the text i- at the 

 bottom of the diagram between the 

 letters .1 and 1 I From / urnalfiir 

 und Physik.) 



PAPER $8: IVRIIISI ELECTROMAGNETIC INSTRUMENTS 



131 



