796 



Magnetism. 



No. (id IX, 



60 139. 1 : 7. 



60137. 1:10. 



60 140. 1 : 8. 



60.135. Pole Balance (Grimsehl's), for determining the pole-density of magnetic needles, 

 Figure (Ztschr. f. d. phys. u. chem. U. 16, p. 334) 



Three stands carry: 1 knitting needle which takes the form of a balance with rider scale; 1 

 vertical rule and 1 horizontally arranged magnetic knitting needle which is adjustable vertically. The 

 repulsion of the two similar poles of the knitting needles is taken up by rider weights and so measured. 



60.136. - - idem, especially for determining the horizontal intensity of terrestrial magnetism, 

 Figs. 60,135 and 60,136 (Ztschr. f. d. phys. u. chem. U. 16, p. 337) 



60.137. Magnetic Pendulum, Figure, as suggested by Bussner (Ztschr. f. d. phys. u. 

 chem. U. 20, 1907, p. 96), for subjective and objective observation; independent appa- 

 ratus, on polished stand 



The apparatus is used for proving Coulomb's Magnetic Law, for proving that the total affect 



of a short magnetic rod on a single pole equals -' for determining the magnetic moment and 



the pole-density of a magnetic bar, the field-density of a short and a long coil (Biot-Savart's Law), 

 the magnetic induction and hysteresis of iron. A complete description and instructions sent on 

 application. 



Given in are: 1 short and 1 long bar magnet; 1 short and 1 long magnet coil, and 1 adjustable 

 projection lens. 



60.138. -The same apparatus, for placing on the optical bench of projection 

 apparatus. Price without stand or projection lens 



<>o, 1 39. Apparatus for determining the horizontal component of terrestrial magnetism, F i g u r e, 

 Kussnci's (Zlschr. f. d. phys. u. chem. V. 20, 1907, p. 172) 



Complete description on application. 



ii. 



I. 



60,140. Thermo-magnetic Apparatus, Figure .................... _. 5. 



A star formed of iron bars is arranged to rotate in front of the poles of a powerful magnet. 

 In the position where ;m iron bar is attracted by the magnet, the latter is heated to a red heat b\ a 

 Bunsen burner which is set up and it thereby loses the magnetism produced in it by distribution. 

 and the next bar is attrarted by the magnet. The star is therefore set into slow rotation. 



01. 5580. 



5589, 



