6 



BEMJ. PIKE S, JR., DESCRIPTIVE CATALOGUE. 



Many pleasing experiments with needles, keys, steel filings, 

 and other iron or steel articles may be performed by the aid 

 of the horse-shoe magnet. 



Price, 2 inch, $0.31 ; 3 inch, $0.50 ; 4 inch, $0.75. 

 " 6 " $1.00; 8 " $1.50; 10 " $2.25. 



Fig 411. 



Compound Horse-shoe Magnet. (Fig. 

 411.) Compound horse-shoe magnet, or 

 battery of single horse-shoe magnets, 

 held together by screws or other contri- 

 vances. The association of several bars 

 is a set. Mounting with an appropriate 

 armature greatly increases the magnetic 

 power, not only for suspending weights, 

 but also the capability of making other 

 magnets. 



Price, 6 -inch, 3 bars, $5.00. 

 $7.50. 

 $10.00. 

 $12.50. 



8-inch, 

 10-inch, 

 12-inch, 



12-inch, 5 bars, $16 and $20. 



Fig. 413. 



Magnetic Needles. (Figs. 412 and 413, as above.) Mag- 

 netic steel needles of various lengths and forms, mounted 

 with central hard metal caps for suspending on pointed 

 stands, for the purpose of illustrating the influence of ter- 

 restrial magnetism as regards the horizontal directive force : 

 also the polarity of a magnetic body, by its attractive and 

 repulsive qualities, in relation to similar and dissimilar poles. 



Price, $0.38 to $1.00. 



