.. Jalbum 8.1 <p> A <a href="http://humboldt.edu/~scimus/Instruments/Elec-Kimball/ResBoxKim.htm">resistance box</a> consists of coils having different resistances, made so as to be conveniently used in measurements. On the ebonite or hard-rubber top of the box are mounted a number of blocks of brass which can be connected by brass plugs fitting between them. Within the box are the resistance coils wound on spools, one end of a coil being soldered to one block and the other end to the next one so that one coil bridges each gap. The external circuit is connected at the terminal binding screws, and when all the plugs are in, the only resistance is that of the brass blocks and plugs themselves. But if a plug is pulled out the current must then flow through the coil joining the blocks, and accordingly that resistance is introduced. </p> slides/DSC_0016.html Sat, 06 Dec 2008 20:48:27 +0000 slides/DSC_0016.JPG slides/DSC_0022.html Sat, 06 Dec 2008 20:48:27 +0000 slides/DSC_0022.JPG slides/GSBA.html Sat, 06 Dec 2008 20:48:27 +0000 slides/GSBA.JPG slides/Philip_Harris_Resistance_Box.html Sat, 06 Dec 2008 20:48:27 +0000 slides/Philip_Harris_Resistance_Box.JPG slides/Post_Office_box_Pye.html Sat, 06 Dec 2008 20:48:27 +0000 slides/Post_Office_box_Pye.jpg slides/Resistance_box_Gambrell.html Sat, 06 Dec 2008 20:48:27 +0000 slides/Resistance_box_Gambrell.jpg slides/Resistance_box_George_Becker.html Sat, 06 Dec 2008 20:48:27 +0000 slides/Resistance_box_George_Becker.jpg