Why does circuit break when jumper inserted to power?

[dbconfession]

Here is a table for wire gauge (AWG) and Ohms (resistance) per 1000 feet. The only columns you need to worry about are the first and third. You can see that 1000 feet of a 22 gauge wire has a resistance of 16.0 Ohms. I would say a good estimate for the length of your wire is 1 foot. This gives a total resistance for your 22 gauge wire of 0.016 Ohms:

$${\frac{16.0 \, Ohms}{1000 \, feet}} = 0.016 \, Ohms.$$

http://www.picwire.com/images/paper9table1.gif
Source: http://www.picwire.com/technical/wire.php

Kavik. You'd posted this chart for copper wire reference. Some of the wire I'm using that came with a radio shack learning kit is visibly not copper (color of bare wire is silver). Do you think it's stats are comparable to those in your chart? And do you know what material is likely being used?

 

[Kavik]

It is probably tinned copper. Tinned copper is a bit easier to work with when soldering so I could easily see it being included in any learning kit. It is also less prone to corrosion.

Any differences in stats would be negligible for what you're doing since it's mostly copper. Try looking at the end of the wire after cutting it, you might be able to see a dot of copper in the center of the end's cross section (easier to see on solid core or larger wire). Scratching the wire down to the core might reveal the copper color as well.