Another newb schematic reading question

First, thanks for the help on my last question! Second, I'm looking at a Fuzz face schematic and seeing a wire (labeled jumper) going from the switch to the neg. wire coming from the input which is going to the switch. How would one go upon wiring this? Is this just going to/creating a ground? Here's the picture:
**broken link removed**

If I'm completely wrong, a simple explanation of what is going on would be great! Thanks

Let's say the pins are numbered from 1 to 6, starting at the top left and going counterclockwise. Just connect pin 1 directly to pin 4 using a short length of wire (a jumper). Pin 1 then also connects to the tip pin on the input jack.


Cheers,

Torben