Here's how to do a Jacob's Ladder:
The basic fabric needed is a combination of double crochet stitches and chain stitches. In this example, I've decided to do one ladder with 5dc on each side. To recreate it, ch22, dc in the fourth chain from the hook, and make 3 more dc stitches:
Skip 10 chains in the base chain, and make a dc in the 11th chain:
Make 4 more dc to take you to the end of the row:
Make a turning chain and dc in the next four stitches:
Chain 10, then dc in the next dc (skipping the ch10 of the previous row) :
dc to the end of this row.
Continue adding rows, working a dc into each dc, and working a ch10 over where a ch10 is.
On the second-to-last row, work the dc's as normal:
But this time, only chain 6:
Then dc to the end of the row as normal
On the last row, work dc stitches until you reach the chain space and then stop - draw the loop out larger so the stitches don't unravel:
Now grab a bigger hook and go down to the base chain. Twist the base chain to make a loop:
Insert the big hook in this loop:
Now, hold the loop on the hook with your left hand, and the hook with your right. Put the hook under the next ch10 loop:
Pull the second loop through the one on the hook while at the same time, lifting the loop on the hook over the second loop:
Put the hook under the next loop and pull that loop through while lifting the loop on the hook over the new loop.
Keep doing this until you pull the last (shorter) loop through:
Put the regular hook back into that big loop you pulled out before (it's time to start crocheting again!). Take the big hook out of the loop and hold it in your left hand. Put the regular hook through the ladder loop, from front to back:
And make a sc:
Then dc to the end of the row:
And you're done!
And no, there's no particular reason why the ch10 spaces have to be directly on top of one another, but don't put them too far apart. Shifting by one stitch is absolutely do-able.
If you want to replace the dc stitches with something else, you'll have to change the chain spaces - for shorter stitches, you'll need shorter chains, I imagine. I'm not sure if anyone has tried it out, yet.