Torching your dome will allow you to move to the next step.  You will keep your pot turning as you apply the torch so that no one spot remains under the torch for an extended period of time.  If you hold the torch for too long in one spot it will cause your dome to crack and the water inside your clay to boil and explode.  As you use the torch the air inside your dome will expand and make the dome a bit tighter.  You will not want this for to long a time period.  After you have used the torch in each spot for a period of about thirty seconds, and made the clay a bit firmer, you want to make sure you remember to use your needle tool to poke a little hole in the top to let the steam escape.