Can you solve the two-fuse puzzle?

Here's a good riddle from Brian Brushwood of Scam Nation.  He found it in Book of Riddles by Fabrice Mazza and Sylvain Lhullier

Imagine that you're making a magic potion. You're a wizard with a long beard. But -- the potion only works if you wait exactly 45 minutes before you stir it. If you stir it before or after the potion's totally ruined. You don't have a smartphone. You don't have a watch. You don't have any kind of time measuring device. What you have is two fuses of irregular consistency. The one thing you know for a fact is that it takes an hour for each of these fuses to burn from one end to the other. How do you use these to measure exactly 45 minutes?

Image: Scam Nation/YouTube

I'm still trying to figure this one out, so I'm not looking at the comments yet!