Our villainous Ned can use the other fuses in lieu of a watch. Here's how:
First, he takes one fuse and forms a loop so that the two ends touch at point A (see the diagram). Call this Fuse AA.
Next, he takes a second fuse and touches one end of it to the two ends of Fuse AA, and straightens it out to point B. Call this Fuse AB.
Then, he takes a third fuse and touches it to the loose end of Fuse AB, at point B. This will be Fuse BC.
Now Ned touches a match to point A. Fuse AA will begin burning at both ends, while Fuse AB will start to burn from A to B.
Because AA is burning at both ends, it will burn twice as quickly. Ned waits patiently, and as soon as AA is completely gone, a half hour has elapsed. He then immediately touches a match to point B, starting BC burning, and igniting the unlit end of AB.
At the moment B ignites, Fuse AB has half an hour left. But now it will burn twice as fast, and finish in fifteen minutes. As soon as AB disappears, Ned extinguishes BC and knows what remains will burn for forty-five minutes.
Now to abscond with Pauline!