I have reached the stage where Holmes is trying to pinpoint where in Whitechapel the murderer lives by using ellipses drawn on the map. I can draw the yellow ellipse, linking Dutfield's Yard and Mitre Square, but cannot pick up the compass to draw the circle starting out from Goulston Street. As a result I'm totally stuck.

Does anyone have a solution?

Managed to solve it myself. The yellow ellipse needs to cover a much larger area than just the two points; eventually it lets you pick up the compass.