Revelation 9:1
And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit. And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.
The fifth trumpet belongs to the prophecy of Revelation 9, whose time periods were calculated to fix a date for the fall of the Ottoman Empire. That calculation pointed to August 11, 1840 as the appointed day. On that day Turkey was to surrender its independence by placing itself under the protection and control of the European powers. When the event took place exactly as predicted, it was taken as a precise fulfillment that confirmed confidence in the rules of prophetic interpretation and gave powerful impetus to the Advent movement.