Revelation 9:17
And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.
Revelation 9, to which this verse belongs, predicts the fall of the Ottoman Empire. It gives prophetic time periods of 150 years followed by 391 years and fifteen days, ending on August 11, 1840, when Ottoman power in Constantinople would be broken. This was exactly fulfilled on August 11, 1840, when Turkey through its ambassadors accepted the protection of the allied powers of Europe. In so doing Turkey surrendered its independence and placed itself under the control of Christian nations.
The fulfillment proved the correctness of the principles of prophetic interpretation used in preaching the second advent. It gave a wonderful impetus to the Advent Movement, so that men of learning and position joined in preaching and publishing the message. The work rapidly extended from 1840 to 1844.