The fact that a considerable number of people sheltering under trees are killed by lightning is generally accepted as a convincing proof of the unwisdom of the proceeding.
When in 1897 King Oscar celebrated his jubilee of twenty-five years as king, the exhibition which had been organized in Stockholm offered a convincing proof of the progress the country had made in every direction.
The chief cause of the wastage of Napoleon's army was the rapidity of its movement, and a convincing proof of this is the corresponding decrease of the Russian army.
Though the provisions of the Tanzimat were not fully observed, they afforded convincing proof that reform was entirely practicable in Turkey.
His remarkable speech of the 24th of November 1791 is a convincing proof of his sagacity.