Other examples of this construction are,—
"It is on the understanding, and not on the sentiment, of a nation, that all safe legislation must be based."
"Then it is that deliberative Eloquence lays aside the plain attire of her daily occupation."
Exercise.
Tell how each noun clause is used in these sentences:—
1. I felt that I breathed an atmosphere of sorrow.
2. But the fact is, I was napping.
3. Shaking off from my spirit what must have been a dream, I scanned more narrowly the aspect of the building.
4. Except by what he could see for himself, he could know nothing.