What is "centinels"

Usage examples of "centinels".

We seemed to enter the harbour of New York upon waves of liquid gold, and as we darted past the green isles which rise from its bosom, like guardian centinels of the fair city, the setting sun stretched his horizontal beams farther and farther at each moment, as if to point out to us some new glory in the landscape.

Along the gallery, and through the protracted hall, centinels are placed with every setting sun.