Past Perfect usage in Literature

I am a little bit confused about the Past Perfect usage in the following fragment which is from George Eliot's Adam Bede. I don't understand why she uses Past Perfect and I wish someone would explain it to me. Thank you!

All hands worked on in silence for some minutes, until the church clock began to strike six. Before the first stroke had died away, Sandy Jim had loosed his plane and was reaching his jacket; Wiry Ben had left a screw half driven in, and thrown his screwdriver into his tool-basket; Mum Taft, who, true to his name, had kept silence throughout the previous conversation, had flung down his hammer as he was in the act of lifting it; and Seth, too, had straightened his back, and was putting out his hand towards his paper cap. Adam alone had gone on with his work as if nothing had happened. But observing the cessation of the tools, he looked up, and said, in a tone of indignation, “Look there, now! I can't abide to see men throw away their tools i' that way, the minute the clock begins to strike, as if they took no pleasure i' their work and was afraid o' doing a stroke too much.”