What mood does the cluster of images in the first stanza create?

Overall, the images in the first stanza of Thomas Gray's "Elegy Written in a Country Churchyard" create a mood of melancholy, tiredness, and finality.

There are four main images here, one in each of the first four lines. In the first line, Gray describes a "curfew" tolling, and we can assume this image refers to a tolling bell in a church yard. In the second line, Gray paints a picture of an ambling herd of cows, and in the third line he discusses a tired plowman heading home after what we can assume was a tiring day. He ends the stanza by describing the falling darkness and the isolation of the narrator, and so we know that the poem takes place during the evening and in solitude.  

There is a certain peaceful element to these images, as Gray is certainly illustrating a classic pastoral scene, one that most of us will probably associate with natural beauty and good, clean farm work. However, there is a persistent melancholy streak at work here; whether Gray is describing the "weary way" (3) of the plowman, or the tolling of the bell (1), a faintly ominous image, we get the sense that this is an exhausted world and that something is coming to an end. By beginning his poem with a mood of sadness and tiredness, Gray prepares us for a discussion on the toil of common folk and the melancholy, bittersweet beauty of a peasant's life.