Although the time of day is not mentioned in the title of this poem by William Wordsworth, it is absolutely fundamental to the sonnet's subject and theme. Wordsworth is writing during a time in which London, and other cities in England and all over the world, were growing at extreme speed. The industrial revolution meant that, during the day, they were rarely still and were filled with smoke and activity brought about by the burgeoning factory trade. In this poem, however, the poet is concerned with the "beauty of the morning." In particular, he is talking about a time of the morning before anything has begun to work; nobody has yet gone into a factory, and nobody has fired up a furnace. As such, the majesty of the scene can still be properly viewed as something akin to what it was before London was a center of industry. It is because it is early morning that the poet can see the towers, ships, and domes of London in their true beauty and majesty, lying "still" and filling the viewer with "calm." At any other time of day, the city would have been a hive of activity, but at this time of day, its "mighty heart" seems still and it can be appreciated in a different way.
The time of day and the location are the most important factors in this poem. William Wordsworth was known for writing romantic poetry based on nature and country scenes. By contrast, here he stands on a bridge that crosses the River Thames, and he studies the way the early morning light reflects on the buildings of the city of London. In another hour, or even sooner, this place will be busy, filled with people and carriages and whatnot. It will look and sound quite different. For now, it’s a peaceful scene. Business hasn’t started yet. The poet can appreciate the calmness of the river flowing by and the sun just starting to rise on this large settlement of residents. He can find his nature even in the most civilized place. The key is to look for it around the edges of the day.