poetic vision.

Wordsworth is a great observer. So often his poems are about a particular sight, or moment, which is given heightened effect in recollection. In the case of the "Westminster Bridge" poem, Wordsworth is characteristically conjuring the memory of a particular sight: a view of the city in early morning. The poem works to evoke the image of the sleeping city: "Ships, towers, domes, theatres, and temples lie / Open unto the fields, and to the sky; / All bright and glittering in the smokeless air." There is an artistic quality to these lines that both creates a mental image and evokes an emotional response. In fact, Wordsworth's purpose would see to be to recreate for the reader the conditions that led him to exclaim "ne'er saw I, never felt, a calm so deep!"

On the other hand, Blake's poem is not about a particular view of the city, but an account of the poet walking through it. The poet sees the city as symbolic of a kind of moral decay, and the poem is like a visionary revelation of this depravity. While Blake also uses concrete details, the nature of these details is not to aid recollection but to reveal moral truths. The "infants cry of fear," the chimney sweepers, the "blackening Church" all name particular aspects of London which the poet (the "I" of the poem) has witnessed, but their meaning is not in and off themselves but in their relationship to the symbolic. What the poet really experiences in his walk are the "mind forg'd manacles," the myriad ways people imprison themselves through sin. It's also significant that Blake ends with the "youthful Harlots curse," which perverts true sexual happiness.

William Wordsworth is best known as the poet of the lakes, composing pastoral verses about the effect of rural tranquility on the human soul. One might, therefore, expect to find him out of his element on Westminster Bridge, in the heart of a great city.

However, Wordsworth's sonnet not only describes the sight that greets him from the bridge as "touching in its majesty," but evokes a city that shares the serenity of the countryside. The great buildings of the city are

Open unto the fields, and to the sky;

All bright and glittering in the smokeless air.

William Blake was often scathing about the effects of the Industrial Revolution on the poorest members of society. What other men saw as progress and prosperity, he saw as degradation and oppressiveness. London in Blake's day may have been the largest, most prosperous city in the world, but for Blake that couldn't hide the filth, poverty, and unimaginable degradation that he saw lurking round every corner.

In "London" Blake peels back the outer layer of London to reveal the rotten heart beneath. This is a city in which misery is etched on almost every face; a place where the exploitation of children—in the form of chimney-sweeps—is rampant. Even the cries of innocent infants are full of fear; it's as if they can already anticipate the kind of life they'll soon be forced to lead. In this godforsaken place all the old values have been turned upside-down. This is symbolized in the blackening of church walls, presumably by the filth and pollution of modern life.

In "Lines Composed upon Westminster Bridge" Wordsworth also digs beneath the surface of London. But what he finds there is completely different to what Blake sees. As the city is just waking up for another day, he doesn't see any poverty, or degradation, or child laborers; he simply sees the glittering "Ships, towers, domes, theatres, and temples" touched by the glow of dawn.

But Wordsworth isn't just enamored of the glittering surface; beneath it he senses a "mighty heart" lying still. This is a living, breathing city, and though the sordid details of life in the capital would certainly not have been to Wordsworth's liking any more than Blake's, from his vantage point on Westminster Bridge all seems well with the world. For now, at least.

William Blake's "London" and Wordsworth's "Composed upon Westminster Bridge, September 3, 1802" are both about London. Blake's poem is four stanzas of four lines each and Wordsworth's is in sonnet form. 

In Wordsworth's poem, he favorably describes London as it appears early in the morning. He begins quite dramatically, saying that there is no sight "so fair" than this image of London in the morning: 

The City now doth, like a garment, wear

The beauty of the morning; silent, bare, 

Ships, towers, domes, theatres, and temples lie

Open unto fields, and to the sky; 

The city wears the morning's beauty like a garment in the morning, before people are awake, before the noise and erratic movement of city life. It is also before the factories and furnaces are churning out smoke into the sky. The speaker notes that the sun shines more beautifully on the buildings than it ever has on valleys, rocks, or hills. This is ironic because much of Wordsworth's poetry is about the beauty of nature and its lack of industrialized distractions. However, it fits with Wordsworth's love of nature that the city is quite literally asleep and is therefore as calm as a scene in nature. The 12th line does directly address nature, noting (at least at this hour of the morning) that the river moves freely. 

Blake's "London" describes the city quite negatively. He notes that each street is "charter'd" which has a double meaning: "given liberty" as in a charter, but also noted as private property and therefore rented out. This is significant to the rest of the poem because Blake comments on how the less fortunate are at the mercy of institutions, government and church. 

In the second line, he also describes the Thames as "charter'd" meaning that it flows freely (given liberty) but also that it is the property of the state. This latter meaning contrasts with Wordsworth's notion that the river "glideth at its own sweet will:" - whereas in Blake's poem, the river is owned. 

Whereas Wordsworth sees beauty in the city's morning, Blake sees "weakness" and "woe" in every face. Blake notes the limits and laws that act like "mind-forg'd manacles" and these include bans which can be legal or political prohibitions (ban can also mean a marriage proclamation, so Blake indicates that this arrangement is also like a business deal and/or a sentence). 

In the last stanza, Blake (or the speaker) notes that at midnight, he hears the prostitutes curse their clients. The curse "Blasts the new-born infants tear," and this indicates that the prostitute, having contracted a venereal disease will pass it on to a man who will then pass it on to his wife; thereafter, the child (of the man's wife or the prostitute) will have a blind child as a result. With the last line, Blake gets another jab at marriage which, as a ritual of an institution (the Church of England) much like a law, people becoming indebted to a certain way of life. 

Clearly, the two poems paint very different pictures of London. Blake's is bleak and Wordsworth's is full of beauty. However, Wordsworth is describing London in the morning, prior to the daily life of the city. Blake notes in the final stanza that he is viewing the city at midnight. Had Blake been writing at sunrise and/or had Wordsworth been writing in the evening or at night, their interpretations might have been different.