Prince Charles, as all London knows, is preparing for his July 29 wedding to Lady Diana Spencer by playing polo and falling off all his favorite horses.

Actually, the prince is lean, atheletic, virile, loya, courteous and kind, and it is well known he is a superb polo player except that he spares the horses.

Which endears him to most of the Britons, of course, since in general they think it is better for you to break your neck than bother the horse. It is true he has taken a tumble or two -- who has not? But you would think he was Gerald Ford, the way the British amuse themselves talking about falling off horses.

His ears also are objects of common reference. His ears are somewhat like Clark Gable's, if you remember him, but Londoners pretend omewhat he can barely walk faster than a funeral procession without becoming airborne.

I have here in my hand a commemorative trinket box made of Staffordshire clay, which shows the prince with one ear concealed by his hair and the other one perfectly unexceptionable. Of course, what they can do nowadays with trinket boxes is amazing. Lady Diana, who is shown with him in this immortal potsherd (pottery fragments outlast empires, you know) has rather a severe, if not petulant, aspect. Dame Rebecca West, a person of letters, said she looks like a thatched cottage, in allusion to her simple minded hairdo, but most Londoners regard her as one of the most desirable cottages anywhere around.

London stores are full of junk commemorating the royal marriage, if one may intrude an opinion, but then one man's junk is another man's art object. Such old companies as Royal Worcester and Wedgwood have burst forth with plates, tankards, mugs and much else with portraits of the happy couple. The English, who have always lagged far behind the rest of the civilized world in every visual art except architecture, really should not be allowed to make plates and saucers with people's pictures on them, but since the English do not know this, they are relatively content with these souvenirs.

The capital itself, in a most English way, is detectably but with deliberate speed garlanding itself for io hymen (as the classic Greeks used to say) and such giddy institutions as the London Ritz have started hanging tremendous swags of blue bunting out the windows at Picadilly.

A bus, a series of city buses, is a fine way to see the spreading air of festivity, which will burst all bounds next week.

"Bus full," cries a functionary of Pakistani origin on the 137 bus. "But surely," compalins a nun heading a delegation of the religious waiting on the sidewalk, "we could squeeze in?"

"Bus full, says the ticket-taker, who has perhaps but one English phrase.

You leap on, ashamed of yourself with the ladies still on the sidewalk, and flash a great American grin.

"Bus full," he says, as he takes your money and you thrust forward to a position from which you can see the wheels of many international cars, thus preparing yourself to describe London decor.

This may be a straw of empire here: dogs are losing status in England. ya reporter must be honest, if it breaks his heart. As you know, a hound rides the bus free, provided he does not occupy the seat of a paying passenger, and provided you hold him. If you have two hounds, you must pay for the second one as if he were a child of 5, and the formula is quite clear, depending on whether the fare is this or that.

But in London now, you see no hounds riding buses. You do see them still in department stores, snuffing among the goods as their masters browse eight feet away. But it is known that you not only see no dogs in city pubs, as you used to, but also there are actually signs, "no dogs allowed" in many places.

This the empire collapse day by day. In the great days, dogs were everywhere, and if they were not in the Church of the Assumption getting regularly blessed, they were in pubs shooting darts. Eh, it is a different city now.

The queen mother, at least, is faithful to her corgis, and in more than one great portrait of her with Prince Charles or other persons of note, she sits in a lawn chair with half a dozen mutts peering out beneath the furniture.

This great lady sometimes has a toddy, and the lowest of the low have been insolent enough to comment on it.

"It endears her to your common bloke, who also likes his toddy at the end of a hard day," said a student and observer of London. "She is now old, she has always performed her duties flawlessly, she has always shown a most gracious expression on her face, no matter what the circumstance. Obviously you do not accomplish all these things if you drink greatly. But some people are forever looking for something snotty to say."

This is an extremely poor time for anyone to be snotty about the royal family. Virtually everyone in the kingdom can remember youth and love, and feelings run warm and sweet for the royal couple.

A portrait has gone on display here of Diana. In pants, God save us all. One does not know what the younger generation is coming to. The painting reminds one of Matisse. The British are not at the cutting edge, but the portrait is sufficiently late 19th century to have outraged those who like to see princesses weighed down with brocades and pretty well Kohinoored over.

She has not even got an ostrich feather. Well, times change.

Beneath the charm, the quite endless charm if one may so, of this old capital, lie the tensions common to all great cities of the world now, at least all great civilized and rich cities.

You can see posters by police stations warning of terrorists. You can see instructions in the subways not to touch any untended parcel but to ring the emergency bell at the next stop.

You can hear, especially in the less rich parts of town (which is most of it) words for racial minorities that have not been heard in America for 20 years.

A sandwich and a cup of tea cost $5 in a modest department store, and most Londoners make substantially less than most Americans, and moreover the unemployment rate is higher. As money pinches more and more, the English struggle harder to keep or to achieve a standard of living that provides minor luxuries, and which for many is increasingly impossible to attain.

It is estimated, for instance, that 30 billion dollars of earned income is not declared for income taxes each year, reflecting the increase in moonlighting, as breadwinners work themselves to the bone after their regular jobs to make extra money. Very often they feel their sweat and energy entitle them to keep this money untaxed, and there is alarm (especially among those who are comfortable) that this tax cheating is not good for the moral climate of the realm.

But the tone of London, despite what you may read of riots, is far from panic, far from despair, far from gloomy. It sparkles.

Race tension of the sort so common in America in the '50s is quite unknown here, despite the ugly words you hear at Earl's Court or Paddington. Reporters speak only to a few people, choosing them, and there is a human tendency to embellish one's fear and to project them.

But it does not seem very like Mississippi in the mid-'60s.

A comedy group here known as the Goons (once including Peter Sellers) is a favorite of the prince. One of them has written a wedding poem, not much in the manner of Edmund Spenser perhaps, but saying in effect the palace is enchanted to be rid of young Charles who really should be on his own and who has been rather an expense to his parents.

It also alludes to falling off horses, of course. The London press solemnly waits for royal reaction, but the affectionate bantering tone of the work almost certainly ensures that the prince, at least, will like it.