Never has London seemed so crowded, and the American visitor foolish enough to arrive without hotel reservations is entitled to panic. Yet there are ways.

First, if money is no object, simply acquire the hotel guide to London (you can buy it in shops in Washington that specialize in travel books) and start phoning the most costly places. Often they can accommodate you, though it may cost better than $200 a night.

There is no point at all phoning the ordinary cruddy London hotel, the kind that goes in for tour groups, since they are counting on Indianapolis Explorers of Merrie Englonde to show up suddenly and take every room they've got.

If your firm has a branch in London, but if you are paying for your visit yourself, there is little point phoning the London office. Miss Blyster-Hyde, to whom you will be referred after a few hearty greetings from the office chief, will simply pick up the phone and get you a room at the Connaught, which will be very nice indeed, but see above.

The way to get a room is to leave your luggage somewhere and set out afoot in the quarter of the city you wish to stay in. I like Belgravia and Chelsea, for example, so I took the subway to Victoria Station and started calling at the many bed-and- breakfast establishments of the neighborhood.

The first one, the Ebury Court, was sick with dismay it could not accommodate me, being packed to the gills, but gave me a list of places it thought respectable and safe. The l2 or l4 on the list were, as it happened, also full. They say "No Vacancy" or, if they want you to know they know all about high life in France, "Hotel Complete."

You should then call on any hall porters you may have tipped adequately on past trips and ask if they know a good place, and they will say upon their word they have never seen the city so crowded, but try across the Eccleston Bridge and in Pimlico and west of Eaton Terrace.

In other words, keep on wandering about.

Sooner or later you will come to a place with a name like the Ashpitt and they do indeed have a room.

You pay in advance, about $40 a night, and walk up four flights, noticing the bathroom, which is located like the Base Camp of Everest. It has a plain door and a small bolt you cannot see from outside, so to use it you give a hearty push (it sticks, even when not occupied) and if somebody is inside he hollers "just a minute, please," and you can try the john ("loo," I think, is the standard term in England now) on the way to the basement.

You will admire the chaste elegance of the staircase, 26 inches wide and missing an occasional baluster from an earlier occupant with larger luggage than yourself, and especially the superb joinery of the mahogany handrail. One would hate to have to duplicate such a rail today. It rises three feet and makes a turn of 180 degrees in a width of only seven inches and yet is fully useful as a handrail every inch of the way. It is, I imagine, late Regency, like the carpet in several tints of rose.

The carpet is a treasure, evidently, since the full exertions of the three women who run the place are expended on its cleaning throughout the day.

The room, when you get to it, is off-cream in color with two single beds sagging a little under the weight of some raspberry-gray fuzzy bed coverlets. The sheets beneath are soft rose. A fireplace of about 1825 has been painted white and blocked with beaver- board in which a ragged hole has been broken, doubtless by a large man putting on his shoes standing up and losing his balance backwards.

A pastoral scene in green and orange is framed brilliantly in gold above the fireplace, and the one window looks east toward the garden, which is large enough for four trash cans and (if they had them) several thin cats. There are gauze curtains against the glass, held up on a curtain rod of string so it is not possible to slide the curtains open. There are only two moral rules in England -- you must not murder innocent people and you must have thin curtains at your windows, no matter how grimy or how near ultimate rot.

There is a light bulb hanging from the ceiling that works in all its 30-watt glory and three other lights that do not work at all. One lamp is two-pronged and the socket is three-pronged, so it will never work, of course. This lamp has sat unplugged, its prongs confessing inadequacy, since 1927. The new lamp, a pottery object of great size modeled on a whale rampant with a red shade, looks as if it should work. And it does once you negotiate with the landlady who expresses baffle- ment and believes the meters are out of order, but if you keep on and on it finally turns out you drop 50 pence in a slot inside the closet and the lamp goes on.

Breakfast is included, generously, in the price of the room. You dine in the basement beneath a color television set turned to Final Clarion volume, with a man and woman jabbering away about nothing, as in morning television in America, except that in England the woman wears a bizarre dress suitable for a late-night cabaret and the man is very thin with an unsuitable necktie and does not seem in good health. I felt every morning his hair might fall out.

Breakfast is a pot of coffee, originally good, but for economy's sake diluted 50-50 with water once it is made, a slice of Canadian bacon, a warmish fried egg that bleeds deep orange when you cut it, and four pieces of toast with excellent butter and marmalade and four knives.

I never ate anywhere in England with fewer than four knives. Other people did not seem to have so many. Something about me made them keep bringing knives wherever I ate. The only thing you need even one knife for is to spread the butter, but I quickly learned to get all four knives dirty so they wouldn't think they had wasted their effort fetching cutlery.

My understanding is that some sort of inspector pops in and looks at the entrance hall and staircase. In any case, the ladies are sufficiently exhausted hoovering it throughout the day that you cannot expect much to be done in the rooms. The raspberry-fuzz bedspread was always put back in place, and the shaving cream can was always carefully removed from the bedroom hand basin and tucked back in the canvas bag, partly to show me I was getting good valet service and partly, I think, to make certain I would spend five minutes each morning poking about to find it.

Of course I have stayed in many other places in England besides the Ashpitt, but since they are all going to be full I thought it well to describe what is actually going to be available and how you find it.

At Oxford, and this may be the place to say there are splendid places to stay outside of London, I greatly admire the Randolph, a hotel built about 1850 and still boasting a grand staircase like the Paris Opera. It has a particularly fine fire alarm, which went off at 5 one morning in a voice different from any fire alarm in America. Still, when you heard it, you sensed you were supposed to get out of bed. Merely wires and smoke; the hotel is intact.

For reasons I cannot say, I feel wonderfully at home in the west of England, though my family came from Lincoln, and I love the Lion Hotel at Shrewsbury. The Lion is typical of old coaching inns adapted to our time, which means that once you get to your floor you prowl about for between four and 12 minutes and by golly there your room is, after all. These wonderful old inns were the original model for rabbit warrens, rabbits not having been introduced into England until the time of William the Conqueror, from France.

Unfortunately you may find the food in these marvelous old places a bit bland. I thought that so far from London -- but, behold, there was the same pink sauce in the dining room. It is sometimes worthwhile, even if dinner has been paid for in advance with the room rent, to plunge down the hill to some recommended wine bar where you may find (as I did) splendid vegetables, medallions of lamb, fine bread and coffee, for about half the price of such food in Washington.

"Of course the chef is English," the pleasant waitress said. "I think it odd that everybody keeps asking that."

You must know that even when staying at places like the Ashpitt, you will find them perfectly adequate. It only got dark about 11 p.m., and it was light by 5 a.m., so the visitor is certain to walk dozens of miles a day as the light lasts. If it's not some glorious St. Mary the Virgin, perhaps with amazing buttresses of a type you have never seen before, then it's the funeral cross set up by Edward the Confessor, or a remarkable wool market where nobody speaks English though all the wool is. Lured from one extraordinary sight and adventure to the next, you will drop exhausted upon the raspberry fuzz and sleep the sleep of the typical innocent American.

You may also, if you spend day after day in London going to the great gardens of Kew and Wisley and to hell with the weather, come down with something rather like pneumonia, which makes the bed at the Ashpitt seem welcome indeed. I read all the "Pickwick Papers," for example, at the Ashpitt, and regard this volume (new to me) as possibly the best guide to travel in England that I have yet come across. It is not new. But then neither is the Ashpitt.