THE ORIGINAL ambition of the gentleman who went over the brink was to have an enlargement made of a photograph of his little grandson. He had taken the picture himself, and had been rather pleased with the result, feeling that it captured the child's peculiar winsomeness, and he was proposing to have a large copy of it made to adorn the child's grandmother's office.

Having observed in his wanderings a small film development shop, of the sort that seem to be popping up in odd quarters everywhere, he made careful notes of the hours of business posted on the door, with the intention of appearing at an appropriate time with his request, negative positively in hand. Thursday hours being 8:30 to 6, he chose 10:45, a time that seemed to avoid extremes.

So far, you will notice, he had done nothing anti-social, illegal or even conspicuous.

Upon his prompt arrival at the shop, he encountered a locked door, with a handwritten note, "Back at 10:30." The gentleman consulted his gold timepiece, did some figuring, and concluded that there had been an error made, but not by his trusted watch. He was not used to whimsical business hours being kept in the center of the city, but nevertheless kept a posture of patience for a decent interval before concluding that it could be hopeless and retired, taking the opportunity to express his indignation by tapping the glass door (with his foot) before quitting the scene.

He was not yet over the brink. He went about his gentlemanly business for some hours, and, after a gentlemanly luncheon, returned to the shop at three in the afternoon.

The clerk, salesperson, film developmental resource, whatever one calls her, was presiding over the establishment, and consented to accept the commission of one photograph of a small grandson--large.

"You're not really literal about your hours, are you?" he remarked in a social tone as the transaction was being completed. "I was here until about 11 and you were locked."

The person looked up. "Oh, well," she said clearly.

"Oh, well?" asked the gentleman.

"Oh, well," she said.

"Oh, well?" he repeated, stupefied. "Oh, well?" His voice rose, and so did the blood into his face. He was still repeating "Oh, well," in increasingly shriller tones, as he departed, as he may be to this minute, for all anyone knows.

One moral of this little story is how near madness lies to all of us city dwellers. But another is that these unfortunate consequences, which may not yet be played out to ultimate tragedy (he still has to pick up the film) could have been averted with a simple apology.

The businesswoman did not feel, obviously, that she needed to make one. Perhaps she had a compelling reason to be out. Perhaps someone else had inconvenienced her, thus delaying her from her own duties.

No matter. What would it have cost to say, "Oh, I'm terribly sorry you were kept waiting--it was an emergency, and I do apologize." What does it ever cost to inject a soothing note, rather than one of defensive indignation, into a jarring situation?

Have you apologized at least once today, on behalf of your employer, your umbrella or your dog, however loyal you may be to what is yours?

No? Because it wasn't its (your) fault. Because it isn't your concern. Because people have done worse to you.

Oh, well. MISS MANNERS RESPONDS

Q. My daughter is getting married for the second time in three years, and wishes to send out invitations. My question is--is it appropriate to send wedding invitations to family and friends the second time around?

A. As long as it is appropriate to get married, it is appropriate to invite family and friends to the wedding. Twice in three years does not seem to Miss Manners to be excessive by today's standards.

However, if your daughter is planning to keep going at this rate--and perhaps even now--you should make allowances for the fact that people will not quite make the same fuss as they would if the event were unique. Presents are by no means as conventionally given for second marriages as for first, for example.

It is also considered polite to vary the event somewhat, to keep the spectators interested, and also to remove from them obvious opportunities for satirical comparison. This is one reason for the "quieter" second wedding, and also a reason why that very custom is often ignored by people who had simple first weddings and wish to do it up thoroughly at the next opportunity.

"Quieter" does not refer to the noise level, and hence the supposed amount of merriment, or even the number of guests. It means that you save on engraving costs by inviting people by individual letters ("Hortense is being married to Arno Smiles on Saturday the twenty-seventh and we do hope you can be with us . . .") and you put the wedding costume money into a stunning dress or suit that a real person might wear in real life. And then you give a wonderful reception and enjoy yourselves. After all, it could turn out to be the last such chance.

Q. All my life, I have been using a knife for cutting and pushing. I use the knife to push the food onto my fork. My wife says it is very poor manners to use a knife for pushing. Is she correct? If so, I will stop.

A. She is correct. "Pushing" is not an activity officially recognized by manners, however much (like other popular activities Miss Manners could name) it is practiced. Please allow Miss Manners to mention her extreme satisfaction at your attitude. Your priorities are correct, and your restraint, in not using the excuse of expedience or hunger, is magnificent.

Q. Please explain to me the proper rules for guests (even if they are relatives) and hostess. Precisely what should guests expect from their hosts beyond food, lodging, gracious treatment and interesting conversation?

We have a constant stream of out-of-town visitors. Most come only for dinner and/or a few days' stay, but some stay up to three weeks. During these stays, of course, the food and entertainment is on our household, but somehow I am always made to feel I did not "give" enough.

We love the theater but can rarely afford to go, and never have the luxury of going just because it is Saturday night. Should we be expected to take guests? What should the rules be on lesser costing events, parking lots, etc.? Frankly, we go out very little because we really cannot afford to go.

How much touring should be expected from me? We live on a major bus and subway route, but guests seem to prefer that I drive them door to door; yet I find this difficult while keeping the house presentable and preparing three meals a day, never mind continuing my regular activities. No one ever offers to pay for meals we have out, so that, too, seems to be expected in my touring role.

Should guests be allowed to change eating habits and times? Some guests make clear the hours (vocally, or by not showing up for breakfast until 10, when the family ate at 7:30) and criticize the content of the meals. I am willing to provide three meals a day (although my family sits for only two) but I prefer to control content and times.

Since most guests come when we are not on vacation, how does one clear the deck for work brought home from the office, or school homework?

Help! I hate to be ungenerous, but trying to be accommodating keeps me exhausted, broke and mad. When I rebel, I feel like the ungracious hostess.

A. In that case, you should continue to provide everything that your guests seem to expect, and see if you cannot add a few conveniences of which they might not have thought. Have you suggested that they make free with your wardrobe, in case there are clothes they might need or want but have not brought? Perhaps they have admired a painting or a special piece of furniture. You could wrap it up and give it to them as a little hostess present.

Miss Manners makes these suggestions with the express purpose of relieving your burden. She believes that if you truly succeed in living up to what seems to be your ideal of a gracious hostess, you will soon end up in a hospital, perhaps the kind with extra protection on the windows, and will be able to get some rest. Also, the obligations of a hostess entertaining visitors under those circumstances are considerably less wearing.

In a society with more modest ambitions than yours, hostesses provide their guests only with beds, towels, access to bathrooms, the opportunity to participate or not in family meals at their regular hours, and cheerful information about the city's transportation and tourist attractions. Anything else, including the "interesting conversation" you have on your list, is provided only if it appeals to the hostess as much as to the guests.

To achieve this standard you must forget everything you know, starting with the names of these dreadful people you call friends, and begin again. Miss Manners' advice to you is to have your house quarantined and, after a suitable interval, to begin again with a fresh set of relatives.