ON MY WAY to work this morning, a huge semi-trailer passed me on the Beltway and threw a rock which badly dented the front fender of my car. I caught the name and number of the truck for future reference.

At the small religious radio station in Potomac where I am a part-time copy writer, the program director greeted me with a hug and the words, "You are a gift from God." I had been away for two weeks on vacation and was glad to be back. Then I was told, "We're going to take you off copy -- you'll hear more about it," before he disappeared into the studios for the day.

I wrote three 60-second spots, answered phones, took notes for the staff meeting, my usual 6-hour stint.

I went to the supermarket for chicken for an evening picnic and swim after work. Bought my husband R. C. a lovely new silk tie at the local haberdashery in the same shopping center as the radio station. Not much business at that moment, but the owner and I shared a minute or two of business gossip.

Met R. C. at Ft. Myer for a swim and a picnic supper. The water was cold and the fried chicken delicious. Our careers are both at a delicate turn. R. C. is strongly thinking he will retire very soon. Tuesday

Today I am wracked with uncertainty about my job. Am I to be fired? I would not like that. I treasure this small job for the fellowship and the chance to be forced to produce copy and especially the regular touch with the business world that's lacking here in suburbia.

In addition, our dog Henry is not at all well these days. I am grieving for the day when I know he must be quietly and painlessly put to sleep. He is 104 years old in human terms, according to Lorne Greene and the dog food commercials. I am hoping that he may just slip away during one of his long naps. He's been a constant companion and a good friend all these 15 years.

Lunch today was shared with our daughter and her two daughters getting their back-to-school supplies and end-of-summer haircuts. Wednesday

The day began with an early morning medical appointment. I injured my right hand using a vacuum sweeper early in June and today have been dismissed by the orthopedist. He warned me that since I am "predisposed," to take care. My husband is talking/thinking retirement and hates the sound of the vacuum sweeper so that may be a problem. I took my car in to be appraised for the rock damage: $65 to repair a one-inch dent and badly chipped paint. The repairman said I was very lucky it had been the fender which was hit and not the windshield, as it apparently hit with quite a force.

Finally, in the afternoon, I called the radio station manager to find out what, if anything, had been meant on Monday regarding my future. He informed me that I am to keep on with the ad copy and to take over the Public Affairs Department and some interviews. In broadcasting this is sometimes known as the "6 a.m. ghetto," but I could care less. By evening I am walking on air, just thinking of this new development.

We joined other middle-aged friends for a dinner party at their new condominium in Arlington. They have hung up the lawn mower and given their dog to some people who have lots of room and two young children. We're not quite ready for an apartment yet, and we couldn't part with Henry. Thursday

Finished some ads for one of my free-lance advertising clients in Virginia and delivered them. Another pleasant chat with old friends and then lunch with my best friend. We shared lots of inside gossip about our jobs and her career as secretary in a big business conglomerate.

I am not scaled for that sort of career, but I am very proud of my friend for getting out there every day. It's a jungle, and when you're 50-plus year old, it's not easy competing with the beautiful young "new people" -- except by being extra-efficient perhaps.

My friend is appreciated and overworked. I still prefer my little cubbyhole at the radio station. To each her own. We are long-time friends and the lunch and laughs are what we both needed to share. Friday

In my mind it's still "Black Friday." Only time will make it gray or who knows, maybe a pale opal. The morning dawned hot and with little puffs of pollution lingering over the hills.

Today, Henry did not get out of his bed at all. I knew the day we had dreaded had come. I called, our son Rick, the real (absentee) owner to come and give Henry his "final walk" as I had been cautioned to do some days before. Rick arrived shortly, and the two took off for a liesurely stroll to their oldest haunts.

While they were gone. I called the vet who had attended Henry (and us) through 15 years of adventures. Adventures which included everything from swallowing a needle and thread and 100 iron pills and the bottle that contained them to the attack by a huge German shepherd on Thanksgiving Eve. (If Henry hadn't been confined I know he'd have taken the othe dog, although he'd never bit anyone.)

The vet said he thought it was about time. It would be inhumane to prolong Henry's fragile life any longer.

The sight of Rick and Henry going up the hill for the last walk together. Henry still gamely plugging along, his wire-haired terrier tail still bobbing but the feet slow and the eyes now cloudly, were too much for me.

"Everyone should have his last ride in a Cadillac," Rick said, so we went in style, in R. C.'s aging but shiny chariot . . . out to the vet in the hills of Virginia.

Walking in with Henry in our arms was nothing compared to walking out without him. Rick and I both had dissolved in tears and left with arms around each other. One good thing about "liberation of the male," at least we weren't ashamed of the tears. While I signed the forms, and paid the bill, Rick sat with his dog and said his goodbye. As we left, all the women in the waiting room with their own dogs, the hands patting in unison as we passed the glass front wall.

Just an hour later my husband called. Retirement had been "looming" . . . the "C. O. L.," the "lookback" the "lookahead" and the 9.1 percent and the 13.4 percent had figured endlessly in our conversations for the past few months. After 39 years of faithful civilian service, including three separate tours of active duty in the Air Force, he had been on the verge of retiring for the past six months.

He had just put the papers in -- on this day of all days. Could I locate the official government passport and drive back with him while he cleared his agency? In no time he appeared and we were off. The clock on the bank near FAA read 99 degrees at 3:03 p.m. as we trudged from one building to another. After all those years in the car pool, turning in the ticket is a moment of truth.

I waited quietly on the lobby balcony while a man meticulously mopped and waxed the marble floors. I had a new New York and read and even dozed a little. Read the review of "The Witnesses" about Ann Hutchinson, who is a remote forbear of mine, they say. Maybe so.

We drove the car pool buddy home. He's in his late 30s and enviously pronounced that my husband had made a good judgement in retiring. Who knows?

We had a quiet dinner out in McLean. I called my sister, a social worker in Connecticut. She warned me that I am "entitled to grieve for at least two days for Henry" and then must face the new life of R. C.'s retirement.

My best friend and her daughter stopped by with some lovely roses saying, "Henry was a friend of ours too," and we each had a glass of wine to commerate the events of this day. Saturday

It's Saturday morning now, very early and the house is terribly quiet. My husband slept very little last night and I wonder where Henry is.