Now that winter is here, the days are getting longer. But for John Virnstein, the process began 20 months ago.

At 61, Virnstein is a retiree on whom the time hangs heavy. These days, he is spending great gobs of it in his Hyattsville living room. He writes a little, reads a little, tinkers a lot. But he is kidding no one, least of all himself. "I miss it," he says. "I miss it a whole lot."

Well he might. For 40 years, Virstein was one of the Senate's flat-out, ail-by-himself, gen-yooine characters.

He was a pal of Dirksen's. He was an admirer of Russell's. He was a drinking buddy of others whose names he protects even now that he has come in from the cold.

But what he was - most of all - was the possessor of one of the sunniest dispositions and most distinctive nich namaes in all of Hildom: Jack the Wrapper.

The reference is to his specialty. Virnstein was the boss, and the force, in the Senate folding room. But he did much more than bale the mail.

He wrapped packages. Beautifully. Carefully. Originally. Reliably. For 40 years, he would say: "Just lay it on the counter and I'll take care of it." For 40 years, he was a Wrapper of his word.

Jack the Wrapper handled Christmas gifts for Senatiorial wives. With a vote riding on every one, they had to be done Right. And they were.

He once shipped two kittens, in a box he designed and air-holed himself, for Vice President Nixon.

He once shipped a bunch of oil paintings home to Massachusetts for a Senator named Kennedy. The year was 1960, and Kennedy had taken another job at the White House.

In his all time marathon effort, he once hand-stuffed and hand-addressed 25,000 Christmas cards for Sen. Estes Kefauver.

"A few of the things I did never got there," says JWT, "but other than that, I never got a single complaint."

That may be understandable. Anyone who entered room 5A of the Old Senate Office Building to complain would probably have ended up wincing in pain instead. The reason was the signs Jack has posted.

"Jack the Wrapper - Cool and Dapper," read the humble one by his desk. Right beside it were "Let Me Give You a Packaged Deal," and "There Are Strings Attached to All My Work." His personal favorite was: "Old Wrappers Die; They Just Get Sick of Their Work."

Of course, the Wrapper's 40 years of service debunk that one all by themselves. And the fact is that Jack was poor when he was a Little Wrapper. He only made it through junior high school, and he considered himself lucky to have a job at all.

He was born the son of a fireman in a small townhouse behind the Library of Congress. Through his youth, he held any number of part-time jobs. Big bucks to him in those days, he recalls, were the eight a month he got for delivering The Washington Post.

In 1936, when he was 20, Virnstein heard that "piece work" was being offered in the Senate folding room - $1 for each 1,000 envelopes a worker could stuff by hand. "it was just supposed to be part time, for two weeks," the Wrapper recalled. It lasted a good while longer.

So has the Wrapper's other sobriquet: Poet Laureate of Capitol Hill.

That one was hung on Virstein as a result of his simple, sunny-days verse. Most of it invokes God's blessing on the Senate, the country and the flag, and it has been published in many local magazines and journals.

"Sometimes I just get melancholy," says a poet who is so boom-voiced and husky that one might not suspect it. "I find poetry very expressive."

The feelings the Senate had for its Wrapper are equally expressive.

There was the time, for example, when some genius landscaper decided to plant trees at First and C Streets NE. A gardener was digging a hole in the ground when Sen. Harrison Williams drifted by.

"Hey, you can't do that," Williams said. "That's where Jack the Wrapper sits to eat his lunch every day." So the earth shook with political force, the sky flashed with the Will of the Hill - and the tree got planted eight yards north.

Then there was the time Sen. Williams Proxmire, the town's most noted morning masochist, invited the Wrapper along for a dawn jog.

"He said, 'Come on, Jack, run with me,'" Virnstein remembers. "I said, 'Senator, I'm lucky to be able to walk.'"

Then, of course, there was the Wrapper's last day. Sen. Robert P. Griffin rose to speak. THe Congressional Record didn't miss a syllable, as usual. Here is some of what Griffin said:

"Jack is a man who took great pride in his work. He distinguished himself . . . We all wish him God-speed."

The entire text of Griffin's remarks hangs in bronze on the Virnstein living room wall. But in a closet is a thank you note from Hubert H. Humphrey that my be closer to the mark. With uncharacteristic brevity, Humphrey wrote the Wrapper: "You're such a good friend."

"Yeah, I had lots of friends, lots of them," Jack the Wrapper muses. His best friend? Sen. James Allen. The most effective Senator? John F. Kennedy. The nicest Senator? He can't answer. "In the old days, they were all nice," the Wrapper said.

And which Senator gave him his wince-worthy nichname? "I can see his face, but you know, I've been around so long I can't remember his name."

Jack the Wrapper ceased to be around the Senate one day in March, 1976. He suffered a stroke at his desk. "I don't remember a thing," he says. While recuperating, he decided that "40 years is enough."

So now they're trying to make a homebody out of Jack the Wrapper. With about as much success as one might expect.

He got antsy after only a few weeks, and he went to his neighborhood church to volunteer for whatever tasks they migh have.

His assignment? What else? Handstuff the midweek mailing, and tie up the bundles.

As they say around the Hill, once you get that twine in your blood . . .