The technological marvel that makes skiing possible here at Ski Liberty, 65 miles from Washington, is snow-making machinery. But sometimes, when the guns are aimed at you, it seems more like a menace than a marvel.

We take you to Dipsy-Doodle, the looping trail that starts at the top of Liberty's 600-foot vertical drop and winds along an outside edge of the hill in a slow, meandering course to the lodge at the bottom.

Dipsy-Doodle begins pleasantly enough with a gentle downhill run. But after a few hundred yards, it flattens out and you begin struggling to sustain momentum. Here the nightmare begins.

The guns are stationed on the left side of the trail, 50 yards or so apart, their fire-hose nozzles shooting out a cloud of pressurized crystals with a roar reminiscent of jets taking off at National Airport.

You inch over to the far right, following the tracks of the frightened rabbits who have come before. Pushing and poling, grunting with exertion, you slide slowly from one nightmarish encounter with the blowguns to the next, until your face goes numb with the cold and the frost is thick on your eyelids and brows.

You can't see, you can't hear, you can't smell, and the only thinking you can do is to wonder when the horror will end, and whether you'll live that long.

As the Canadian fishing guides say when you capsize the canoe in a frigid rapid, "Some fun, eh?"

Well, the miracle isn't that it's done well, as Samuel Johnson put it two centuries ago, but that it's done at all. Liberty is, after all, only 90 minutes' drive from a city where British diplomats used to get hardship pay for semitropical duty.

Nor is Liberty's management apologetic. "We try to make as much snow as possible and we make it whenever we can," said marketing director Lori Smith. "We need the base. If we didn't make snow when we could, we'd have to close down every time we got a warm spell.

"Snow-making is a necessary evil here," she added. "It's just something we have to live with if we're going to provide skiing for Washington and Baltimore people close to home."

That's one way of looking at it. Others feel that shelling out $50 for skis, boots, poles, lift ticket and a lesson, as I did last week, ought to entitle you to ski comfortably in something other than a survival suit.

"Oh, I think it's dangerous, and it's definitely unpleasant," said my instructor, who will remain anonymous, as we rode up the chairlift on the way to the lesson.

"My feeling is, when you're making snow on a trail, you ought to close that trail to skiing. When the guns are going, you can't hear somebody coming up behind you, you can't see where you're going, and the snow that comes out of the gun is a lot stickier than the snow that's been packed down, so when you hit a fresh spot, it stops you."

For certain, skiing at a resort like Liberty, which relies almost exclusively on snow-making, requires a different outlook than skiing a natural snow area. For example, days that seem perfect probably aren't. If it's cold and dry out, chances are the guns will be going full blast. Better to wait for a warm, drizzly day when the machinery is out of commission.

Also, on days when the guns are on, you can expect to wind up trying trails that might not match your skill level, but which aren't undergoing snow-making. I did this, moving off Dipsy-Doodle to a more challenging slope prematurely, and instead of frozen, I wound up horizontal. Some fun, eh?

On the other hand, Liberty has snow, though the surrounding hills are bare, and it did manage to stay open last weekend when the temperature soared to 65 in Washington.

Serious skiers say several new trails opened recently on the back side are first-rate for a resort its size.

If not for Liberty, major ski areas nearest Washington would be Roundtop near Harrisburg or Bryce in Virginia, both nearly an hour's drive further away. After that, you're looking at 300-mile round trips, minimum, which puts day-skiing just about out of reach.

Liberty must be doing something right. Last year, it attracted 160,000 skiers, and management is trying to clear out political and environmental obstacles to building another resort at College Mountain in Emmitsburg, Md., 10 miles closer to Baltimore, Washington and, incidentally, the Equator.