Here are the facts:

What: A double-racing wooden roller coaster with the

world's longest vertical drop--147 feet.

Where: An amusement park north of Chicago.

When: Last summer.

Why: Good question.

Note: I become very sick to my stomach after riding a merry-go-round.

The first thing I noticed was the screaming. Then I looked up ... and up ... and up ... and there, 14 stories above me, the front car climbed over the apex and began to plunge. My stomach did the opposite, rising inside me as though I was hurtling earthward at a 55-degree angle. I looked away. But morbid curiosity got the better of me, and I followed the train. It rose; it dipped; it soared; it whipped--spinning finally into a whirlpool of track to the base.

Sure, I'd been on roller coasters before, but never one like this: the Great American Eagle. It was bigger, faster, noisier, and above all scarier. It also presented a challenge of sorts. It required getting psyched.

After watching the Eagle careen around its mile-long track, I was definitely not psyched. So I decided on a plan for working my way up to the Mt. Everest of roller coasters--I would ride the park's lesser ones first. The name of the tiniest one should have been enough to turn me away. "Willard's Whizzer" whirled like the spin-dry cycle of a washing machine, and anything that goes in circles makes me sick. I rode it anyway.

I staggered away from the "Whizzer" and stumbled into the line for "The Demon." This ride seemed a more conventional roller coaster with a hill, a turn, a rise, a dip, none of which looked terribly menacing. But as the line snaked its way around a plaster mountain placed there for atmospheric effect, "The Demon's" devilish aspects revealed themselves. I had seen the tame initial drop; I had not seen the loop that towered over the fake mountain. My first inclination was to leave the line, but embarrassment is a powerful force. I stayed put. A few minutes later I saw the next terror: another loop, this one even higher than the first; then there were two corkscrew loops and, as the finale, a sharply banked turn.

I had little time to vacillate, however, for my turn in line had come. I slumped into a deep bucket seat, pulled the thick harness over my head, and pressed it to my chest so hard that I could barely breathe. I don't remember the ride, but I left it a bit numb.

Numb, yes. Diverted, no. Having been turned upside down four times already, I decided that twice more couldn't hurt. I headed for the "Tidal Wave"--and got a terrifying lesson in the wonders of centrifugal force. Somehow--the red marks on my palms where I had clutched the safety bar gave me a clue--I managed to survive this assault on my sense of spatial order, and I even enjoyed it.

Thus initiated, I headed for the Eagle. Maybe all the spinning had impaired my better judgment, but I felt less intimidated by the Eagle now. I strode securely through the line, smiling self-assuredly as I watched train after train leave the loading point and inch its way up the first rise. I laughed nonchalantly as I buckled my seatbelt and pulled the safety bar toward my lap. I thanked the attendant when she wished me a pleasant ride.

Panic set in only after the train started climbing. Slowly--agonizingly slowly--we rose toward the summit, balanced for an instant--and plummetted. The two people sitting in front of me let go of the car and raised their arms into the air. Somehow they stayed in their seats. The plunge took forever, becoming a sensory blur of red and white railings, roaring wind, clattering wheels, screaming passengers, and green countryside as we hit the bottom. Subtle twists in the track threw me right and left. Unseen rises lifted me from my seat, and the inevitable dips threw me back down. They say the ride lasts for two-and-a-half minutes; it seemed like an hour. They say the train hits 65 miles an hour; it seemed like 500.

When the ride was over, I did it again. And again. And again. Three times in an hour. I stayed away from "Willard's Whizzer," but I rode the "Tidal Wave" and "The Demon" twice more each. In my euphoria, I decided I could do just about anything. So I ended the day with a spin on the merry-go-round. It made me very sick to my stomach.