Why is there a hesitation before a soda machine coughs up the goods?

We live in an electronic world and have every right to expect machines to behave in chop-chop fashion, like maybe the speed of light wouldn't be too shabby, and yet if you pop 60 cents into a soda machine and hit the Diet Cherry 7-Up button there is always a long pause as though the machine is trying to decide whether it has any Diet Cherry 7-Up left or, even if it did, whether this is truly a well-conceived beverage.

The thing is, if you intensely crave a Diet Cherry 7-Up this interval seems to last approximately as long as the entire Watergate hearings. It may even trigger a memory of the time in high school that you asked a dreamy person to go on a date with you and the answer came back after a delay sufficiently long to plan your entire suicide including the dosage-to-body-weight ratios.

Who makes these machines? Intrepidly we journeyed to the vending alcove of the Why Things Are International Command Bunker, and on the side of the Coke machine we found a small metal plate that read: Dixie-Narco. That's a company in Ranson, W.V. (Kids, yet another possible name for your new garage band: Dixie Narco and the Soda Jerks.)

Dick Bline, manager of engineering for the company, gave us the answers. There are two styles of machines. "Serpentine" is the kind in which the instant you hit the button, you hear the can making noise inside the machine and it appears a second later at the bottom. This is because a hinged panel has dropped out from under the can and it has rolled down a winding rail.

But serpentine machines are not quite as popular anymore, giving way to what Bline calls "dual-adaptable" machines that can handle either cans or bottles. And these are slower -- painfully slower for some of us. That's because these machines are gentler, so as not to break any bottles. The can or bottle rests on its side in a trough. When you put your money in and hit the button, a motor turns a shaft that slowly tilts the trough to one side, until the can or bottle spills out and rolls down a slanted panel. But in the meantime there's that horrible delay while the trough tilts.

We timed it, by the way. It ranges from about 1.75 to 3.5 seconds. Either way, an eternity.

Why didn't the American Indians invent the wheel?

They did, actually. At least the Aztecs did, if not the more nomadic and less technological "Indians" who roamed what is now the United States. Archaeologists have found toys with wheels among the Aztec ruins. Things like little doggies on dollies.

What no one totally understands, though, is whey they didn't build big things with wheels, like carts and wagons. They carried stuff on their backs. Or they dragged it on sleds. You have to wonder: If those cavemen in the comic strip B.C. can invent the wheel, why not the Sioux or the Incas?

The academics' answer is that it has to do with animals. The New World had an animal deficit, at least in the category of beasts of burden. In the Old World, the wheel was first used in Sumeria around 3500 B.C., in the form of wheeled vehicles. An essential ingredient was a domesticated animal. Unfortunately, there were no cows or horses or donkeys in the New World. The only domesticated animals in North America were dogs. "The buffalo weren't prone to that sort of thing," says Sam Wilson, an anthropologist at the University of Texas at Austin. "They're kind of more like bears."

We don't find the animal hypothesis totally satisfactory. The Incas domesticated llamas. They also had roads in the coastal plains -- but they functioned merely as paths for humans and animals. They never built a cart. Nor did they use the wheel for other basic functions; they had no waterwheels, no pulleys. Why not? Certainly not because of ignorance: The Incas and Aztecs were brilliant engineers, building pyramids and cities and even suspension bridges.

The real answer may be that it is presumptuous to assume that any culture's technology should follow a fixed pattern, from stone to bronze to iron and so forth. The Chinese invented gunpowder but only used it for fireworks! Technology develops according to need, and the technological cultures of pre-Columbian America did fine without the wheel. The Incas wiped out hunger in an empire of 20 million people even though they didn't even have a very good version of the plow.

(Next week we'll explain why an empire of 20 million people couldn't repel fewer than 200 Spanish invaders.)

The Mailbag:

You may recall that a while back we said there was no rhyme for the words orange, purple and silver. Now an annoying person has sent us a page from the Oxford English Dictionary listing the word "curple." It's a Scottish word meaning buttocks. Coming soon to a Scrabble game near you.

Arthur H. of North Miami Beach offers some rhymes:

Restraining a burp'll

Cause your face to turn purple.

Which is virtually King Lear compared to:

I smashed my orange

Inside a door-hinge.