April Fools' pranks are a beloved tradition

Don't change that dial. Your senses are not fooling you. Indeed, the television is emitting smells, thanks to a new technology called Smell-O-Vision.

At least, that was the announcement broadcast by the BBC in 1965, when the British TV network declared it was conducting an experiment in which odors would be transmitted through the television. Although many viewers called in to report the success of the experiment, Smell-O-Vision was simply a harmless hoax set by the station to celebrate April Fools' Day.

The history behind this day of hijinks is a bit hazy, but it supposedly began in 1582 when France switched to the Gregorian calendar and moved New Year's Day from March 25 back to January 1. Prior to the change, the New Year's celebration had lasted a full week, from March 25 to April 1. Those who were unaware of the change were called April Fools, according to The Old Farmer's Almanac.

- By staff writer Anna Ferguson

World-famous hoaxes We consulted with The Old Farmer's Almanac and the Museum of Hoaxes, a Web blog that examines famous hoaxes and urban legends, to find some of the best known capers to date.

Taco Liberty Bell

Fast-food tycoon Taco Bell got in on the April Fools' Day action in 1996. Taking out a full-page advertisement in the New York Times, the company announced they had purchased the Liberty Bell to reduce the country's debt and renamed it the Taco Liberty Bell. When asked about the sale, White House press secretary Mike McCurry replied that the Lincoln Memorial had also been sold and would be known as the Ford Lincoln Mercury Memorial.

- Museum of Hoaxes

See spaghetti grow

In 1957, the pranksters at the British Broadcasting Corp. aired a newsreel explaining how the mild winter had produced a higher-than-usual harvest for Swiss spaghetti farmers. Swiss women were shown plucking strands of pasta from trees, while a well-known broadcaster noted that the disappearance of the so-called spaghetti weevil had helped boost the growth of more pasta. Viewers were so intrigued that they called the BBC and asked where they could buy their own spaghetti bushes.

- The Old Farmer's Almanac

Alabama changes

the value of pi

Even mathematicians have a sense of humor when it comes to April Fools' Day. In the April 1998 newsletter of New Mexicans for Science and Reason, an article claimed that the Alabama Legislature had voted to change the value of the mathematical constant pi to the Biblical value of 3.0. Originally, the claim appeared as a news story in the 1961 sci-fi classic "Stranger in a Strange Land" by Robert A. Heinlein.

- Museum of Hoaxes

Cave of the treasures

In the mid-1800s, an April Fools' Day article in the Boston Post reported that workers removing trees from the Boston Common had uncovered a hidden trap door leading to a cave filled with treasure. Treasure seekers flocked to the Common, but, alas, they didn't find a hidden door.

- The Old Farmer's Almanac

- By staff writer

Anna Ferguson