Professor Beetoven Presents:
A Very Special Clock
NARRATOR
Let’s join Professor Beetoven and his friends Tad, the frisky frog and Big Kat, the cat without stripes, as they learn about Giovanni de’ Dondi, and the invention of the first mechanical clock.
BIG KAT
Oh man, that thing sure is loud!
TAD
Well, Big Kat, why did you bring an alarm clock along on a camping trip in the country anyway? We would have been woken up by the sun anyway!
BIG KAT
Yeah Tad, but like, how would we have known what time it was all day if I hadn’t brought the clock along?
TAD
Well, we would just have to go by the sunrise, sunset and high noon, that’s all.
BIG KAT
Well like, I like to keep track of time, you dig.
TAD
I dig that I’m hungry, Big Kat…I smell breakfast cooking on the campfire.
BIG KAT
Well, I’m just going to reset this here alarm…and get a little more shut eye.
TAD
Well Big Kat, don’t sleep through your alarm, or you’ll sleep through breakfast. Ha, ha, ha.
PROFESSOR BEETOVEN
Ah, good morning, Tad. Nothing like an early start in the country, is there? It must be just after 6. The sun’s just coming up. Look at the sunrise lighting up the eastern sky.
TAD
Its 4 minutes after 6, Professor Beetoven.
PROFESSOR
Why Tad, how do you know the exact time? I don’t see you wearing a watch.
TAD
Well Professor, Big Kat has his wind-up alarm clock with him in our tent.
PROFESSOR
Ah, ha! I thought I heard a strange ticking noise in the night. Well, he’ll have to remember to wind it if he wants to keep track of the time because I didn’t bring a watch, and I see you’re not wearing one, Tad.
TAD
I never wear one, Professor. There’s a clock in every room at home, and the bells ring in school, and there’s a big clock in town over the bank, and the clock on top of the church chimes every half hour, so I always pretty much know what time it is.
PROFESSOR
Well Tad, it’s true that there are plenty of ways to be reminded of the time when you’re at home, but out here in the country, without Big Kat’s alarm clock, why we’d have to rely on nature to help us.
TAD
That’s true…there aren’t any electric clocks out here in the woods.
PROFESSOR
That is right, Tad. You know, people had ways of telling time before there were any clocks.
TAD
Using the sun and the stars, right Professor?
PROFESSOR
That’s exactly how they did it, Tad. Early man observed that the sun rose in the east in the morning and set in the west in the evening, and was directly overhead in the middle of the day.
TAD
Didn’t they use sundials, Professor?
PROFESSOR
Yes, matter of fact they did. Sundials were devices which used the shadow of the sun to record its movement across the sky, but if the sun wasn’t shining the sundial wasn’t much help.
TAD
Were there any other ways to keep track of time, Professor?
PROFESSOR
Well Tad, water-clocks were the next development. Water was dripped into a container at regular intervals, and as the container filled, it raised a stick which turned a wheel but this was still an inefficient way of marking time.
TAD
When exactly were clocks invented, Professor?
PROFESSOR
I’ll tell you what Tad, you go make sure Big Kat is up and I’ll tell you all about the invention of the first mechanical clock.
TAD
I’m sure Big Kat won’t want to miss that, and besides his appetite is as regular as clockwork.
BIG KAT
Oh, man I’m hungry…good morning Professor, sure smells good.
PROFESSOR
Good morning, Big Kat! As you can see, it’s a bee-utiful day. It must be just about 6:30 now.
BIG KAT
Wow Professor, like how’d you know that without a clock?
PROFESSOR
That’s because I’m paying attention to where the sun is in the sky, Big Kat.
BIG KAT
Ah, it’s much easier to pay attention to my clock.
TAD
Guess what, Big Kat! Professor Beetoven’s going to tell us all about the invention of the first mechanical clock. There weren’t always clocks you know.
BIG KAT
Like wow, that sounds cool! I’m totally ready for the story of the first mechanical clock, Professor.
PROFESSOR
Well, it is believed that clock-making began towards the end of the thirteenth century in Italy. One of the most remarkable clocks ever invented is called de’ Dondi’s Clock.
TAD
de’ Dondi? What on earth does that mean?
PROFESSOR
Well Tad, the inventor of this clock was Giovanni de’ Dondi.
BIG KAT
Who was this de’ Dondi dude anyway, Professor?
PROFESSOR
He was a brilliant man, Big Kat. He was a Professor of Astronomy at the University of Padua in Italy until 1356.
BIG KAT
Astronomy…what does that have to do with making clocks?
PROFESSOR
Quite a bit, Big Kat! You see, de’ Dondi knew that the movement of planets and the sun and the moon was in a fixed pattern sequence, over the course of a day.
TAD
So he wanted his clock to work the same way, Professor?
PROFESSOR
Right on the money, Tad! It was called a planetarium clock. He said, “We desire nothing more from it than the uniform and equal motion of a wheel which shall complete its course in the space of a natural day.”
BIG KAT
Wow man, a wheel, that’s easy.
PROFESSOR
Well Big Kat, de’ Dondi had to figure out how to place the wheel so that it moved the planetarium.
TAD
How’d he do it?
PROFESSOR
He invented a complex system of gears set in a heptagonal brass and copper frame.
BIG KAT
Say, what?
PROFESSOR
Heptagonal means seven sided, Big Kat.
TAD
Gee Professor, what made him decide on seven sides?
PROFESSOR
Well Tad, at the time there were only five known planets and those five, plus the moon and the sun, were each represented on one side of the clock’s planetarium. The planetarium was placed above the gears which were set in motion by a wheel-type balance.
BIG KAT
Man, that de’ Dondi must have been pretty smart to figure this out.
PROFESSOR
Oh yes Big Kat, indeed he was. Why it took sixteen years to make the clock.
TAD
Sixteen years!
PROFESSOR
Well, it was made entirely by hand and stood fifty inches high.
TAD
Gosh, that’s bigger than I am.
BIG KAT
Man, I wouldn’t want to take a clock that big along on a camping trip.
PROFESSOR
No Big Kat, it wouldn’t be very practical. And besides the original clock built by de’ Dondi was believed to have been destroyed by fire in the 1600’s.
TAD
So how do we know it really existed, Professor?
PROFESSOR
Well Tad, de’ Dondi kept detailed notebooks including an 85 page description of the planetarium clock. A replica of it was built for the Smithsonian Institute in Washington D.C.
BIG KAT
Professor, like what I don’t understand is, how can my little clock tell the time, if de’ Dondi needed such a big clock.
PROFESSOR
Well Big Kat, de’ Dondi’s invention of the moving gears led the way to the later development of a tightly coiled spring mechanism which gradually uncoils and moves the hands of the clock. That’s why you have to rewind your clock if it’s not electric.
TAD
And the gears moved the hands on de’ Dondi’s clock, Professor?
PROFESSOR
Actually, the gears turned the dial or face of the clock around a fixed pointer.
BIG KAT
So, that’s just the opposite of the way clocks work now, since now, the hands move instead of the face, right Professor?
PROFESSOR
Right on the money, Big Kat! And most clocks after de’ Dondi’s were made from iron…
TAD
An iron clock…that would be heavy.
PROFESSOR
Well, in the fifteenth century, clocks were still too big and heavy to be used in people’s homes. They were made for churches. But by the end of the sixteenth century, clock-making had spread through Italy to Germany and the rest of Europe. Soon they were able to develop clocks that struck the time on the hour and had alarms.
BIG KAT
And now, like we take clocks for granted.
PROFESSOR
I suppose we do, Big Kat. Now I think its time we finished up our discussion of time and enjoy the rest of the day before sundown.
The End
