Next three classes, which means, not next Tuesday. So this is spread over four weeks, but three classes. They're all gonna look at the period, primarily 1650 to 1680. The first of them tonight is gonna be on mechanics, which means primarily Huygens. In fact, I'll pass around now the one other major book in mechanics in that period is by John Wallace.

This is not the original edition of it. This is from his collected works after he died. It's called Mechanics. A beat up old book of, well it's actually not a book as you can see. It's Xeroxes that Bernard Cohen had bound but I'll pass it around so you can see.

We'll mention John Wallace in passing but we're gonna be focusing overwhelmingly on Huygens. Even though Newton did read John Wallace's Mechanics a very much read Christian Huygens as a matter of face you'll see the first class next semester when he tells you what you should read before reading the Principia.

What's singled out because it's the book that most influenced him by far. So that's what we're gonna do tonight. Some mechanics In the period 1650 to 1680, focusing almost exclusively on Huygens. Then in two weeks we're gonna look at Astronomy from 1650 to 1680, where he shows up again briefly at the beginning.

Because for a period in the mid 1650s, he and his brother were producing the world's best telescopes, far superior to any telescope before, and it enabled him discover Titan, the moon of Saturn, which nobody had discovered. Also, not with the telescope, he also figured out the rings of Saturn.

But then he drops out or Huygens drops. By the way, the name is correctly pronounced but I'm not gonna rip my throat apart trying to do gutturals for a whole evening, and the French call it and I think Huygens is more respectable than. You know, when you're talking with French people you're never quite sure they're talking about.

but it is Hauykens. Okay, so next week will be, or two weeks from now, Astronomy in the period 1650 to 1680. Then the week after that will be Newton, though we'll start more like 1660, when he goes off to college in 1662. Before that he's not he doesn't do anything of any real note and we'll look at Newton up to 1680 late 1679 when Hook puts him on to the questions that turned into the Principia.

All right so Christian Huygens, some general biographical information. I put on supplementary material, The Dictionary of Scientific Biography entry on Huygens. The Dictionary of Scientific Biography is, I'm not sure how many volumes, somewhere around 15 or 20 volumes, it's been updated. I'm actually responsible for the update on Newton and Huygens.

But the original was done by Hank Voss, and it's a great work, the dictionary of scientific biography. You should all know of its existence, because any time you have a serious question about the history of science, that's the first place to turn to, even though it was done in the 1960s and there's more recent information.

So I've just given you the whole of that for Huygens, which is much more thorough than I'm going to be able to do. And I will put up Bernard Cohen's DSB entry for Newton next semester, so you can look at that. So some background on Christian Huygens. First of all we should talk about his father.

I'll pass this around, I just downloaded it from Wikipedia a few years ago. His father is sufficiently extraordinary that the second time I taught this course, 1991, I had a sophomore, tough sophomore named Eric Slasher, who's now quite prominent in early modern philosophy, and he raised, he was from Holland.

He raised his hand and when I mentioned Christian Huygens and said is he any relation to Constantijn Huygens, his father. In my notes I think the irony of it, I'll make sure everybody gets. In my notes I make a remark to the effect that Constantijn Huygens is the Thomas Jefferson of Holland but it's silly on two accounts of course.

Constantijn Huygens was 100 years before Jefferson, so what we should be saying is Thomas Jefferson was the Constantijn Huygens of America, except he wasn't as good as Constantijn Huygens. He was too limited of a person. Thomas Jefferson no less was too limited of a person side by side with Constantijn Huygens.

Constantijn Huygens produced a little over 750 compositions of music. I've heard two or three of them performed at the 300th anniversary of his son's death and they are beautiful music. I also heard some of his son's music performed at the same occasion, and they're not beautiful they're rather mundane.

His father was a serious, important composer, 17th century composer. His father was the first major poet in the Dutch language, and is still regarded as one of the two or three greatest Dutch poets ever. And for a 50 year period, he was the most powerful person, politically, in all of Holland, except for the royal family where he was for much of this time, he was either the secretary of the royal family or the president of the council, that did the bidding of the royal family.

He was knighted both in London and in Paris. He was emissary to both, trying to stop wars or prevent wars. He lived 90 years and somewhere around 60 of those he was a major political figure. So Christians born into a family, by the way, his father, Constantine's father, Christian's grandfather, was also secretary to royalty.

So this is an extraordinarily powerful political family that Christiaan has born into. And his father's intent was very strongly that he follow in his father's footsteps. They had, he and his wife, his wife only lived 10 years when, in their marriage, he died in childbirth on their first daughter, Suzanne.

He had four sons, one of them died fairly young, Phillip. The other three lived quite some time. Constantine Sr., the oldest of the sons, was Ambassador to England at the time Newton was a member of Parliament, et cetera and just to tell you when I said he was secondary.

When the royal family lost their leader to death and the replacement was only 12 years old, William. So for a roughly 15 year period Constantine was what we would in France call the regent. He was basically running the country for this teenage kid. This teenage kid is the William of William and Mary and as he became King of England in 1688, something Newton was very happy about and that's when Newton's political career took off, because he was a supporter of William and William and Mary.

So Constantine's in the middle of this, he dies in 1687. The year that published at age 90.