# Course Report: A Brief History of Timekeeping 03

It’s been a little while since I wrote up what I’ve been doing in my “Brief History of Timekeeping” class, because I was out of town, and then catching up from being out of town. Some of this material has already appeared here, though, so I can hopefully catch up a lot of stuff in one post.

The material that will be most interesting to random readers of the blog is the “How to” section, from a couple of weeks ago, which were the lecture form of the How to Read a Scientific Paper and How to Present Scientific Data posts here. The paper-reading class was on Monday and the data-presentation class on Friday, with a class going through a particular paper on The mechanics of the sandglass sandwiched in between. This also served as the explanation of the working of sand timers, one of our historical timekeeping technologies.

The next week was shortened because I was out of town for the weekend, and introduced mechanical clocks. I started off with this video clip from Connections, which provides a very nice illustration of early mechanical clocks:

Also, you could land an airplane on the lapels of that jacket. As I told the students, I’m just barely old enough to remember the brief moment when that didn’t look ridiculous.<.p>

That was a pretty minimal lecture, not worth posting the slides from, because I had them spend about half of the class measuring the period of a pendulum under different conditions. They measured the time required to complete some number of oscillations as a function of length, mass, and amplitude, and I collected the data from them. On that Friday, I went through a quick lecture on the physics of the pendulum and a couple of different types of escapements for pendulum clocks (PDF Slides for the lecture). Also in that class, I took their data from Wednesday, and showed how to plot it and verify that it fit the theoretical predictions.

This week was all about Dava Sobel’s Longitude, and the making of seaworthy chronometers. I said half-jokingly that the week followed a sort of a course through Union’s curriculum: Monday was on the science of navigation, using the experimental results presented here; Wednesday was about the engineering of clocks, specifically John Harrison’s innovations for his marine clocks; and today was the humanities side of things, presenting the story of Harrison’s attempts to get paid. Those last slides are really sketchy because I spent most of the class having them provide details of the Harrisons’ grievances against the Board of Longitude, as related by Sobel. I then provided a bit of the other side of the story, from the Board of Longitude blog: (Rehabilitating Nevil Maskelyne, Part One: Reassessing the accusations, Part Two: Why lunar distance?, Part Three: Cultural differences, Part Four: The Harrisons’ accusations, and conclusions

) and this law review article (PDF) looking at the case in a more balanced way than Sobel’s book.

I’ve been saying repeatedly that this class is about learning how to make arguments, and so introduced the additional material by asking them if they could find holes in Sobel’s argument. They did a pretty good job of picking up on places where she glosses over inconvenient details, so I think it was a useful class.

And that’s where things stand. Next week, we move into modern physics and the book Einstein’s Clocks, Poincaré’s Maps. I’m a little uneasy about this book, because it’s a bit on the long side, but I’m going to fill a class or two on the basics of relativity, anyway, so they should have time to read it.

Next week is also when they need to pick topics for their final papers/ projects, so I’ll be spending a lot of time meeting with individual students to talk about what they want to research. Which will be time-consuming (roughly five hours of meetings outside of class), but is usually fairly rewarding, so we’ll see how that goes.

1. #1 beckyfh
February 4, 2012

I’m one of the authors of the Longitude blog, and have been doing some research on Maskelyne (although didn’t write the particular posts you linked to), so thank you very much for taking time to read it, and for getting your students to think beyond Sobel.

I tried to comment on the previous post on how to pronounce Maskelyne, but it seems to have not got through for some reason. Fortunately Thony Christie made some of the points I wanted to. Whatever the personal bad feeling between Harrison and Maskelyne, by and large the latter was a fair and often generous man. More importantly, it’s worth understanding that the timekeeping and astronomical longitude solutions were complementary rather than rivals. The lunar distance method requires timekeepers (for timing observations, both in the observatory and on board ship), and the timekeeping method requires astronomy (to check local time and to check the running of the timekeeper – which, until later in the 19th century, was a long way from completely reliable).

2. #2 Thony C.
February 4, 2012

Chad, thank you for taking the criticism of Sobel’s book seriously. I find what you are doing with this course really interesting.

Rebekah ‘Becky’ Higgitt who is a curator at the National Maritime Museum at Greenwich and one of the leaders of the Board of Longitude research group has an interesting post on her own blog, “Teleskopos”, The place of science in history and history in science which has generated a lively discussion in the comments. As you are using the history of science to teach a physics course I sure that Becky would appreciate some input in the comments on the subject from yourself or even some of your students.

BTW Becky commented on your Critical Pronunciation Poll post but her comment seems to have got lost in moderation or in the spam filter!?