As soon as the students arrived I put them to work building quadrants. This way the glue had time to dry while they watched presentations. There are a LOT of free patterns available on the internet for making quadrants. The one I downloaded had little sights to glue in place but I prefer having a straw to sight through. Some of the kids tied beads to the ends of the string instead of a washer and that works fine, they just serve to weigh down the string.
While the glue was drying I gave a presentation on Prince Henry the Navigator and Portugal’s efforts to explore the African coastline. Again I used material from The Road to There, Mapmakers and Their Stories by Val Ross to update an old slideshow I had from when we did Story of the World classes. Another book I used was Around the World in a Hundred Years, from Henry the Navigator to Magellan by Jean Fritz.
I also found this nice slideshow on latitude and longitude by Mr. Kreeger. I switched out some of the images and deleted some of the slides but it was so nice not having to start from scratch, so thank you Mr. Kreeger. We talked about the difference betweeen latitude and longitude, how latitude is found easily in the northern hemisphere by measuring the altitude of Polaris (the north star) and how longitude was a much more difficult thing to determine. I talked about the Longitude Prize and John Harrison the carpenter who made a huge leap in accurate time keeping pieces on land and sea. There is a very good book, Longitude, on this subject by Dava Sobel and a movie that can be found on youtube. I actually got the illustrated version of Longitude out of the library.
Here’s the full length movie Longitude, which I have not watched,
and a 30 minute program on Harrison and the longitude problem by BBC, this I have watched and its pretty good.
To practice using the quadrants I taped a pieced of paper high up on my wall with a ‘north star’ on it and the longitude of Tokyo written on it, but not the name of the city. The kids were told to sit in a certain spot and measure the altitude of the ‘north star’, then find the coordinates on the inflatable globe, in effect finding their ‘location’. They then found the coordinates for another location and put up ‘north stars’ of their own and the other students had to find the latitude then try to find the secret location on the globe. This worked pretty well and is an activity I found on The Universe at Your Fingertips DVD. I think using the globe instead of a flat map made it more meaningful as well.
For homework I asked the students to try to find the north star (Polaris) tonight and see if they get the right latitude for where they live.