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Lost at Sea -- The Search for Longitude

Ideas from Teachers

(Gr. 6)
There are several ways NOVA's "Lost at Sea: the Search for Longitude" program could be used:

  • Current Events: The missile bombing of Sudan and Afghanistan by the United States used the Global Positioning System to program the longitude and latitude coordinates into the missiles. The satellites then guided the missiles to their targets (with the exception of one missile that landed in Pakistan). Whatever your views on the incident are, the fact remains that this information of knowing where things are kept American soldiers out of harm's way.

    Many surveyors are now using GPS technology as well.

  • Science: John Harrison is providing an excellent example of living out the scientific method.

    Hurricanes are tracked and their positions are given in longitude and latitude coordinates. (By the way, an excellent site for following these storms, which includes being able to print out a map for you to track them yourself can be found at:

Sent in by
Daniel Reidy
Moultonborough Central School
Moultonborough, NH

(Gr. 6-8)
Tom Snyder software has an excellent software package called "The Search" that can be directly tied in with NOVA's "Lost at Sea: The Search for Longitude" program. The software is a simulation of an ancient sailing voyage and may be used with one computer in the classroom. The search entails using stars to navigate latitude, winds to determine knots, and timepieces to determine longitude. If not careful, students even "die at sea" and have to start over.

Sent in by
Paula Webb
Manhattan Junior High

(Gr. 6-8)
NOVA's "Lost at Sea: The Search for Longitude" program has wonderful historical content and application as well as good scientific applicability. The Voyage Around the World printable activity is very good. It is quite effective in teaching directions, longitude and latitude, geography, and the conversion of map scale distances.

Sent in by
Catherine Atria
Oak View Middle School
Newberry, Fl

(Gr. 7)
Topics of interest in NOVA's "Lost at Sea: The Search for Longitude" program include:

  • the origin of knots as a measure of speed at sea

  • the life of watchmaker John Harrison who showed a persistence and willingness to scrap old ideas for new

  • the state of the art of navigation today with the Global Positioning System (that essentially uses the same method of calculating longitude as they did in the 1800s)

Some student activities might include:
  1. Have students, prior to the program, list the supplies that they would take on a voyage in the 1800s. They probably wouldn't list a reliable timepiece, hence a lead in for the program or lesson.

  2. Have students calculate longitude where they are via the sun and the time in Greenwich, England.

  3. Here's one for the truly ambitious: Group the class and have them act out what Harrison went through to achieve his monumental results.

Sent in by
Michael Lenz
Bandera Independent Public School
Bandera, TX

(Gr. 7-12)
I have developed a comprehensive unit in the use of the marine sextant, complete with actual sighting time, that could be used with NOVA's "Lost at Sea: The Search for Longitude" program.

The unit includes:

  1. history of celestial navigation (including astrolabes ans staves)

  2. problems of grids on curved surfaces

  3. calibrating the sextant to ensure mirror accuracy

  4. determining and taking a local noon shot

  5. using an ephemeris to find "equation of time" and "declination" for any given date

  6. calculating latitude and longitude from a local noon sighting

  7. using an artificial horizon

Materials and equipment:

  1. student tract entitled "Celestial Navigation"

  2. classroom transparency set

  3. 24 - Mark 3 Davis student sextants

  4. 1 - Mark 15 teacher sextant

  5. internet access to the USNO clock for

  6. videotape recommended: "Lost at Sea"

Associated studies:

  1. high school advanced placement classes: use of the sextant as a "pelorus" to calculate distance/height and thereby better understand the use of trigonometric functions in surveying

  2. calculation of pinhole images of the Sun through the leaves of deciduous trees, thereby describing the principles of similar triangles (a key basis of celestial navigation)

Editor's note: To read more about this idea, see Featured Teachers. For PDF files of Branting's unit, visit

Sent in by
Steven Branting
Jenifer Junior High School
Lewiston, ID

(Gr. 8)
I really liked NOVA's "Lost at Sea: The Search for Longitude" program. It would be a great one to start off the year when we talk about the parts of the scientific method, the history of science, etc. I will probably use all of the program with my kids in class. It will tie in very well with a unit I have developed on scientists. My kids are given a list of scientists born on their birthdays and they research one of them, produce several products and them become that scientist and present at a convention. This will be a great resource for making the scientists "real." I will likely use the program as a wrap-up following the activity, after students do the research and participate in the presentations when the program will probably mean a bit more to them. The program also illustrates very well the integration of math, technology, social science, and science.

I really like the Voyage Around the World printable activity associated with the program. It is very interdisciplinary: math, geography, measurement, map reading and some critical thinking skills. It gives lots of choices for the students, so that each team can up with their own particular route, and it is not a rote activity.

Sent in by
Nancy Nega
Churchville Junior High School
Elmhurst, IL

(Gr. 8)
Teachers might want to show only clips of NOVA's "Lost at Sea: The Search for Longitude" program and give additional background on the concept of time as well. A project that I would suggest is one that I do. I challenge my students to build a one-minute timer. It is graded on the basis of creativity and accuracy. No clock parts are allowed. Prior to this lesson, we work with pendulum laws. They learn that the period of a pendulum depends only on its length. So they gain an understanding of a regular action being needed to time something. Successful builders use some forms of sand or water clock, length of a song (some that they wrote themselves), time for a birthday candle to burn down (or go out when under a bowl), time for a toast to pop, etc. This is an exciting and fun activity and a good tie to the program.

Sent in by
Dale Rosene
Marshall Middle School
Marshall, MI

(Gr. 9-10)
I assigned the book Longitude by Dava Sobel as an extra credit assignment in my geometry classes because of its relevance to spherical geometry.

I asked my students to write a short essay that included answers to a series of geometry questions relating to non-euclidean or spherical geometry. We also watched most of NOVA's "Lost at Sea: The Search for Longitude" program in class.

Sent in by
Lisa Krueger
Princeton High School
Princeton, NJ

(Gr. 9-12)
If I were teaching junior high I would connect NOVA's "Danger in the Jet Stream program or "Three Men and a Balloon" program to NOVA's "Lost at Sea: The Search for Longitude" printable activity, Voyage Around the World. I would also have students select a vacation spot and describe why they would vacation there. Then I would have them locate the exact longitude and latitude for that vacation spot. Then I would have students figure out which biome and climate that spot enjoyed and relate that to the sun's angle.

For high school biology, I will relate this idea to ecology and biomes. I would have students learn about the biomes and longitude and latitude. Also, prevailing winds and weather which would lead into concepts from NOVA's "Chasing El Niño" program. I like the Voyage Around the World printable activity, but would tie that into history of around the world. For ecology, my classes also do forest and river watch monitoring in our state. They have to find the longitude and latitude of the area we monitor. We could tie this into why it is important to collect this information on exact locations in our state.

Sent in by
Suzanne Asaturian
Carbondale Community High School
Carbondale, IL

(Gr. 10-12)
I did the NOVA activity in my classes (I have 154 kids) for NOVA's "Lost at Sea: The Search for Longitude" program. We started with the longitude/latitude printable activity, Voyage Around the World. It was a great activity, and had students thinking about where they might see a penguin (other than at a zoo) or where there was a port where oil is produced, or a port providing exotic spice.

Then we watched the program. Then for an after-viewing activity I had my classes do an orienteering activity. And did they ever get the connection about how important it is to be able to find out where you are! They were even able to related how much more difficult it was for sailors in the 1700s than it is for us now. They really had a good time with this particular program.

Sent in by
Shannon C'de Baca
Thomas Jefferson High School
Council Bluffs, IA

(High School/Early College)
Navigating Around the World by Observing the Sun
NOVA's "Lost at Sea: The Search for Longitude" program provides an exciting view of navigation at sea and how that skill shaped world exploration. But how does that work? You find your position by pointing a cross staff at the sun and checking a clock? Actually, the process is fairly easy and provides an interesting opportunity for your class to relive the vital skills of the marine navigator..." (continue to full Introduction and Student Exercise Packet)

Sent in by
James I. Sammons
Jamestown School
Jamestown, RI

These books could be used with NOVA's "Lost at Sea: The Search for Longitude" program. I have been using Dava Sobel's Longitude for two semesters for my English II composition class. We use several texts for the class, and the theme for my class is "time." The first book I use is Einstein's Dreams, and here we talk about physics and the imagination of Einstein—physics applied to human situation. Then we read Longitude, and study the practical and historical aspects of knowing what time it is. The third book we read is Bruce Chatwin's The Songlines, and now we study how Aborigines view the world and time, using a cultural perspective. All three books constitute studies of time, how humans perceive it, use it, and apply it.

Sent in by
Renate W. Prescott
Kent State University, Geauga Campus
Burton, OH

Teacher's Guide
Lost at Sea -- The Search for Longitude

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