The Story of Longitude The Greatest Intellectual Puzzle of the 16 th and 17 th Centuries

What Are We Doing? Content Area Study Cross Discipline Unit Social Studies is Everything! Using Technology for Differentiation First, a Story

Latitude & Longitude

Latitude is Easy to Find The angle of the sun over the horizon on any given day is directly related to the location one is viewing from.

Determining Latitude

Was Chris Really Taking a Chance?

Columbus would have used a magnetic compass, a speed log, and a logbook. He was what we now call a dead reckoning navigator. Because he could NOT determine longitude,his course would have looked like this:

We Understand Latitude - But What About Longitude?

Longitude is a Measurement of TIME translated to DEGREES Longitude - measured in minutes, seconds 1 degree=60 minutes= 69 miles 1 second=1.15 miles (eq) So, put it together

Location is Now a Grid Expressed in degrees N or S of the equator – Latitude & degrees E or W of Greenwich (Prime Meridian)-Longitude

But the Devil is in the Details In 1700, there was no accurate way to measure time. In 1700, there was no accurate way to measure time. In order to be practical, time measurement must be accurate to within a few seconds every month. In order to be practical, time measurement must be accurate to within a few seconds every month. A time keeping device must function perfectly on a sailing ship at sea – in the most corrosive atmosphere possible. A time keeping device must function perfectly on a sailing ship at sea – in the most corrosive atmosphere possible. Enter John Harrison, clockmaker Enter John Harrison, clockmaker

Harrison’s Successful Chronometer – H4

Time at the Prime Meridian Less local time measured at Noon = Longitude

Now, English Ships Could Travel Diagonally

H4 – A Technological Advancement Led to…. Superior English Navigation Superior English Navigation English Mastery of the Seas English Mastery of the Seas Establishment of a World Wide Empire Establishment of a World Wide Empire Fundamental Shift in the World’s Power Fundamental Shift in the World’s Power Alteration of World History…..and Alteration of World History…..and Made our World Made our World