How did ancient sailors find their way across the world’s great oceans ?

1. How did ancient sailors find their way across the world’s great oceans? They began to lay out the earth in a gridsystem, known as latitude and longitude.

2. On a map or globe, lines of latitude run east and west, which means to measure from one to another, you would go north or south. Thus latitude is always measured with a direction of north or south.

3. The earth is divided into two latitudinal hemispheres, northern and southern. The dividingline of latitude is called the equator and it is measured as 0˚. All lines of latitude above it are in the northern hemisphere and have a directional latitude of north. Those below the equator have a directional latitude of south.

4. Lines of longitude run north and south, thus measuring east and west. The “starting point” line of longitude is known as the PrimeMeridian (0˚) and all lines of longitude east of it have a longitudinaldirection of east. All lines west of it have a longitudinal direction of west.

5. Longitudinal lines all meet at the poles on a globe, but on a map that proves to be very difficult. That is why there are so many types of world maps.

6. In any kind of worldmap, some land masses will be distorted, either near the poles or near the equator.

7. Since the PrimeMeridian (0˚ longitude) could have been any line running north and south, do you know why that particular line was chosen? It runs through Greenwich, England (just outside London), in order to honor the Royal Geographical Society of England, because of its contributions to sailing, map making, and astronomy.

11. In which two hemispheres does Georgetown, Texas lie?

12. One degree of latitude or longitude is approximately 73 miles.