How did latitude come to be put on maps?

Question

And do you know of any websites that discuss it?

Answer 1

http://www.broward.org/library/bienes/li...

The use of grid lines (latitude and longitude) was first suggested by the Greek astronomer Hipparcus about 300 years before Christ. Shortly after, Hipparcus devised the method of fixing the location of places on earth by observation of the celestial bodies--the sun, moon and stars. He worked out the mathematics of spherical trigonometry, which allowed the results of these observations to be plotted on an earth that he perceived to be a sphere.