Story of the contour lines

As industrial designers, we often use contour lines to quickly communicate a form while sketching. We use these lines to visually describe the features of a form even without using markers. It is empowering that you can communicate depth in a 3D form by utilizing just a pen and without any fancy tools. Here’s how contour lines can really make a difference.

If you noticed, I’ve used the same outline and explored various forms with just variations in the contour lines. The lines give character and expression to each form, through which a unique story is narrated.

Contour line is defined as ‘a line on a map joining points of equal height above or below sea level.’ Contour lines have commonly been used in topographic maps for centuries.

But did you know that contour lines was invented by a mathematician?

Several astronomers in the 18th century were on quests to determine the mass of the earth. Maskelyne was one such astronomer who set out to conduct the gravitational deflection experiment at the Schiehallion mountain in the summer of 1774. The idea was to calculate the mass of the mountain by determining its volume and the mean density of the rocks, and extrapolate the results to determine the mean density and mass of the Earth.

Amongst other mountains, Schiehallian was considered ideal for this experiment thanks to its nearly-symmetrical shape. So Maskylene and his team of surveyors camped near the mountain for four months and gathered measurements from every possible position. A map was then created with hundreds of numbers all over, representing the elevations across the mountain.

Since it required some difficult calculations, a mathematician, Charles Hutton was roped in to calculate the mass of the mountain. That’s when he figured that if he used a pencil to connect points at the same height in the map, it gave a sense of the shape and slope of the mountain and also simplified the calculations. That’s how the contour lines came into the world and would go on to be used not only by cartographers and mathematicians, but also by product designers today!