How to Get a Realistic Map of the Land

In the Middle Ages, you didn't need to know exactly how far away Bruges was. But now we're getting into this era where there is a kind of practical need. And so by fits and starts in the 1780s and then officially in 1791, Britain is finally like, "We should also probably know where everything is" So they built two triangulation stations about 12 miles apart,. They used a series of glass tubes. Like I think each glass tube was like 12 feet long. Then they just kept placing them end on end over the course of like many, many months until they finally could add them all up. Those two triangulated stations were within sight