I’ve heard of it too. You would need an analytical balance to get accurate measurements weighing a piece of paper. Just cut out the part you want to take an integral of, then cut out a piece of paper with known size (or cut several pieces with different sizes to get more accurate results) and weigh each of them. I guess this used to be cheaper and faster than using computers when computers were big and expensive.
I’ve heard of it too. You would need an analytical balance to get accurate measurements weighing a piece of paper. Just cut out the part you want to take an integral of, then cut out a piece of paper with known size (or cut several pieces with different sizes to get more accurate results) and weigh each of them. I guess this used to be cheaper and faster than using computers when computers were big and expensive.