We do, of course. https://www.youtube.com/watch?v=a8g-pg50bf4 https://www.youtube.com/watch?v=a8g-pg50bf4 But it needs constant attention, that's why we tend

We do, of course. https://www.youtube.com/watch?v=a8g-pg50bf4 https://www.youtube.com/watch?v=a8g-pg50bf4 But it needs constant attention, that's why we tend to use more convenient things like batteries these days.