Fire, a few times a day. It's quite useful. Or do you mean 'oldest technological artifact' you still use? I have a banjo that was made in 1895. Not techy enoug

Fire, a few times a day. It's quite useful. Or do you mean 'oldest technological artifact' you still use? I have a banjo that was made in 1895. Not techy enough for you? Maybe a c. 1960 waffle iron? An old cast-iron skillet?