If you think the 21st century is too overrated then this piece of marvelous 16th century technology will take you back in time when there was no smartphones.
The intricate design of this da Vinci’s clock uses connected weights and gears to accurately measure time.
no need for batteries , Im not sure they had batteries in the 16h century, did they?
anyways the clock’s speed is controlled by adjusting the weight and balance of the pendulum.