New moon

Watch news and tools for
collectors and the curious.

Accuracy

How many seconds a day your watch gains or loses, heard through your phone’s microphone.

Jacob & Co. Casino Tourbillon Black Aventurine Dial CA100.40.AA.AB.A
Jacob & Co. · CA100.40.AA.AB.A

Casino Tourbillon Black Aventurine Dial

Change

Somewhere quiet, lay the watch caseback up on something soft. Rest the bottom edge of your phone on the caseback and keep both still.