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Four Handed Quartz Tide Clock Update

My four handed time clocks arrived from Cousin’s Clocks, I took one partly apart to look at the output chain. Better still, I put it together again and it still ticked.

The clock has four hands mounted on four concentric output shafts or arbores, the three outer shafts being hollow.  The centre shaft carries the seconds hand, The next shaft from the centre caries the minutes hand.  Outside these is the shaft carrying the hours hand, and the shaft outside that carries the tide hand.  An hours wheel is mounted on the hours shaft using a stiff sliding fit, so you can adjust the tide hand separately without affecting the real time.  After several tries, I decided the hours wheel had 57 teeth.

Meshing onto the hours wheel, there’s a lay wheel mounted externally. The lay wheel has one more tooth than the hours wheel so has 58 teeth.  Also meshing with the lay wheel is the tide wheel, which is cast as part of the tide shaft, which carries the tide hand.  The tide wheel has one more tooth than the lay wheel so has 59 teeth.  The tide shaft turns freely on the hours shaft. See diagram.

This means that for the tide wheel to turn one complete revolution the hours wheel must turn 1 + 2/57^ths of a turn.
I.e.  The tide pointer turns one revolutions in 12hrs + 2 x 12/57 hrs
= 12hrs 2x60x12/57 min = 12hrs 25.2631min
So for the tide pointer to turn twice takes 24hrs 50.5263min =24hrs 50min 31.6 seconds, which is very close.  

Now, we’ve got the hours, we’ve got the tide due to the Moon alone, and we’ve also got an hours shaft.  Which of you clever people is going to come up with a mod which will weave in mechanically the effect of the Sun as well? More on tables next time. DaveP

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