The Second Clock



The second Clock shows also the Moon. Sun and Moon are moving in the Ecliptic. In reality the Moon can be up to 5 degrees above and below the ecliptic. The place where the Moon crosses the ecliptic is called a lunar node . The lunar nodes are the points where the Moon crosses the ecliptic (which is the apparent path of the Sun across the heavens, against the background stars). The ascending node is where the moon crosses to the north of the ecliptic. The descending node is where it crosses to the south. The Sky is moving in 23h 56m 3.934428s, should be 23h 56m 4.0905s. (Difference daily 0.156072s)
In this clock the Synodic Moon moves in mean time. (24h 50m 28,3783776s)
should be 24h 50m 28.3286526s. (Difference daily 0.049725s) The disc of the Sun covers the difference between mean and real Sun.
Because the Moon moves in a elliptical path around the earth, the time it takes is always different. 
The length of the mean synodic month (New Moon to New Moon) is 29.530588 days (=29d12h44m03s). (But the length of the synodic month can vary from 29.26 to 29.80 days due to perturbing effects of the Sun on the Moon's eccentric orbit)
At the photo it is almost full Moon. The month is September. Every day the Sun will be a little lower above the horizon. In fact there is a lot more to see!






 Photos of the wheel trains





These nice 3D computer drawings are made by Peter Held, thank you for the contribution Peter! 


The original first Drawings?? 


On this design from 1998 two wheels that engage the 57/59 wheels, use the same number of teeth -36-
but then they are consequently a little out of pitch when you only have a cutter with full Module like M 0.75 or M 0.8


Recently I found a better design from 2000 with the wheels (synodical Moon) 43/37 x 57/64 x 24 = 24.841216216   24h 50m 28,3783776

(In geocentric view it would have been better to place the Moon in front of the Sun)


(Many gear combinations can be found in books, others with software like -Gearfind- (Links page- Utilities/ (Bevel) gear software/ Tips))
Using Continued Fractions is also possible (Links page) 


Some years later I bought Britten's handbook and found the same gear combinations,
calculated by Ferguson 1710-1776.
  Eise Eisinga used the combination  20h x 73/61





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