Base for clock gear cutting machine (0446)

Curiosa

May 24

Index: 0446

Year: 1800-1825 ?

Maker: ? Swiss ?

Dimensions: 38 x 21 x 25 cm

Info

The apparatus has a central disc with 37 circles of indents in which the index point can be set. From the inner circle to the outer circle the number of points: 30, 11,13,50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88, 92,94,96,98,104,108,112,116,120,128,144,360,365 and finally 366 indents.

This allowed the following divisions to be made:

7 days per week (56:8)
12 months/year en hours/12h day (60:5)
24 hours/day (72:3)
28 days/month (56:2)
29 days/month (58:2)
30 days/month (30)
31 days/month (62:2)
52 weeks/year
60 sec/min en minuts/hour
144 periods of 10 min per day
360 periods of 10 sec per hour
365 days/year
366 days/leap year

Also, for normal straightforward circle divisions:

180°(360:2), 120°(30:10), 90°(52:13), 72°(30:6), 60°(30:5), 45°(56:7), 36°(30:3), 30°(60:5), 24°(30:2), 18°(60:3), 15°(72:3), 12°(30:1), 10°(72:2), 9°(80:2), 8°(360:8), 6°(60:1), 5°(72:1), 4°(360:4), 3°(360:3)

The machine is not in its original state as the slide and support for the driven mill are missing (see drawing (a)). A support for a chisel was added later on to make divisions.

(a) From the book "Het boek der uitvindingen, ambachten en fabrieken. Deel 6" ( = The book of inventions, crafts and factories. Part 6) published in 1895. See link below.