Peter's dad has a formidable project on his hands. It is a slow one too. It may take a year to complete since the parts are coming at a trickle pace because they are part of a magazine subscription. Though the marketing seems dodgy, the parts that come are real precision engineered brass and go together very well.
An orrery is a model solar system, usually clockwork, showing the relative positions of the planets in our solar system, but not in true scale both in size and distance from the sun. That would need a football field. Yet, the gearing is fascinating and the design remarkable both for what it is and for the way the marketers can supply a trickle of parts and still allow the machine to grow, using all the parts that come at one time.
These devices are named after the fourth Earl of Orrery, Charles Boyle (1676-1731), who in 1712 commissioned an artisan to copy an early clockmaker's version.
Peter's dad has reached earth's mechanism which has the extra gearing designed to move the moon in its own orbit about earth, hence the wide engraved brass piece in the picture to manage this additional rotation. Some of the grub threads are very hard for dad to screw in so Peter (or Mon) will help.
No comments:
Post a Comment