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Harrison's first timekeeper, H1: the repairs continue

Dismantling of H1 has progressed well and the timekeeper is now almost totally in pieces. As parts come off I'm taking the chance to look at them closely and am developing a much more detailed idea of the restoration carried out by Gould and the Chronometer Section in the 1960s.

h1_bits.jpg

In spite of his descriptions of the restorations in his notebooks, Gould did not provide complete data, and I am now busy counting teeth on wheels, measuring parts and keeping a tally of the total number of parts in H1. Some statistics are proving quite surprising. For example, just the two fusee chains (which link the driving springs with the wheels of the clock) between them total almost 4,000 bits!

fussee_chains.jpg

Now that the wheels and roller bearings are all out it is becoming clear that the timekeeper is in very fine condition. Almost no wear is perceptible on the bearings, and Harrison's 'rolling contact' arrangement has stood the test of time extremely well. The only evidence of long use is what one might call the 'computer mouse' problem, where the rolling contact has caused thin layers of dust to become compacted on the rollers (just as it does inside the mouse sometimes).

Next is extensive photography and measuring, and I have to decide on the best (and most conservative) way to repair the broken balance spring connection.

Comments (4)

John Haine:

Given all the measurements that are being made, will it be possible to make available (preferably online) a set of dimensioned drawings please? Given the historic importance of the clock, would it not be fitting to make the technical details available to all for study and possible replication? After all, I understand that the Ordnance Survey is making its map data available, so what objection could there be to making the H1 details available?

Bruno Adam:

I just would support the suggestions John Haine made concerning details and measurements of the H1

I enthusistically support suggestions that dimensional and technical details should be published. Such details should, at the very least, be recorded and safely stored elsewhere, should any disaster befall Harrison's original machine.

This request is valid for every Harrison timepiece, although I do appreciate that many dimensions and details should await unavoidable dissassembly for essential maintenance.

I'm well aware of a policy to discourage inferior and shoddy replication; it does, however, seem to me that 'natural selection' would eliminate such replicas. Witholding information can only lead to inexact replication, which is arguably a less desirable outcome.

RON CHAMBERS:

I also endorse the request by John Haine. Or a set of sequenced photos showing dismantling and reassembly (which you are surely taking). Better still - an "exploded" drawing or photo. Shouldn't think the Official Secrets Act applies any longer to this masterpiece!!

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This page contains a single entry from the blog posted on March 27, 2009 5:05 PM.

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