Captain Cook's Marine Chronometer

[VWatchie]

This video is a must-see for anyone into horology!

There's a lot to enjoy but one of the most fascinating sections of the video explains that the balance wasn't temperature compensated, so it constantly needed to be regulated depending on the current temperature. However, 300 years ago moving a regulator arm by hand would have been too primitive so they (Harrison) automated the process.

Seeing this blew me away. Enjoy!

 

Edited March 19 by VWatchie
Typo: "400 years" => "300 years"

[nickelsilver]

Derek Pratt made a replica of Harrison's H4 in the last years of his life. The hardest part was making the pallets for the verge escapement, which were in diamond. How Harrison did it is a mystery; Derek told me he spent several years perfecting them, with modern machines and easily bought graded diamond powder at his disposal.

 

He also said that while studying the original, he found that you could remove the upper balance jewels and the watch would continue to run, and the upper pivot would remain centered in the hole. That hairspring looks ultra basic, but Harrison shaped it very specifically.

 

There's a fantastic book on Harrison called Longitude by Dava Sobel, well worth the read.

[VWatchie]

I hadn't heard about Derek Pratt so I made some research:

"Derek Pratt (1938–2009) was a highly respected British horologist known for his exceptional craftsmanship and contributions to precision watchmaking. He was considered one of the finest independent watchmakers of his time, often compared to George Daniels.

Pratt worked closely with Urban Jürgensen & Sønner and was instrumental in developing their detent escapement. He was also known for his intricate engine-turning (guilloché) work and innovative timepieces. Despite being relatively low-profile, his influence on modern horology was profound, and his technical skills were admired by experts in the field."

[RichardHarris123]

13 minutes ago, nickelsilver said:

There's a fantastic book on Harrison called Longitude by Dava Sobel, well worth the read.

I have read it, still have a copy. 

[nickelsilver]

At Derek's memorial service, if someone had dropped a bomb 99% of the best watchmakers in the world would have disappeared. Amazing watchmaker and amazing guy.

[Neverenoughwatches]

3 hours ago, RichardHarris123 said:

I have read it, still have a copy. 

An old book I was reading recently mentions Harrison building his H1 in Barton. I got curious so reasearched him more. Turns out he grew up in Barton not far from me. And tested his first chronometer clock on the river Humber, about 4 miles from my house. I courted my missus on the shores of the Humber estuary, watching the tides come and go 250 years later lol.