PaddleWise by thread

From: Bradford R. Crain <crainb_at_pdx.edu>
subject: RE: [Paddlewise] Longitude and astronomy
Date: Sat, 31 Jul 2010 10:11:43 -0700
Peter:

     Seems like a terrible waste of 'roos.

Bradford R. Crain

Quoting PeterO <rebyl_kayak_at_energysustained.com>:

> Brad wrote
> .........Craig: Is the answer to the last question kangaroos?...........
>
> Cook wrote in his journal
> http://southseas.nla.gov.au/journals/cook/contents.html
> ..........
> 17 April 1770
>
> Tuesday 17th At 2 PM the wind came to WSW at which time we tack'd and stood
> to the NW, before 5 oClock we was obliged to close reef our topsails having
> a strong gale with very heavy squals, about this time a small land bird was
> seen to pearch upon the riging, we sounded but had no ground with 120
> fathoms of line. At 8 oClock we wore and stood to the Southward until 12 at
> night than wore and stood to the NW untill 4 AM when we again stood to the
> Southd haveing a fresh ^gale at WSW attend with squals and dark hazey
> unsettled weather untill 9 oClock at which time it fell little wind and the
> weather ^soon after clear'd up which a little after a 11 gave us an
> oppertunity of takeing several observations of the Sun and Moon the mean
> result of which gave 2070..56' West Longitude from the Meridion of
> Greenwich, from these observations the Longitude of the Ship at Noon was
> 2070..58' and by the Log 2080..20' the difference being on^ly 22' and ^this
> error may as well lay in the one as the other, our Latitude at noon was
> 390..36' So and Longde made from Cape Farewell 220.22' Wt
> ...........
>
> G'Day,
>
> Cook didn't make any mention of kangaroos in his journal Brad:~) However, he
> was trained in astronomy and had astronomers with him for measuring the
> transit of Venus in Tahiti. I think he was also on the Board of Longitude
> and would have been well aware of the tables produced by Warner and
> Maskelyne. I was well pleased to have found his journal entry above. It
> looks as if Cook might have used a process such as recalibrating his clock
> for local time every day against sunrise, sunset and noon. The clock would
> then only have to remain within spec for 24 hours and not for months or
> years to maintain synchronism with Greenwich. Presumably there were enough
> stars visible in both the southern and northern hemispheres so that Cook in
> Australia could use the tables developed at Greenwich. Cook was within a
> degree of longitude when he reached the equator after surveying the east
> coast of Australia on his first voyage. As Robert said it was such a tricky
> method and judging from the above journal entry not much better than using
> the kind of clock that was available prior to Harrison. When Cook went on
> his 2nd voyage he took along a Harrison clock.
>
> Robert, Longitude is a wonderful book and the illustrated version is well
> worth getting, it has a great many side notes that are missing from the text
> only version.
>
> All the best, PeterO
***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************

This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:33:53 PDT