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    Captain Schufeldt's report on marine sextants
    From: Jared Sherman
    Date: 2002 Dec 26, 14:51 -0500

    Well George, I must confess to being amazed at finding the article both 
    enlightening and good reading. The author apparently is/was a co-author of 
    "Dutton's" which is a famous text here. (I haven't read that, no.)
    I expect the list would be very interested to read it if we could get permission to post it online.
    It may be worth asking our ONR for a release of the original full report, 
    although I'm sure they will wonder why on earth someone is only now asking 
    for an obscure 40-year old report. If the ONR actually published the 
    report here, then that publication would be in the public domain. Does anyone 
    here have a contact at the US Office of Naval Research?
    I didn't see a date on the journal article but it appears to be circa 1960, 
    soon after the report, which makes the references to a dekstop computer, 
    electric computer [sic] and electronic computer somewhat odd since none of 
    those would have been available for civilian or commercial use at sea until 
    the mid-80's at least. Assuming the journal article is then at least from the 
    1980's rather than the 1960's I wonder what else got quietly edited along the 
    The references to air/water temperature differences and the poor horizon from 
    a land site are totally news to me, I don't think they are taught or even 
    mentioned in most "civilian" circles here. The same for the mention of 
    "Japanese" tables to correct for them, I was unaware there were tables of any 
    kind to correct sextant sightings for air/water temperature differences, 
    although I am familiar with thermal mirage and similar problems on a larger 
    Likewise a web search for "Garvisheff dip-meter" returned no hits, whatever 
    these gadgets are they apparently are as common as hens' teeth although a 
    Cmdr. Gavrisheff has won some recent USN engineering awards. Perhaps other 
    members of the list could shed some light on these.
    Interestingly, and somewhat contrary to the spirit of this list, the author 
    does suggest the use of electronic devices for sight reduction and gently 
    condemns the use of the Nautical Almanac as being simply too crude a tool for 
    good positions.
    overall a very interesting report from what can only be regarded as a highly qualified author.

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