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    Today's octant sights
    From: Frank Reed
    Date: 2010 Mar 17, 14:32 -0700

    Here are the Sun sights I took with an old ebony octant c.1840 this morning on the shore of Lake Michigan:

    10:29:00 35-00
    10:31:35 35-23
    10:33:31 35-38
    10:35:39 35-52
    10:37:49 36-12
    10:39:39 36-27
    10:41:44 36-44
    10:43:11 36-58
    10:45:39 37-13
    10:47:23 37-29

    Times are CDT. The "watch" was 10 seconds slow, so add 05:00:10 to get to GMT. These are all Sun LL (35-00 means 35 deg 00'). Index correction was 0 since those old octants were supposed to be zeroed out every time. Height of eye was 16 feet above Lake Michigan, weather conditions near standard, and the actual location was 41d 57.6N, 87d 38.1W. The horizon was a little vague. By my reductions, the mean error in the sights is about 1 minute of arc and the standard deviation is about 1 minute of arc. Pretty good considering that this is a normal octant with no telescope and a discolored vernier that I really have to squint at to read.

    "Rapid-fire" fix anyone?


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