# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Longhand Sight Reduction
From: Hanno Ix
Date: 2014 Jun 27, 17:04 -0700
Greg,

I can see where you are coming from. Of course, though,
this is a matter of personal preference.

I like to do CelNav calculations by hand. I admit I am
a purist in this regard. Most importantly, it keeps my old brain
lubricated. Also, my logic tells me if I used a calculator for CelNav
I might as well use one with built-in GPS and be done.

When I analyzed some time ago where I make mistakes most
often, it was multi-digit multiplications and sexagesimal arithmetic.
Ridiculous but true: 23 deg 52 min + 14deg 12 min could make me
insecure about my result. And, horror,  L+D and L- D occurs in Doniol.

For multiplication I use only Vedic anymore. Since I started using
Vedic and arcmin only I end up with much less errors.

Less, I say, not none :(

Hanno

On Fri, Jun 27, 2014 at 2:56 PM, Greg Rudzinski wrote:

Hanno,

The problem with working in minutes of arc is that the Nautical Almanac and charts are in degrees and minutes. Too much trouble to convert to all minutes. I don't think the space savings justifies the extra work. Best not to go too small on print size. Not worth it just to save a page if it is hard to read.

Actually I prefer to work with number tables vs. graduated rules. So the pages of ruled sins, cosines, & haversines is not to be.

Greg Rudzinski

Re: Longhand Sight Reduction
From: Hanno Ix
Date: 2014 Jun 27, 12:55 -0700

Greg,

yet another RIC - this time for Doniol. Clear and to the point.
How is your graphic sin/cos table coming?  Are you still interested in making one?

It appears my two page cos() list did not find your favor. Could you let me know why?
Is the list too dense or otherwise too difficult to read? What do you think about my proposal to convert all angles to arcmin for simpler calculations by hand  - other than doing so is not the tradition?

Hanno

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