NavList:

Thanks for the replies.

I had calculated Hc for both an assumed and my actual position. When I worked the time sight I mixed up the data. Using the correct data for my actual position in the time sight gave me a perfect result.  The two Sumner lines now cross at my location.

I wanted to use the multi-latitude method because that was how Sumner discovered the position line.

I now know how to reduce a time sight and plot Sumner lines. If I have problems in the future it will be a numerical error on my part.

I will modify the t formula to account for same and contrary lat & dec.

I have a brand new artificial horizon sitting beside me but when I look out of the window all I can see is an overcast sky.  Grrr!!!  Maybe I should use my spare time to can learn Ageton's method (-;

David