Celestial Nav problem I can't solve

[RayCam]

Morning Clen & Fred.

Thanks for joining in.

The problem is listed here. http://www.seasources.net/youtube%20vide...uction.mp4

Scroll 5 mins into the video. It's problem 3.

Their notation for the chronometer is here - http://www.seasources.net/youtube%20vide...ometer.mp4 (apparently it always has to be set to GMT, but you just need to work out if it's am or pm)

Their notation on adding or subtracting index error is http://www.seasources.net/youtube%20vide...extant.mp4

From the examples at the back - It seems to me that if they say a corrections is -2.5 then you simply take 2.5 away from Hs.

Best
Ray