Here is a method to help you out: Take a piece of tracing paper and rule a vertical line on it.
"Lectures in Navigation"
Ernest Gallaudet Draper
If not, move the paper about, keeping the vertical line due N and S, till you find the place on the chart that does agree with you.
"Lectures in Navigation"
Ernest Gallaudet Draper
If your A.M. sight was taken when the sun was on or near the prime vertical, a change in latitude at noon will make no change in longitude.
"Lectures in Navigation"
Ernest Gallaudet Draper