It is not a chart we are promised but a guide.
"The Expositor's Bible: The Gospel of St. John, Vol. I"
Marcus Dods
Parallel Rulers The parallel rulers need no explanation except for the way in which they are used on a chart.
"Lectures in Navigation"
Ernest Gallaudet Draper
You should be able to understand any kind of information given you on a chart.
"Lectures in Navigation"
Ernest Gallaudet Draper