Line of Sight - Close Wyes
A location to place transport is needed where well-described fixed spot can be readily found on opposite sides of it at a distance away as great as the telescope will show them clearly. It is well to have the marks at about the same angular distance, above on one side and below on the other, from the place chosen. The plate levels should be in adjustment, and the reversions of the transit made about the axis they are adjusted for. https://civilguidelines.com/surveying/lineof-sight.html
