24901/360 = 69 miles *1 degree/ or 8 inch per mile squared
The 1.22 Angular resolution of the eye. Take the Diameter of a flat circe of 7918 times it by 5280 for feet. Square root the 418107040 and then / 5280 = 1.22459. You times the 1.22 to the square root of any height in ft of the observer and you will get the distance to the horizon in miles.
Modern science says boats go over the curvature of earth at 4 miles. This is for the observer 6 ft on the shore.