The horizontal, scale should look like the one drawn below. The lines show the hours. This one is correct for a person at 51

The table below shows the angle A for different hours at various latitudes

The angle from the noon line (12:00) is called the hour angle (H). Since the Sun moves through 15

You can calculate the angle (A) from the noon line for various hours using your latitude (L).

Don't forget to change the angle of your gnomon to that of your latitude.