a scale ranking ten minerals from softest to hardest; used in testing the hardness of minerals. Define DENSITY: A measure of how much matter there is in a given amount of space.
Jerusalem is a hilly city so the altitude varies but it is approximately 750 Meters (2,500 feet) above sea level.
Elevation angles for objects above the horizon range from 0 (on the horizon) up to 90 degrees (at the zenith). Sometimes the range of the elevation coordinate is extended downward from the horizon to -90 degrees (the nadir).