Question

Give reason why a map is incomplete without a scale

Answer 1

Features of a map- A map is symbolic representation of selected characteristics of a place, usually drawn on a flat surface. Mapmakers, called cartographers, create maps for many different purposes. Some common features of a map are as explained here.
1.Title- The first part of a map we need to know is the title. The title tells us what the map is showing. For example a map of the street in any town would have the town's name as title.
2.Direction- The next important part of a map is direction. a compass rose is a symbol that helps us to find direction. A simple compass rose looks like a plus sign with arrows. At the end of the arrows the four cardinal directions would be listed. They are north,south,east and west. The top arrow would point to the top of the map,which is north and the bottom arrow points at south to the bottom of the map.
3.Symbols- The next important part of a map is symbols. Maps show a smaller picture of the Earth's surface. We can't draw a life-size mountain on a small piece of paper.That's why cartographers use small pictures. Symbols are the points,lines and patterns that are listed in the map key. The key is a box located in one of the bottom corners   of the map. Symbols have different colors depending on the physical feature the drawing represents. For example water features like river,oceans etc. are colored blue.
4.Scale- The relationship between distance on a map and distance on the ground is called as scale of the map. Scale may be represented by words(e.g. "one inch equals to one mile") or ratio or fraction(e.g.1:63360) or a divided bar. Bar scale is best to use when enlarging or reducing the size of a map, since the scale size will change the map size.

Answer 2

The scale of a map is the ratio of a distance on the map to the corresponding distance on the ground. This simple concept is complicated by the curvature of the Earth's surface, which forces scale to vary across a map. Because of this variation, the concept of scale becomes meaningful in two distinct ways. The first way is the ratio of the size of the generating globe to the size of the Earth. The generating globe is a conceptual model to which the Earth is shrunk and from which the map is projected.

The ratio of the Earth's size to the generating globe's size is called the nominal scale (= principal scale = representative fraction). Many maps state the nominal scale and may even display a bar scale (sometimes merely called a 'scale') to represent it. The second distinct concept of scale applies to the variation in scale across a map. It is the ratio of the mapped point's scale to the nominal scale. In this case 'scale' means the scale factor (= point scale = particular scale).