Calculation of distances between settlements is required when planning an optimum route of the movement, for assessment of time of a way, definition of expenses of fuels and lubricants. Any of ways of calculation has strong both weaknesses and limits of applicability. Defining distance between the cities, it is necessary to consider an error of measurement and curvature of an estimated route.
It is required to you
- - card;
- - curvimeter;
- - compasses;
- - ruler;
- - help tables;
- - specialized programs for calculation of distances.
Instruction
1. Define distance between the cities by means of the card and the special device – the curvimeter. It represents adaptation constructed according to the mechanical scheme. Establish a wheel of the device in the first point on the map. Then carry out by a wheel in the area of an estimated route on a terminal point, repeating route bends. On the dial of the curvimeter the real distance on the area expressed in kilometers will be displayed. Dials of curvimeters can have several scales for cards of different scale.
2. If the curvimeter is absent, use simpler, but less exact method which is also based on use of the card. Arm with compasses, having established its solution at a certain, predetermined size.
3. Consistently postpone pieces on the card, moving compasses legs along the line of the route connecting two cities. Increase the number of shifts of compasses by device step size, and then transfer to kilometers taking into account card scale. Consider that the compasses step is less, the calculation of distance will be made more precisely.
4. Use help tables for calculation of distances. They allow to receive quickly the value corresponding to distance between large settlements. This method quicker and more conveniently cartographic, but is less evident. Therefore for laying of a concrete route it is all the same desirable to use the card in addition. The second lack of a way – the limited list of the settlements included in tables.
5. Define distance between the cities by means of one of specialized programs. They can be established on the personal computer or to use the online versions offered, in particular, by many websites of cargo carriers. Help data are also the cornerstone of a method, but definition of an optimum route and the corresponding distances is automatic. In need of the program allow to add calculation, having included any given intermediate points in a route.
6. Using any of the described methods for practical purposes, consider that each of them gives only approximate value, to a greater or lesser extent corresponding to real distance between settlements. In particular, calculation of transport services is recommended to be made only according to the actual indications of transportations, but not according to preliminary determination of distances.