Direct Method of Measuring Distance.
Direct Method of Measuring Distance
Where approximate result is required, distance may be determined pacing. This method is used for reconnaissance survey, for preparation of military plans. Also used for approximate checking distance. The method consists of walking over a line and counting the number of paces (80cm) the required distance may be obtained by multiplying the number of paces by the average length of pace. The length of pace varies with the:
Individual, age, height and physical condition
The nature of the ground (uphill and down hill)
The slope of the country and
The speed of pacing
It is a pocket instrument. It automatically records the number of paces. It should be carried vertically, in waistcoat pocket or suspended from a button. The mechanism being operated by motion and strain of the body
It is similar to passometer. But it registers the distance walked by the persons carrying it. The distance is read by means of an indicator. It is fitted with a stud or
Knob, which when pressed release indicator to zero, it may be carried in the same way as the passometer.
It measures the distance approximately. It can be attached to the wheel of any vehicle, such as carriage, cart bicycle, etc. It registers the number of revaluation of the wheel. Knowing the circumference of the wheel, the distance traversed may be obtained by multiplying the number of revolutions. By the circumference of the wheel
The Speedometer of an automobile may be used to measure distances approximately. It gives better results than pacing, provided the route is smooth.
It can measure distance rapidly. It consist a single wheel provide with forks and a handle. It is wheeled along the line, the length of which is desire. The distance traversed is automatically registered on the dial. The reading approximates an rough ground.
7. Judging distance:
This is very rough method of determining distance. It is used reconnaissance survey.
8. Time Measurement:
Distance is roughly determined by time intervals of travel. Knowing the average time per km for a person at walk or a horse, the distance traversed may be easily obtained.
Measuring distance with chain or rope is the most accurate and common method, called as chaining. For work of ordinary precision a chain is used. Where great accuracy is required, a steel tape is used.