Identify whether the given statements is/are correct or incorrect with respect to chain surveying.

📝 Detailed Explanation: Principles of Chain Surveying

Both statements provided in the question accurately describe the fundamental aspects of chain surveying. To fully understand why, let's break down each statement in more detail.

Statement i Analysis: Suitability of Chain Surveying

This statement is correct. Chain surveying is a basic and foundational method that relies solely on linear measurements. Its suitability is limited to specific conditions:

• Small Extent: Because it lacks angular measurements for cross-verification, small errors in chaining can accumulate over long distances. Therefore, it's best for projects like single property boundaries, small building sites, or creating localized site plans.
• Open Grounds: The method requires clear lines of sight (intervisibility) between survey stations. Obstacles like dense woods, buildings, or hilly terrain can make direct chaining impossible.
• Relatively Level: Measuring on sloped ground introduces errors because the measured slope distance is longer than the required horizontal distance. While corrections can be applied, chain surveying is simplest and most accurate on ground that is not steep.

Essentially, it's the perfect tool for securing the boundary data for a piece of land when the conditions are right, as the statement suggests.

Statement ii Analysis: The Principle of Triangulation

This statement is also correct and describes the core methodology of chain surveying. The entire area to be surveyed is divided into a framework of connected triangles.

• Why Triangles? A triangle is the simplest geometric shape that is rigid and can be plotted if the lengths of all three sides are known. This makes it a stable foundation for a survey map.
• Well-Conditioned Triangles: For accurate plotting, surveyors aim to create "well-conditioned triangles," where no angle is too small (less than 30°) or too large (more than 120°). This minimizes the distortion when the survey is drawn on paper.
• Framework: The main survey stations are connected to form these primary triangles. The longest line, known as the "baseline," often runs through the center of the area and serves as the backbone of the survey. Other lines like "check lines" are measured to verify the accuracy of the triangle measurements.

By measuring the sides of these triangles, the entire survey area is mapped. Details like buildings or fences are then located by taking perpendicular measurements (offsets) from the triangle sides (chain lines).