In this article, we will discuss Ceylon ghat tracer.
Ceylon Ghat Tracer is a very useful instrument for setting out gradients. It essentially consists of a long circular tube having a peephole at one end and cross-wires at other ends.
The tube is supported by an A-frame having a hole at its top to fix the instrument to a straight rod or stand. The tube is also engraved to give readings of gradients.
A heavy weight slides along a tube by a suitable rack and pinion arrangement. The weight, at its top, contains one beveled edge which slides along the graduation of the bar and serves as an index.
The line of sight is defined by the line joining is horizontal. For the elevated gradients, the weight is a slide towards the observer. For falling gradients, the weight is slid away from the observer.
2. Uses of Ceylon Ghat Tracer
(a) To measure a slope
1. Fix the instruments on the stand and hold them to one end of the line. Keep the target at the other end.
2. Looking through the eye hole, move the sliding weight till the line of sight passes through the cross mark of the sight vane.
(b) To set out a gradient
1. Hold the instrument at one end.
2. Send the assistant to the other end with the target.
3. Slide the weight to set it to the given gradient, say 1 in n.
4. Direct the assistant to raise or lower the target till it is bisected.
Drive a peg at the other end so that the top of the peg is at the same level as that the bottom of the target.
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