Theory
It consist of straight links of galvanized mild wire, each links are bent into a coop and connected together by means of oval or circular ring. These rings provides flexibility to the chain and make it less liable to become kinkeel. The joint of the rings are necessary thoroughly open. The end of the chain are provided with brass handle for dragging the chain on the ground. The handle is linked or joint with a swivel joint at the end so that chain can be turned round without twisting. The length of the link is the distance between center of the two consecutive rings and a length of the one chain is measured from the put side of the one handle. The end link also include the handle. In 30 meter metric chain the length of the link is 20 cm to hence the no. of links is equal to 150 links. To unable to measure the fraction of a chain easily brass tags are provided at every 5 m length and small brass ring at every one meter length. The full length of chain is mark over the handle 5 m length small brass rings at every meter length. The full length of chain is marked over the handle.
Application
Chain are used for measuring linear distance between the two points in the field as on ground field chain is preferred to the tape distance it can bear to wear to tear of the rub ground.
Diagram
Folding And Unfolding Of A Chain
Unfolding
- Hold both handles in left hand and unfold two or unfolds.
- Hold the handle remaining folded bundle in right hand.
- Thoroughly the chain in forward direction on the ground with force by right hand.
- Move it forward direction by taking one handle of the chain until the chain is extended till the full length without any kinds or bent link.
Folding
- Bring the two handle together and pull the chain by the middle.
- Commenceing from middle take two pair of links at a time with a right hand and place them folded across the other in the left hand.
- After the chain is folded, tie it with a leather belt at the center.
