Cautions to be observed in the use of any Chain.
IN measuring a large distance with your Chain, you may casually mistake or misse a Chain or two in keeping your account, from whence will ensue a considerable errour: Also in measuring of di∣stances (when you go not along by a hedge side) you can hardly keepe your Instrument, Chain, and Mark, in a right line, which if you do not, you must necessarily make your measured distance great∣er then in reality it is. For the avoyding of either of these mistakes, you ought to provide ten small sticks or Arrows, which let him that leadeth the Chain carry in his hand before, and at the end of every Chain, stick one of these Arrows into the ground, which let him that followeth the Chain take up, so going on till the whole num∣ber of Arrows be spent, and then you may conclude that you have measured ten Chains, without any further trouble, and these ten Chains (if the distance you are to measure be large) you may call a Change, and so you may denominate every large distance by Chang∣es, Chains, and Links. Or you may at the end of every ten Chains set up another kinde of stick, by which (standing at the Instrument) you may see whether your eye, the stick, and the Mark to which you are to measure be in a right line or not, and accordingly guide those