38 



To bring this quantity to acres, it will be requisite to 

 divide it by 100,000, this being the number of square 

 links in 1 acre. This operation is speedily effected by 

 simply cutting off five figures on the right hand. Those 

 that are left indicate the acres. By cutting five figures on 

 the right hand side off 202,500, 2 is left, which shows 

 that there are 2 acres. The five figures cut off are then 

 multiplied; first, by 4, to show the roods, as "02500 X 4 

 = 10,000. With this proceed, as before, to cut olf the 

 five right hand figures; but as there are only five altogether, 

 therefore there are no roods. It is now multiplied by 40 

 to show the perches, as 10,000 X 40 =400,000, and by 

 cutting off five figures, here the remainder is 4 i.e., 4 

 perches. Therefore the total contents of a field whose 

 sides measured 4 -50 respectively, are 2A. OR. 4p. or two 

 acres, and four perches. 



As it is, however, unfortunately, of too frequent occur- 

 rence to meet with fields, which are not square, but some- 

 times extremely irregular in their outline, it is necessary 

 to understand how all shapes and figures can be accurately 

 measured. 



For small surveys, it is a good way to sketch on a 

 pieco of paper, a figure resembling the ground to 

 be surveyed, and then to write the dimensions as they 

 are found on the corresponding part of the plan. These 

 can be afterwards accurately laid down according to some 

 suitable scale. 



In surveying with a chain two persons are required ; 

 the foremost, or leader, is provided with ten arrows, one 

 of which he sticks in the ground, when he comes to the 

 end of the chain, and goes on ; when the follower reaches 

 the arrow thus left, he lifts it, and the leader being then 

 another chain length further off, sticks in another arrow, 

 and so on. The arrows in the hand of the follower 

 show the number of chains measured, and the residue 

 of the ground, if it be less than a full chain, is expressed 

 in links. 



When thero are no natural marks to guide the surveyor 



