THE LEVEL 87 



5. SUMMARY 



The transit of late years has gained a considerable field 

 of use among working foresters for map making and other 

 purposes. The instrument has for woods work great 

 advantages over the plane table in that it is more portable, 

 is less liable to accident, and is not so easily driven off the 

 field by bad weather. 



The uses for it, present and prospective, are as follows: 



(1) It is the instrument for land surveys when great ac- 

 curacy is required or the needle is seriously disturbed. 

 When it is so employed the stadia wires in some cases 

 afford the most effective means of distance measurement. 



(2) It may be used as a level in dam and road building 

 or for topographic purposes. 



(3) Two men using transit and stadia can traverse roads, 

 streams, or lake shores very rapidly, using the needle and, 

 except for a check on local attraction, setting up the instru- 

 ment on alternate points only. 



(4) Uses (2) and (3) may be combined, allowing a 

 traverse and a profile to be run at the same time by the 

 same party. 



(5) A skeleton of accurately run lines, embracing both 

 horizontal and vertical angles, may be made the basis of 

 topographic surveys, and the method is in fact highly 

 serviceable in some kinds of country. 



(6) With its various capacities again utilized, the 

 transit is sometimes employed to work out the detail 

 of small tracts requiring great accuracy. 



SECTION II 

 THE LEVEL 



The engineer's level consists of a telescopic line of sight 

 joined to a spirit level, the whole properly supported, and 

 revolving on a vertical axis. The outside parts of the frame 

 which support the telescope are called the wyes, and the 



