SECTION DIAGRAM AND KEY THERE- 

 TO AND NATURAL SECANTS. 



The Diagram and Key will enable a Compass- 

 man to easily approach, from a given point, any 

 of the several corners bounding a Section and 

 call out the various 40 lines to the Cruiser. (One 

 may, too, solve other problems from it, should 

 circumstances require). The seven courses 

 shown on diagram are North-Easterly, 

 but the method applies to any direction. 

 It may occur at times that the Compassman 

 may have to solve his own problem. (The 

 key will assist him). If Compassman stands, 

 for instance, at 1-8 post, four tallies North of 

 the S. E. corner of Section, desiring to reach 

 center of Section (course 6 suggests itself, 

 latitude being half of departure). See course 

 6 in Key. One tally equals 69 paces, 2 

 forties equal 554 paces. Angle 63 26' 

 (marked on inner edge of Compass Circle) 

 Therefore, run North 63 26' West, a distance 

 of 554 paces, and you have center of section. At 

 four tallies of 69 paces each you have the 40 

 line (call it to your Cruiser), at 8 tallies (4 

 more from 40 line) you reach central point of 

 Section. 



The compiler of this book recommends (the 

 use of paces) the value of one pace equaling 

 64 inches or two ordinary steps. Therefore 

 62 paces equals one tally, equals 20 rods 

 distance, etc. 



NATURAL SECANTS. 



In furnishing the natural secants for each 

 course, perhaps a rapid, easy and accurate 

 means will be found to determine on a given 

 course the diagonal distances. Multiply 

 secant number by length of one side of the 

 square, product will be required distance. 

 If for instance, you desire to ascertain dis- 

 tance in rods from corner of Section diagon- 

 ally to opposite corner, the angle is 45 degrees, 

 secant number 1.41421. Multiply 1.41421 by 

 320 rods, the result is 452.54720. Cut off 

 5 decimals. Therefore the result is 452 J rods. 



33 



