THE TRAVERSE BOARD 



99 



on it is known by the crossing of a section line. The 

 instrument should be set up at the known point, with one 

 edge of the board set north and south as shown by the 

 needle. A point is then chosen on the sheet to represent 

 the one occupied on the ground, the edge of the ruler is 

 swung about it until the sights range- toward the second 

 point to be occupied, say the next turn of the stream, and 



TRAVERSE BOARD 



a line is drawn in its direction. The distance between the 

 two points is then chained or paced, and when this has 

 been scaled off a second point on the map is obtained. 

 The board must then be set up at the new point and 

 oriented as before, when, the ruler being swung about the 

 new point, a ray may be drawn from it to a third, and 

 so on. Little difficulty will be experienced by one who 

 understands compass surveying in working this instru- 

 ment. A point on the sheet always represents the point 

 occupied, and that is always the point to work from. 

 The map is carried to completion right in the field and 

 that, as regards both cost and accuracy, constitutes the 

 advantage of the method. 



