338 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 19 39 



nationality by joining a larger creek which was already known, or by 

 maintaining one direction for so long as to preclude the possibility of 

 its turning back. A small party of four Indians equipped with com- 

 passes, and fondly referred to as the Advance Guard Cavalry, kept 

 ahead of the boundary cut doing this work. They never stuck it for 

 long and usually became badly infected by bush yaws and sores. It 

 was their job to mark saddles on the international watershed, and 

 connect their marks by a sirrahee or line just cut sufficiently to allow 

 passage. 



The Indian has one great failing. He has no idea of direction or, 

 if he has, is quite incapable of explaining his wanderings or of mak- 

 ing the simplest of diagrams to illustrate them. Time and again 

 they would report that they had discovered a big creek ahead. When 

 asked where they invariably answered, "Right away back," and 

 usually pointed straight above their heads. Comparisons of size 

 were conveyed entirely by inflexion of the voice: Thus a "big" hill 

 was not uncommon; but a "BIG" hill meant something quite 

 remarkable. 



The boundary locaters' sirrahee was traversed by rope and sound 

 for planimetry, and by aneroid barometer for height. Next came 

 boundary cutters, who cleared the line sufficiently for the carriers 

 and instrumental traverse. A day's work for a line clearer was 250 

 meters, and it was not easy. The boundary traverse was made with 

 a 3-inch vernier theodolite set up on magnetic north at every second 

 station. Distances were obtained by stadia, and heights were carried 

 forward by vertical angles. 



In the meantime the two topographical parties worked on either 

 flank, running a chain of rope and sound, and aneroid traverses with 

 their apexes on the boundary and bases parallel thereto. The tech- 

 nique of rope and sound is simple but effective. The rope is one-third 

 of 100 meters, minus what it is expected to stretch, plus an allowance 

 for not being laid in one straight line. The party is preceded by 

 two cutters with a compass, who cut a sirrahee on an ordered bearing. 

 Two men lay the rope down the requisite number of times, then the 

 front man commences to sing. A compass bearing is taken on this 

 sound from the last station and booked, together with the aneroid 

 reading. The station is numbered and the party moves on. The 

 traverse is plotted as the party moves along, streams and hill features 

 being rapidly sketched by intelligent guessing. The Indian took 

 well to such work, although he found the compass difficult to master. 



The instrumental traverse was computed on magnetic north as 

 the work progressed, and finally adjusted between the astronomical 

 positions. The topographical traverses were plotted on scale 1/50,000, 



