A NEW TOPOGRAPHY METHOD. 

 By C. H. Amadon. 



The taking of data necessary for the production of an accurate 

 topographical map, was recently carried on in connection with 

 the strip method of estimating hard wood timher in West 

 Virginia, and with very satisfactory results. 



It required the services of no extra men, the chain crew being 

 made up of two native West Virginians, the man using the hand 

 level never having done such work before, although he had had 

 previous experience with surveying crews. His only duty was 

 to determine the degree of slope and keep the record of the days 

 work on the form which is printed herewith, and to tell the topo- 

 grapher, (or in this specific instance, the compass man) when- 

 ever a contour was crossed, in order that the latter might make 

 his sketch as he went along- 



A table was made showing the number of links to be added per 

 200 links, for each degree of slope, to obtain horizontal chainage, 

 and the number of feet difference in elevation for 200 links dis- 

 tance for each degree of slope. Thus for a 12 degree slope the 

 head chainman added 4 links to the 200; and the difference in 

 elevation between the two points, that is, at 204 links, and not 

 200 links, on the 12 degree slope, is 28.1 feet. 



Consulting the printed sample tally sheet, it will be seen, that 

 the days work started with a predetermined elevation of 2,906 

 feet and that the first sight was one of 150 links on a 2 degree 

 slope. In this case, the level man took | of the tabular distance 

 4.6 feet, (see table) namely 3.4 feet, and throwing off the fraction, 

 added three feet to his starting elevation, giving 2,909 for the 

 elevation of his first station. Similarly, the second sight of 140 

 links, on a I degree slope, gave him 1.54 feet to add, and this 

 time he threw the fraction to the next foot, adding 2 feet giving 

 2,911 for the elevation of the second station. It might be well 

 to state that the number looi plus 92, is the number of a point 

 on a road traverse from which on a bearing S. 40° W, 150 links, 

 was a point on the strip line 42116212 plus 740. The latter 



