16 



HIGHWAY CONSTRUCTION 



60.OO 





55.00 



- 54.20 



- 54,4- 



- 54.62 



Fig. 4 shows an imaginary tract of country, the physical features 

 of which are shown by contour lines. 



Map. The map should show the 

 lengths and direction of the different por- 

 tions of the line, the topography, rivers, 

 water courses, roads, railroads, and other 

 matters of interest, such as town and 

 county lines, dividing lines between property, 

 timbered and cultivated lands, etc. 



Any convenient scale may be adopted; 

 400 feet to an inch will be found the most 

 useful. 



Memoir. The descriptive memoir 

 should give with minuteness all information, 

 such as the nature of the soil, character of 

 the several excavations whether earth or 

 rock, and such particular features as can- 

 not be clearly shown upon the map or 

 profile. 



Special information should be given re- 

 garding the rivers crossed, as to their width, 

 depth at highest known flood, velocity of 

 current, character of banks and bottom, 

 and the angle of skew which the course 

 makes with the line of the road. 



Levels. Levels should be taken along 

 the course of each line, usually at every 100 

 feet, or at closer intervals, depending upon 

 the nature of the country. 



In taking the levels, the heights of 

 all existing roads, railroads, rivers, or 

 canals should be noted. "Bench marks" 

 should be established at least every half 

 mile, that is, marks made on any fixed 

 object, such as a gate post, side of a house, 

 or, in the absence of these, a cut made 

 on a large tree. The height and exact 



7H-54.50 



54.80- 



-55.20 



55.10- 



55.00- 



Fig. 5. Preliminary Profile 



