WILSON ON GEOGRAPHICAL WORK OF THE SURVEY. 737 



after the angle, but instead of the simple numbers write (1-1), (2-1), 

 (3-1), which signifj^, as before stated, point 1 from station 1, point 2 

 from station 1, &c. ; and this designation or name, as it may be called, 

 is always used thereafter, except where they are afterward occupied as 

 stations ; it is then more convenient to substitute the number of the 

 station in place of the old one. 



Any new points sighted from station 2 are numbered again, com- 

 mencing with one as before, and these become (1-2), (2-2), (3-2), and so 

 on from station to station as above, (16-115), (14-115), the first number 

 always referring to the number from the given station, while the second 

 gives the number of the station. 



This system of numbering was originally developed by myself, and I 

 have used it for several years in connection with this class of topo- 

 graphical works, and find it about as short and at the same time as 

 complete a system of giving names to the many points that are neces- 

 sary to sight iis any that I have seen. It also facilitates the plotting 

 very much. For instance, in plotting you come to a point in the notes 

 of station 125 marked 14-115 5 you know at once by turning to station 

 115 that you will find another bearing to this point 14, and that you 

 will probably find it sighted from the intermediate stations. Thus much 

 time is saved in looking for the necessary checks to any point that yoii 

 may wish to locate. 



" Sometimes the bearings are simply placed on the sketches, especially 

 of points that are not likely to be sighted often, such as minor points, 

 stream junctions, &c. ; in that case the horizontal angle is first recorded, 

 then follows the vertical angle, with a plus or minus sign placed before 

 it to show whether it be an angle of elevation or depression, thus : 83° 

 15' + ic> 30'. 



Over the more settled portions of the country the principal roads 

 have been meandered with compass and odometer. 



