252 HYDROGRAPHICAL SURVEYING [chap. x. 



very fair approximation of the position and shape of the 

 more conspicuous elevations in the land, visible from seaward, 

 will be made. The officer coast-lining will have got the 

 entrances of all little streams fixed, and from the ship ofif 

 shore we can recognise which ravines, or at any rate which 

 of the larger ones, join on to these entrances. Topography 

 put in in this way will present a somewhat detached appear- 

 ance, and we can only fill up the hiatus by writing on the 

 chart the general appearance of the land intervening between 

 the hills, as far as we can see it from aloft, as, " rolling grassy 

 plain," " densely wooded and undulating," etc. Sometimes, 

 on a coast of this description, we can get back from time to 

 time to an elevation we see from the ship to be partially clear, 

 and a sketch from a position of that kind will materially 

 improve our knowledge of the topography. 



By referring to the sketch at p. 94 it will be seen how, with 

 similar views from different points, ravines and valleys may 

 be cut in, and roughly drawn on the chart. 

 Regular When, however, we can spare the time to perfect our chart, 

 eraphy ^^^ *^® nature of the country permits it, we should walk all 

 over it, and sketch the topography on the ground. To do this, 

 we must have as many conspicuous objects as possible fixed 

 beforehand, and pricked on to a board, as for sounding or 

 coast-line. Topography can be plotted afterwards, the same 

 as can be done with coast-line or any other work, but it w ill be 

 much more satisfactorily done if plotted at the time. 



We then walk over our country, fixing ourselves with angles 

 on commanding spots, plotting the stations by the station 

 pointer or tracing-paper, and drawing lines from them to all 

 things we want to plot — spurs of hills, houses, valleys, etc. — 

 and sketching the details immediately around us. To fix 

 details for this purpose w^e shall often have to content ourselves 

 with two angles only, and as long as we do not use such points 

 to carry on our stations with, this will be sufficient. A good 

 deal of judgment is necessary in selecting spots to make 

 stations, which cannot come without experience. 



In placing the details on the paper on the rough board, 

 sketch in the line of a valley first by the stream at the bottom, 

 and then the adjacent hills or spurs. 



A 10-foot or longer pole may be used with advantage in 



