PAINKANUA SECTIONS. 89 



that the outlines given in my sections will be found correct for all 

 practical purposes. I adopted the following process for constructing 

 the sections. On the assumed base-line of io,oco feet above sea-level, 

 I marked off all the horizontal distances of the chief points included 

 in the line of section, and of all the points of which I knew the 

 elevation. On co-ordinates drawn from these points I mark off the 

 heights according to the same scale as the horizontal distances. By 

 connecting the points so obtained, a rough outline of the section 

 results, which only requires to be corrected for minor details, character 

 of slopes, peaks, etc. The latter is easy enough in most cases. 

 Most of the sections may be actually viewed in detached portions 

 from adjoining heights, from which points I made camera lucida 

 sketches, which serve to correct the character and outline of my 

 ideal sections. So, for instance, the mass of the Chango may be seen 

 from any of the heights on the left (east) side of the Dhauli valley, or 

 from the Niti Pass. 



There are some geologists who question the use of such sec- 

 tions. I believe the fallacy of such opinion 

 Use of ideal sections. 



needs scarcely any refutation ; but I may remark 



that, in the first place in describing the geology of any area, I wish to 

 put before the reader, not only the facts as I found them, but also 

 must endeavour to give my own interpretation of them as graphically 

 as I can. For this purpose I give not only natural profiles but also 

 the sections, which will show my own intrepretation of the former. 

 Without the aid of ideal sections I believe it is next to impossible to 

 give a lucid description of a complicated mass of strata. Any one 

 conversant with the construction of sections or diagrams will at once 

 understand how far such sections are only to be understood to be 

 diagrams, and how far they represent actual facts. 



As regards the natural profiles I have only to remark that they 

 have all been drawn with the aid of a camera lucida, and may there- 

 fore be absolutely relied on for accuracy of outline and propor- 

 tions. 



( 89 ) 



