22 



must always appear. It is important that such sections should give 

 accurate horizontal as well as vertical measurements, and a convenient 

 horizontal datum line is one drawn through the bottom of the lowest 

 fosse. 



7. The artificial earthwork should be shown on the plan by hachuring. 



8. The natural slopes of the ground should be kept visibly distinct from 

 the artificial work by contouring. Approximate contours, or "form lines," 

 can be sketched in between the O.S. contours (printed on the 6in. maps) 

 and will have the effect of throwing the position into relief. 



9. On every plan should be noted : 



(a) signature of observer and date of his survey ; 



(b) name of the county in which the work is situated ; 



(c) name of the parish ; 



(d) Latitude and longitude, from iin. or 6in. O.S. map ; 



(e) reference numbers of 25m. (or 6in.) and iin. O.S. maps. 



North points and scales should always be inserted, and the north should 

 be always at the top of the plan. 



10. Other information under the following heads will be useful and 

 should be written on a separate sheet, together with descriptive notes : 



(a) local names for the work, whether obsolete or still current ; 



(b) nature of soil ; 



(c) materials employed in the ramparts (where dry walling or 



masonry appears the fact must of course be stated) ; 



(d) source of probable water-supply and distance from the work ; 



(e) bibliographical references, if any ; 

 (/) name and address of present owner. 



11. As an aid to uniformity, the chief conventional signs in ordinary use 

 are appended. 



