138 THE BOOK OF NATURE STUDY 



used to prepare a plan of some out-door area like the playground, 

 and to insert the position of outside objects which may be visible, 

 in relation to the boundaries of the ground. Work of this 

 character may be compared with the plan of the same area as 

 shown in the sheet of the 25-inch ordnance map (Fig. 37). Then 

 more of the area on that map can be traversed with a view of 

 verifying the details shown upon it, and ascertaining the meaning 

 of every symbol employed. It will be soon realised that this map 

 is excellent as an accurate representation of all the human and 

 natural topography ; but there is no indication of the slope and 

 relief of the ground. 



The 6-inch map should be the next stage in progress (Fig. 38). 

 It has the great advantage that it is an absolute copy of the 25- 

 inch map, with the omission only of the numbering and acreage 

 of fields. It is true that contouring is also introduced, but this 

 may for the moment be ignored. The scale is sufficiently large 

 to make the map extremely easy to read, and the insertion of 

 hedges, of some of the trees, the exact shape of the roads, and 

 innumerable other details, makes it possible to ascertain positions 

 with extreme accuracy. At first attention should be mainly directed 

 to this exact localisation, to the following of roads and paths 

 marked upon it, to the verification of objects indicated, and to 

 the insertion of other objects not recognised by the map. After 

 this, the map should be used for the purpose of working out 

 routes from one point to another, the routes being afterwards 

 verified on the ground. The great object throughout should be 

 to realise the value of accurate representation of facts, and to 

 show that an accurate map is the best of all means for recording 

 them, and for bringing a large collection of topographic data 

 into a convenient compass, and in a readable form. 



If a portion of a 6-inch map be photographed down to the 

 scale of one-sixth linear, a map on the scale of i inch to the 

 mile will be produced. But it will be found from inspection 

 of the photograph that the limit of clearness has been reached 

 and passed. The details have become too crowded, the roads 

 are too narrow, and the map cannot be used without a magnifying 

 glass. This shows that if a map on such a scale is required, 

 it is necessary to select the most important data only for repre- 



