ATLAS, TEXTUAL, AND WALL MAPS. 157 



Conventional Signs. 



In general , conventional signs should not be multiplied or created 

 ad hoc. The few recognised signs are sufficient, unless to indicate any 

 new feature, such as a first-class wii'eless telegraphy station, or the 

 employment of river water for power or irrigation. The limit of 

 navigation on a river may well be shown by an anchor. The solid black 

 dot for town sites has advantages over the fine open circle, as better 

 revealing concentration of urban population. Larger towns require a 

 lai'ger dot or a dot within a circle. Eailways and canals should be 

 shown by single lines of a distinctive character; a fine single black line 

 should be avoided. On large-scale maps a symbol is required for roads 

 also, since motor traffic has restored their significance. 



Words or conventional signs indicating the distribution of economic 

 production are strongly deprecated. If economic factors must be ex- 

 hibited on a general map, solid colour or shading should be used to show 

 the concentration of industrial population, or the locality of high pro- 

 duction of two or three commodities of first importance. 



Black and white maps in school books (textual maps) should not 

 attempt to supersede Atlas maps, but should be confined to their function 

 of illustrating statements in the text. Mechanical shading is often either 

 too coarse or too light. The use of large areas of solid black should 

 be cautiously exercised. White letters on a black ground, and black 

 letters on a shaded area, too often tend to print obscurely. The size of 

 type, if intended to be read, should be as carefully considered as in the 

 Atlas, and additional allowance should be made for imperfection in 

 reproduction. Over-reduction in the camera from the original drawing 

 is one of the commonest faults in block-maps, and owing to limitations 

 imposed by the size of the page, the fault lies usually in the drawing. 

 In general a textual map must be simple and not attempt to show high 

 detail, and features tending to mutual obscuration should not be shown 

 on the same map. Thus the same phenomenon for different seasons 

 or associated phenomena (e.g., isotherms for January and July, or 

 isotherms and isohyets) should not be shown on the same map — the 

 particular examples cited apply equally to coloured maps. But this rule 

 is not rigid. It is sometimes difficult to compare the phenomena shown 

 on two maps (e.g., the climatic and the form divisions of a large 

 country) when the two might have been exhibited on the same map 

 without obscurity. 



Wall Maps. 



The recommendations of the Committee in regard to the style of a 

 School Atlas apply almost without modification to wall maps. 



The scales employed should be as few as possible, and should be 

 simple multiples of each other. This is more easily arranged in a set 

 of wall maps than in an Atlas, because there is here no necessity that 

 the maps should be of uniform size, or that the amount of margin should 

 be uniform throughout the series. For the same reason, it is far less 

 necessary that the map area should be foursquare, especially in maps 

 of continents and oceans, where every effort should be made to 

 emphasise the fact that the objects represented lie upon a spheroidal 

 surface. Awkward blank areas in the margin, which would be dis- 



