THE FOREST ATLAS. 71 



and is not obscured by data which is of special rather 

 than general value. The first reconnaissance of any 

 area should include the drainage and contour, otherwise 

 it will not be possible to ' 'register 7 ' a second or supple- 

 mental reconnaissance with it. 



General maps, showing an entire Forest or region are 

 compiled at Washington from data on the corrected 

 Atlas sheets, and are issued for the use of forest officers. 

 The usual process is photolithography. Every request 

 for the issuance of a map should be submitted to the 

 Forester with a recommendation regarding the data to 

 be shown or omitted, scale, kind of paper, and number 

 of copies required. Any project for the issuance of a 

 "three-color map" with blue drainage, brown con- 

 tours, and black culture should be taken up by corre- 

 spondence with the Forester before the final tracings 

 are prepared, in order that the manuscript may be in 

 good shape for the engraver. 



The Forest Atlas legend page, which has been sup- 

 plied to all forest officers, shows the standard scheme 

 of colors and symbols which are used in the prepara- 

 tion of all atlas sheets. 



It should be borne in mind that National Forests are 

 established in widely different regions; as far north as 

 Alaska and as far south as Florida and Porto Rico. 

 On no two forests will the data suggested on the legend 

 page be of equal importance, and it may be necessary 

 or convenient to adopt additional symbols or colors to 

 show unusual conditions. This is quite permissible 

 providing the marginal notes are made explanatory or 

 if the sheet is subject to only one interpretation by 

 forest officers who will have to use it. 



