AN AUSTRALIAN STUDY OF AMERICAN FORESTRY. 109 
Cuapter X. 
THE U.S.A. FOREST SURVEY AND ASSESSMENT SCHEME. 
Forest survey and assessment work is the foundation of forest organisation 
and administration. 
Boundary survey is necessary for the effective control of the forest 
business; intensive reconnaissance is essential to the extension of forest 
management. 
The United States of America Forest Service has developed this branch 
of forest practice to a very high degree of efficiency, and has evolved a 
standardised scheme for carrying it out which furnishes a very useful guide 
for elaboration of Australian methods. 
Necessarily the plan has to fall in with the United States of America 
Public Lands Survey system. That system differs basically from the 
Australian practice, and it is necessary, therefore, to describe it briefly in 
passing. 
The United States of America Public Lands Survey plan dates from the 
time of the Revolutionary War, when General Putnam conceived the idea of 
parcelling the country into regular rectangular blocks with 24-mile sides. 
These blocks have been cut up since into “townships” of 6-mile sides, 
and still later the “townships” themselves were subdivided into thirty-six 
sections each a mile square. These “sections” again have been parcelled 
out into “forties,” z.e., sixteen blocks of forty acres each. 
It was an after discovery that the convergency of meridians towards the 
North Pole interfered with the ideal of regularity, and ‘“ correction lines” had 
to be introduced on the northern side of the “ townships,” throwing all errors 
of convergency into the north half of the north tier of “sections,” which 
were reduced in consequence below the original standard area of 640 acres. 
All existing data with regard to the national forests is consolidated in the 
Forest Atlas at Washington. This Forest Atlas is the “central repository 
of maps, diagrams, statistics, and history of the national forests.” 
It comprises now 204 volumes, containing map sheets exactly 18 in. by 
21 in., on the standard scale of eighty chains to the inch. 
In each District Office is kept a District Atlas, holding copies of the map 
sheets for the district. It consists generally of twenty or more volumes. 
The sheets covering a national forest are assembled into a “folio”; 
which forms the basis for all further forest mapping. 
The United States of America Forest Manual declares that— 
“ Accurate base maps on a large scale showing the topography 
and culture are essential for the proper and successful management 
of the timber and forage, of special uses and settlement, and for 
the improvement and protection of the forests.” 
The entire forest survey work is vested in the Office of Geography, whose 
broad aim is to build up a series of topographic base maps on a standard 
scale of twenty chains to the inch, with 50 ft. contours, and of sufficient 
accuracy and detail to serve every purpose of forest administration for at least 
twenty-five years ahead. 
The base maps are to be called “ Working Plan Maps,” and are to cover 
eventually the entire National Forest Area. 
