682 



Yearboo\ of Agriculture 1949 



graphs which requires only a minimum 

 of costly supplemental ground work. In 

 somewhat oversimplified terms, that 

 means the ability to identify tree spe- 

 cies, to measure diameter, height, and 

 width of crown, and to determine fac- 

 tors of tree condition, such as sound- 

 ness, quality, and thrift, on aerial 

 photos with accuracy and adequacy. 

 The results could then be applied to 

 special tables to get volume, quality, 

 defect, and possibly growth, without 

 any on-the-ground measurements. 



To summarize: We need to know 

 much more about taking and reading 

 aerial photographs, but present tech- 

 niques are good enough to aid greatly 

 in the Forest Survey and to meet emer- 

 gency needs for a quick inventory. 



An example is the inventory of the 

 forest fire in Maine in 1947, when 220,- 

 000 acres burned over in a few days 



and a critical situation developed be- 

 cause it was felt that the fire-killed 

 timber had to be utilized within a year 

 before insects and storms could destroy 

 it. A map and timber inventory to show 

 the location, kind, and volume of the 

 timber was immediately needed to aid 

 in the necessary salvage plans. The area 

 was flown, maps were prepared from 

 the photographs, ground plots were 

 measured, and reports made ready in 

 only 8 weeks. 



RAYMOND D. GARVER is director of 

 the Nation-wide Forest Survey., Divi- 

 sion of Forest Economics, in the Forest 

 Service. He is a graduate of the Uni- 

 versity of Nebraska and holds a mas- 

 ter's degree in forestry from Iowa State 

 College. For more than 30 years he has 

 worked in forest research and adminis- 

 tration of national forests. 



RAILROADS AND FORESTERS 



ROBERT N. HOSKINS 



Railroads have always run on wood. 

 Wooden rails made the road over 

 which the horse-drawn vehicles hauled 

 brick and clay products up Beacon 

 Hill in Boston in 1795. Three miles 

 of wooden track was the total length 

 of the first railroad incorporated in 

 Massachusetts in 1826. When new 

 frontiers opened, railroads pushed 

 across the continent; for the 227,355 

 miles of track they laid, they needed 

 wood wood for cross ties, wood for 

 piling, wood for switch ties, wood for 

 a hundred other uses. Their need for 

 wood continues in an age of steel, plas- 

 tics, and glass ; actually, in Class I rail- 

 way track today there are 994,516,000 

 wooden cross ties. 



The history of railroading can be 

 told as the history of the use of wood. 

 With mechanization, notably the steam 

 locomotives, the use of horses for the 

 motive power was discontinued. As 

 heavier equipment moved greater and 

 greater distances, the originally de- 



signed wooden rails, capped by strips 

 of iron, became obsolete and were re- 

 placed by all-steel rails. The demands 

 of the lusty, growing giants, the rail- 

 roads, and the expanding Nation they 

 served and, indeed, nourished, grew as 

 the railroads grew. To meet the neces- 

 sities of a growing Nation, our virgin 

 forests were cut over rapidly. The 

 effort was little and the need small to 

 carry on any program of conservation 

 to insure future operations on those 

 timberlands. 



The real demand for action to be 

 taken came much later. One reason 

 for it when the need did arise was that 

 durable species were declining in the 

 volumes needed. Maintenance costs 

 increased yearly because the materials 

 needed for operation had to come from 

 the less durable species like the red oak, 

 gum, and pine. To meet the rising 

 costs, extensive studies were under- 

 taken in wood preservation. Railroads, 

 aware of their problem, which was one 



