240 JOURNAL OF FORESTRY 



SOIL, WATER, AND CLIMATE 



Air. Lehman, who was connected with the Ohio 



Forests Flood Commission, presented before the Forestry 



and Conference at Pittsburgh a paper describing in 



Floods detail the upper Ohio River basin. We quote 



from his statements the following: 



"In connection with the extensive investigations of the Flood Commission, 

 which had its origin in the Pittsburgh Chamber of Commerce, it was thought 

 advisable to know the extent of the forest cover of the combined basins, and in 

 this regard the United States Forest Service and the Pennsylvania Forestry 

 Department co-operated with very valuable results. Using the forest map pro- 

 vided, as a basis, it was found, in 1912, in totaling the many hundreds of de- 

 tached areas, that about 7,700 square miles, or, say, 41 per cent of the basin above 

 Pittsburgh, was wooded, the rest of the country being denuded and composed of 

 cultivated and barren land. A very considerable part of the 41 per cent, of 

 course, consists of second and third growth trees of little or no present com- 

 mercial value. x\bout 360 square miles, or 2 per cent of the basin, remains in 

 virgin forest, the greater portion being situated on the higher elevations of the 

 northeast parts of the basin. Most of the good timber is now found above an 

 elevation of 1,500 feet above sea. 



"Judging from indications obtaining at the time of the investigations, over 400 

 square miles of timber were destroyed by fire, involving some of the virgin timber. 

 "The tree types are distributed in general as follows : White pine, in the north- 

 eastern part of the Allegheny; hemlock, mixed oaks, and chestnuts, scattered over 

 the combined basin; also beech, birch, maple, and basswood, but these largely on 

 the high elevations. 



"Incidentally an estimate is ventured of the quantity of virgin timber cut from 

 the combined basin. Under the assumption that about 14,000 square miles, or 70 

 per cent, were in commercial growth, and that there were only 12,000 board meas- 

 ure produced to the acre, the amount would reach nearly 168 billion feet for the 

 first cutting alone. If only half of the present stand, say 3,800 square miles, were 

 properly treated, a yearly asset of considerable proportions for all interests can 

 be calculated. 



"As to floods, it was found that from 1872 to the end of 191 1 there were 53 

 floods that reached heights above the danger stage at Pittsburgh, which is 22 

 feet above zero at the gage. The flood of March 15, 1907, reached a height of 

 35/4 feet. Dividing the time, 1872 to 1912, into five-year periods, it was seen that 

 there was an increase in the frequency and height of floods, as indicated by the 

 following : 



1st period 2 



2d period 3 



3d period 6 



4th period 8 



5th period 7 



6th period 5 



7th period II 



8th period 1 1 



Total 53 



