370 EXPERIMENT STATION RECORD. 



given for carrying out thonc; plans, and statements regarding tlie future yield, mar- 

 ket, (>ecupati(in. etc., ami directions fur the lunil>ering of the tract are also given. 



The diminished flow of the Rock River in Wisconsin and Illinois, and its 

 relation to the surrounding- forests, ( f. F. Schwakz ( U. S. Dcjd. Ayr., Bureau of 

 Forcxtr)/ Jlul. 44, }>]>. '^7, pix. <i). — The purpose of the investigation here reported was 

 to ascertain the principal factors upon which the flow of the Rock River depends, 

 and to discover, if possible, practical means for increasing the flow or equalizing the 

 volume of the river. In the region drained by this river the forests have been 

 greatl}^ reduced in area and the condition of those still remaining is far from satisfac- 

 tory. Since 1S85 there appears to have been a decrease in the rainfall, and this has 

 aided materially in diminishing the volume of the river flow. The improvement of 

 the conditions depends on the storing of water, accomplished l)y the construction of 

 artificial reservoirs, or by equalizing its flow through the agency of forest growth. 



The present condition of the wood lots in the region is such that the wooded area 

 might be extended with decided profit to the farm. This could be done without 

 expert assistance or any considerable outlay of capital or other expenditure aside 

 from protection of wooded areas from fires and the care and management of the 

 present areas, together with the planting of additional ones. Detailed descriptions 

 are given, showing some of the deficiencies of the wood lots and how they may be 

 improved. 



Injuries to shade trees from electricity, (1. E. Stone [Massachusetts Stu. Bui. 

 91, pp. 31, firjs. 12). — On account of the increased interest regarding shade trees and 

 roadside improvement and the adverse conditions which trees grown in these situa- 

 tions have to contend with, the author has investigated a number of the problems 

 and in the present bulletin shows the effect of electrical injury to shade trees. 



A considerable amount of damage is found to be due to wires in causing abrasions, 

 destruction of limbs, burning, etc., which necessitates much injudicious pruning. 

 The greatest amount of damage is the local burnings caused by the electrical current, 

 and the higher the electro-motive force the more injury is likely to occur to the 

 trees. There appears to be little or no leakage from wires during dry weather, but 

 in wet weather when a film of water is formed on the l^ark there is considerable 

 transfer of electric current. No authentic cases, so far as the author could ascertain, 

 have been observed where the alternating current, such as is used for electric light- 

 ing, has killed trees, although cases are recorded where the direct current used in 

 operating street railways has destroyed large shade trees. This has been accom- 

 plished by reversing the polarity, causing the positive current to traverse the rail 

 and the return current the feed wire, which usually carries the positive current. 



In general, trees possess such high resistance to electric current as to serve as a 

 protection against their destruction. Different portions of the trees were tested and 

 it was found that the least resistance occurs in the cambium layer and those tissues 

 adjacent to it. Electric currents of a certain intensity when applied to plants act as 

 a stimidus, the alternating current acting more as a stimulus than the direct current. 

 There seems to be some evidence that even though the current is not of sufficient 

 strength to cause burning, it may overstimulate the plant, causing a retardation of 

 its activities, which subsequently results in its death. 



Investigations carried on in connection with these experiments show that the 

 earth discharges during thunderstorms are more common than are generally sup- 

 posed, and are known to disfigure and cause the death of many trees. 



The honey locust in western Kansas, R. S. Kellogg {Forestry and Irrig., 9 

 {1903), No. S, pp. 387-390, figs. 5). — A description is given of the honey locust 

 {Gleditschia triacanthos) , which grows naturally in the valleys of eastern Kansas and 

 has proved to be one of the hardiest trees for planting on the uplands of the western 

 part of the State, where the annual rainfall is 20 in. or less. It has demonstrated its 

 abilitv to withstand adverse conditions of soil and climate, being exceeded in this 



