ULTRA SHORT WAVE TRA NSMISSIOX PHENOMENA 207 



Record " B" was taken along another radial road not far distant and 

 roughly parallel to that of "A." This is an old road and has the usual 

 string of nondescript trees along the road edges. These trees roughen 

 up the pattern always, sometimes badly, but the ground slope changes 

 can usually be identified (compare with the previous record). The 

 marked maximum at 0.47 mile, where direct and reflected radiations 

 add favorably, is the equivalent of the "brow-of-hill effect" found for 

 short waves.^ The very marked undulation at 0.85 mile is apparently 

 due to the overlapping of two extensive patches of woods which here, 

 for a short distance, blanket both sides of the road. In the written 

 comment on the records the direction of the arrows indicates the side 

 of the road on which the objects mentioned lie. 



Record "C" is that for a radial road southeast of the transmitter. 

 This is an old tree-bordered road and has several turns in it. The 

 trees are mostly locust and there are quite a few vertical guy wires on 

 the power and telephone poles. In the pattern these guy wires are 

 usually indistinguishable from trees. The correspondence with topog- 

 raphy appears in several places, but there is an unexpected and deep 

 minimum at 0.74 mile. There are no trees or other objects to explain 

 this, and our feeling is that it is due to a topographical peculiarity 

 whereby the direct and reflected radiations nearly cancel. The road is 

 rising here, in a cut about four feet deep, and in the direction of the 

 transmitter the ground billows up so that one can visualize the ex- 

 planation given. 



Records " D" and "£" were taken along a new radial road (an exten- 

 sion of "^," in fact New Jersey highway No. 34). At the right of "P" 

 the road starts downward towards the transmitter at the same time 

 entering a cut. There are no trees and the resulting record is a fast 

 dropping smooth one. Farther on the marked effects of a pair of guy 

 wires and some clumps of trees can be seen; the absence of other trees 

 giving an undisturbed background to work against. A favorable slope, 

 or "brow-of-hill" effect, is seen at 1.4vS miles. The latter part of the 

 record is through a succession of cuts and fills, with trees about, and 

 the record is correspondingly rough. 



Record "£" continues the previous record. There is an initial rise 

 at the start, due to rising ground, and woods to the right roughen up 

 the pattern. From here on to the end there is a slow ground rise, a 

 slight fall, and a final rise. At the center of the stretch is an isolated 

 clump of trees with farm buildings and a straggly orchard below. The 

 contrast between the treeless stretch and that with trees is very 

 marked. The effect of the trees begins suddenly, at about 150 feet in 

 from the edge of the grove. 



^ Potter and Friis, Proc. I. R. E., vol. 20, p. 699; April (1932). 



