224 



Popular Science Monthly 



When these txees were young, fence boards were 

 tninks. The boards are now completely buried 



A Tree Captures a Fence 



MANY years ago a row of Irish 

 poplar trees was used for the 

 posts of a fence, and boards were nailed 

 to the trees. The trunks of the trees, in 

 the process of growing, gradually over- 

 lapped the boards, until now the boards 

 are near the center of the trunks. Not 

 needing the fence any longer, the owner 

 sawed off the boards, the remnants of 

 which still protrude from the trunks of 

 the trees. 



To Keep Automobiles off 

 Railroad Tracks 



THE new long distance railroad 

 signal has been brought about by 

 the new conditions arising from the 

 general use of the automobile. Chauf- 

 feurs are so frequently found driving 

 through country which is new to them 

 that they often find themselves on the 

 tracks of a railroad line before they 

 know it. The long distance signal 

 was designed to give them sufficient 

 warning of the proximity of the rail- 

 road tracks to enable them to be on 

 the alert and to avoid accidents on the 

 tracks. The new signal was designed 

 by the officials of the Southern Pacific 

 Railroad, and the first one w^as placed 

 at the crossing of the main street in 

 Tropieo, Cal., but such excellent re- 

 sults attended the experimental instal- 

 lation that others are now being in- 

 stalled. The use of the new signal will 

 be further extended. 



The lines of the sig- 

 nal are such a departure 

 from the typical rail- 

 road signal that it can- 

 not help being observed 

 by the wayfarer, either 

 mounted or afoot. It 

 consists of a tube of 

 metal eight inches in di- 

 ameter and two and a 

 half feet long, mounted 

 on a support, which, in 

 this case is a piece of 

 three-inch pipe. The 

 pipe also offers accom- 

 modation for the elec- 

 tric wires which supply 

 the current. The tube- 

 is painted black and is 

 mounted in the direction of the road, so 

 that the red light inside may be seen at 



a great distance 



before reach- 



i ng the 



sisrnal. 



nailed to their 

 in the tree 



A red light inside the tube of this railway 

 signal is visible for a great distance, and 

 the disk attracts attention in the daytime 



