Popular Science Monthly 



German Trenches as Comfort- 

 able as Houses 



GERMAN trenches taken by 

 the enemy have excited con- 

 siderable comment because of the 

 complete manner in which they are 

 fitted up. Many of these trenches 

 have been found to be unaffected by 

 the heaviest bombardment. Some 

 of the shelters taken had been ex- 

 cavated to a depth of about forty 

 feet. They had galleries one hun- 

 dred and fifty yards long and seven 

 feet high. Large rooms opened out 

 from the galleries. Both galleries 

 and rooms were lined with strong 

 timber. Ventilation was afforded 

 by oblique shafts. The exits, of 

 which there were many, consisted 

 of staircases. The steps were fitted 

 with steel treads, and ramps having 

 a gentle incline. 



88^ 



The device is nothing more than a phonograph diaphragm 

 and a horn which amplifies the weak sounds of the relay 



Wearing Spikes on Your Feet to 

 Prevent Slipping on Ice » 



EVERYBODY knows the difficulty of 

 maintaining a foothold when walking 

 on ice or sleet and slush-covered streets. 

 A device which can be worn either on shoes 

 or rubbers to prevent slipping has been 

 invented by C. A. Anderson and G. H. 

 Schepstrom of Illinois. Mr. Anderson, 

 who is a shoemaker, noticed that every 

 winter there was a demand for creepers 

 but that few of the creepers on the market 

 gave satisfaction to the wearers. Not 

 having facilities 

 to make the 

 steel spikes nec- 

 essary to con- 

 struct creepers, 

 he called for as- 

 sistance on his 

 friend, Mr. 

 Schepstrom, 

 who is a sheet 

 metal worker. 

 Together they 

 produced a 

 type of creeper 

 which has dis- 

 tinct advan- 

 tages over the ordinary kinds in use 

 The new creepers are fastened by straps 

 in much the same way as are some skates. 

 There are steel studs on both the sole 

 and the heel which enable the wearer 

 to stand securely in any position. 



A new ice-creeper which 

 boots or rubbers. It is 



Applying the Principle of the Phono- 

 graph to the Telegraph Sounder 



ON long telegraph lines, the current 

 coming into a station is generally so 

 weak that it cannot even pull down the 

 magnet of the loud-sounding instrument. 

 The current can, however, operate a small 

 magnet on a very sensitive telegraph instru- 

 ment. By making this small magnet close 

 a heavy battery circuit in which the loud 

 sounder is placed, the sensitive instrument 

 acts as a relay and overcomes the difficulty. 

 Extra batteries and instruments are 

 therefore needed 

 at every station. 

 In any large size 

 telegraph sys- 

 tem, the ex- 

 penses of their 

 upkeep are con- 

 siderable. 



A very clever 

 invention of 

 R.A.andB. M. 

 Grout.ofDaven- 

 port, Iowa, does 

 away with this 

 expense by am- 

 plifying the 

 weak relay clicks directly by means of a 

 diaphragm and horn such as are used in all 

 phonograph instruments. The weak clicks 

 are transmitted to the diaphragm whose 

 vibrations act upon the air and shoot their 

 corresponding sounds out through the horn. 



may be worn over shoes, 

 strapped on like a skate 



