Popular Science Monthly 



All Kinds of Commotion at This Shells That Burn and 



Theater; Electric Signs Cause It Suffocate 



MANY things would interest you if 

 you happened to pass a certain 

 moving picture theater out in a California 

 city. For instance, a big cloth sign, 

 mounted upon a framework, keeps moving 

 back and forth on suspension wires above 

 the doorway. Then too, the head of the 

 actor depicted on this sign has an odd way 

 of turning 

 'round and 

 'round in the 

 most eye-ar- 

 resting man- 

 ner. Mere 

 movement 

 seems to be a 

 good adver- 

 tisement, for 

 crowds of 

 people are 

 attracted by 

 the sign. 



The re- 

 volving of 

 the actor's 

 head is sim- 

 ple enough. 

 A small fan 

 motor back 



of the sign does the work. Suitable pul- 

 leys and cord-belts reduce the speed. The 

 sign, revolving head and all, is pulled back 

 and forth by cords at each end, which run 

 to a winding drum concealed at some point 

 about the front entrance. The drum is 

 operated by a second motor. When the 

 sign reaches the right or left end of its 

 travels, it trips a switch which reverses 

 the driving motor and sends the sign in 

 the opposite direction — this operation 

 being continuous and 

 automatic, of course, 

 as long as the current 

 is turned on. Motors 

 may be reversed by 

 reversing the field 

 windings, by shifting 

 the brushes or by re- 

 arranging phase con- 

 nections. If you de- 

 sire to experiment 

 wnth electric signs, 

 ask your local electri- 

 cian about the motor. 



The rectangular sign filling most of the picture is moved 

 back and forth by an electric motor. The head revolves 



The sign In position on exterior of 



theater. It is simple in construction 



203 



THE so-called "tear shell" used in the 

 war in Europe is a hybrid between 

 poisonous gas and the high explosive shell 

 It is an ordinary shell of high bursting 

 quaUties which is filled with a charge of 

 intensely irritating chemicals. These, as 

 they shower from the shell upon the men 

 in the trenches, affect the eyes and cause 



great dis- 

 comfort. 

 The men 

 who are at- 

 tacked un- 

 prepared, be- 

 come over- 

 powered 

 almost in- 

 stantly, for 

 none can 

 stand the in- 

 tense irrita- 

 tion for more 

 than a sec- 

 ond. The 

 tear-ducts 

 open to wash 

 the eyes, but 

 their action 

 has little 

 efifect upon the strong chemicals. 



The nature of the active substances 

 used has been the cause of much specula- 

 tion. It is believed that very common 

 substances are employed, for such un- 

 mysterious edibles as onions and peppers, 

 can produce intensely irritating effects 

 on the eyes. Red pepper abounds in 

 Hungary, so it is likely that some of it 

 is used because of its cheapness. This 

 pepper is not only irritating, but it is 

 known to give off an 

 extremely pungent 

 odor which renders 

 the air difficult to 

 breathe. Fortunately, 

 preventive meas- 

 ures can be adopted. 

 The hoods that have 

 been used over the 

 head during poisonous 

 gas attacks are just as 

 effective here in miti- 

 gating the action of 

 irritants. 



