578 Popular Science Monthly 



Spotting the Submarine From the Using a Maxim Silencer as an 

 Observation Balloon 



THE man who, in his youth was adept 

 at climbing ropes, performing on the 

 trapeze and in indulging in other acro- 

 batic feats 



I 



\ 



finds limitless 

 field for the 

 use of his skill 

 in this war. 

 Here we have 

 a French ob- 

 servation-bal- 

 loonist sliding 

 down a rope 

 from his basket 

 to a steamer 

 that has been 

 towing him 

 around. A 

 hard day's 

 work has just 

 been com- 

 pleted. He 

 has been look- 

 ing for sub- 

 marines in 

 English wa- 

 ters, directing 

 the work of 

 destroyers, 

 and otherwise 

 acting as a 

 lookout. It is 

 climb around 

 in rigging ad- 

 justing ap- 

 paratus, slide down ropes, strain eyes 

 out over wide stretches of water, 

 and operate delicate wireless apparatus 

 all day long. The responsibility and 

 strain are great, and it needs a man 

 in tip-top condition and with a natural 

 p.ptitude to do the job. 



Both armies and navies of practically 

 all the countries at war use observation 

 balloons in great number. They are in- 

 dispensable for finding out what opposing 

 forces are doing. The side temporarily 

 without balloons is blind. The observer's 

 job is one of the least 

 spectacular and most 

 important in the 

 whole of the service, 

 and requires men fit 

 in every way. 



Observer slides down after looking all day from a 

 kite balloon for submarines and other hostile craft 



Automobile Muffler 



F, said one western manufacturer, the 

 Maxim silencer will deaden the sound 

 of a gun explosion, why would it 



not deaden 

 the noise cf 

 the automo- 

 bile engine's 

 exhaust ? 

 Convinced of 

 the sound- 

 ness of this ar- 

 gument, the 

 manufacturer 

 has just placed 

 on the market 

 the Maxim 

 muffler shown 

 in the accom- 

 panying illus- 

 ^.ation. ^\ hile 

 cylindrical in 

 shape like 

 other mufflers, 

 the new type 

 has no baffle 

 plates or per- 

 forated disks 

 through which 

 the gas must 

 be forced, so 

 that the muf- 

 fler is eventu- 

 ally torn apart 

 through the 

 direct imping- 



New silencer for automobile engines 

 on principle of Maxim silencer for guns 



ing pressure of the gases, to the accompa- 

 niment of rattles, which are the automo- 

 bilist's bane. Instead, it has two end 

 plates with a series of non-concentric 

 tubes between. As shown, each tube has 

 an overlapping opening into the one of 

 the next larger diameter through which 

 the gas may expand gradually on its way 

 from one end of the muffler to the other. 

 As everyone is aware, it is the sudden 

 expansion of the hot gases under pressure, 

 to the atmospheric pressure which pro- 

 duces the noise. The object of a silencer 

 is to allow them to 

 expand so gradually 

 that when they reach 

 the outside aperture 

 they are at atmos- 

 pheric pressure. 



