Popular Science Monthly 



329 



Above: The two hundred sound-proof rooms 

 were finished in five days by using a quickly- 

 appl'ed, ready-to-put-up composition board 



At right: Putting up the sound-proof board 

 material. Standard lengths were used and 

 practically unskilled workmen employed 



Two Hundred Sound-Proof Rooms and 

 How They Were Built in Record Time 



WITH only five working days in which 

 to erect two hundred sound-proof 

 rooms in the large Coliseum in Chicago, 

 the management of the National Music 

 Show was confronted with an extraordinary 

 problem. The difficulty was made all the 

 greater by the impossibility 

 of getting a sufficient force 

 of workmen on account of 

 the unusual war demands. 

 The problem was solved 

 by the use of a composition 

 board material which proved 

 highly efficient in deadening 

 sound. In fact, although the 

 walls were very thin, as is shown 

 in the photographs, no sound of 

 the numerous musical instru- 

 ments or of voices penetrated 

 from one room to the next. 

 The rooms also made a very 

 handsome appearance. The 

 auditorium built for concerts 



had much the appearance of a real audi- 

 torium built to stay. 



The rapid construction work was made 

 possible by the lightness of the material, 

 and the fact that comparatively unskilled 

 workers could put it in place. 



A Paper-Disk Flipper for the 

 Youthful "Cut-Up/' 



GI RLS and boys alike derive 

 endless amusement from a 

 new device which throws a 

 paper disk larger than a 

 "\ silver dollar from a hundred 

 , to a hundred and fifty feet 

 into the air. The device is 

 very simple in its opera- 

 tion, but flips the disks to a 

 surprising height. You 

 simply hold it in your right 

 hand, with the thumb on the 

 trigger member in the position 

 shown in the illustration, then 

 remove the thumb suddenly, 

 and up or out the disk shoots. 



By removing the thumb 

 suddenly from the trigger 

 the disk is shot up into 

 the air or out, as desired 



