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Agricultural Survey of South America
And conclusions. pp. 73.
The Bomb ...
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Cornstalk Acoustical Board
Increased interest in the elimination of unnecessary noises prompted an investigation of the sound-absorption properties of various acoustical boards made from cornstalks. The coefficients of sound absorption of the boards was obtained by means of automatic apparatus which gave the reverberation times of the test room. This apparatus -- which was designed, built, and perfected in the acoustics laboratory here -- was found to be both rapid and accurate. A complete description is given. The effect of composition of the pulp and of surface treatment such as holes, grooves, and beveled edges was studied. Tests were made of certain types of hollow acoustical boards including ones made of insulating board surfaced with perforated pressed board. Cornstalk acoustical board was applied to the underside of chairs and tables and found to be only slightly less efficient than when tested in the laboratory according to standard methods.
Puppetry
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Wallaces Farmer
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