div class=trans-pagebutton class=gotoPage data-page=1Page 1button div class=trans-imageimg data-url=documentwhispering-gallery-in-the-museum-of-science-and-industry-in-chicago-is-473-ft-longhtmlpage=1 data-page=1 class=trans-thumb lazyload alt=Page 1: · The whispering gallery in the museum of science and industry in chicago is 473 ft long The distance from the center of room to the foci is 203 ft loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader034fdocumentsinreader034viewer20220522015ac8e7f37f8b9aa1298c9fd6html5thumbnails1jpg width=140 height=200 divdivdiv class=trans-pagebutton class=gotoPage data-page=2Page 2button div class=trans-imageimg data-url=documentwhispering-gallery-in-the-museum-of-science-and-industry-in-chicago-is-473-ft-longhtmlpage=2 data-page=2 class=trans-thumb lazyload alt=Page 2: · The whispering gallery in the museum of science and industry in chicago is 473 ft long The distance from the center of room to the foci is 203 ft loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader034fdocumentsinreader034viewer20220522015ac8e7f37f8b9aa1298c9fd6html5thumbnails2jpg width=140 height=200 divdivdiv class=trans-pagebutton class=gotoPage data-page=3Page 3button div class=trans-imageimg data-url=documentwhispering-gallery-in-the-museum-of-science-and-industry-in-chicago-is-473-ft-longhtmlpage=3 data-page=3 class=trans-thumb lazyload alt=Page 3: · The whispering gallery in the museum of science and industry in chicago is 473 ft long The distance from the center of room to the foci is 203 ft loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader034fdocumentsinreader034viewer20220522015ac8e7f37f8b9aa1298c9fd6html5thumbnails3jpg width=140 height=200 divdivdiv...