TABLE IV.——FOR REDUCING OBSERVATIONS OF THE BAROMETER TO SEA LEVEL.——_Continued._ ==========+======================================================================= Height, in| Temperature of external air——degrees Fahrenheit. feet. | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100° ----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 550| .704| .687| .670| .655| .640| .626| .613| .600| .587| .575| .564| .553| .542 560| .717| .699| .683| .667| .652| .638| .624| .611| .598| .586| .574| .563| .552 570| .729| .712| .695| .679| .663| .649| .635| .622| .608| .596| .584| .573| .562 580| .742| .724| .707| .690| .675| .660| .646| .632| .619| .606| .595| .583| .571 590| .754| .737| .719| .702| .686| .672| .657| .643| .629| .617| .605| .593| .581 | | | | | | | | | | | | | 600| .767| .749| .731| .714| .698| .683| .668| .654| .640| .627| .615| .603| .591 610| .780| .761| .743| .726| .709| .694| .679| .665| .650| .637| .625| .613| .601 620| .792| .774| .755| .738| .721| .705| .690| .675| .661| .648| .635| .623| .611 630| .805| .786| .767| .749| .732| .717| .701| .686| .671| .658| .645| .633| .620 640| .817| .798| .779| .761| .744| .728| .712| .697| .682| .668| .655| .643| .630 | | | | | | | | | | | | | 650| .830| .811| .791| .773| .755| .739| .723| .708| .692| .679| .666| .653| .640 660| .843| .823| .803| .785| .767| .750| .734| .718| .703| .689| .676| .662| .650 670| .855| .835| .815| .797| .778| .761| .745| .729| .713| .699| .686| .672| .660 680| .868| .847| .827| .808| .790| .773| .756| .740| .724| .709| .696| .682| .669 690| .880| .860| .839| .820| .801| .784| .767| .750| .734| .720| .706| .692| .679 | | | | | | | | | | | | | 700| .893| .872| .851| .832| .813| .795| .778| .761| .745| .730| .716| .702| .689 710| .905| .884| .863| .844| .824| .806| .789| .772| .755| .740| .726| .712| .698 720| .918| .896| .875| .855| .836| .817| .800| .782| .766| .751| .736| .722| .708 730| .930| .909| .887| .867| .847| .829| .811| .793| .776| .761| .746| .732| .718 740| .943| .921| .899| .879| .859| .840| .822| .804| .787| .771| .756| .742| .728 | | | | | | | | | | | | | 750| .955| .933| .911| .891| .870| .851| .833| .815| .797| .782| .767| .752| .738 760| .968| .945| .922| .902| .881| .862| .843| .825| .808| .792| .777| .761| .747 770| .980| .957| .934| .914| .893| .873| .854| .836| .818| .802| .787| .771| .757 780| .993| .970| .946| .926| .904| .885| .865| .847| .829| .812| .797| .781| .767 790|1.005| .982| .958| .937| .916| .896| .876| .857| .839| .823| .807| .791| .776