==========+======================================================================= Height, in| Temperature of external air——degrees Fahrenheit. feet. | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- | -20°| -10°| 0° | 10°| 20°| 30°| 40°| 50°| 60°| 70°| 80°| 90°| 100° ----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----- 10| .013| .013| .012| .012| .012| .012| .011| .011| .011| .011| .010| .010| .010 20| .026| .025| .025| .024| .023| .023| .023| .022| .022| .021| .021| .020| .020 30| .039| .038| .037| .036| .035| .034| .034| .033| .032| .032| .031| .030| .030 40| .052| .050| .049| .048| .047| .046| .045| .044| .043| .042| .041| .040| .040 | | | | | | | | | | | | | 50| .065| .063| .061| .060| .059| .058| .056| .055| .054| .053| .052| .051| .050 60| .077| .076| .074| .072| .070| .069| .068| .066| .065| .063| .062| .061| .059 70| .090| .088| .086| .084| .082| .081| .078| .077| .076| .074| .072| .071| .069 80| .103| .101| .098| .096| .094| .092| .090| .088| .086| .084| .082| .081| .079 90| .116| .113| .111| .108| .105| .104| .101| .099| .097| .095| .093| .091| .089 | | | | | | | | | | | | | 100| .129| .126| .123| .120| .117| .115| .112| .110| .108| .105| .103| .101| .099 110| .142| .139| .135| .132| .129| .126| .123| .121| .119| .116| .113| .111| .109 120| .155| .151| .148| .144| .140| .138| .134| .132| .129| .126| .124| .121| .119 130| .168| .164| .160| .156| .152| .149| .146| .143| .140| .137| .134| .131| .129 140| .181| .176| .172| .168| .164| .161| .157| .154| .151| .147| .144| .141| .139 | | | | | | | | | | | | | 150| .194| .189| .185| .180| .176| .172| .168| .165| .162| .158| .155| .152| .149 160| .206| .201| .197| .192| .187| .183| .179| .176| .172| .168| .165| .162| .158 170| .219| .214| .209| .204| .199| .195| .190| .187| .183| .179| .175| .172| .168 180| .232| .227| .222| .216| .211| .206| .202| .198| .194| .189| .185| .182| .178 190| .245| .239| .234| .228| .222| .218| .213| .209| .204| .200| .196| .192| .188 | | | | | | | | | | | | | 200| .258| .252| .246| .240| .234| .229| .224| .220| .215| .210| .206| .202| .198 210| .271| .264| .258| .252| .246| .240| .235| .231| .226| .221| .216| .212| .208 220| .284| .277| .270| .264| .257| .252| .246| .242| .236| .231| .227| .222| .218 230| .296| .289| .283| .276| .269| .263| .257| .253| .247| .242| .237| .232| .228 240| .309| .302| .295| .288| .281| .275| .269| .264| .258| .252| .248| .242| .238 | | | | | | | | | | | | | 250| .322| .314| .307| .300| .293| .286| .280| .275| .269| .263| .258| .253| .248