THEATMOSPHERICHEAVENS^49"Menwereeverywhereusingtheirrudedevicesfor
raisingwaterinpumps,withouttheleastideaofwhat
theywere doing. The actionthat wastaking place
before their eyes never entered into their compre-
hension. Ifanyonehadtoldthemthat,inraisinga
pumpbucket,theywereliftingaportionoftheweight
oftheatmospherefromthewaterunderthebucket,
sothattheexcessofthispressure,exertedonthesur-
faceofthewaterinthewell,wouldforcethecolumn
ofwaterinthepumpbarrelupafterthebucket,there
were centurieswhensuchateacherwouldhavebeen
indangerofbeingburnedup.
"This, with all similar phenomena, was explained
by the dictum thatnature abhors avacuum. This
nonsense passedfor science through manyages. It
is interestingtorecall thelongperiodduringwhich
thiswasassumedas anaxiom thatnoonedaredto
question.. ..
"The raising of the question whether the atmos-
pheremighthaveweight, wasitselfanotableevent,
as markingthebeginningof scientificinquiry. But
an experiment wasmade, which waslong regarded
amongthelearnedassettlingthisquestioninthenega-
tive. Thisexperimentconsistedinweighingabladder,
whendistendedwithairandwhenempty. Nodiffer-
encecouldeverbedetected."
Mendidnotseethefallacyofthisexperiment.
"This fallacy lay in the unobserved factthat the
bladder was filledwith, and immersed in, the same
fluid. Whetherfull,orapproximatelyempty,italways
displaced, in additionto its own proper bulk, very