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barometer. vpon this some querys being made concering the spring of the air
mr. Hooke explaind that theory and shewd that as the pressure of the water in the
greater cylinder increased it raisd the mercury in the opposite leg and as that
rose soe the air soe included would be condensed into a lesse room and consequent
=ly haue soe much the stronger spring.

Dr. Whistler obiected that though the air were more condensd yet he conceiud that
the spring of it Did not increase proportionably but mr Hooke explaining his
supposition by the Instance of a fleece of wool which would only spring soe
much & noe more -
But mr. Hooke affirmed that though that might serue a little to explaine what
is meant by the springinesse of the air, yet it was noe way fitt to make
out all the appearances of these phenomena of springing . . . of it, for tht
as he had also formerly proued in this Society the spring of the air was always
condesible & rarefyable wch. the wool was not. and that the force of the
very spring was always proportionate to the Condensation of its bulk.

And here vpon the President desired that such an expt. might againe be shewn at the next
meeting of the society which mr. Hooke promised to take care of and contriue
accordingly - mr Hooke also at the Presidents Desire promisd hereafter to shew his Theory
/of springs in generall hauing seuerall years since shewd it to the King -/
Vpon this seuerall querys were made whether the air neer the earth were not of
very differing degrees of Specifick grauitation, and whether that whether also
the spring of the air also neer the earth were not differing when the pressure was
the same. To wch. mr. Hook answerd that the parts of the air as to their Expan
sion Did very much vary according to Diuers circumstances attending them to wit
pressure, heat, &c. that oftentimes the parts of the air neer the earth might
be much lighter in specie than those at a considerable height aboue it that
though in the Expts. the Rarefaction of the air It were shewd that the higher parts
must always gradually grow lighter & more rarefyed, yet that in the atmosphere
it did not always happen soe but that sometimes the Rarefaction & condensation -
went by /per/ saltus, and by very great Leapes, an argument for this he vrged
the swimming of the clouds in the air. wch seemd to Lye vpon the smooth
surface of some fluid vnderneath them, all the vndersides of them being
perfectly defined smooth & horizontall whereas all the vpersides of them
are vndefined and in heaps. /Herevpon mr Hooke affirmd that he had an Instrument
for examining the specifique grauity of the air wch was Distinct from spring or pressure./
Dr Holder mentiond that somewt like this was also to be obserued in smo
smoke which will run along and spread it self a great way keeping
as it were the same Distance from the ground.

Dr King Instanced that a Gentleman that was a patient of his could 2 or 3
mile off from London Discouer when he came to enter into the London
smoke.

vpon this some Discourses arose about the reason of the smoking & why /some/ chimneys doe
smoke that is doe not conuey the smoke from the fire vp the funnel but suffers
it too smoke /spread/ into the Room. Dr. Whistler affirmed said that there were 4 ways vsed
for curing chimneys according as the cause of their smoking was Differing -
1. by pipes added to the top where the funnells being too short was the cause -
2. by a small pipe in the chimney if the room were too little to supply a constant current of air
3. by a couer turning like a weather cock where A free exitus of the smoke was desired
4. by lessening the chimney and making a chimney wthin a chimney when the chimney was too big

Ref: CELL/RS/HF_149  © Centre for Editing Lives and Letters