Salusbury, Thomas, Mathematical collections and translations (Tome I), 1667

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1as far one way as another. Having obſerved all theſe particulars,
though no man doubteth that ſo long as the veſſel ſtands ſtill, they
ought to ſucceed in this manner; make the Ship to move with
what velocity you pleaſe; for (ſo long as the motion is uniforme,
and not fluctuating this way and that way) you ſhall not diſcern
any the leaſt alteration in all the forenamed effects; nor can you
gather by any of them whether the Ship doth move or ſtand ſtill.
In leaping you ſhall reach as far upon the floor, as before; nor for
that the Ship moveth ſhall you make a greater leap towards the
poop than towards the prow; howbeit in the time that you ſtaid
in the Air, the floor under your feet ſhall have run the contrary way
to that of your jump; and throwing any thing to your companion
you ſhall not need to caſt it with more ſtrength that it may reach
him, if he ſhall be towards the prow, and you towards the poop,
then if you ſtood in a contrary ſituation; the drops ſhall all diſtill
as before into the inferiour bottle and not ſo much as one ſhall
fall towards the poop, albeit whil'ſt the drop is in the Air, the Ship
ſhall have run many feet; the Fiſhes in their water ſhall not ſwim
with more trouble towards the fore-part, than towards the hinder
part of the tub; but ſhall with equal velocity make to the bait
placed on any ſide of the tub; and laſtly, the flies and gnats
ſhall continue their flight indifferently towards all parts; nor
ſhall they ever happen to be driven together towards the ſide of
the Cabbin next the prow, as if they were wearied with
lowing the ſwift courſe of the Ship, from which through their
ſuſpenſion in the Air, they had been long ſeparated; and if
burning a few graines of incenſe you make a little ſmoke,
you ſhall ſee it aſcend on high, and there in manner of a cloud
ſuſpend it ſelf, and move indifferently, not inclining more to one
ſide than another: and of this correſpondence of effects the cauſe
is for that the Ships motion is common to all the things contained
in it, and to the Air alſo; I mean if thoſe things be ſhut up in the
Cabbin: but in caſe thoſe things were above deck in the open Air,
and not obliged to follow the courſe of the Ship, differences more
or leſſe notable would be obſerved in ſome of the fore-named
fects, and there is no doubt but that the ſmoke would ſtay behind
as much as the Air it ſelf; the flies alſo, and the gnats being
dered by the Air would not be able to follow the motion of the
Ship, if they were ſeparated at any diſtance from it.
But keeping
neer thereto, becauſe the Ship it ſelf as being an unfractuous
brick, carrieth along with it part of its neereſt Air, they would
follow the ſaid Ship without any pains or difficulty.
And for the
like reaſon we ſee ſometimes in riding poſt, that the troubleſome
flies and ^{*} hornets do follow the horſes flying ſometimes to one,

ſometimes to another part of the body, but in the falling drops