COROLARY I.

[Sidenote: Much less shall the said Cone swim, if one immerge a

part thereof.]

_I say farther; that much lesse shall the said Cone stay afloat, if

one immerge a part thereof._

Which you may see, comparing with the water as well the part that

shall immerge as the other above water. Let us therefore of the Cone A

B D, submergeth part N T O S, and advance the Point N S F above water.

The Altitude of the Cone F N S, shall either be more than half the

whole Altitude of the Cone F T O, or it shall not be more: if it shall

be more than half, the Cone F N S shall be more than half of the

Cylinder E N S C: for the Altitude of the Cone F N S, shall be more

than Sesquialter of the Altitude of the Cylinder E N S C: And, because

the Matter of the Cone is supposed to be double in Specificall Gravity

to the water, the water which would be contained within the Rampart E

N S C, would be less grave absolutely than the Cone F N S; so that the

whole Cone F N S cannot be sustained by the Rampart: But the part

immerged N T O S, by being double in Specificall Gravity to the water,

shall tend to the bottom: Therefore, the whole _C_one F T O, as well

in respect of the part submerged, as the part above water shall

descend to the bottom. But if the Altitude of the Point F N S, shall

be half the Altitude of the whole Cone F T O, the same Altitude of the

said Cone F N S shall be Sesquialter to the Altitude E N: and,

therefore, E N S C shall be double to the Cone F N S; and as much

water in Mass as the _C_ylinder E N S C, would weigh as much as the

part of the _C_one F N S. But, because the other immerged part N T O

S, is double in Gravity to the water, a Mass of water equall to that

compounded of the _C_ylinder E N S C, and of the Solid N T O S, shall

weigh less than the _C_one F T O, by as much as the weight of a Mass

of water equall to the Solid N T O S: Therefore, the _C_one sha{l}l

also descend. Again, because the Solid N T O S, is septuple to the

Cone F N S, to which the _C_ylinder E S is double, the proportion of

the Solid N T O S, shall be to the _C_ylinder E N S C, as seaven to

two: Therefore, the whole Solid compounded of the _C_ylinder E N S C,

and of the Solid N T O S, is much less than double the Solid N T O S:

Therefore, the single Solid N T O S, is much graver than a Mass of

water equall to the Mass, compounded of the _C_ylinder E N S C, and of

N T O S.

A Discourse Presented to the Most Serene Don Cosimo II., Great Duke of Tuscany, Concerning the Natation of Bodies Vpon, and Submersion In, the Water. · 第 30 / 37 题