i$6 Sir Is aac Ne vvton’s BookI.

divided the whole discourse os resistance into. And in thisdisquisition he finds a very surprizing and unthought os dif-ference, between free and compressed fluids.. He proves,that in the former kind, a globe suffers but half the resist-ance, which the cylinder, that circumscribes the globe, willdo, if it move in the direction of its axis a . But in the lat-ter he proves, that the globe and cylinder are resisted a-like b . And in general, that let the shape os bodies beever so different, yet is the greatest sections of the bodiesperpendicular to the axis of their motion be equal, the.bodies will be resisted equally c .

la. Pursuant to the difference found between the re-sistance of the globe and cylinder in rare and uncompressedfluids, our author gives us the result of some other inquiriescf the same nature. Thus of all the frustums of a cone,that can be described upon the fame base and with the samealtitude, he shews how to find that, which of all otherswill be the least resisted, when moving in the direction ofits axis d . And from hence he draws an easy method,ot al-tering the figure of any spheroidical solid, so that its capa-city may be enlarged, and yet the resistance of it diminish-ed e : a note which he thinks may not be useless to ship-wrights. He concludes with determining the solid, whichwill be resisted the least that is possible, in these discontinuedfluids f .

a Lib. II. Prop. 34' I Prop. 34. schol.

b Lib. II. Lcm.7. p.341? I ' Ibid.

> SctoL to Ltna.7. J f Ibid,

21. That