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<s>A DISCOVRSE <lb/> Pre&longs;ented to the Mo&longs;t Serene DON COSIMO II. <lb/> GREATDUKE of <emph type="italics"/>TUSC ANY:<emph.end type="italics"/><lb/> CONCERNING<lb/> <emph type="italics"/>The Natation of BODIES Upon, or Submer&longs;ion <lb/> In, the WATER.<emph.end type="italics"/></s> </p>
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<s>Con&longs;idering (Mo&longs;t Serene Prince) that the <lb/> publi&longs;hing this pre&longs;ent Treati&longs;e, of &longs;o <lb/> different an Argument from that which <lb/> <arrow.to.target n="marg1393"></arrow.to.target><lb/> many expect, and which according to the <lb/> intentions I propo&longs;ed in my ^{*} A&longs;tronomi­<lb/> call <emph type="italics"/>Advi&longs;o,<emph.end type="italics"/> I &longs;hould before this time <lb/> have put forth, might peradventure make <lb/> &longs;ome thinke, either that I had wholly <lb/> relinqui&longs;hed my farther imployment <lb/> about the new Cele&longs;tiall Ob&longs;ervations, <lb/> or that, at lea&longs;t, I handled them very <lb/> remi&longs;&longs;ely; I have judged fit to render an account, a&longs;well of my <lb/> deferring that, as of my writing, and publi&longs;hing this treati&longs;e.</s></p>
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<s>As to the fir&longs;t, the la&longs;t di&longs;coveries of <emph type="italics"/>Saturn<emph.end type="italics"/> to be tricorporeall, and <lb/> of the mutations of Figure in <emph type="italics"/>Venus,<emph.end type="italics"/> like to tho&longs;e that are &longs;een in the
<lb/> Moon, together with the Con&longs;equents depending thereupon, have
<lb/> not &longs;o much occa&longs;ioned the demur, as the inve&longs;tigation of the times
<lb/> of the Conver&longs;ions of each of the Four Medicean Planets about <emph type="italics"/>Ju­
<lb/> piter,<emph.end type="italics"/> which I lighted upon in <emph type="italics"/>April<emph.end type="italics"/> the year pa&longs;t, 1611, at my being in
<lb/> <emph type="italics"/>Rome<emph.end type="italics"/>; where, in the end, I a&longs;&longs;ertained my &longs;elfe, that the fir&longs;t and neere&longs;t
<lb/> to <emph type="italics"/>Jupiter,<emph.end type="italics"/> moved about 8 <emph type="italics"/>gr.<emph.end type="italics"/> & 29 <emph type="italics"/>m.<emph.end type="italics"/> of its Sphere in an houre, make­
<lb/> ing its whole revolution in one naturall day, and 18 hours, and almo&longs;t
<lb/> an halfe. </s><s>The &longs;econd moves in its Orbe 14 <emph type="italics"/>gr. </s><s>13 min.<emph.end type="italics"/> or very neer,
<lb/> in an hour, and its compleat conver&longs;ion is con&longs;ummate in 3 dayes, 13
<lb/> hours, and one third, or thereabouts. </s><s>The third pa&longs;&longs;eth in an hour,
<lb/> 2 <emph type="italics"/>gr. </s><s>6 min.<emph.end type="italics"/> little more or le&longs;s of its Circle, and mea&longs;ures it all in 7
<lb/> dayes, 4 hours, or very neer. </s><s>The fourth, and more remote than the
<lb/> re&longs;t, goes in one houre, o <emph type="italics"/>gr 54 min.<emph.end type="italics"/> and almo&longs;t an halfe of its Sphere,
<lb/> and fini&longs;heth it all in 16 dayes, and very neer 18 hours. </s><s>But be­
<lb/> cau&longs;e the exce&longs;&longs;ive velocity of their returns or re&longs;titutions, requires a
<lb/> mo&longs;t &longs;crupulous preci&longs;ene&longs;&longs;e to calculate their places, in times pa&longs;t
