Book N. Mechanick Popers. 25 5

Secondly, à reaſon appears why the turning the Cylinderabout with a greater velocity, or more ſwiftly, that it doth notonly raiſe greater plenty f water proportionally, but alſomakes the fame aſcent more abundantly eaſy; for ſince theoppoſite motion of the Tube avails much to the aſcent of theWater, as we have ſaid, by how much ſwifter this motion15, Which is made by turning about of the Cylinder, by ſo muchthe more the aſcent of the water is advanced. 5 5

Add, that chat little ſpace of time which the water or theGlobe reſts in ſome lower part of the Tube tis raiſed higher,mat therefore the reſt ceaſing it ought to deſcend leſs, andafter the deſcent tis now much higher raiſed above the Horizonthan before: moreover, ſince that little ſtay of the Globe hap-pens from the impediment, or roughneſs of che Tube, ſuppoſethe Globe to be in E, and ſome impediment or roughneſs inthe Superficies of che Tube, to be in its way on the part to-wards H; when this kind of roughneſs is moved forward to-wards Por G, and let that which raiſes the Globe be as faras P, if the Tube be moved more ſwiftly, it impreſſes a greaterImpetus, and raiſes it higher.Tbirdih, tis manifeſt alſo, why if che ſcrew be leſs elevatedabove the Horizon, that the water aſcends the eaſier, I ſay, theeaſier, that is, with leſs force and labour of him, or that whichturns che Cylinder:(for if the Cylinder being turn'd about

with che ſame ſwiftneſs, an equal quantity of water ſhould aſ-cend, whether it be more or leſs irclinded) the reaſon ismanifold: Firſt, becauſe when the Axes AC are more Elevatedthe weight gravitates morę upon the prop of the Axis in A,but leſs upon the prop in C, but if the Axis be leſs raiſed abovethe Horizon, or comes nearer to an Horizontal ſite, the wholeweight is diſtributed to the Props A and C with leſs inequality,from whence it comes to paſs that the Circumvolution or turn-ing about is eaſier. Secondly, and chiefly becauſe the entranceof the water into the Tube by the lower mouth D, reſiſts andſtrives againſt the weight or preſſure of che water Which is inthe whole Tube, and that weight or force of preſſure is notcomputed from the quantity of water which is in the Tube( forthat is always the ſame whether the Cylinder be more or leſs in-clined) but tis computed from the greater or leſſer perpendicu-lar CB; therefore When the perpendicular CB is greater, thewater exiſting within che Tube preſſes more, and reſiſts more theenter-

—