6o X^esei-al Refu^s of hydraulic Expcrinunts. 



of theory — caufe of this defeft. Exper. 13, 14, 15. p. 275 — Limits of the augmeatatiort 

 of expenditure in the fame horizontal conical tube. Exper. 16, jj, ibid. — In horizontal 

 cylindrical tubes, the increafe of expenditure does not approach the maximum fo nearly as 

 in conical tubes. Prop. VI. exper. 18, p. 423. — Cafe of the fimple cylindrical tube mora 

 particularly examined. Hid. — The Velocity of the fluid ftream ifl^uing through a tube is lefs 

 than that which flows through an orifice in a tliin plate-. Caufe of this diiFerence. Exper. 19,, 

 p. 424. — The fame law, and the fame caufes, alfo determine the expenditure through afcend- 

 ing and defccnding tubes. Exper. 20,21, ibid. — The effeift of the lateral communicatioa 

 «f motion is produced in a very fhort portion of the length of the inner cavity of the cylin- 

 drical tube. Exper. 22. p^425. — The efFeft itfelf is greater than could have arifea from the 

 mutual attraftion of the particles of the fluid, ibid. — The expendi-ture which takes place 

 throuo-h a cylindrical tube of given dimcnfions, and under the fame charge, may be increafed: 

 to nearly double by proper adjutages. Prop.. VII. ibid. — Roman law relaiive to this obje£t, 

 p. 426. — Application of the fame law to the flues of chimnies. Ibid. 



How far elbows and fmuouties diminilh the expenditure through tubes. Exper. S3, 

 p. 487. — Lofs of expenditure occafioned by enlargements or inflated parts in tubes. It is 

 neceflary to- have regard to this in the conftruition of hydraulic machines. Exper. 24. 

 p. 488. 



In the machine for blowing by means of a fall of water, the air is afforded to the furnace 

 by the accelerating force of gravity, and the lateral communication of motion combined 

 together. Prop. VIIL ibid. — Wind produced by falls of water in the internal parts of 

 mountains, p. 489.' — The wind of the water-blowing machine is not produced by the de- 

 compofition of water. Exper. 25. p. 490. — Quantity of wind which one of thefe machines 

 is capable of affording in a given time. Ibid. 



It is poflible, in certain circumftanees, by means of a fall of water, to drain a piece of 

 ground without the help of machines, even though the ground fhould be on a lower level 

 than the eftablifhed current below the falL Prop. IX. p. 491. — Application of the fame 

 principle to the tail water of mills. Ibid. 



The eddies of water in rivers are produced by motion communicated from the more rapid 

 parts of the ftream to the lateral parts which are lefs rapidly moved. Prop. X. p. 492, — 

 Vertical Eddies at the furface and at the bottom of the ftream of rivers. Ibid. — Thefe cir- 

 cular motions conftitute one of the principal caufes of the lofs of aftive force» and the retard- 

 ation of the current of rivers> p. 493. — In a river of which the courfe is permanent, and the 

 fedlions of its bed unequal, the water continues more elevated than it would have done if the 

 whole river had been equally contracted to the dimenfions of its finalleft fedlLon. Ibid. 



Whirling motions, or eddies, formed in a refervoir from which the water iffues by an hori- 

 xontal aperture. Theory deduced from the do£lrine of central forces. Prop. XI. vol. III. 

 p. 13. The cavity of thefe whirls is convex on the fide next the axis. III. p. 14. — Phenomena, 

 relative to thefe whirls, and their explanation. Exper. 26, 27, 28, 29, 30. III. p. 15. 

 The lateral commuriicatioaof motion, takes place in the air as well as ia water. Prop. XII. 



HI. p. 



