PREFACE. THE eminent position of M. Bresse in the scientific world, and in the French Corps of Civil Engineers, is my best apology for attempting to supply a want, felt by the students of civil engineering in our country, of some standard work on Hydraulic Motors, by furnish- ing a translation of the chapter on this subject con- tained in the second volume of M. Bresses lectures on Applied Mechanics, delivered to the pupils of the School of Civil Engineers Icole des Ponts et CJiaus- sees at Paris. In making the translation, I have retained the French units of weights and measures in the numerical exam- ples given, as the majority of our students are conver- sant with them. WILLETTS POINT,K Y., July, 1869. F. A. MAHAK CONTENTS. I. PRELIMINARY IDEAS ON HYDRAULIC MOTORS. ART. PAGK. Definitions theorem of the transmission of work in machines 1 9 Analogous ideas applied to a waterfall General observations on the means of securing a good effective 2 11 delivery for a waterfall driving a hydraulic motor 3 14 II. WATER WHEELS WITH A HORIZONTAL AXLE. Undershot wheel with plane buckets or floats moving in a confined race 4 17 Wheels arranged according to Poncelets method 5 28 Paddle wheels in an unconfined current 6 34 BREAST WHEELS. Wheels set in a circular race, called breast wheels 7 36 Example of calculations for a rapidly moving breast wheel 8 48 OVERSHOT WHEELS. Wheels with buckets, or overshot wheels 9 51 III. WATER WHEELS WITH VERTICAL AXLES. Old-fashioned spoon or tub wheels 10 66 TURBINES. Of turbines 11 69 Fourneyrons turbine 12 70 Fontaines turbine 13 73 Koscklins turbine 14 76 Theory of the three preceding turbines 15 78 Remarks on the angles , y, 0, and on the dimensions 5, , r, r, h. h... . 16 90 yiii CONTENTS. ART. PAGE. Examples of the calculations to be made in constructing a turbine. . 17 93 Of the means of regulating the expenditure of water in turbines. .. 18 98 Hydropneumatic turbine of Girard and Gallon 19 103 Some practical views on the subject of turbines 20 105 Reaction wheels. . .... 21 107 IV. OF A FEW MACHINES FOR RAISING WATER. Pumps 22 111 Spiral noria 23 122 Lifting turbines centrifugal pump 24 127 Authorities on Water Wheels. . 134 APPENDIX. Comparative table of French and United States measures 135 Note A, Article 1 135 Note B, Article 2 136 Note C, Article 4 137 Note D, Article 9 Note E, Boyden turbines, from Lowell Hydraulic Experiments, by 140 James B. Francis, Esq 141 HYDRAULIC MOTORS, AND SOME MACHINES FOR RAISING WATER, . PRELIMINARY IDEAS ON HYDRAULIC MOTORS. 1. Definitions y theorem of the transmission of work in ma- chines. The term machine is applied to any body or collection of bodies intended to receive at some of their points certain forces, and to exert, at other points, forces which generally differ from the first in their intensity, direction, and the velocity of their points of application. The dynamic effect of a machine is the total work, generally negative or resisting, which it receives from external bodies subject to its action. It happens that the dynamic effect is sometimes positive work for example, when we let down a load by a rope passed over a pulley, the weight of the load pro- duces a motive work on the system of the rope and pulley... --This text refers to the Paperback edition.