Jonvaln.

1851 Jrnl. Franklin Inst. 52 419 The advantage of the Jonval Turbine over the over-shot wheel, using the same amount of water, is consequently seven per cent.

1873 Spons' Dict. Engin. VI. 1930 Jonval's turbine may generally be placed, in the case of moderate or high falls, considerably above the highest back-waters.

1875 E. H. Knight Amer. Mech. Dict. III. 2656/2 In the Jonval turbine, the water is received above and the discharge is downward.

1880 Engineering 26 Mar. 245/3 The motors..consist of three turbines of the Jonval system.

1892 P. Benjamin Mod. Mech. 893 All this type of Jonval wheels give high results at ‘full gate’.

1892 P. Benjamin Mod. Mech. 893 This name of ‘Jonval’ is applied to wheels set with a ‘draft tube’.

1894 W. J. Lineham Text-bk. Mech. Engin. xi. 724 The Jonval turbine, like the Fourneyron, is a pressure turbine; but while the latter works best above tail water, the Jonval is always drowned or else connected to tail water by a ‘suction’ tube.

1909 H. Louis Dressing of Minerals xii. 491 For lower falls turbines are best employed; a twin Jonval parallel-flow turbine..offers many advantages, amongst which may be reckoned the fact that the turbine itself may be situated 10 to 15 feet above the level of the tailwater.

1957 Encycl. Brit. XXII. 580/2 In..the Fourneyron, the guide vanes were inside the runner, and the water flowed outward. This was followed by the Jonval turbine, in which the guide vanes are above the runner and the water flows axially into and through the wheel. Both types are now obsolete.