23 | ·7098| ·5940| ·5080| ·4417| ·3892 24 | ·7433| ·6241| ·5341| ·4657| ·4097 --------+------+------+------+------+------ | Elevation of discharge above | delivery valve of ram in feet. Height +------+------+------+------+------ of fall | 60 | 70 | 80 | 90 | 100 in feet.+------+------+------+------+------ | Percentage. --------+------+------+------+------+------ 2 | -- | -- | -- | -- | -- 3 | ·0063| ·0017| -- | -- | -- 4 | ·0180| ·0112| ·0063| ·0027| -- 5 | ·0307| ·0217| ·0150| ·0099| ·0063 6 | ·0441| ·0325| ·0243| ·0180| ·0132 7 | ·0580| ·0441| ·0340| ·0264| ·0205 8 | ·0724| ·0560| ·0441| ·0351| ·0281 9 | ·0870| ·0682| ·0545| ·0441| ·0360 10 | ·1020| ·0807| ·0651| ·0533| ·0441 11 | ·1172| ·0934| ·0760| ·0627| ·0524 12 | ·1327| ·1063| ·0870| ·0723| ·0608 13 | ·1483| ·1194| ·0983| ·0821| ·0694 14 | ·1640| ·1327| ·1096| ·0920| ·0782 15 | ·1800| ·1460| ·1211| ·1020| ·0870 16 | ·1960| ·1595| ·1327| ·1121| ·0960 17 | ·2123| ·1731| ·1444| ·1223| ·1050 18 | ·2286| ·1868| ·1561| ·1327| ·1142 19 | ·2449| ·2006| ·1680| ·1430| ·1262 20 | ·2614| ·2145| ·1800| ·1535| ·1327 21 | ·2780| ·2286| ·1920| ·1640| ·1420 22 | ·2947| ·2425| ·2041| ·1746| ·1514 23 | ·3114| ·2567| ·2163| ·1853| ·1609 24 | ·3282| ·2708| ·2185| ·1960| ·1704 _For explanation of these tables see page 177._ HYDRAULIC RAM. _A hydraulic ram or water-ram is a substitute for a pump_ for raising water by means of the energy of the moving water, of which a portion is to be raised. It was considered a notable discovery when it was demonstrated by Daniel Bernovilli, in the beginning of the 18th century, _that water flowing through a pipe, and arriving at a part in which the pipe is suddenly contracted, would have its velocity at first very greatly increased_. The hydraulic ram owes its efficacy to the fact that when a flow of water in a pipe is suddenly stopped, a considerable force is generated by the momentum of the water, by its change from a state of motion to a state of rest. In practice, the pipe conveying water from the reservoir or head, connects with a chamber which has a valve opening downward, or outlet valve, allowing the current of water to pass on or escape when the valve is open; but on flowing the current in the pipe acquires sufficient force to close this valve, which checks the flow in the pipe.