The claims of this construction of pumps have been thus summarized—
1st. The speed of the piston is automatically slowed down at the end of its stroke, giving time for the column of water to come gradually to rest, and for the valves to seat gently and quietly, avoiding all concussion, jar, or the slightest tremor.
2d. The speed of the engine can be adjusted and automatically maintained as desired under any pressure. Should it be working under full head of steam and against a heavy pressure, and the pressure be instantly removed the speed would continue unchanged.
3d. The piston works to the end of its stroke under all pressures, avoiding the waste of steam incident to the piston falling short of its stroke.
It will be understood that there is only a slight waste of oil caused by the use of this apparatus—all the waste that there is, being the small amount leaking through the stuffing boxes.
The term “Isochronal,” pump meaning equal spaces in equal times has been applied to both these pumps and their valve gear.
The sizes, capacities, etc., of the pump described on the opposite page are given in the following
Table.
| No. | Diameter of Steam Cylinder Inches | Diameter of Plunger Inches | Length of Stroke | Size of Steam Pipe | |
|---|---|---|---|---|---|
| 1 | 61⁄2 | 4 | 20 in. | 11⁄4 in. | |
| 2 | 9 | 6 | 3 ft. | 11⁄2 „ | |
| 3 | 11 | 6 | 3 „ | 11⁄2 „ | |
| 4 | 14 | 8 | 3 „ | 2 „ | |
| 5 | 18 | 9 | 4 „ | 21⁄2 „ | |
| 6 | 20 | 101⁄8 | 4 „ | 3 „ | |
| 7 | 22 | 121⁄4 | 6 „ | 31⁄4 „ | |
| 8 | 25 | 141⁄4 | 6 „ | 31⁄4 „ | |
| 9 | 30 | 161⁄4 | 6 „ | 31⁄2 „ | |
| No. | Ordinary Speed Stroke | Maximum Speed Stroke | Capacity at ordinary Speed in Gals. | Capacity at maximum speed in Gallons | Vertical Lift in Feet |
| 1 | 50 | 80 | 52 | 85 | 230 |
| 2 | 27 | 40 | 110 | 170 | 180 |
| 3 | 27 | 40 | 110 | 170 | 290 |
| 4 | 27 | 40 | 200 | 300 | 250 |
| 5 | 20 | 30 | 275 | 390 | 320 |
| 6 | 20 | 30 | 320 | 480 | 320 |
| 7 | 15 | 22 | 500 | 750 | 270 |
| 8 | 15 | 22 | 700 | 1000 | 250 |
| 9 | 15 | 22 | 900 | 1300 | 270 |