■ 112 [Assembly 



tain extent, but was found to be liable to some of the same objec- 

 tions as the preceding plan, and the shafts and gearing were 

 much in the way of the workmen. Revolving eccentrics were 

 then proposed to be placed at each end of the roll and bearing on 

 the journals. These presented no substantial advantage over 

 eccentric rolls. Then a hydrostatic press was suggested to force 

 down the roller as the iron was passing through, but it was found 

 not to act with sufficient promptitude. 



Mr. Clay's plan is more simple and more efficient than any of 

 these, and at the same time is unlimited as to the length or rate 

 of taper that may be obtained by it. The principle on which it 

 acts is that of hydrostatic pressure by means of a small chamber 

 set on top of each housing, the plunger of which acts downwards, 

 but instead of forcing water into the press, the chamber is first 

 filled with water, and the pressure of the iron in passing between 

 the rolls, tends to lift the top one, which is held down by the 

 plunger of the press. An escape pipe, provided with a valve, is 

 placed on the top of the chamber. When any upward pressure 

 acts on the top roller, it is communicated by the plunger to the 

 water, which then is forced out through the valve and the roll 

 rises. By partially closing the valves, the water escapes more 

 slowly, and the rise of the roll, and consequently the taper of the 

 iron is more gradual. Thus it will be perceived that any rate of 

 taper may be had by simply regulating the size of the opening in 

 the escape valve. If the water is all drawn out before the bar is 

 entirely through the rolls, the top roll ceases to rise, and the iron 

 is parallel from that point. Then if the bar is turned end for 

 end, and again put through the rolls, the parallel portion will be 

 tapered. By this arrangement there can be obtained a bar regu- 

 larly tapered from end to end, or tapered part of its length and 

 parallel the remainder; tapered from both ends to a point any 

 where in its length; tapered at each end and parallel in the 

 middle, or alternately tapered and parallel, by opening and shut- 

 ting the valve as the iron is passing tlirough the rolls. 



Wrought iron thus pressed, enters into the following uses : It 



\ is applied for iron knees in ship building. Vessels constructed 



with iron knees, will stow a greater bulk than when wooden knees 



