168 
Hydrostatic Engine. 
Fig. 4. An internal view of one side of the groove-box, in which 
the sliders are so disposed, as to keep the sides of the rack alter- 
nately in gear, with the rack-wheel. The sliders represented by- 
shades in this figure, are to consist of iron, and to be made fast to 
the sides of the groove-box, by means of screw-bolts. The upper- 
most is so constructed, as to permit the regulator in the end of the 
rack to pass around it. 
Fig. 5. A view of a part of the dog, and its friction wheel, up* 
on which the weight of the rack is supported. 
Fig. 6. A view of one side of the frame at the back part of the 
machine, showing one of the grooves, in which that part of the car- 
riage moves, to which the sweep is attached. 
Fig. 7. A side view of the valve, with the winch by which it is 
turned. 
Fig. 8. The pullies in the top of the dog, together with a part 
of the valve-rod. 
Fig. 9. The carrier or regulator, to be attached to the lower 
part of the rack, at its outermost end. The ears upon the sides are 
fitted to the grooves of the groove-box, so that they pass entirely 
round the uppermost slider. 
Figs. 10 and 11. The parts of the machine represented by 
these figures, are intended for a substitute for the groove-box and 
sliders. A model has been constructed on this plan, and it is found 
to answer the purpose far better, than the original plan. The 
greater part of the friction of the rack is completely done away by 
it. These figures represent different views of a catch-frame, with 
friction-wheels, bolts, and bolt-mortices. The friction wheels are 
placed so far asunder, as to admit the rack to pass freely between 
them. The frame at every change of the rack, rises and falls with 
it. It is confined in such a manner by the bolts, that it keeps the 
sides of the rack alternately in gear, with the rack-wheel. The 
bolts slip alternately into the mortices, by means of small weights, 
acting upon angular leavers or dogs ; and are drawn out of them 
again, by the ends of the rack striking against pins or knobs, in 
the bolts. 
According to Fig. 1, as the water acts alternately upon the pis- 
tons, it follows, that a reciprocated rectilinear motion is produced. 
This motion is accompanied by a power equal to the weight of a 
column of water, whose base is the area of one of the pistons, and 
whose height is equal to the whole perpendicular fall of the water. 
Foj’ instance let the whele perpendicular fall fee 33 feet \ the weight 
