But again, “a great part of the weight of the man (half of it, if the inclination be 30 degrees) lies directly on the plane, and has no tendency to produce motion,” which one sided truism is placed there to give relief to the portentous dictum, which follows:—that “there remains then another stage of improvement with regard to the construction of Cranes, in which the weight of the labourers shall operate without diminution at the end of an horizontal lever: and that stage has been effected by Mr. D. H. of the East India Company’s Bengal warehouse.”

But is this conclusion definitive? are there no countervailing evils? Will Dr. Gregory presume to say there is no disadvantage attending this advantage? Did the Doctor ever ascend an upright ladder? and did he prefer that, to going up an easy flight of stairs? was he ever in the geometrical stairs of St. Paul’s? or in any large winding stair-case? and if so did he prefer ascending close to the nucleus? or did he quickly seek a point where the step was wider than high? most certainly the latter; and why then did he not perceive that if the weight of my man is diminished one half on the plane, for the very same reason, a given elevation of his feet (on which his fatigue depends) will cause a circular motion twice as extensive; yet this is quite as clear as the Doctor’s ex-parte proposition.

But I must wade on a little further, trusting that my readers will exert a little more patience to follow me: for this same dictum of the Doctor’s accuses indirectly, the Society of Arts of being a set of blockheads, for remunerating an Invention with only supposed properties. I really wish these self-constituted judges of other people’s labours would utter their oracles with more regard to truth and propriety! and above all, not mix up their passions (which alas! are not always purified by science) with their judgement on the merits of other men’s inventions. Had the author of this article been wise enough to proceed thus, he would not have supposed me capable of offering suppositions for realities; nor the Society of Arts of rewarding as genuine, suppositious merit; and still less would he have emblazoned the very properties he calls supposed, with reality written in glaring characters on every one of them! These properties are in fact only the transcript of what the society required of the candidates: and I therefore said my Crane is simple: Can this author say it is not? I said it has little friction? will he say it has much? I said it is durable: Is it now possible to contradict this? I said it is safe: and will Dr. G. say it is not, when it is moveable, only during the wish of the workman: since whatever suspends this wish, (whether accident or design) the Crane becomes of itself immoveable. In fine, I observed, that this Crane admits of an indefinite number of powers, without any modification of it’s parts; and can any one say these are supposed properties? If the Doctor or his coadjutors persist in saying so, I must suppose them actuated by improper motives; for truth will never bear them out in these allegations. I take leave to add, that but for the interests of truth, these strictures had never appeared. Even self-defence would not have provoked one line of them: But I felt it incumbent on me to deter, if possible, inadvertency as well as malevolence, from infesting with the thorns of misrepresentation, the paths which genius explores, in search of useful knowledge.

OF
A DIRECT AND DIFFERENTIAL PRESS,
With two Powers: of which ONE immense.

The effects intended to be obtained from this Press, are to introduce two distinct powers; the one to raise and lower the pressing cap with convenient speed; the other to press with very great force. In [Plate 10], A B is a frame, the under part of which contains the goods to be pressed. The toothed wheel C D turns the screw S, and that E F turns the nut G H, both the same way. The long pinions I K, turn both these wheels C D, and E F; and occasionally one only, as will be seen presently. L M are two bevil wheels on the axes of the long pinions I K; and N O, are two similar ones, on the power shaft P Q. This latter shaft runs in two boxes R T, the stems of which fit and turn in the gudgeons of the long pinions, or rather suffer these to revolve round them: being pinned on through a circular groove which connects them in the perpendicular direction only. Finally, the rope and pulleys indicated at X Y Z, serve to raise both shaft and pinions; thus disengaging the latter from the wheel E F, when the nut G H, is not to be turned. We may remark, that the parts M T O are doubled in this machinery, at L R N; merely to take away the side tendency from the screw S: as otherwise one half of this mechanism would produce the very same effect, and leave the Machine the more simple. Supposing now, this Press charged with goods in it’s present position,

The wheelC D, having69teeth; -with proportionate
diameters.
The thatE F,„70„
The pinions I & K, each10„
The wheels L N & M Oequal;