TO THE READER

It is very easy for those who envy the labor of others to estimate that they could have done the same or better, but this presumption provides no testimony other than in the reprobation and censure they make lightly, and without weighing the reasons and foundations of the works and inventions of those who precede them. I admit that what I hold to be my own may have been done or invented previously (as it is possible, and happens ordinarily, that two persons meet upon the same invention), but since it comes first from my workshop, I will attribute it to myself by right until another discovers the theft, or until it is convinced of being false through geometric reasons and demonstrations. I will, however, receive any error that is shown to me with as much good will as I abandon it to the judgment of the good, and not to the envy of the indiscreet and the slanderous.

DECLARATION OF THE FIGURES, OF THIS

present book.

1 The foundation being set, any weight may be lifted by another given weight.
2 Diverse demonstration of the trispast a pulley system with three wheels and engine of Archimedes, by which he intended to lift any given weight by given forces.
3 New manner of lathe by which one can turn every sort of screw without any model.
There are enough people who can easily turn a screw having a model and form upon which they will turn a cylinder, and render it the same as the model, but this way of doing is deceitful, because it is necessary first to have a screw that is good; otherwise, the one that one makes upon it will always be false. Thus, the true invention for turning a screw will be to make it without any model, as one can see by this third figure.
4 Instrument taken from the trispast, very easy and convenient for ruining walls or for lifting some great loads.
5 Other instrument, very easy and portable, for lifting or dragging things of great weight.
6 New type of device by which one can easily transport and drag great stones or other similar things here and there.
7 Composition of the Archimedean trispast, by which, with one hand and a single rope, he pulled a large ship from the earth into the sea.