"8. A new construction of air-guns, thousands of which may be discharged in a moment by means of one siphon.
"9. A universal musical instrument, by means of which one who is quite unacquainted with music may execute all kinds of airs that are marked on paper by notes.
"10. Sciagraphia universalis. The universal art of delineating shades, or a mechanical method of delineating engravings of any kind, upon any surface, by means of fire.
"11. A water-clock, in which water serves the purpose of an index, and in which, by the flow of water, all the movable bodies in the heavens are demonstrated, with other curious effects.
"12. A mechanical carriage containing all sorts of works, which are set in motion by the movement of the horses. Also a flying carriage, or the possibility of remaining suspended in the air, and of being conveyed through it.
"13. A method of ascertaining the desires and the affections of the minds of men by analysis.
"14. New methods of constructing cords and springs, with their properties.
"These are my mechanical inventions which were heretofore lying scattered on pieces of paper, but nearly all of which are now brought into order, so that, when opportunity offers, they may be published. To all these there is added an algebraic and a numerical calculation, from which the proportions, motion, times, and all the properties which they ought to possess are deduced. Moreover, all those things which I have in analysis and astronomy require each its own place and its own time. Oh, how I wish, my beloved friend and brother, that I could submit all these to your own eyes, and to those of Professor Elfvius! But as I cannot show you the actual machines, I will at least, in a short time, forward you the drawings, with which I am daily occupied. I have now time also to bring my poetical efforts into order. They are only a kind of fables, like those of Ovid, under cover of which those events are treated which have happened in Europe
