"I remain, most respected Sir, your most dutiful
The last sentence of this letter possesses a pathetic interest in view of later developments. In another letter, of the same month. Polhem writes,—
"If the learned wish to have real satisfaction and honor from that which they teach others, they ought to have a better understanding of many things that are now taught; for nature is in many things quite differently constituted than is thought by Descartes and almost all his followers. And this can scarcely be taught better than by daily experience in mechanics and an investigation into its principles; and, although what I have gained there is extremely little in comparison with what still remains to be done, I nevertheless hope that my principles may pave the way for the rest. For I never approve of anything which does not apply to all cases and all consequences flowing from it; and whenever there is one single thing opposed to it, I hold its fundamental principle to be false. Moreover, it would be no small honor for the learned mathematicians if they could point out what their principal and most intricate figures are good for in practice, especially the geometric curves, etc., which I found useful in mechanics on more occasions than I expected while teaching them at Upsal, ignorant of their use."
This eagerness to develop practical, useful results from their science, it is pleasant to find, was a marked characteristic of Polhem, as well as of Swedenborg himself. A gap of a few months in the correspondence of these friends indicates a time when they enjoyed each other's company, and when the elder presented young Swedberg and his Dædalus to Charles XII., at once the most sagacious, the most bold, and the most obstinate of men. The occasion was a brief lull in the warrior monarch's stormy career, when, after reducing his coun-
