say it is so far off.' . . . A hundred thousand kind remembrances to sister Anna and brother Eric."
In point of fact, Charles XII, never went to Stockholm after his departure in 1700, not choosing to show himself again in his capital unless as a victor. In the same month Polhem[1] writes to his young friend as follows:—
"Noble and most respected friend,— With great pleasure I read through the fourth number of your Dædalus, which, as far as I could see, is worked up with great industry and understanding. With regard to the article on 'Resistance,' I may perhaps mention that it seems to depend rather on some additional deductions, which might follow hereafter, and which we might meanwhile discuss orally, than to need any changes or corrections that I can point out; but, if I may be allowed to express candidly my opinion, it seems to me that the last correction was somewhat unnecessary. With respect to flying by artificial means, there is perhaps the same difficulty contained in it as in making a perpetual motion, or gold by artificial means, although at first sight it seems as easy to be done as it is desirable; for whatever any one approves strongly, he has generally a proportionate desire to carry out. In examining it more closely, some difficulty arises; for nature, as in the present case, is opposed to all common machines' preserving their same relations when constructed on a large as on a small scale, though all parts be made exacily alike and after the same proportions. For instance, although some stick or pole may be capable of bearing itself and some weight besides, still this does not apply to all sizes, although the same proportion may be preserved between the length and thickness; for while the weight increases in a triple ratio, the strength increases only in a double ratio. The same rule applies to surfaces, so that at last large bodies are incapable of sustaining themselves; and accordingly nature itself provides birds with a much lighter and stronger substance for their feathers, and also quite different sinews and bones in the body itself, which are required for the sake of strength and lightness, and which do not exist in any other organisms. Wherefore it is so much more difficult to have any success in the air, the same qualities being required in this case, and all the materials being wanted, which are necessary when a human body is to be carried in a machine. . . . Your arrival in Stiernsund will be most agreeable to me; and if my
- ↑ About this time Polhammar was ennobled by the King with the name of Polhem, by which we shail now call him. But for a time Polhem called himself Pollheimer, having discovered Polheim to be the ancestral name.
