Full resolution (JPEG) - On this page / på denna sida - Sidor ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
DOCUMENT 65.
POLHEM TO SWEDENBORG.*
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 upon some additional deduc
tions, which might follow here-after, and which we might
meanwhile discuss orally, than to need any changes or correc
tions 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 con
tained in it as in making a perpetuum mobile 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 a small scale, though all parts be made exactly
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.
on
* Polhem’s MSS. in the Benzelius Collection at Linköping, p. 367.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
