1. The first is, _To make the least Sound_ (by the help of Instruments)
_as loud as the greatest_; a whisper to become as loud as the shot of a
Cannon.
By the help of this _Problem_, the most minute Sounds in Nature may be
clearly and distinctly heard.
2. The second is, _To propagate any_ (the least) _Sound to the greatest
distance_.
By the help hereof any Sound may be convey'd to any, and therefore heard
at any distance, (I must add, within a certain, tho' very large Sphere.)
Moreover, by this means, a _Weather-cock_ may be so contriv'd, as that
with an ordinary blast of Wind it shall cry (or whistle) loud enough to
be heard many Leagues: Which happily may be found of some use, not only
for _Pilots_ in mighty tempestuous Weather, when _light Houses_ are
render'd almost useless, but also for the measuring the strength of
Winds, if allowance be made for their different moisture. For I
conceive, that the more dry any Wind is, the louder it will whistle
_cæteris paribus_; I say, _cæteris paribus_, because, besides the
strength and dryness of Winds or Breath, there are a great many other
things (hereafter to be considered) that concur to the increase or
magnifying of Sounds, begotten by them in an Instrument exposed to their
Violence, or blown into.
3. The third _Problem_, is, _That a Sound may be convey'd from one
extreme to the other_ (or from one distant place to another) _so as not
to be heard in the middle_.
By the help of this _Problem_ a Man may talk to his Friend at a very
considerable distance, so that those in the middle space shall hear
nothing of what passed betwixt them.