The Speaking Trumpet (Tuba Stentoro-Phonica)

THE LOUD-SOUNDING TRUMPET

a greater number of reundulating waving back and forth Circles, and reverberating bouncing Rays to meet in each respective Center and focal point, whereby the same Voice is prodigiously magnified and augmented.

Wherefore, if this Instrument A B C D were cut off in the points M M, it would not magnify one-eighth of what it does at the whole length, which I have sufficiently experimented, and am entirely satisfied therein.

And as to the points of Reundulation and Reverberation, my opinion was very much confirmed to me by a late Experiment I made with a Vessel of mercury original: "Quicksilver", of the same Figure with this illustration original Latin: "Iconismus" H E G F I, in the midst whereof were small thin Hoops, or pieces of wood bent and fixed in the same Figure as is C K O V A V O K D, being closed at the end A, and open at the end C D. Into this Vessel I put enough mercury to cover the whole Figure, and consequently the Figure A B C D. And then striking the mercury smartly in A with the end of a stick, it begot a numberless number of Curvilineal Undulating and Reundulating Figures, not unlike to the Figures V V, T T, S S, R R, etc. from the point A, to the point B, which were bounced back from the sides A N C, and A N D, as they were driven along one by another.

This Experiment, together with another which I lately made, by carrying one Ear along the Line E F and W G, with what exactness I possibly could, whilst a Gentleman did me the favour to read some pages of a Book, with an even tone, in each of the four Instruments B, C, D, and E, in Illustration 1 separately and distinctly: At which time I plainly found, that as my Ear advanced towards the point B, the Voice was sensibly magnified; but as it was removed towards W, it was somewhat abated; and as it was removed either towards C, D, or G, it was abated two, three, four, five, six, and more degrees; made me conclude for certain, that in every point of the imaginary Axis there is a focal point or multiplication of sound original Latin: "Polyphonismus", but that the principal and chiefest focal point where the greatest multiplication of sound of all is, that is to say, the point where the Voice is most of all magnified or multiplied; is B.

This focal point (or multiplication of sound) being now no longer imprisoned in the Tube, dilates itself by spherical waves into the surrounding air original: "Medium" (as in Illustration 2 may more plainly appear) till such time as it meets with some opposition; as for example, let us suppose it in the points H, E, G, F, I, from which points, and innumerable others, it is waved back, multiplied, and reverberated throughout the Sphere of its activity: For by how much stronger the percussion is in B, so much greater is the Sphere of Undulation and Reverberation, and consequently the Voice is heard at a greater distance.

And that such Reundulations and Reverberations do exceedingly magnify or multiply Sounds, I cannot but recommend to the Readers contemplation, a famous Experiment made in the Year of Our Lord 1615 by one Bernard Varenius (a sober and learned Writer) as he himself relates it in his General Geography original Latin title: "Geographia Generalis", Book 1, Proposition 41, who, after he had with much pains and difficulty climbed up to the top of Carpathus, a Mountain of Hungary, (whose perpendicular height he judged to be