[483 ] 
Figures , of the fmalleft Animals. 
4. As hjPolyfcopes or Multiplying GlaJJes, one thing is re- 
pref:nted to the Eye as many, whether in the fame or 
different fliapes( for fo multiplying Glaffes may be con- 
triv'd: ) fo by a Polyphone or Polyacoufiic}^ well order d one 
Sound may be heard as many, either of the fame or a 
different Note. Infomuch that who ufes this Inftrument, 
he fliall at the Sound of a fingleViol feem to hear a whole 
Confort, and all true Harmony. By which means this 
Inftrument has much the advantage of the Poly/cope, 
And thus much may fuffice for comparing the Im- 
provements made w^on l{efr ailed Seeing and Hearing I 
call it jR^frailed Hearing, becaufe made through a Me- 
dium, vi^, thick Air or an Inftrument, through which the 
Sound paffing is broken or refradted. 
III. ^fleUedVifiOn has been improved by the invention of 
Looking'Glajfes and Polipd Metals whether plane. Con- 
cave ot: Convex ^ and thele two laft either Spherical^ Oval, 
Cylindrical , Conical, Hyperbolical , or of feveral other 
fliapes ; all which caufe a different refledion, and vary 
t]\Q Phcenomena. ■ • 
Thus alto l{efiexd Audition, made by Ecchoes, may be 
improved, by contriving feveral forts of Artificial Ec- 
choes J as 'tis no hard matter to do in almoft any 
place. 
For (Speaking in the general) Any Sound, falling 
direUly or obliquely upon any denfe body^ of a Smooth 
( whether Plane or Arch'd) Superficies^ is beat back^ again 
and rejietied , or does Eccho more or lefs. 
I fay ( I ) failing direUly or obliquely; becaufe , if the 
Sound be fent out and propagated parallel to the Surface 
oit\\^T)enfe Body ^o'^ht madefo/^r and fo w^^/^, that it 
cannot reach it; there will be no refledion of Sound, no 
Eccho. 
I fay C z) upon a body ef a fmooth fuperfici^s becaufe if 
thefurface of the Corpus Objlans be uneven, the Air b)^ 
re- 
