reverberation will be p^tout of it's regular Motion , and 
the Sound tfiereby broken and extingnifht ; So that tho' 
in this cafe alfo the air be beaten back again, yet Sound 
is not reflected, nor is there any Eccho. 
lhY{j)'it does Eccho more er lefs^ to fliew, that whea 
M tWi*|s are, as 15 before defcrib'd, there is ftiil an Ec- 
ehoing; though it be: ^riot always heard, either becaulc 
tht Dir ell Sound is too weak to be beaten quite back a- 
gaintohini that made it^ or that it does return home 
to him, but fo weak that without the help of a good 0- 
tacoujiicl^ it c^nncftbQdifcQrnd ; or that he ftands in a 
wrong place to receive therefle£ted Sound, which paffes 
over his head, under his feet, or to one fide of him ; 
which theref ore may be heard by a man ftanding in that 
place, where the refledted Sound will come, provided no 
interpos'd body does intercept it 3 but not by him, that 
firft made it. 
I ihall further make out the comparifon twixt 
flex d 0Jt on 2inA Audition by thefe followiiig PropoHtii^ns. 
.1. As 2i Plane Speculum xcQ.Qdist\iQ Obj'efl inits due D/- 
menjions and Colours allowiiig for their dixivrence ot ap- 
pearance according to their diftance : So sl Plane Ccrrpus 
6? ^/^35 reflects the Soundh'^i'^ in it's due To'^e And Laud- 
nefs ; if aliowance.bx likewife made for the iproportioiir 
able decrea e of the Sound according to it s diffance. / 
2. As a Convex Speculum, refledts the Obje-61: "L^J^s but 
(omewhat brighter or clearer : So a Convex Corpus 'Ob jtan^s 
repels the Sound ( inierifibly ) 7??z^//^r ; but fome-what 
qutcktr ( though weaker ) then otherwife it would be. 
3. As ^Concave Speculum refleCts the Objed Bigger ^ 
mare Obfcure and Inverted: So a Concave Corpus Obftams 
Ecchoes back the Sound(jnfenfibly;) Bigger, Slower f-though 
fir onger ) ^.nd2di^o inverted', but never accordin-g to the 
order of words. Nor do I think it poffible for the Art of 
man to contrive a Single Eccho, that fliall invert the 
Sound and repeat backwards^ becaufe then the words Uft 
fpoken, 
I 
