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from the College to the Grcve, and clap, the Echo will 
return to you from the B:iU Court ^ though a Line drawn 
from you to the Bau^Court be not perpeodicular to the 
Wall there, but as much oblique as the Line AB in Fig i 
is to the Line BC ; where A reprefenrs the Gate, BC the 
B^iS-Ccurt'lVaU, andrBD another Wall. Or it you ftand 
at E the Corner cf the Grove ne^t to Trinity, and crap^ 
the Echo will return to you from the BaS-Ccart, 
Lithe fame Grovel ftocd about Twenty Yards from 
the fame Gate, and the Gate being (hut, I clapt, a net ac 
other times ftamped, and the Echo returned from the 
Gate as loud, if not louder, than the Ckp cr Scamp. 
An Echo refleded from a Gate or Door has ufually a 
bafer and duller Sound than that which is returned from 
a Wall, this being much brisker. 
As 1 have been walking towards a Wall, I have clap* 
ed my Hands together feveral times, and I could diftin- 
guiih the Echo trom the Clap, till I came within Seven 
cr Eight Yards of xhe Wall. 
Ln the Cloifters, where, as was faid before, the Echa 
was repeated feveral times, the firfl Repetition feem.ed to 
be flower than the fecond cr the third ; but of all the Re- 
petitions,, befides the firft, the fubfequent feemed flower 
than the precedent. 
I have obferved the Tofllng of a Sound forward and 
back again, in very many Places where there are paral- 
lel Walls; and where the Diftance of the Walls is leCs, 
there the Echoes follow one another quicker. 
Wherefoever a Sound was thus tolled betwixt T^vo 
Walls, if I flood about the middle, I could hear the Sound 
twice as quick, that is, twice as often repeated in i", as 
if I flood near one Wall the Sound being refleded to 
me from both ends, w hen I flood in the middle. 
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