ECHOES. 203 
re-echo much more articulately than hanging woods or vales ; 
because in the latter the voice is as it were entangled, and em- 
barrassed in the covert, and weakened in the rebound. 
The true object of this echo, as we found by various experi- 
ments, is the stone-built, tiled hop-kiln in Gally-lane, which 
measures in front forty feet, and from the ground to the eaves 
twelve feet. The true centrum phonicum, or just distance, is one 
particular spot in the King's-field, in the path to Nore-hill, on 
the very brink of the steep balk above the hollow cart-way. In 
this case there is no choice of distance ; but the path, by mere 
contingency, happens to be the lucky, the identical spot, because 
the ground rises or falls so immediately, if the speaker either 
retires or advances, that his mouth would at once be above or 
below the object. 
We measured this polysyllabical echo with great exactness, 
and found the distance to fall very short of Dr. Plot's rule for 
distinct articulation : for the Doctor, in his history of Oxford- 
shire, allows 120 feet for the return of each syllable distinctly : 
hence this echo, which gives ten distinct syllables, ought to mea- 
sure 400 yards, or 120 feet to each syllable; whereas our dis- 
tance is only 258 yards, or near 75 feet, to each syllable. Thus 
our measure falls short of the Doctor's, as five to eight : but then 
it must be acknowledged that this candid philosopher was con- 
vinced afterwards, that some latitude must be admitted of in the 
distance of echoes according to time and place. 
When experiments of this sort are making, it should always 
be remembered that weather and the time ■ of day have a vast 
influence on an echo ; for a dull, heavy, moist air deadens and 
clogs the sound ; and hot sunshine renders the air thin and weak, 
and deprives it of all its springiness ; and a ruffling wind quite 
defeats the whole. In a still, clear, dewy evening the air is most 
elastic ; and perhaps the later the hour the more so. 
Echo has always been so amusing to the imagination, that 
the poets have personified her ; and in their hands she has been 
the occasion of many a beautiful fiction. Nor need the gravest 
man be ashamed to appear taken with such a phenomenon, since 
it may become the subject of philosophical or mathematical 
enquiries. 
One should have imagined that echoes, if not entertaining, 
must at least have been harmless and inoffensive ; yet Virgil ad- 
vances a strange notion, that thev are injurious to bees. After 
