NATUEAL HISTORY OE SELBOENE. 
157 
summer evening walk, and was calling after them, stumbled upon a 
very curious one in a spot where it might least be expected. At first 
he was much surprised, and could not be persuaded but that he was 
mocked by some boy ; but repeating his trials in several languages, 
and finding his respondent to be a very adroit polyglot, he then 
discerned the deception. 
This echo in an evening, before rural noises cease, would repeat ten 
syllables most articulately and distinctly, especially if quick dactyls 
were chosen. The last syllables of 
" Tityre, tu patulsa recubans . . 
were as audibly and intelligibly returned as the first ; and there is no 
doubt, could trial have been made, but that at midnight, when the air 
is very elastic, and a dead stillness prevails, one or two syllables more 
might have been obtained ; but the distance rendered so late an 
experiment very inconvenient. 
Quick dactyls, we observed, succeeded best ; for when we came to try 
its powers in slow, heavy, embarrassed spondees of the same number of 
syllables, 
* * Monstrum horrendum, informe, ingens . . 
we could perceive a return but of four or five. 
All echoes have some one place to which they are returned stronger 
and more distinct than to any other ; and that is always the place 
that lies at right angles with the object of repercussion, and is not too 
near, nor too far ofi*. Buildings, or naked rocks, re-echo much more 
articulately than hanging woods or vales ; because in the latter the 
voice is as it were entangled, and embarrassed in the covert, and 
weakened in the rebound. 
The true object of this echo, as we found by various experiments, 
is the stone-built, tiled hop-kiln in G ally-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 Nbre-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 Oxfordshire, allows a hundred and 
twenty feet for the return of each syllable distinctly ; hence this echo, 
which gives ten distinct syllables, ought to measure four hundred 
yards, or one hundred and twenty feet to each syllable; whereas our 
distance is only two hundred and fifty-eight yards, or near seventy-five 
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 convinced afterwards, that some latitude must be 
admitted of in the distance of echoes according to time and place. 
