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of birds, very agreeably : but we were still at a loss for a polysyllabical, articulate echo, till a young gen tleman, who had parted from his company in a 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
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,
*“ Beneath the shade which beechen boughs diffuse You, Tityrus, entertain your sylvan muse.”
(DRYDEN's Virg. Eil. i. 1.)
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 off. Buildings, or naked rocks, reecho much more articulately than hanging wood 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 source of this echo, as we found by various experiments, is the stone-built, tiled hop-kiln in Gally-lane, which measures in front 40 feet, and from the ground to the eaves 12 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.
*“A monster grim, tremendous, vast and high."
(DRYDEN's Virg. Æn. iii. 658.)
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 120 feet for the return of each syllable distinctly : hence this echo, which gives ten distinct syllables, ought to measure 400 yards, or 120 feet to each syllable; whereas our distance 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 acknowl
edged that this candid philosopher was convinced 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 inquiries.
One should have imagined that echoes, if not entertaining, must at least have been harmless and inoffensive; yet Virgil advances a strange notion, that they are injurious to bees. After enumerating some probable and reasonable annoyances, such as prudent owners would wish far removed from their beegardens, he adds
“ - - - - - - aut ubi concava pulsu
Saxa sonant, vocisque offensa resultat imago.”*
* “ Nor place them where too deep a water flows,
Or where the yew, their poisonous neighbour, grows;
There is a natural occurrence to be met with upon the highest part of our downs in hot summer days, which always amuses me much, without giving me any satisfaction with respect to the cause of it; and that is a loud audible humming as of bees in the air, though not one insect is to be seen. This sound is to be heard distinctly the whole common through, from the Moneydells, to my avenue gate.
Any person would suppose that a large swarm of bees was in motion, and playing about over his head. This noise was heard last week, on June 28th.
“Resounds the living surface of the ground,
To him who muses . . . at noon.”
This wild and fanciful assertion will hardly be admitted by the philosophers of these days; especially as they all now seem agreed that insects are not furnished with any organs of hearing at all. But if it should be urged, that though they cannot hear, yet perhaps they may feel the repercussion of sounds, I grant it is possible they may. Yet that these impressions are distasteful or hurtful, I deny, because
Nor near the steaming stench of muddy ground,
(Dryden's Virg. Georg. iv. 47-50.)