One of the most remarkable echoes of which we have read is that which
Dr. Birch describes as existing at Roseneath, in Argyllshire. When a
person at a proper distance played eight or ten notes on a trumpet, they
were correctly repeated, but a third lower; after a short silence,
another repetition was heard in a yet lower tone, and alter another
short interval, they were repeated a third time in a tone lower still.

We extract the following account of two very interesting echoes from Mr.
Herschell's work:--

"In the cathedral of Girgenti, in Sicily, the slightest whisper is borne
with perfect distinctness from the great western door to the cornice
behind the high altar, a distance of 250 feet. By a most unlucky
coincidence, the precise focus of divergence at the former station was
chosen for the place of the confessional. Secrets never intended for the
public ear thus became known, to the dismay of the confessors and the
scandal of the people, by the resort of the curious to the opposite
point (which seems to have been discovered accidentally), till at length
one listener, having had his curiosity somewhat overgratified by hearing
his wife's avowal of her own infidelity, this tell-tale peculiarity
became generally known, and the confessional was removed.[2]

"Beneath the Suspension Bridge across the Menai Strait in Wales, close
to one of the main piers, is a remarkably fine echo. The sound of a blow
on the pier with a hammer is returned in succession from each of the
cross-beams which support the road-way, and from the opposite pier at a
distance of 576 feet; and in addition to this, the sound is many times
repeated between the water and the road-way. The effect is a series of
sounds which may be thus described:--The first return is sharp and
strong from the road-way overhead; the rattling which succeeds dies away
rapidly, but the single repercussion from the opposite pier is very
strong, and is succeeded by a faint palpitation, repeating the sound
at the rate of twenty-eight times in five seconds, and which therefore
corresponds to a distance of 184 feet, or very nearly the double
interval from the road-way to the water. Thus it appears, that in the
repercussion between the water and road-way, that from the latter
only affects the ear, the line drawn from the auditor to the water
being too oblique for the sound to diverge sufficiently in that
direction.--Another peculiarity deserves especial notice, namely, that
th