A. Because sound travels with such velocity, that the echo is blended with the original sound, and produce but one impression on the ear.
Sound travels 13 miles in a minute.
Q. Why do very large buildings (as cathedrals), often reverberate the voice of the speaker?
A. Because the walls are so far off from the speaker, that the echo does not get back in time to blend with the original sound; and, therefore, each is heard separately.
Q. Why do some echoes repeat only one syllable?
A. The further the echoing body is distant, the more sound it will reflect. If, therefore, the echoing body be near, it will repeat but one syllable.
Q. Why does an echo sometimes repeat two or more syllables?
A. Because the echoing body is far off; and, therefore, there is time for one reflection to pass away before another reaches the ear.
Q. Why do windows rattle when carts pass by a house?