330 A, M. Mayer— Researches in Acoustics. 
and fainter at the coincidences, and when the watch had been 
removed to a distance of nine inches from the ear, the ticks of 
the watch were utterly obliterated during three whole seconds 
of its ticks about the time of coincidence.’ On removing the 
watch to a distance of twenty-four inches, I found that I lost 
its ticks during nine seconds about the time of coincidence. 
It is here important to remark that the ticks of the clock are 
longer in duration, as well as dower in pitch, than those of the 
watch’s. With the watch remaining at the distance of twenty- 
four inches from the ear, I listened with all my attention, as 
tick by tick the watch approached the time of coincidence. 
Since the ticks of the watch are shorter in duration than those 
of the clock, they are overlapped by the other about the time of 
coincidence. Hence as, so to speak, the short ticks of the watch 
glided tick after tick, under the long ticks of the clock, I per 
ceived that more and more of the duration of each successive 
watch-tick became extinguished by the tick of the clock, until 
sod the tail end of the short tick of the watch was left audible 
and at last even this also crept under the long tick of the clock 
and the whole of the ticks of the watch were rendered inaudible 
for nine seconds, at the end of which time the front or head of 
the watch-tick, as we may call it, protruded beyond the cloc : 
tick, and then slowly grew up into a complete watch-tick as 
before. In this succession of events the tick of the old silver 
watch (made by Tobias) disappears with a sharp chirp, like a 
cricket's, and re-appears with a sound like that made bya boys 
marble falling upon others in his pocket. By this experiment, 
therefore, a gradual analysis is made of the effect. of the tick of 
the clock on the tick of the watch, affording a beautiful illus 
tration of the fact that one sonorous sensation may overcome 
and obliterate another. bs 
axperiments to determine the relative intensity of the Clock-ti 
which obliterate the Watch-ticks.—The clock was placed on pari 
in the middle of an open level field in the country, oD MS ts 
when the air was calm and noiseless. The ticks o 
became just inaudible when my ear was removed to a ¢ ta 
of 350 feet. The ticks of the watch became just inaudible ae 
distance of- twenty feet. The ratio of the squares of t is 
numbers makes the ticks of the clock about 300 times oat 
intense than those of the watch. On the same nights thé t 
made the above determinations I also put the clock on 9 oi 
and placing against my zygomatic process a slender sti¢ a 
duated to inches and tenths, I stood with my ear at _ 
from the clock of from eight to sixteen feet, and then. e 4 oi 
watch above and along the stick (taking care that It oe tg 
touch it) until it reached such a distance from the eat ote 
fifth tick just disappeared. Knowing the relative in i 
the ticks of clock ‘and watch when placed at the same ® 
