158 THE POPULAR SCIENCE MONTHLY 
before it was generally known.” Another woman, in poor health, 
ascribed the peculiar feeling that she experienced to an attack of heart 
disease, and sank frightened in bed. Experiences of this kind have 
been noted in other earthquakes and appear to be due to a morbidly 
excitable condition of the ill-defined and unspecialized sense of general 
well being. Some people perceived the earthquake chiefly through the 
sense of touch, as when a man, seated in a chair and resting his legs 
on a railing, “felt his legs shake,” or as when a chief of police, also 
seated, felt that his chair shook. In several other cases the earthquake 
was likewise merely “ felt.”” No doubt the sense of touch entered as 
an important element in a far greater number of instances when men- 
tion is made that something shook, trembled, quivered or rocked, or 
when there was a jar or a tremor. The sense of equilibrium or of 
poise was evidently involved in the case of a man who felt * digzy,” 
and in the case of people who “ wabbled on the streets,” in cases where 
occupants of houses noted a “ heaving,” “rocking” or a “ swaying ” 
motion, and when people “were thrown down,” or “ nearly tumbled 
over,” or “found difficulty in keeping on their feet.” 
The reports mention only five instances of sounds accompanying 
the earthquake. Such sounds are general in the mesoseismal area in all 
severe earthquakes in all parts of the world, except in Japan, and one 
noted seismologist believes that their absence in that country is due to 
a racial inability among the Japanese to hear sounds of very low 
pitch. The general absence of sounds in the Illinois earthquake is 
readily accounted for by its comparative weakness. It was faintly 
audible only in three epicentral tracts. Some parties claim to have 
heard a distinct rumbling before the shock in Dubuque. In Waukegan 
one man described the quake as a rush of wind, and said that he had 
heard it. This swishing noise is one of the many known characteristic 
forms of earthquake sounds. In Springfield, Ill, a faint rumbling 
was heard, and a janitor in one of the school buildings in Peoria made 
a similar observation. One man heard a sound like the “bumping of 
a locked door.” This is another variation of earthquake noises, which, 
when more powerful, resemble volleys of musketry and artillery, and 
which, like the other noises, originate under the ground. Many ob- 
servations involve sounds which are, as it were, proxies of the quake, 
induced by secondary_ events, such as the rattling of windows and 
dishes, the crash of falling brick and the like. The student of earth- 
quakes depends, as we have seen, on such noises for much of his in- 
formation on the progress of the earth waves in the peripheral region 
of the disturbed area. 
The sense that gives us the most reliable information on earth- 
quakes, as on most other physical phenomena, is the sense of sight. 
Visible earth waves are, however, rarely seen except in severe disturb- 
ances. It is uncertain whether they appeared anywhere in this case, 
