III.— On the Dynamics of Earthquakes ; being an Attempt to reduce their 
observed Phenomena to the known Laws of Wave Motion in Solids and 
Fluids. By Rosert Mau.et, Ese., Mem. Ins. C. E., M.R.1I.A., Pres. 
Geol. Soc. Ireland, &c. 
Read 9th F ebruary, 1846. 
Tue present Paper constitutes, so far as I am aware, the first attempt to bring the 
phenomena of the earthquake within the range of exact science, by reducing to 
system the enormous mass of disconnected and often discordant and ill-observed 
facts which the multiplied narratives of earthquakes present, and educing from 
these, by an appeal to the established laws of the higher mechanics, a theory of 
earthquake motion. 
If I shall have in any degree succeeded in this, I must believe that a consider- 
able advance will have been made in one of the most important, but, up to this 
time, one of the most absolutely unsystematized and unscientific regions of phy- 
sical geology. 
If the foundation for such a theory be really laid, it must become the means 
of guiding and directing future observers during earthquakes ; enabling them 
to pass by that which is accidental, and to apply right methods and suitable 
instruments in ascertaining the really important elements of their motions in 
measures of time and space, &c., by which hereafter the narratives of earthquakes, 
ceasing to be merely scrolls written “ with mourning and lamentation and woe,” 
may become systematized records of facts, which a true theory shall render avail- 
able, and in the highest degree valuable, for the advancement of terrestrial 
physics and geology. 
My speculations upon earthquake motion commenced with an attempt to 
unravel and explain a single partial and minute phenomenon occasionally observed 
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