chwengjwendy Wed May 04, 2011 7:42 amOwing to the factsOwing to the facts that the crust of the earth is not homogeneous, and that the focus or center of impulse is not a mathematical point, this center of impulse sometimes occupies determinate and not unfrequently wide dimensions. The angle of emergence from any given depth of focus consequently does not diminish in many cases with regularity from any given MBT Shoes Sale point of the surface from the earthquake vertical. On account ot the reasons just stated, neither the socalled meizoseismic curve that of maximum earthquake overthrow, nor the iso f seismic curves or those of equal earthquake overthrow, are found to form circles, or any kind of perfectly regular closed curves, nor are the curves concentric.With these general observations, I shall now proceed to describe the modes employed by Mr. Mallet in pursuing his earthquake inquiries.The method of investigation which Mr. Mallet adopted is based upon MBT Shoes the very obvious truth that the disturbances MBT Sale and dislocations of various solid objects by the shock of earthquake, if carefully observed with reference to their direction and extent of disturbance, and to the mechanical conditions m play, must afford the means of tracing back from their effects, the direction, velocity, and other MBT Trainers circumstances of the movements or MBT forces that caused them. This mode of examination.Mr. Mallet adds,strange to say. appears to be perfectly new.and to have escaped the attention of all previous examiners of earthquakeshaken districts, as well as of all writers upon the subject"Excepting that of Mr. Wm. Hopkins, noticed in a prior note, as illustrative oi inis iact. mr, inauec anuaesme circumstance mac tne isrovernmem reporter iinon tne sweat uaiaonan earcnauaKe oi lYoo. ana, more recently, jraimieri ana dcaccni reporters. uoon tnac of Basihcata in , appear to have been perfectly unconscious that in the fractured walls and overthrown objects scattered in all directions beneath their eyes, they possessed the most precise data for determining the velocities and directions of the shocks that had produced them.
