Show i ea 1 i 1 ii i uck ii i I 1 II 11 t I 1 11 i period i all MI if n it 11 irly trl y 30 inn 1 pt jajjo it re rc kati ki lit not moro than four minutes elapsed A few fe v seconds we learn from our earth and its story are usually a more frequent time for alie shock or shocks to last yet while Carcas in iii venezuela was almost destroyed 12 of its inhabitants killed hilled by the earthquake of 1812 within the limits or of half a nii minute nute there are cases in in which constantly recurring shocks last for weeks months and even yea years rs as eftie ift ie laboring earth was twill trying to relieve itself of sonic some or its superabundant energy for example tile the earthquake of february 1783 was not quite finished before december 1786 and it is a common observation ahat that the lie preliminary shock is usually followed by one 0 of f grea greater t er severity and this in its turn by others less intense like the distant claps rif nf thunder which herald the passing storm but in this brief pan apan the most frightful 0 havoc can be wrought and t the he wave of destruction truc tion propagated abed from the most distant regions the rumbling earth sound travels for instance at the rr efte te of foot feet per second and tho the earth wave on an average 0 about 1200 foot feet in tho the same space of time though 0 in charleston as we have seon seen a much higher rata was attained attai nod |